# -*- coding: utf-8 -*-
# Copyright: Ankitects Pty Ltd and contributors
# License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html

from __future__ import annotations

import html
import json
import re
import sre_constants
import time
import unicodedata
from dataclasses import dataclass
from enum import Enum
from operator import itemgetter
from typing import Callable, List, Optional, Union

import anki
import aqt.forms
from anki import hooks
from anki.cards import Card
from anki.collection import _Collection
from anki.consts import *
from anki.lang import _, ngettext
from anki.models import NoteType
from anki.notes import Note
from anki.rsbackend import StringsGroup
from anki.utils import fmtTimeSpan, htmlToTextLine, ids2str, intTime, isMac, isWin
from aqt import AnkiQt, gui_hooks
from aqt.editor import Editor
from aqt.exporting import ExportDialog
from aqt.qt import *
from aqt.sound import av_player, play_clicked_audio
from aqt.theme import theme_manager
from aqt.utils import (
    MenuList,
    SubMenu,
    askUser,
    getOnlyText,
    getTag,
    openHelp,
    qtMenuShortcutWorkaround,
    restoreGeom,
    restoreHeader,
    restoreSplitter,
    restoreState,
    saveGeom,
    saveHeader,
    saveSplitter,
    saveState,
    shortcut,
    showInfo,
    showWarning,
    tooltip,
    tr,
)
from aqt.webview import AnkiWebView


@dataclass
class PreviewDialog:
    dialog: QDialog
    browser: Browser


@dataclass
class FindDupesDialog:
    dialog: QDialog
    browser: Browser


# Data model
##########################################################################


class DataModel(QAbstractTableModel):
    def __init__(self, browser):
        QAbstractTableModel.__init__(self)
        self.browser = browser
        self.col = browser.col
        self.sortKey = None
        self.activeCols = self.col.conf.get(
            "activeCols", ["noteFld", "template", "cardDue", "deck"]
        )
        self.cards = []
        self.cardObjs = {}

    def getCard(self, index):
        id = self.cards[index.row()]
        if not id in self.cardObjs:
            self.cardObjs[id] = self.col.getCard(id)
        return self.cardObjs[id]

    def refreshNote(self, note):
        refresh = False
        for c in note.cards():
            if c.id in self.cardObjs:
                del self.cardObjs[c.id]
                refresh = True
        if refresh:
            self.layoutChanged.emit()

    # Model interface
    ######################################################################

    def rowCount(self, parent):
        if parent and parent.isValid():
            return 0
        return len(self.cards)

    def columnCount(self, parent):
        if parent and parent.isValid():
            return 0
        return len(self.activeCols)

    def data(self, index, role):
        if not index.isValid():
            return
        if role == Qt.FontRole:
            if self.activeCols[index.column()] not in ("question", "answer", "noteFld"):
                return
            row = index.row()
            c = self.getCard(index)
            t = c.template()
            if not t.get("bfont"):
                return
            f = QFont()
            f.setFamily(t.get("bfont", "arial"))
            f.setPixelSize(t.get("bsize", 12))
            return f

        elif role == Qt.TextAlignmentRole:
            align = Qt.AlignVCenter
            if self.activeCols[index.column()] not in (
                "question",
                "answer",
                "template",
                "deck",
                "noteFld",
                "note",
            ):
                align |= Qt.AlignHCenter
            return align
        elif role == Qt.DisplayRole or role == Qt.EditRole:
            return self.columnData(index)
        else:
            return

    def headerData(self, section, orientation, role):
        if orientation == Qt.Vertical:
            return
        elif role == Qt.DisplayRole and section < len(self.activeCols):
            type = self.columnType(section)
            txt = None
            for stype, name in self.browser.columns:
                if type == stype:
                    txt = name
                    break
            # give the user a hint an invalid column was added by an add-on
            if not txt:
                txt = _("Add-on")
            return txt
        else:
            return

    def flags(self, index):
        return Qt.ItemFlag(Qt.ItemIsEnabled | Qt.ItemIsSelectable)

    # Filtering
    ######################################################################

    def search(self, txt):
        self.beginReset()
        t = time.time()
        # the db progress handler may cause a refresh, so we need to zero out
        # old data first
        self.cards = []
        invalid = False
        try:
            self.cards = self.col.findCards(txt, order=True)
        except Exception as e:
            if str(e) == "invalidSearch":
                self.cards = []
                invalid = True
            else:
                raise
        # print "fetch cards in %dms" % ((time.time() - t)*1000)
        self.endReset()

        if invalid:
            showWarning(_("Invalid search - please check for typing mistakes."))

    def reset(self):
        self.beginReset()
        self.endReset()

    # caller must have called editor.saveNow() before calling this or .reset()
    def beginReset(self):
        self.browser.editor.setNote(None, hide=False)
        self.browser.mw.progress.start()
        self.saveSelection()
        self.beginResetModel()
        self.cardObjs = {}

    def endReset(self):
        t = time.time()
        self.endResetModel()
        self.restoreSelection()
        self.browser.mw.progress.finish()

    def reverse(self):
        self.browser.editor.saveNow(self._reverse)

    def _reverse(self):
        self.beginReset()
        self.cards.reverse()
        self.endReset()

    def saveSelection(self):
        cards = self.browser.selectedCards()
        self.selectedCards = dict([(id, True) for id in cards])
        if getattr(self.browser, "card", None):
            self.focusedCard = self.browser.card.id
        else:
            self.focusedCard = None

    def restoreSelection(self):
        if not self.cards:
            return
        sm = self.browser.form.tableView.selectionModel()
        sm.clear()
        # restore selection
        items = QItemSelection()
        count = 0
        firstIdx = None
        focusedIdx = None
        for row, id in enumerate(self.cards):
            # if the id matches the focused card, note the index
            if self.focusedCard == id:
                focusedIdx = self.index(row, 0)
                items.select(focusedIdx, focusedIdx)
                self.focusedCard = None
            # if the card was previously selected, select again
            if id in self.selectedCards:
                count += 1
                idx = self.index(row, 0)
                items.select(idx, idx)
                # note down the first card of the selection, in case we don't
                # have a focused card
                if not firstIdx:
                    firstIdx = idx
        # focus previously focused or first in selection
        idx = focusedIdx or firstIdx
        tv = self.browser.form.tableView
        if idx:
            tv.selectRow(idx.row())
            # scroll if the selection count has changed
            if count != len(self.selectedCards):
                # we save and then restore the horizontal scroll position because
                # scrollTo() also scrolls horizontally which is confusing
                h = tv.horizontalScrollBar().value()
                tv.scrollTo(idx, tv.PositionAtCenter)
                tv.horizontalScrollBar().setValue(h)
            if count < 500:
                # discard large selections; they're too slow
                sm.select(
                    items, QItemSelectionModel.SelectCurrent | QItemSelectionModel.Rows
                )
        else:
            tv.selectRow(0)

    # Column data
    ######################################################################

    def columnType(self, column):
        return self.activeCols[column]

    def columnData(self, index):
        row = index.row()
        col = index.column()
        type = self.columnType(col)
        c = self.getCard(index)
        if type == "question":
            return self.question(c)
        elif type == "answer":
            return self.answer(c)
        elif type == "noteFld":
            f = c.note()
            return htmlToTextLine(f.fields[self.col.models.sortIdx(f.model())])
        elif type == "template":
            t = c.template()["name"]
            if c.model()["type"] == MODEL_CLOZE:
                t += " %d" % (c.ord + 1)
            return t
        elif type == "cardDue":
            # catch invalid dates
            try:
                t = self.nextDue(c, index)
            except:
                t = ""
            if c.queue < 0:
                t = "(" + t + ")"
            return t
        elif type == "noteCrt":
            return time.strftime("%Y-%m-%d", time.localtime(c.note().id / 1000))
        elif type == "noteMod":
            return time.strftime("%Y-%m-%d", time.localtime(c.note().mod))
        elif type == "cardMod":
            return time.strftime("%Y-%m-%d", time.localtime(c.mod))
        elif type == "cardReps":
            return str(c.reps)
        elif type == "cardLapses":
            return str(c.lapses)
        elif type == "noteTags":
            return " ".join(c.note().tags)
        elif type == "note":
            return c.model()["name"]
        elif type == "cardIvl":
            if c.type == 0:
                return _("(new)")
            elif c.type == 1:
                return _("(learning)")
            return fmtTimeSpan(c.ivl * 86400)
        elif type == "cardEase":
            if c.type == 0:
                return _("(new)")
            return "%d%%" % (c.factor / 10)
        elif type == "deck":
            if c.odid:
                # in a cram deck
                return "%s (%s)" % (
                    self.browser.mw.col.decks.name(c.did),
                    self.browser.mw.col.decks.name(c.odid),
                )
            # normal deck
            return self.browser.mw.col.decks.name(c.did)

    def question(self, c):
        return htmlToTextLine(c.q(browser=True))

    def answer(self, c):
        if c.template().get("bafmt"):
            # they have provided a template, use it verbatim
            c.q(browser=True)
            return htmlToTextLine(c.a())
        # need to strip question from answer
        q = self.question(c)
        a = htmlToTextLine(c.a())
        if a.startswith(q):
            return a[len(q) :].strip()
        return a

    def nextDue(self, c, index):
        if c.odid:
            return _("(filtered)")
        elif c.queue == QUEUE_TYPE_LRN:
            date = c.due
        elif c.queue == QUEUE_TYPE_NEW or c.type == CARD_TYPE_NEW:
            return tr(StringsGroup.STATISTICS, "due-for-new-card", number=c.due)
        elif c.queue in (QUEUE_TYPE_REV, QUEUE_TYPE_DAY_LEARN_RELEARN) or (
            c.type == CARD_TYPE_REV and c.queue < 0
        ):
            date = time.time() + ((c.due - self.col.sched.today) * 86400)
        else:
            return ""
        return time.strftime("%Y-%m-%d", time.localtime(date))

    def isRTL(self, index):
        col = index.column()
        type = self.columnType(col)
        if type != "noteFld":
            return False

        row = index.row()
        c = self.getCard(index)
        nt = c.note().model()
        return nt["flds"][self.col.models.sortIdx(nt)]["rtl"]


# Line painter
######################################################################


class StatusDelegate(QItemDelegate):
    def __init__(self, browser, model):
        QItemDelegate.__init__(self, browser)
        self.browser = browser
        self.model = model

    def paint(self, painter, option, index):
        self.browser.mw.progress.blockUpdates = True
        try:
            c = self.model.getCard(index)
        except:
            # in the the middle of a reset; return nothing so this row is not
            # rendered until we have a chance to reset the model
            return
        finally:
            self.browser.mw.progress.blockUpdates = True

        if self.model.isRTL(index):
            option.direction = Qt.RightToLeft

        col = None
        if c.userFlag() > 0:
            col = theme_manager.qcolor(f"flag{c.userFlag()}-bg")
        elif c.note().hasTag("Marked"):
            col = theme_manager.qcolor("marked-bg")
        elif c.queue == -1:
            col = theme_manager.qcolor("suspended-bg")
        if col:
            brush = QBrush(col)
            painter.save()
            painter.fillRect(option.rect, brush)
            painter.restore()

        return QItemDelegate.paint(self, painter, option, index)


# Sidebar
######################################################################


class SidebarStage(Enum):
    ROOT = 0
    STANDARD = 1
    FAVORITES = 2
    DECKS = 3
    MODELS = 4
    TAGS = 5


class SidebarItem:
    def __init__(
        self,
        name: str,
        icon: str,
        onClick: Callable[[], None] = None,
        onExpanded: Callable[[bool], None] = None,
        expanded: bool = False,
    ) -> None:
        self.name = name
        self.icon = icon
        self.onClick = onClick
        self.onExpanded = onExpanded
        self.expanded = expanded
        self.children: List["SidebarItem"] = []
        self.parentItem: Optional[SidebarItem] = None
        self.tooltip: Optional[str] = None

    def addChild(self, cb: "SidebarItem") -> None:
        self.children.append(cb)
        cb.parentItem = self

    def rowForChild(self, child: "SidebarItem") -> Optional[int]:
        try:
            return self.children.index(child)
        except ValueError:
            return None


class SidebarModel(QAbstractItemModel):
    def __init__(self, root: SidebarItem) -> None:
        super().__init__()
        self.root = root

    # Qt API
    ######################################################################

    def rowCount(self, parent: QModelIndex = QModelIndex()) -> int:
        if not parent.isValid():
            return len(self.root.children)
        else:
            item: SidebarItem = parent.internalPointer()
            return len(item.children)

    def columnCount(self, parent: QModelIndex = QModelIndex()) -> int:
        return 1

    def index(
        self, row: int, column: int, parent: QModelIndex = QModelIndex()
    ) -> QModelIndex:
        if not self.hasIndex(row, column, parent):
            return QModelIndex()

        parentItem: SidebarItem
        if not parent.isValid():
            parentItem = self.root
        else:
            parentItem = parent.internalPointer()

        item = parentItem.children[row]
        return self.createIndex(row, column, item)

    def parent(self, child: QModelIndex) -> QModelIndex:  # type: ignore
        if not child.isValid():
            return QModelIndex()

        childItem: SidebarItem = child.internalPointer()
        parentItem = childItem.parentItem

        if parentItem is None or parentItem == self.root:
            return QModelIndex()

        row = parentItem.rowForChild(childItem)
        if row is None:
            return QModelIndex()

        return self.createIndex(row, 0, parentItem)

    def data(self, index: QModelIndex, role: int = Qt.DisplayRole) -> QVariant:
        if not index.isValid():
            return QVariant()

        if role not in (Qt.DisplayRole, Qt.DecorationRole, Qt.ToolTipRole):
            return QVariant()

        item: SidebarItem = index.internalPointer()

        if role == Qt.DisplayRole:
            return QVariant(item.name)
        elif role == Qt.ToolTipRole:
            return QVariant(item.tooltip)
        else:
            return QVariant(theme_manager.icon_from_resources(item.icon))

    # Helpers
    ######################################################################

    def iconFromRef(self, iconRef: str) -> QIcon:
        print("iconFromRef() deprecated")
        return theme_manager.icon_from_resources(iconRef)

    def expandWhereNeccessary(self, tree: QTreeView) -> None:
        for row, child in enumerate(self.root.children):
            if child.expanded:
                idx = self.index(row, 0, QModelIndex())
                self._expandWhereNeccessary(idx, tree)

    def _expandWhereNeccessary(self, parent: QModelIndex, tree: QTreeView) -> None:
        parentItem: SidebarItem
        if not parent.isValid():
            parentItem = self.root
        else:
            parentItem = parent.internalPointer()

        # nothing to do?
        if not parentItem.expanded:
            return

        # expand children
        for row, child in enumerate(parentItem.children):
            if not child.expanded:
                continue
            childIdx = self.index(row, 0, parent)
            self._expandWhereNeccessary(childIdx, tree)

        # then ourselves
        tree.setExpanded(parent, True)


# Browser window
######################################################################

# fixme: respond to reset+edit hooks


class Browser(QMainWindow):
    model: DataModel
    mw: AnkiQt
    col: _Collection
    editor: Optional[Editor]

    def __init__(self, mw: AnkiQt) -> None:
        QMainWindow.__init__(self, None, Qt.Window)
        self.mw = mw
        self.col = self.mw.col
        self.lastFilter = ""
        self.focusTo = None
        self._previewWindow = None
        self._closeEventHasCleanedUp = False
        self.form = aqt.forms.browser.Ui_Dialog()
        self.form.setupUi(self)
        self.setupSidebar()
        restoreGeom(self, "editor", 0)
        restoreState(self, "editor")
        restoreSplitter(self.form.splitter, "editor3")
        self.form.splitter.setChildrenCollapsible(False)
        self.card: Optional[Card] = None
        self.setupColumns()
        self.setupTable()
        self.setupMenus()
        self.setupHeaders()
        self.setupHooks()
        self.setupEditor()
        self.updateFont()
        self.onUndoState(self.mw.form.actionUndo.isEnabled())
        self.setupSearch()
        self.show()

    def setupMenus(self) -> None:
        # pylint: disable=unnecessary-lambda
        # actions
        f = self.form
        f.previewButton.clicked.connect(self.onTogglePreview)
        f.previewButton.setToolTip(
            _("Preview Selected Card (%s)") % shortcut("Ctrl+Shift+P")
        )
        f.previewButton.setShortcut("Ctrl+Shift+P")

        f.filter.clicked.connect(self.onFilterButton)
        # edit
        f.actionUndo.triggered.connect(self.mw.onUndo)
        f.actionInvertSelection.triggered.connect(self.invertSelection)
        f.actionSelectNotes.triggered.connect(self.selectNotes)
        if not isMac:
            f.actionClose.setVisible(False)
        # notes
        f.actionAdd.triggered.connect(self.mw.onAddCard)
        f.actionAdd_Tags.triggered.connect(lambda: self.addTags())
        f.actionRemove_Tags.triggered.connect(lambda: self.deleteTags())
        f.actionClear_Unused_Tags.triggered.connect(self.clearUnusedTags)
        f.actionToggle_Mark.triggered.connect(lambda: self.onMark())
        f.actionChangeModel.triggered.connect(self.onChangeModel)
        f.actionFindDuplicates.triggered.connect(self.onFindDupes)
        f.actionFindReplace.triggered.connect(self.onFindReplace)
        f.actionManage_Note_Types.triggered.connect(self.mw.onNoteTypes)
        f.actionDelete.triggered.connect(self.deleteNotes)
        # cards
        f.actionChange_Deck.triggered.connect(self.setDeck)
        f.action_Info.triggered.connect(self.showCardInfo)
        f.actionReposition.triggered.connect(self.reposition)
        f.actionReschedule.triggered.connect(self.reschedule)
        f.actionToggle_Suspend.triggered.connect(self.onSuspend)
        f.actionRed_Flag.triggered.connect(lambda: self.onSetFlag(1))
        f.actionOrange_Flag.triggered.connect(lambda: self.onSetFlag(2))
        f.actionGreen_Flag.triggered.connect(lambda: self.onSetFlag(3))
        f.actionBlue_Flag.triggered.connect(lambda: self.onSetFlag(4))
        f.actionExport.triggered.connect(lambda: self._on_export_notes())
        # jumps
        f.actionPreviousCard.triggered.connect(self.onPreviousCard)
        f.actionNextCard.triggered.connect(self.onNextCard)
        f.actionFirstCard.triggered.connect(self.onFirstCard)
        f.actionLastCard.triggered.connect(self.onLastCard)
        f.actionFind.triggered.connect(self.onFind)
        f.actionNote.triggered.connect(self.onNote)
        f.actionTags.triggered.connect(self.onFilterButton)
        f.actionSidebar.triggered.connect(self.focusSidebar)
        f.actionCardList.triggered.connect(self.onCardList)
        # help
        f.actionGuide.triggered.connect(self.onHelp)
        # keyboard shortcut for shift+home/end
        self.pgUpCut = QShortcut(QKeySequence("Shift+Home"), self)
        qconnect(self.pgUpCut.activated, self.onFirstCard)
        self.pgDownCut = QShortcut(QKeySequence("Shift+End"), self)
        qconnect(self.pgDownCut.activated, self.onLastCard)
        # add-on hook
        gui_hooks.browser_menus_did_init(self)
        self.mw.maybeHideAccelerators(self)

        # context menu
        self.form.tableView.setContextMenuPolicy(Qt.CustomContextMenu)
        self.form.tableView.customContextMenuRequested.connect(self.onContextMenu)

    def onContextMenu(self, _point) -> None:
        m = QMenu()
        for act in self.form.menu_Cards.actions():
            m.addAction(act)
        m.addSeparator()
        for act in self.form.menu_Notes.actions():
            m.addAction(act)
        gui_hooks.browser_will_show_context_menu(self, m)
        qtMenuShortcutWorkaround(m)
        m.exec_(QCursor.pos())

    def updateFont(self):
        # we can't choose different line heights efficiently, so we need
        # to pick a line height big enough for any card template
        curmax = 16
        for m in self.col.models.all():
            for t in m["tmpls"]:
                bsize = t.get("bsize", 0)
                if bsize > curmax:
                    curmax = bsize
        self.form.tableView.verticalHeader().setDefaultSectionSize(curmax + 6)

    def closeEvent(self, evt):
        if self._closeEventHasCleanedUp:
            evt.accept()
            return
        self.editor.saveNow(self._closeWindow)
        evt.ignore()

    def _closeWindow(self):
        self._cancelPreviewTimer()
        self.editor.cleanup()
        saveSplitter(self.form.splitter, "editor3")
        saveGeom(self, "editor")
        saveState(self, "editor")
        saveHeader(self.form.tableView.horizontalHeader(), "editor")
        self.col.conf["activeCols"] = self.model.activeCols
        self.col.setMod()
        self.teardownHooks()
        self.mw.maybeReset()
        aqt.dialogs.markClosed("Browser")
        self._closeEventHasCleanedUp = True
        self.mw.gcWindow(self)
        self.close()

    def closeWithCallback(self, onsuccess):
        def callback():
            self._closeWindow()
            onsuccess()

        self.editor.saveNow(callback)

    def keyPressEvent(self, evt):
        if evt.key() == Qt.Key_Escape:
            self.close()
        else:
            super().keyPressEvent(evt)

    def setupColumns(self):
        self.columns = [
            ("question", _("Question")),
            ("answer", _("Answer")),
            ("template", _("Card")),
            ("deck", _("Deck")),
            ("noteFld", _("Sort Field")),
            ("noteCrt", _("Created")),
            ("noteMod", _("Edited")),
            ("cardMod", _("Changed")),
            ("cardDue", tr(StringsGroup.STATISTICS, "due-date")),
            ("cardIvl", _("Interval")),
            ("cardEase", _("Ease")),
            ("cardReps", _("Reviews")),
            ("cardLapses", _("Lapses")),
            ("noteTags", _("Tags")),
            ("note", _("Note")),
        ]
        self.columns.sort(key=itemgetter(1))

    # Searching
    ######################################################################

    def setupSearch(self):
        self.form.searchButton.clicked.connect(self.onSearchActivated)
        self.form.searchEdit.lineEdit().returnPressed.connect(self.onSearchActivated)
        self.form.searchEdit.setCompleter(None)
        self._searchPrompt = _("<type here to search; hit enter to show current deck>")
        self.form.searchEdit.addItems(
            [self._searchPrompt] + self.mw.pm.profile["searchHistory"]
        )
        self._lastSearchTxt = "is:current"
        self.search()
        # then replace text for easily showing the deck
        self.form.searchEdit.lineEdit().setText(self._searchPrompt)
        self.form.searchEdit.lineEdit().selectAll()
        self.form.searchEdit.setFocus()

    # search triggered by user
    def onSearchActivated(self):
        self.editor.saveNow(self._onSearchActivated)

    def _onSearchActivated(self):
        # convert guide text before we save history
        if self.form.searchEdit.lineEdit().text() == self._searchPrompt:
            self.form.searchEdit.lineEdit().setText("deck:current ")

        # grab search text and normalize
        txt = self.form.searchEdit.lineEdit().text()
        txt = unicodedata.normalize("NFC", txt)

        # update history
        sh = self.mw.pm.profile["searchHistory"]
        if txt in sh:
            sh.remove(txt)
        sh.insert(0, txt)
        sh = sh[:30]
        self.form.searchEdit.clear()
        self.form.searchEdit.addItems(sh)
        self.mw.pm.profile["searchHistory"] = sh

        # keep track of search string so that we reuse identical search when
        # refreshing, rather than whatever is currently in the search field
        self._lastSearchTxt = txt
        self.search()

    # search triggered programmatically. caller must have saved note first.
    def search(self) -> None:
        if "is:current" in self._lastSearchTxt:
            # show current card if there is one
            c = self.card = self.mw.reviewer.card
            nid = c and c.nid or 0
            if nid:
                self.model.search("nid:%d" % nid)
                self.focusCid(c.id)
        else:
            self.model.search(self._lastSearchTxt)

        if not self.model.cards:
            # no row change will fire
            self._onRowChanged(None, None)

    def updateTitle(self):
        selected = len(self.form.tableView.selectionModel().selectedRows())
        cur = len(self.model.cards)
        self.setWindowTitle(
            ngettext(
                "Browse (%(cur)d card shown; %(sel)s)",
                "Browse (%(cur)d cards shown; %(sel)s)",
                cur,
            )
            % {
                "cur": cur,
                "sel": ngettext("%d selected", "%d selected", selected) % selected,
            }
        )
        return selected

    def onReset(self):
        self.editor.setNote(None)
        self.search()

    # Table view & editor
    ######################################################################

    def setupTable(self):
        self.model = DataModel(self)
        self.form.tableView.setSortingEnabled(True)
        self.form.tableView.setModel(self.model)
        self.form.tableView.selectionModel()
        self.form.tableView.setItemDelegate(StatusDelegate(self, self.model))
        self.form.tableView.selectionModel().selectionChanged.connect(self.onRowChanged)
        if not theme_manager.night_mode:
            self.form.tableView.setStyleSheet(
                "QTableView{ selection-background-color: rgba(150, 150, 150, 50); "
                "selection-color: black; }"
            )
        elif theme_manager.macos_dark_mode():
            grid = theme_manager.str_color("frame-bg")
            self.form.tableView.setStyleSheet(
                f"""
QTableView {{ gridline-color: {grid} }}           
            """
            )
        self.singleCard = False

    def setupEditor(self):
        self.editor = aqt.editor.Editor(self.mw, self.form.fieldsArea, self)

    def onRowChanged(self, current, previous):
        "Update current note and hide/show editor."
        self.editor.saveNow(lambda: self._onRowChanged(current, previous))

    def _onRowChanged(self, current, previous) -> None:
        update = self.updateTitle()
        show = self.model.cards and update == 1
        self.form.splitter.widget(1).setVisible(not not show)
        idx = self.form.tableView.selectionModel().currentIndex()
        if idx.isValid():
            self.card = self.model.getCard(idx)

        if not show:
            self.editor.setNote(None)
            self.singleCard = False
        else:
            self.editor.setNote(self.card.note(reload=True), focusTo=self.focusTo)
            self.focusTo = None
            self.editor.card = self.card  # type: ignore
            self.singleCard = True
        self._updateFlagsMenu()
        gui_hooks.browser_did_change_row(self)
        self._renderPreview(True)

    def refreshCurrentCard(self, note: Note) -> None:
        self.model.refreshNote(note)
        self._renderPreview(False)

    def onLoadNote(self, editor):
        self.refreshCurrentCard(editor.note)

    def refreshCurrentCardFilter(self, flag, note, fidx):
        self.refreshCurrentCard(note)
        return flag

    def currentRow(self):
        idx = self.form.tableView.selectionModel().currentIndex()
        return idx.row()

    # Headers & sorting
    ######################################################################

    def setupHeaders(self):
        vh = self.form.tableView.verticalHeader()
        hh = self.form.tableView.horizontalHeader()
        if not isWin:
            vh.hide()
            hh.show()
        restoreHeader(hh, "editor")
        hh.setHighlightSections(False)
        hh.setMinimumSectionSize(50)
        hh.setSectionsMovable(True)
        self.setColumnSizes()
        hh.setContextMenuPolicy(Qt.CustomContextMenu)
        hh.customContextMenuRequested.connect(self.onHeaderContext)
        self.setSortIndicator()
        hh.sortIndicatorChanged.connect(self.onSortChanged)
        hh.sectionMoved.connect(self.onColumnMoved)

    def onSortChanged(self, idx, ord):
        ord = bool(ord)
        self.editor.saveNow(lambda: self._onSortChanged(idx, ord))

    def _onSortChanged(self, idx, ord):
        type = self.model.activeCols[idx]
        noSort = ("question", "answer", "template", "deck", "note", "noteTags")
        if type in noSort:
            if type == "template":
                showInfo(
                    _(
                        """\
This column can't be sorted on, but you can search for individual card types, \
such as 'card:1'."""
                    )
                )
            elif type == "deck":
                showInfo(
                    _(
                        """\
This column can't be sorted on, but you can search for specific decks \
by clicking on one on the left."""
                    )
                )
            else:
                showInfo(
                    _(
                        "Sorting on this column is not supported. Please "
                        "choose another."
                    )
                )
            type = self.col.conf["sortType"]
        if self.col.conf["sortType"] != type:
            self.col.conf["sortType"] = type
            # default to descending for non-text fields
            if type == "noteFld":
                ord = not ord
            self.col.conf["sortBackwards"] = ord
            self.search()
        else:
            if self.col.conf["sortBackwards"] != ord:
                self.col.conf["sortBackwards"] = ord
                self.model.reverse()
        self.setSortIndicator()

    def setSortIndicator(self):
        hh = self.form.tableView.horizontalHeader()
        type = self.col.conf["sortType"]
        if type not in self.model.activeCols:
            hh.setSortIndicatorShown(False)
            return
        idx = self.model.activeCols.index(type)
        if self.col.conf["sortBackwards"]:
            ord = Qt.DescendingOrder
        else:
            ord = Qt.AscendingOrder
        hh.blockSignals(True)
        hh.setSortIndicator(idx, ord)
        hh.blockSignals(False)
        hh.setSortIndicatorShown(True)

    def onHeaderContext(self, pos):
        gpos = self.form.tableView.mapToGlobal(pos)
        m = QMenu()
        for type, name in self.columns:
            a = m.addAction(name)
            a.setCheckable(True)
            a.setChecked(type in self.model.activeCols)
            a.toggled.connect(lambda b, t=type: self.toggleField(t))
        m.exec_(gpos)

    def toggleField(self, type):
        self.editor.saveNow(lambda: self._toggleField(type))

    def _toggleField(self, type):
        self.model.beginReset()
        if type in self.model.activeCols:
            if len(self.model.activeCols) < 2:
                self.model.endReset()
                return showInfo(_("You must have at least one column."))
            self.model.activeCols.remove(type)
            adding = False
        else:
            self.model.activeCols.append(type)
            adding = True
        # sorted field may have been hidden
        self.setSortIndicator()
        self.setColumnSizes()
        self.model.endReset()
        # if we added a column, scroll to it
        if adding:
            row = self.currentRow()
            idx = self.model.index(row, len(self.model.activeCols) - 1)
            self.form.tableView.scrollTo(idx)

    def setColumnSizes(self):
        hh = self.form.tableView.horizontalHeader()
        hh.setSectionResizeMode(QHeaderView.Interactive)
        hh.setSectionResizeMode(
            hh.logicalIndex(len(self.model.activeCols) - 1), QHeaderView.Stretch
        )
        # this must be set post-resize or it doesn't work
        hh.setCascadingSectionResizes(False)

    def onColumnMoved(self, a, b, c):
        self.setColumnSizes()

    # Sidebar
    ######################################################################

    class SidebarTreeView(QTreeView):
        def __init__(self):
            super().__init__()
            self.expanded.connect(self.onExpansion)
            self.collapsed.connect(self.onCollapse)

        def onClickCurrent(self) -> None:
            idx = self.currentIndex()
            if idx.isValid():
                item: SidebarItem = idx.internalPointer()
                if item.onClick:
                    item.onClick()

        def mouseReleaseEvent(self, event: QMouseEvent) -> None:
            super().mouseReleaseEvent(event)
            self.onClickCurrent()

        def keyPressEvent(self, event: QKeyEvent) -> None:
            if event.key() in (Qt.Key_Return, Qt.Key_Enter):
                self.onClickCurrent()
            else:
                super().keyPressEvent(event)

        def onExpansion(self, idx: QModelIndex) -> None:
            self._onExpansionChange(idx, True)

        def onCollapse(self, idx: QModelIndex) -> None:
            self._onExpansionChange(idx, False)

        def _onExpansionChange(self, idx: QModelIndex, expanded: bool) -> None:
            item: SidebarItem = idx.internalPointer()
            if item.expanded != expanded:
                item.expanded = expanded
                if item.onExpanded:
                    item.onExpanded(expanded)

    def setupSidebar(self) -> None:
        dw = self.sidebarDockWidget = QDockWidget(_("Sidebar"), self)
        dw.setFeatures(QDockWidget.DockWidgetClosable)
        dw.setObjectName("Sidebar")
        dw.setAllowedAreas(Qt.LeftDockWidgetArea)
        self.sidebarTree = self.SidebarTreeView()
        self.sidebarTree.mw = self.mw
        self.sidebarTree.setUniformRowHeights(True)
        self.sidebarTree.setHeaderHidden(True)
        self.sidebarTree.setIndentation(15)
        self.sidebarTree.expanded.connect(self.onSidebarItemExpanded)  # type: ignore
        dw.setWidget(self.sidebarTree)
        # match window background color
        bgcolor = QPalette().window().color().name()
        self.sidebarTree.setStyleSheet("QTreeView { background: '%s'; }" % bgcolor)
        self.sidebarDockWidget.setFloating(False)
        self.sidebarDockWidget.visibilityChanged.connect(self.onSidebarVisChanged)  # type: ignore
        self.sidebarDockWidget.setTitleBarWidget(QWidget())
        self.addDockWidget(Qt.LeftDockWidgetArea, dw)

    def onSidebarItemExpanded(self, idx: QModelIndex) -> None:
        item: SidebarItem = idx.internalPointer()
        # item.on

    def onSidebarVisChanged(self, _visible: bool) -> None:
        self.maybeRefreshSidebar()

    def focusSidebar(self) -> None:
        self.sidebarDockWidget.setVisible(True)
        self.sidebarTree.setFocus()

    def maybeRefreshSidebar(self) -> None:
        if self.sidebarDockWidget.isVisible():
            # add slight delay to allow browser window to appear first
            def deferredDisplay():
                root = self.buildTree()
                model = SidebarModel(root)
                self.sidebarTree.setModel(model)
                model.expandWhereNeccessary(self.sidebarTree)

            self.mw.progress.timer(10, deferredDisplay, False)

    def buildTree(self) -> SidebarItem:
        root = SidebarItem("", "")

        handled = gui_hooks.browser_will_build_tree(
            False, root, SidebarStage.ROOT, self
        )
        if handled:
            return root

        for stage, builder in zip(
            list(SidebarStage)[1:],
            (
                self._stdTree,
                self._favTree,
                self._decksTree,
                self._modelTree,
                self._userTagTree,
            ),
        ):
            handled = gui_hooks.browser_will_build_tree(False, root, stage, self)
            if not handled and builder:
                builder(root)

        return root

    def _stdTree(self, root) -> None:
        for name, filt, icon in [
            [_("Whole Collection"), "", "collection"],
            [_("Current Deck"), "deck:current", "deck"],
        ]:
            item = SidebarItem(
                name, ":/icons/{}.svg".format(icon), self._filterFunc(filt)
            )
            root.addChild(item)

    def _favTree(self, root) -> None:
        assert self.col
        saved = self.col.conf.get("savedFilters", {})
        for name, filt in sorted(saved.items()):
            item = SidebarItem(
                name,
                ":/icons/heart.svg",
                lambda s=filt: self.setFilter(s),  # type: ignore
            )
            root.addChild(item)

    def _userTagTree(self, root) -> None:
        assert self.col
        for t in sorted(self.col.tags.all(), key=lambda t: t.lower()):
            item = SidebarItem(
                t, ":/icons/tag.svg", lambda t=t: self.setFilter("tag", t)  # type: ignore
            )
            root.addChild(item)

    def _decksTree(self, root) -> None:
        assert self.col
        grps = self.col.sched.deckDueTree()

        def fillGroups(root, grps, head=""):
            for g in grps:
                item = SidebarItem(
                    g[0],
                    ":/icons/deck.svg",
                    lambda g=g: self.setFilter("deck", head + g[0]),
                    lambda expanded, g=g: self.mw.col.decks.collapseBrowser(g[1]),
                    not self.mw.col.decks.get(g[1]).get("browserCollapsed", False),
                )
                root.addChild(item)
                newhead = head + g[0] + "::"
                fillGroups(item, g[5], newhead)

        fillGroups(root, grps)

    def _modelTree(self, root) -> None:
        assert self.col
        for m in sorted(self.col.models.all(), key=itemgetter("name")):
            item = SidebarItem(
                m["name"],
                ":/icons/notetype.svg",
                lambda m=m: self.setFilter("note", m["name"]),  # type: ignore
            )
            root.addChild(item)

    # Filter tree
    ######################################################################

    def onFilterButton(self):
        ml = MenuList()

        ml.addChild(self._commonFilters())
        ml.addSeparator()

        ml.addChild(self._todayFilters())
        ml.addChild(self._cardStateFilters())
        ml.addChild(self._deckFilters())
        ml.addChild(self._noteTypeFilters())
        ml.addChild(self._tagFilters())
        ml.addSeparator()

        ml.addChild(self.sidebarDockWidget.toggleViewAction())
        ml.addSeparator()

        ml.addChild(self._savedSearches())

        ml.popupOver(self.form.filter)

    def setFilter(self, *args):
        if len(args) == 1:
            txt = args[0]
        else:
            txt = ""
            items = []
            for c, a in enumerate(args):
                if c % 2 == 0:
                    txt += a + ":"
                else:
                    txt += a
                    for chr in " 　()":
                        if chr in txt:
                            txt = '"%s"' % txt
                            break
                    items.append(txt)
                    txt = ""
            txt = " ".join(items)
        if self.mw.app.keyboardModifiers() & Qt.AltModifier:
            txt = "-" + txt
        if self.mw.app.keyboardModifiers() & Qt.ControlModifier:
            cur = str(self.form.searchEdit.lineEdit().text())
            if cur and cur != self._searchPrompt:
                txt = cur + " " + txt
        elif self.mw.app.keyboardModifiers() & Qt.ShiftModifier:
            cur = str(self.form.searchEdit.lineEdit().text())
            if cur:
                txt = cur + " or " + txt
        self.form.searchEdit.lineEdit().setText(txt)
        self.onSearchActivated()

    def _simpleFilters(self, items):
        ml = MenuList()
        for row in items:
            if row is None:
                ml.addSeparator()
            else:
                label, filter = row
                ml.addItem(label, self._filterFunc(filter))
        return ml

    def _filterFunc(self, *args):
        return lambda *, f=args: self.setFilter(*f)

    def _commonFilters(self):
        return self._simpleFilters(
            ((_("Whole Collection"), ""), (_("Current Deck"), "deck:current"))
        )

    def _todayFilters(self):
        subm = SubMenu(_("Today"))
        subm.addChild(
            self._simpleFilters(
                (
                    (_("Added Today"), "added:1"),
                    (_("Studied Today"), "rated:1"),
                    (_("Again Today"), "rated:1:1"),
                )
            )
        )
        return subm

    def _cardStateFilters(self):
        subm = SubMenu(_("Card State"))
        subm.addChild(
            self._simpleFilters(
                (
                    (_("New"), "is:new"),
                    (_("Learning"), "is:learn"),
                    (_("Review"), "is:review"),
                    (tr(StringsGroup.FILTERING, "is-due"), "is:due"),
                    None,
                    (_("Suspended"), "is:suspended"),
                    (_("Buried"), "is:buried"),
                    None,
                    (_("Red Flag"), "flag:1"),
                    (_("Orange Flag"), "flag:2"),
                    (_("Green Flag"), "flag:3"),
                    (_("Blue Flag"), "flag:4"),
                    (_("No Flag"), "flag:0"),
                    (_("Any Flag"), "-flag:0"),
                )
            )
        )
        return subm

    def _tagFilters(self):
        m = SubMenu(_("Tags"))

        m.addItem(_("Clear Unused"), self.clearUnusedTags)
        m.addSeparator()

        tagList = MenuList()
        for t in sorted(self.col.tags.all(), key=lambda s: s.lower()):
            tagList.addItem(t, self._filterFunc("tag", t))

        m.addChild(tagList.chunked())
        return m

    def _deckFilters(self):
        def addDecks(parent, decks):
            for head, did, rev, lrn, new, children in decks:
                name = self.mw.col.decks.get(did)["name"]
                shortname = name.split("::")[-1]
                if children:
                    subm = parent.addMenu(shortname)
                    subm.addItem(_("Filter"), self._filterFunc("deck", name))
                    subm.addSeparator()
                    addDecks(subm, children)
                else:
                    parent.addItem(shortname, self._filterFunc("deck", name))

        # fixme: could rewrite to avoid calculating due # in the future
        alldecks = self.col.sched.deckDueTree()
        ml = MenuList()
        addDecks(ml, alldecks)

        root = SubMenu(_("Decks"))
        root.addChild(ml.chunked())

        return root

    def _noteTypeFilters(self):
        m = SubMenu(_("Note Types"))

        m.addItem(_("Manage..."), self.mw.onNoteTypes)
        m.addSeparator()

        noteTypes = MenuList()
        for nt in sorted(self.col.models.all(), key=lambda nt: nt["name"].lower()):
            # no sub menu if it's a single template
            if len(nt["tmpls"]) == 1:
                noteTypes.addItem(nt["name"], self._filterFunc("note", nt["name"]))
            else:
                subm = noteTypes.addMenu(nt["name"])

                subm.addItem(_("All Card Types"), self._filterFunc("note", nt["name"]))
                subm.addSeparator()

                # add templates
                for c, tmpl in enumerate(nt["tmpls"]):
                    # T: name is a card type name. n it's order in the list of card type.
                    # T: this is shown in browser's filter, when seeing the list of card type of a note type.
                    name = _("%(n)d: %(name)s") % dict(n=c + 1, name=tmpl["name"])
                    subm.addItem(
                        name, self._filterFunc("note", nt["name"], "card", str(c + 1))
                    )

        m.addChild(noteTypes.chunked())
        return m

    # Favourites
    ######################################################################

    def _savedSearches(self):
        ml = MenuList()
        # make sure exists
        if "savedFilters" not in self.col.conf:
            self.col.conf["savedFilters"] = {}

        ml.addSeparator()

        if self._currentFilterIsSaved():
            ml.addItem(_("Remove Current Filter..."), self._onRemoveFilter)
        else:
            ml.addItem(_("Save Current Filter..."), self._onSaveFilter)

        saved = self.col.conf["savedFilters"]
        if not saved:
            return ml

        ml.addSeparator()
        for name, filt in sorted(saved.items()):
            ml.addItem(name, self._filterFunc(filt))

        return ml

    def _onSaveFilter(self):
        name = getOnlyText(_("Please give your filter a name:"))
        if not name:
            return
        filt = self.form.searchEdit.lineEdit().text()
        self.col.conf["savedFilters"][name] = filt
        self.col.setMod()
        self.maybeRefreshSidebar()

    def _onRemoveFilter(self):
        name = self._currentFilterIsSaved()
        if not askUser(_("Remove %s from your saved searches?") % name):
            return
        del self.col.conf["savedFilters"][name]
        self.col.setMod()
        self.maybeRefreshSidebar()

    # returns name if found
    def _currentFilterIsSaved(self):
        filt = self.form.searchEdit.lineEdit().text()
        for k, v in self.col.conf["savedFilters"].items():
            if filt == v:
                return k
        return None

    # Info
    ######################################################################

    def showCardInfo(self):
        if not self.card:
            return
        info, cs = self._cardInfoData()
        reps = self._revlogData(cs)

        card_info_dialog = CardInfoDialog(self)
        l = QVBoxLayout()
        l.setContentsMargins(0, 0, 0, 0)
        w = AnkiWebView(title="browser card info")
        l.addWidget(w)
        w.stdHtml(info + "<p>" + reps, context=card_info_dialog)
        bb = QDialogButtonBox(QDialogButtonBox.Close)
        l.addWidget(bb)
        bb.rejected.connect(card_info_dialog.reject)
        card_info_dialog.setLayout(l)
        card_info_dialog.setWindowModality(Qt.WindowModal)
        card_info_dialog.resize(500, 400)
        restoreGeom(card_info_dialog, "revlog")
        card_info_dialog.show()

    def _cardInfoData(self):
        from anki.stats import CardStats

        cs = CardStats(self.col, self.card)
        rep = cs.report()
        m = self.card.model()
        rep = (
            """
<div style='width: 400px; margin: 0 auto 0;
border: 1px solid #000; padding: 3px; '>%s</div>"""
            % rep
        )
        return rep, cs

    def _revlogData(self, cs):
        entries = self.mw.col.db.all(
            "select id/1000.0, ease, ivl, factor, time/1000.0, type "
            "from revlog where cid = ?",
            self.card.id,
        )
        if not entries:
            return ""
        s = "<table width=100%%><tr><th align=left>%s</th>" % _("Date")
        s += ("<th align=right>%s</th>" * 5) % (
            _("Type"),
            _("Rating"),
            _("Interval"),
            _("Ease"),
            _("Time"),
        )
        cnt = 0
        for (date, ease, ivl, factor, taken, type) in reversed(entries):
            cnt += 1
            s += "<tr><td>%s</td>" % time.strftime(
                _("<b>%Y-%m-%d</b> @ %H:%M"), time.localtime(date)
            )
            tstr = [_("Learn"), _("Review"), _("Relearn"), _("Filtered"), _("Resched")][
                type
            ]
            import anki.stats as st

            fmt = "<span style='color:%s'>%s</span>"
            if type == CARD_TYPE_NEW:
                tstr = fmt % (st.colLearn, tstr)
            elif type == CARD_TYPE_LRN:
                tstr = fmt % (st.colMature, tstr)
            elif type == 2:
                tstr = fmt % (st.colRelearn, tstr)
            elif type == 3:
                tstr = fmt % (st.colCram, tstr)
            else:
                tstr = fmt % ("#000", tstr)
            if ease == 1:
                ease = fmt % (st.colRelearn, ease)
            if ivl == 0:
                ivl = _("0d")
            elif ivl > 0:
                ivl = fmtTimeSpan(ivl * 86400, short=True)
            else:
                ivl = cs.time(-ivl)
            s += ("<td align=right>%s</td>" * 5) % (
                tstr,
                ease,
                ivl,
                "%d%%" % (factor / 10) if factor else "",
                cs.time(taken),
            ) + "</tr>"
        s += "</table>"
        if cnt < self.card.reps:
            s += _(
                """\
Note: Some of the history is missing. For more information, \
please see the browser documentation."""
            )
        return s

    # Menu helpers
    ######################################################################

    def selectedCards(self):
        return [
            self.model.cards[idx.row()]
            for idx in self.form.tableView.selectionModel().selectedRows()
        ]

    def selectedNotes(self):
        return self.col.db.list(
            """
select distinct nid from cards
where id in %s"""
            % ids2str(
                [
                    self.model.cards[idx.row()]
                    for idx in self.form.tableView.selectionModel().selectedRows()
                ]
            )
        )

    def selectedNotesAsCards(self):
        return self.col.db.list(
            "select id from cards where nid in (%s)"
            % ",".join([str(s) for s in self.selectedNotes()])
        )

    def oneModelNotes(self):
        sf = self.selectedNotes()
        if not sf:
            return
        mods = self.col.db.scalar(
            """
select count(distinct mid) from notes
where id in %s"""
            % ids2str(sf)
        )
        if mods > 1:
            showInfo(_("Please select cards from only one note type."))
            return
        return sf

    def onHelp(self):
        openHelp("browser")

    # Misc menu options
    ######################################################################

    def onChangeModel(self):
        self.editor.saveNow(self._onChangeModel)

    def _onChangeModel(self):
        nids = self.oneModelNotes()
        if nids:
            ChangeModel(self, nids)

    # Preview
    ######################################################################

    _previewTimer = None
    _lastPreviewRender: Union[int, float] = 0
    _lastPreviewState = None
    _previewCardChanged = False

    def onTogglePreview(self):
        if self._previewWindow:
            self._closePreview()
        else:
            self._openPreview()

    def _openPreview(self):
        self._previewState = "question"
        self._lastPreviewState = None
        self._previewWindow = QDialog(None, Qt.Window)
        self._previewWindow.setWindowTitle(_("Preview"))

        self._previewWindow.finished.connect(self._onPreviewFinished)
        self._previewWindow.silentlyClose = True
        vbox = QVBoxLayout()
        vbox.setContentsMargins(0, 0, 0, 0)
        self._previewWeb = AnkiWebView(title="previewer")
        vbox.addWidget(self._previewWeb)
        bbox = QDialogButtonBox()

        self._previewReplay = bbox.addButton(
            _("Replay Audio"), QDialogButtonBox.ActionRole
        )
        self._previewReplay.setAutoDefault(False)
        self._previewReplay.setShortcut(QKeySequence("R"))
        self._previewReplay.setToolTip(_("Shortcut key: %s" % "R"))

        self._previewPrev = bbox.addButton("<", QDialogButtonBox.ActionRole)
        self._previewPrev.setAutoDefault(False)
        self._previewPrev.setShortcut(QKeySequence("Left"))
        self._previewPrev.setToolTip(_("Shortcut key: Left arrow"))

        self._previewNext = bbox.addButton(">", QDialogButtonBox.ActionRole)
        self._previewNext.setAutoDefault(True)
        self._previewNext.setShortcut(QKeySequence("Right"))
        self._previewNext.setToolTip(_("Shortcut key: Right arrow or Enter"))

        self._previewPrev.clicked.connect(self._onPreviewPrev)
        self._previewNext.clicked.connect(self._onPreviewNext)
        self._previewReplay.clicked.connect(self._onReplayAudio)

        self.previewShowBothSides = QCheckBox(_("Show Both Sides"))
        self.previewShowBothSides.setShortcut(QKeySequence("B"))
        self.previewShowBothSides.setToolTip(_("Shortcut key: %s" % "B"))
        bbox.addButton(self.previewShowBothSides, QDialogButtonBox.ActionRole)
        self._previewBothSides = self.col.conf.get("previewBothSides", False)
        self.previewShowBothSides.setChecked(self._previewBothSides)
        self.previewShowBothSides.toggled.connect(self._onPreviewShowBothSides)

        self._setupPreviewWebview()

        vbox.addWidget(bbox)
        self._previewWindow.setLayout(vbox)
        restoreGeom(self._previewWindow, "preview")
        self._previewWindow.show()
        self._renderPreview(True)

    def _onPreviewFinished(self, ok):
        saveGeom(self._previewWindow, "preview")
        self.mw.progress.timer(100, self._onClosePreview, False)
        self.form.previewButton.setChecked(False)

    def _onPreviewPrev(self):
        if self._previewState == "answer" and not self._previewBothSides:
            self._previewState = "question"
            self._renderPreview()
        else:
            self.editor.saveNow(lambda: self._moveCur(QAbstractItemView.MoveUp))

    def _onPreviewNext(self):
        if self._previewState == "question":
            self._previewState = "answer"
            self._renderPreview()
        else:
            self.editor.saveNow(lambda: self._moveCur(QAbstractItemView.MoveDown))

    def _onReplayAudio(self):
        self.mw.reviewer.replayAudio(self)

    def _updatePreviewButtons(self):
        if not self._previewWindow:
            return
        current = self.currentRow()
        canBack = current > 0 or (
            current == 0
            and self._previewState == "answer"
            and not self._previewBothSides
        )
        self._previewPrev.setEnabled(not not (self.singleCard and canBack))
        canForward = (
            self.currentRow() < self.model.rowCount(None) - 1
            or self._previewState == "question"
        )
        self._previewNext.setEnabled(not not (self.singleCard and canForward))

    def _closePreview(self):
        if self._previewWindow:
            self._previewWindow.close()
            self._onClosePreview()

    def _onClosePreview(self):
        self._previewWindow = self._previewPrev = self._previewNext = None

    def _setupPreviewWebview(self):
        jsinc = [
            "jquery.js",
            "browsersel.js",
            "mathjax/conf.js",
            "mathjax/MathJax.js",
            "reviewer.js",
        ]
        web_context = PreviewDialog(dialog=self._previewWindow, browser=self)
        self._previewWeb.stdHtml(
            self.mw.reviewer.revHtml(),
            css=["reviewer.css"],
            js=jsinc,
            context=web_context,
        )
        self._previewWeb.set_bridge_command(
            self._on_preview_bridge_cmd, web_context,
        )

    def _on_preview_bridge_cmd(self, cmd: str) -> Any:
        if cmd.startswith("play:"):
            play_clicked_audio(cmd, self.card)

    def _renderPreview(self, cardChanged=False):
        self._cancelPreviewTimer()
        # Keep track of whether _renderPreview() has ever been called
        # with cardChanged=True since the last successful render
        self._previewCardChanged |= cardChanged
        # avoid rendering in quick succession
        elapMS = int((time.time() - self._lastPreviewRender) * 1000)
        delay = 300
        if elapMS < delay:
            self._previewTimer = self.mw.progress.timer(
                delay - elapMS, self._renderScheduledPreview, False
            )
        else:
            self._renderScheduledPreview()

    def _cancelPreviewTimer(self):
        if self._previewTimer:
            self._previewTimer.stop()
            self._previewTimer = None

    def _renderScheduledPreview(self) -> None:
        self._cancelPreviewTimer()
        self._lastPreviewRender = time.time()

        if not self._previewWindow:
            return
        c = self.card
        func = "_showQuestion"
        if not c or not self.singleCard:
            txt = _("(please select 1 card)")
            bodyclass = ""
            self._lastPreviewState = None
        else:
            if self._previewBothSides:
                self._previewState = "answer"
            elif self._previewCardChanged:
                self._previewState = "question"

            currentState = self._previewStateAndMod()
            if currentState == self._lastPreviewState:
                # nothing has changed, avoid refreshing
                return

            # need to force reload even if answer
            txt = c.q(reload=True)

            if self._previewState == "answer":
                func = "_showAnswer"
                txt = c.a()
            txt = re.sub(r"\[\[type:[^]]+\]\]", "", txt)

            bodyclass = theme_manager.body_classes_for_card_ord(c.ord)

            if self.mw.reviewer.autoplay(c):
                if self._previewBothSides:
                    # if we're showing both sides at once, remove any audio
                    # from the answer that's appeared on the question already
                    question_audio = c.question_av_tags()
                    only_on_answer_audio = [
                        x for x in c.answer_av_tags() if x not in question_audio
                    ]
                    audio = question_audio + only_on_answer_audio
                elif self._previewState == "question":
                    audio = c.question_av_tags()
                else:
                    audio = c.answer_av_tags()
                av_player.play_tags(audio)

            txt = self.mw.prepare_card_text_for_display(txt)
            txt = gui_hooks.card_will_show(
                txt, c, "preview" + self._previewState.capitalize()
            )
            self._lastPreviewState = self._previewStateAndMod()
        self._updatePreviewButtons()
        self._previewWeb.eval("{}({},'{}');".format(func, json.dumps(txt), bodyclass))
        self._previewCardChanged = False

    def _onPreviewShowBothSides(self, toggle):
        self._previewBothSides = toggle
        self.col.conf["previewBothSides"] = toggle
        self.col.setMod()
        if self._previewState == "answer" and not toggle:
            self._previewState = "question"
        self._renderPreview()

    def _previewStateAndMod(self):
        c = self.card
        n = c.note()
        n.load()
        return (self._previewState, c.id, n.mod)

    # Card deletion
    ######################################################################

    def deleteNotes(self):
        focus = self.focusWidget()
        if focus != self.form.tableView:
            return
        self._deleteNotes()

    def _deleteNotes(self):
        nids = self.selectedNotes()
        if not nids:
            return
        self.mw.checkpoint(_("Delete Notes"))
        self.model.beginReset()
        # figure out where to place the cursor after the deletion
        curRow = self.form.tableView.selectionModel().currentIndex().row()
        selectedRows = [
            i.row() for i in self.form.tableView.selectionModel().selectedRows()
        ]
        if min(selectedRows) < curRow < max(selectedRows):
            # last selection in middle; place one below last selected item
            move = sum(1 for i in selectedRows if i > curRow)
            newRow = curRow - move
        elif max(selectedRows) <= curRow:
            # last selection at bottom; place one below bottommost selection
            newRow = max(selectedRows) - len(nids) + 1
        else:
            # last selection at top; place one above topmost selection
            newRow = min(selectedRows) - 1
        self.col.remNotes(nids)
        self.search()
        if len(self.model.cards):
            newRow = min(newRow, len(self.model.cards) - 1)
            newRow = max(newRow, 0)
            self.model.focusedCard = self.model.cards[newRow]
        self.model.endReset()
        self.mw.requireReset()
        tooltip(
            ngettext("%d note deleted.", "%d notes deleted.", len(nids)) % len(nids)
        )

    # Deck change
    ######################################################################

    def setDeck(self):
        self.editor.saveNow(self._setDeck)

    def _setDeck(self):
        from aqt.studydeck import StudyDeck

        cids = self.selectedCards()
        if not cids:
            return
        did = self.mw.col.db.scalar("select did from cards where id = ?", cids[0])
        current = self.mw.col.decks.get(did)["name"]
        ret = StudyDeck(
            self.mw,
            current=current,
            accept=_("Move Cards"),
            title=_("Change Deck"),
            help="browse",
            parent=self,
        )
        if not ret.name:
            return
        did = self.col.decks.id(ret.name)
        deck = self.col.decks.get(did)
        if deck["dyn"]:
            showWarning(_("Cards can't be manually moved into a filtered deck."))
            return
        self.model.beginReset()
        self.mw.checkpoint(_("Change Deck"))
        mod = intTime()
        usn = self.col.usn()
        # normal cards
        scids = ids2str(cids)
        # remove any cards from filtered deck first
        self.col.sched.remFromDyn(cids)
        # then move into new deck
        self.col.db.execute(
            """
update cards set usn=?, mod=?, did=? where id in """
            + scids,
            usn,
            mod,
            did,
        )
        self.model.endReset()
        self.mw.requireReset()

    # Tags
    ######################################################################

    def addTags(self, tags=None, label=None, prompt=None, func=None):
        self.editor.saveNow(lambda: self._addTags(tags, label, prompt, func))

    def _addTags(self, tags, label, prompt, func):
        if prompt is None:
            prompt = _("Enter tags to add:")
        if tags is None:
            (tags, r) = getTag(self, self.col, prompt)
        else:
            r = True
        if not r:
            return
        if func is None:
            func = self.col.tags.bulkAdd
        if label is None:
            label = _("Add Tags")
        if label:
            self.mw.checkpoint(label)
        self.model.beginReset()
        func(self.selectedNotes(), tags)
        self.model.endReset()
        self.mw.requireReset()

    def deleteTags(self, tags=None, label=None):
        if label is None:
            label = _("Delete Tags")
        self.addTags(
            tags, label, _("Enter tags to delete:"), func=self.col.tags.bulkRem
        )

    def clearUnusedTags(self):
        self.editor.saveNow(self._clearUnusedTags)

    def _clearUnusedTags(self):
        self.col.tags.registerNotes()

    # Suspending
    ######################################################################

    def isSuspended(self):
        return not not (self.card and self.card.queue == -1)

    def onSuspend(self):
        self.editor.saveNow(self._onSuspend)

    def _onSuspend(self):
        sus = not self.isSuspended()
        c = self.selectedCards()
        if sus:
            self.col.sched.suspendCards(c)
        else:
            self.col.sched.unsuspendCards(c)
        self.model.reset()
        self.mw.requireReset()

    # Exporting
    ######################################################################

    def _on_export_notes(self):
        cids = self.selectedNotesAsCards()
        if cids:
            ExportDialog(self.mw, cids=cids)

    # Flags & Marking
    ######################################################################

    def onSetFlag(self, n):
        if not self.card:
            return
        # flag needs toggling off?
        if n == self.card.userFlag():
            n = 0
        self.col.setUserFlag(n, self.selectedCards())
        self.model.reset()

    def _updateFlagsMenu(self):
        flag = self.card and self.card.userFlag()
        flag = flag or 0

        f = self.form
        flagActions = [
            f.actionRed_Flag,
            f.actionOrange_Flag,
            f.actionGreen_Flag,
            f.actionBlue_Flag,
        ]

        for c, act in enumerate(flagActions):
            act.setChecked(flag == c + 1)

        qtMenuShortcutWorkaround(self.form.menuFlag)

    def onMark(self, mark=None):
        if mark is None:
            mark = not self.isMarked()
        if mark:
            self.addTags(tags="marked", label=False)
        else:
            self.deleteTags(tags="marked", label=False)

    def isMarked(self):
        return not not (self.card and self.card.note().hasTag("Marked"))

    # Repositioning
    ######################################################################

    def reposition(self):
        self.editor.saveNow(self._reposition)

    def _reposition(self):
        cids = self.selectedCards()
        cids2 = self.col.db.list(
            f"select id from cards where type = {CARD_TYPE_NEW} and id in "
            + ids2str(cids)
        )
        if not cids2:
            return showInfo(_("Only new cards can be repositioned."))
        d = QDialog(self)
        d.setWindowModality(Qt.WindowModal)
        frm = aqt.forms.reposition.Ui_Dialog()
        frm.setupUi(d)
        (pmin, pmax) = self.col.db.first(
            f"select min(due), max(due) from cards where type={CARD_TYPE_NEW} and odid=0"
        )
        pmin = pmin or 0
        pmax = pmax or 0
        txt = _("Queue top: %d") % pmin
        txt += "\n" + _("Queue bottom: %d") % pmax
        frm.label.setText(txt)
        if not d.exec_():
            return
        self.model.beginReset()
        self.mw.checkpoint(_("Reposition"))
        self.col.sched.sortCards(
            cids,
            start=frm.start.value(),
            step=frm.step.value(),
            shuffle=frm.randomize.isChecked(),
            shift=frm.shift.isChecked(),
        )
        self.search()
        self.mw.requireReset()
        self.model.endReset()

    # Rescheduling
    ######################################################################

    def reschedule(self):
        self.editor.saveNow(self._reschedule)

    def _reschedule(self):
        d = QDialog(self)
        d.setWindowModality(Qt.WindowModal)
        frm = aqt.forms.reschedule.Ui_Dialog()
        frm.setupUi(d)
        if not d.exec_():
            return
        self.model.beginReset()
        self.mw.checkpoint(_("Reschedule"))
        if frm.asNew.isChecked():
            self.col.sched.forgetCards(self.selectedCards())
        else:
            fmin = frm.min.value()
            fmax = frm.max.value()
            fmax = max(fmin, fmax)
            self.col.sched.reschedCards(self.selectedCards(), fmin, fmax)
        self.search()
        self.mw.requireReset()
        self.model.endReset()

    # Edit: selection
    ######################################################################

    def selectNotes(self):
        self.editor.saveNow(self._selectNotes)

    def _selectNotes(self):
        nids = self.selectedNotes()
        # bypass search history
        self._lastSearchTxt = "nid:" + ",".join([str(x) for x in nids])
        self.form.searchEdit.lineEdit().setText(self._lastSearchTxt)
        # clear the selection so we don't waste energy preserving it
        tv = self.form.tableView
        tv.selectionModel().clear()
        self.search()
        tv.selectAll()

    def invertSelection(self):
        sm = self.form.tableView.selectionModel()
        items = sm.selection()
        self.form.tableView.selectAll()
        sm.select(items, QItemSelectionModel.Deselect | QItemSelectionModel.Rows)

    # Hooks
    ######################################################################

    def setupHooks(self) -> None:
        gui_hooks.undo_state_did_change.append(self.onUndoState)
        gui_hooks.state_did_reset.append(self.onReset)
        gui_hooks.editor_did_fire_typing_timer.append(self.refreshCurrentCard)
        gui_hooks.editor_did_load_note.append(self.onLoadNote)
        gui_hooks.editor_did_unfocus_field.append(self.on_unfocus_field)
        hooks.tag_added.append(self.on_item_added)
        hooks.note_type_added.append(self.on_item_added)
        hooks.deck_added.append(self.on_item_added)

    def teardownHooks(self) -> None:
        gui_hooks.undo_state_did_change.remove(self.onUndoState)
        gui_hooks.state_did_reset.remove(self.onReset)
        gui_hooks.editor_did_fire_typing_timer.remove(self.refreshCurrentCard)
        gui_hooks.editor_did_load_note.remove(self.onLoadNote)
        gui_hooks.editor_did_unfocus_field.remove(self.on_unfocus_field)
        hooks.tag_added.remove(self.on_item_added)
        hooks.note_type_added.remove(self.on_item_added)
        hooks.deck_added.remove(self.on_item_added)

    def on_unfocus_field(self, changed: bool, note: Note, field_idx: int) -> None:
        self.refreshCurrentCard(note)

    # covers the tag, note and deck case
    def on_item_added(self, item: Any) -> None:
        self.maybeRefreshSidebar()

    def onUndoState(self, on):
        self.form.actionUndo.setEnabled(on)
        if on:
            self.form.actionUndo.setText(self.mw.form.actionUndo.text())

    # Edit: replacing
    ######################################################################

    def onFindReplace(self):
        self.editor.saveNow(self._onFindReplace)

    def _onFindReplace(self):
        sf = self.selectedNotes()
        if not sf:
            return
        import anki.find

        fields = anki.find.fieldNamesForNotes(self.mw.col, sf)
        d = QDialog(self)
        frm = aqt.forms.findreplace.Ui_Dialog()
        frm.setupUi(d)
        d.setWindowModality(Qt.WindowModal)
        frm.field.addItems([_("All Fields")] + fields)
        frm.buttonBox.helpRequested.connect(self.onFindReplaceHelp)
        restoreGeom(d, "findreplace")
        r = d.exec_()
        saveGeom(d, "findreplace")
        if not r:
            return
        if frm.field.currentIndex() == 0:
            field = None
        else:
            field = fields[frm.field.currentIndex() - 1]
        self.mw.checkpoint(_("Find and Replace"))
        self.mw.progress.start()
        self.model.beginReset()
        try:
            changed = self.col.findReplace(
                sf,
                str(frm.find.text()),
                str(frm.replace.text()),
                frm.re.isChecked(),
                field,
                frm.ignoreCase.isChecked(),
            )
        except sre_constants.error:
            showInfo(_("Invalid regular expression."), parent=self)
            return
        else:
            self.search()
            self.mw.requireReset()
        finally:
            self.model.endReset()
            self.mw.progress.finish()
        showInfo(
            ngettext(
                "%(a)d of %(b)d note updated", "%(a)d of %(b)d notes updated", len(sf)
            )
            % {"a": changed, "b": len(sf),},
            parent=self,
        )

    def onFindReplaceHelp(self):
        openHelp("findreplace")

    # Edit: finding dupes
    ######################################################################

    def onFindDupes(self):
        self.editor.saveNow(self._onFindDupes)

    def _onFindDupes(self):
        d = QDialog(self)
        self.mw.setupDialogGC(d)
        frm = aqt.forms.finddupes.Ui_Dialog()
        frm.setupUi(d)
        restoreGeom(d, "findDupes")
        fields = sorted(
            anki.find.fieldNames(self.col, downcase=False), key=lambda x: x.lower()
        )
        frm.fields.addItems(fields)
        self._dupesButton = None
        # links
        frm.webView.title = "find duplicates"
        web_context = FindDupesDialog(dialog=d, browser=self)
        frm.webView.set_bridge_command(self.dupeLinkClicked, web_context)
        frm.webView.stdHtml("", context=web_context)

        def onFin(code):
            saveGeom(d, "findDupes")

        d.finished.connect(onFin)

        def onClick():
            field = fields[frm.fields.currentIndex()]
            self.duplicatesReport(
                frm.webView, field, frm.search.text(), frm, web_context
            )

        search = frm.buttonBox.addButton(_("Search"), QDialogButtonBox.ActionRole)
        search.clicked.connect(onClick)
        d.show()

    def duplicatesReport(self, web, fname, search, frm, web_context):
        self.mw.progress.start()
        res = self.mw.col.findDupes(fname, search)
        if not self._dupesButton:
            self._dupesButton = b = frm.buttonBox.addButton(
                _("Tag Duplicates"), QDialogButtonBox.ActionRole
            )
            b.clicked.connect(lambda: self._onTagDupes(res))
        t = ""
        groups = len(res)
        notes = sum(len(r[1]) for r in res)
        part1 = ngettext("%d group", "%d groups", groups) % groups
        part2 = ngettext("%d note", "%d notes", notes) % notes
        t += _("Found %(a)s across %(b)s.") % dict(a=part1, b=part2)
        t += "<p><ol>"
        for val, nids in res:
            t += (
                """<li><a href=# onclick="pycmd('%s');return false;">%s</a>: %s</a>"""
                % (
                    "nid:" + ",".join(str(id) for id in nids),
                    ngettext("%d note", "%d notes", len(nids)) % len(nids),
                    html.escape(val),
                )
            )
        t += "</ol>"
        web.stdHtml(t, context=web_context)
        self.mw.progress.finish()

    def _onTagDupes(self, res):
        if not res:
            return
        self.model.beginReset()
        self.mw.checkpoint(_("Tag Duplicates"))
        nids = set()
        for s, nidlist in res:
            nids.update(nidlist)
        self.col.tags.bulkAdd(nids, _("duplicate"))
        self.mw.progress.finish()
        self.model.endReset()
        self.mw.requireReset()
        tooltip(_("Notes tagged."))

    def dupeLinkClicked(self, link):
        self.form.searchEdit.lineEdit().setText(link)
        # manually, because we've already saved
        self._lastSearchTxt = link
        self.search()
        self.onNote()

    # Jumping
    ######################################################################

    def _moveCur(self, dir=None, idx=None):
        if not self.model.cards:
            return
        tv = self.form.tableView
        if idx is None:
            idx = tv.moveCursor(dir, self.mw.app.keyboardModifiers())
        tv.selectionModel().setCurrentIndex(
            idx,
            QItemSelectionModel.Clear
            | QItemSelectionModel.Select
            | QItemSelectionModel.Rows,
        )

    def onPreviousCard(self):
        self.focusTo = self.editor.currentField
        self.editor.saveNow(self._onPreviousCard)

    def _onPreviousCard(self):
        self._moveCur(QAbstractItemView.MoveUp)

    def onNextCard(self):
        self.focusTo = self.editor.currentField
        self.editor.saveNow(self._onNextCard)

    def _onNextCard(self):
        self._moveCur(QAbstractItemView.MoveDown)

    def onFirstCard(self):
        sm = self.form.tableView.selectionModel()
        idx = sm.currentIndex()
        self._moveCur(None, self.model.index(0, 0))
        if not self.mw.app.keyboardModifiers() & Qt.ShiftModifier:
            return
        idx2 = sm.currentIndex()
        item = QItemSelection(idx2, idx)
        sm.select(item, QItemSelectionModel.SelectCurrent | QItemSelectionModel.Rows)

    def onLastCard(self):
        sm = self.form.tableView.selectionModel()
        idx = sm.currentIndex()
        self._moveCur(None, self.model.index(len(self.model.cards) - 1, 0))
        if not self.mw.app.keyboardModifiers() & Qt.ShiftModifier:
            return
        idx2 = sm.currentIndex()
        item = QItemSelection(idx, idx2)
        sm.select(item, QItemSelectionModel.SelectCurrent | QItemSelectionModel.Rows)

    def onFind(self):
        self.form.searchEdit.setFocus()
        self.form.searchEdit.lineEdit().selectAll()

    def onNote(self):
        self.editor.web.setFocus()
        self.editor.loadNote(focusTo=0)

    def onCardList(self):
        self.form.tableView.setFocus()

    def focusCid(self, cid):
        try:
            row = self.model.cards.index(cid)
        except:
            return
        self.form.tableView.selectRow(row)


# Change model dialog
######################################################################


class ChangeModel(QDialog):
    def __init__(self, browser, nids) -> None:
        QDialog.__init__(self, browser)
        self.browser = browser
        self.nids = nids
        self.oldModel = browser.card.note().model()
        self.form = aqt.forms.changemodel.Ui_Dialog()
        self.form.setupUi(self)
        self.setWindowModality(Qt.WindowModal)
        self.setup()
        restoreGeom(self, "changeModel")
        gui_hooks.state_did_reset.append(self.onReset)
        gui_hooks.current_note_type_did_change.append(self.on_note_type_change)
        self.exec_()

    def on_note_type_change(self, notetype: NoteType) -> None:
        self.onReset()

    def setup(self):
        # maps
        self.flayout = QHBoxLayout()
        self.flayout.setContentsMargins(0, 0, 0, 0)
        self.fwidg = None
        self.form.fieldMap.setLayout(self.flayout)
        self.tlayout = QHBoxLayout()
        self.tlayout.setContentsMargins(0, 0, 0, 0)
        self.twidg = None
        self.form.templateMap.setLayout(self.tlayout)
        if self.style().objectName() == "gtk+":
            # gtk+ requires margins in inner layout
            self.form.verticalLayout_2.setContentsMargins(0, 11, 0, 0)
            self.form.verticalLayout_3.setContentsMargins(0, 11, 0, 0)
        # model chooser
        import aqt.modelchooser

        self.oldModel = self.browser.col.models.get(
            self.browser.col.db.scalar(
                "select mid from notes where id = ?", self.nids[0]
            )
        )
        self.form.oldModelLabel.setText(self.oldModel["name"])
        self.modelChooser = aqt.modelchooser.ModelChooser(
            self.browser.mw, self.form.modelChooserWidget, label=False
        )
        self.modelChooser.models.setFocus()
        self.form.buttonBox.helpRequested.connect(self.onHelp)
        self.modelChanged(self.browser.mw.col.models.current())
        self.pauseUpdate = False

    def onReset(self):
        self.modelChanged(self.browser.col.models.current())

    def modelChanged(self, model):
        self.targetModel = model
        self.rebuildTemplateMap()
        self.rebuildFieldMap()

    def rebuildTemplateMap(self, key=None, attr=None):
        if not key:
            key = "t"
            attr = "tmpls"
        map = getattr(self, key + "widg")
        lay = getattr(self, key + "layout")
        src = self.oldModel[attr]
        dst = self.targetModel[attr]
        if map:
            lay.removeWidget(map)
            map.deleteLater()
            setattr(self, key + "MapWidget", None)
        map = QWidget()
        l = QGridLayout()
        combos = []
        targets = [x["name"] for x in dst] + [_("Nothing")]
        indices = {}
        for i, x in enumerate(src):
            l.addWidget(QLabel(_("Change %s to:") % x["name"]), i, 0)
            cb = QComboBox()
            cb.addItems(targets)
            idx = min(i, len(targets) - 1)
            cb.setCurrentIndex(idx)
            indices[cb] = idx
            cb.currentIndexChanged.connect(
                lambda i, cb=cb, key=key: self.onComboChanged(i, cb, key)
            )
            combos.append(cb)
            l.addWidget(cb, i, 1)
        map.setLayout(l)
        lay.addWidget(map)
        setattr(self, key + "widg", map)
        setattr(self, key + "layout", lay)
        setattr(self, key + "combos", combos)
        setattr(self, key + "indices", indices)

    def rebuildFieldMap(self):
        return self.rebuildTemplateMap(key="f", attr="flds")

    def onComboChanged(self, i, cb, key):
        indices = getattr(self, key + "indices")
        if self.pauseUpdate:
            indices[cb] = i
            return
        combos = getattr(self, key + "combos")
        if i == cb.count() - 1:
            # set to 'nothing'
            return
        # find another combo with same index
        for c in combos:
            if c == cb:
                continue
            if c.currentIndex() == i:
                self.pauseUpdate = True
                c.setCurrentIndex(indices[cb])
                self.pauseUpdate = False
                break
        indices[cb] = i

    def getTemplateMap(self, old=None, combos=None, new=None):
        if not old:
            old = self.oldModel["tmpls"]
            combos = self.tcombos
            new = self.targetModel["tmpls"]
        map = {}
        for i, f in enumerate(old):
            idx = combos[i].currentIndex()
            if idx == len(new):
                # ignore
                map[f["ord"]] = None
            else:
                f2 = new[idx]
                map[f["ord"]] = f2["ord"]
        return map

    def getFieldMap(self):
        return self.getTemplateMap(
            old=self.oldModel["flds"], combos=self.fcombos, new=self.targetModel["flds"]
        )

    def cleanup(self) -> None:
        gui_hooks.state_did_reset.remove(self.onReset)
        gui_hooks.current_note_type_did_change.remove(self.on_note_type_change)
        self.modelChooser.cleanup()
        saveGeom(self, "changeModel")

    def reject(self):
        self.cleanup()
        return QDialog.reject(self)

    def accept(self):
        # check maps
        fmap = self.getFieldMap()
        cmap = self.getTemplateMap()
        if any(True for c in list(cmap.values()) if c is None):
            if not askUser(
                _(
                    """\
Any cards mapped to nothing will be deleted. \
If a note has no remaining cards, it will be lost. \
Are you sure you want to continue?"""
                )
            ):
                return
        self.browser.mw.checkpoint(_("Change Note Type"))
        b = self.browser
        b.mw.col.modSchema(check=True)
        b.mw.progress.start()
        b.model.beginReset()
        mm = b.mw.col.models
        mm.change(self.oldModel, self.nids, self.targetModel, fmap, cmap)
        b.search()
        b.model.endReset()
        b.mw.progress.finish()
        b.mw.reset()
        self.cleanup()
        QDialog.accept(self)

    def onHelp(self):
        openHelp("browsermisc")


# Card Info Dialog
######################################################################


class CardInfoDialog(QDialog):
    silentlyClose = True

    def __init__(self, browser: Browser, *args, **kwargs):
        super().__init__(browser, *args, **kwargs)
        self.browser = browser

    def reject(self):
        saveGeom(self, "revlog")
        return QDialog.reject(self)