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

from concurrent.futures import Future
from copy import deepcopy
from dataclasses import dataclass

import aqt
from anki.errors import DeckRenameError
from anki.rsbackend import DeckTreeNode
from aqt import AnkiQt, gui_hooks
from aqt.qt import *
from aqt.sound import av_player
from aqt.toolbar import BottomBar
from aqt.utils import TR, askUser, getOnlyText, openLink, shortcut, showWarning, tr


class DeckBrowserBottomBar:
    def __init__(self, deck_browser: DeckBrowser):
        self.deck_browser = deck_browser


@dataclass
class DeckBrowserContent:
    """Stores sections of HTML content that the deck browser will be
    populated with.

    Attributes:
        tree {str} -- HTML of the deck tree section
        stats {str} -- HTML of the stats section
    """

    tree: str
    stats: str


@dataclass
class RenderDeckNodeContext:
    current_deck_id: int


class DeckBrowser:
    _dueTree: DeckTreeNode

    def __init__(self, mw: AnkiQt) -> None:
        self.mw = mw
        self.web = mw.web
        self.bottom = BottomBar(mw, mw.bottomWeb)
        self.scrollPos = QPoint(0, 0)

    def show(self):
        av_player.stop_and_clear_queue()
        self.web.set_bridge_command(self._linkHandler, self)
        self._renderPage()
        # redraw top bar for theme change
        self.mw.toolbar.redraw()

    def refresh(self):
        self._renderPage()

    # Event handlers
    ##########################################################################

    def _linkHandler(self, url):
        if ":" in url:
            (cmd, arg) = url.split(":")
        else:
            cmd = url
        if cmd == "open":
            self._selDeck(arg)
        elif cmd == "opts":
            self._showOptions(arg)
        elif cmd == "shared":
            self._onShared()
        elif cmd == "import":
            self.mw.onImport()
        elif cmd == "create":
            deck = getOnlyText(tr(TR.DECKS_NAME_FOR_DECK))
            if deck:
                self.mw.col.decks.id(deck)
                gui_hooks.sidebar_should_refresh_decks()
                self.refresh()
        elif cmd == "drag":
            draggedDeckDid, ontoDeckDid = arg.split(",")
            self._dragDeckOnto(draggedDeckDid, ontoDeckDid)
        elif cmd == "collapse":
            self._collapse(int(arg))
        return False

    def _selDeck(self, did):
        self.mw.col.decks.select(did)
        self.mw.onOverview()

    # HTML generation
    ##########################################################################

    _body = """
<center>
<table cellspacing=0 cellpading=3>
%(tree)s
</table>

<br>
%(stats)s
</center>
"""

    def _renderPage(self, reuse=False):
        if not reuse:
            self._dueTree = self.mw.col.sched.deck_due_tree()
            self.__renderPage(None)
            return
        self.web.evalWithCallback("window.pageYOffset", self.__renderPage)

    def __renderPage(self, offset):
        content = DeckBrowserContent(
            tree=self._renderDeckTree(self._dueTree),
            stats=self._renderStats(),
        )
        gui_hooks.deck_browser_will_render_content(self, content)
        self.web.stdHtml(
            self._body % content.__dict__,
            css=["css/deckbrowser.css"],
            js=[
                "js/vendor/jquery.min.js",
                "js/vendor/jquery-ui.min.js",
                "js/deckbrowser.js",
            ],
            context=self,
        )
        self.web.key = "deckBrowser"
        self._drawButtons()
        if offset is not None:
            self._scrollToOffset(offset)
        gui_hooks.deck_browser_did_render(self)

    def _scrollToOffset(self, offset):
        self.web.eval("$(function() { window.scrollTo(0, %d, 'instant'); });" % offset)

    def _renderStats(self):
        return '<div id="studiedToday"><span>{}</span></div>'.format(
            self.mw.col.studied_today(),
        )

    def _renderDeckTree(self, top: DeckTreeNode) -> str:
        buf = """
<tr><th colspan=5 align=start>%s</th><th class=count>%s</th>
<th class=count>%s</th><th class=optscol></th></tr>""" % (
            tr(TR.DECKS_DECK),
            tr(TR.STATISTICS_DUE_COUNT),
            tr(TR.ACTIONS_NEW),
        )
        buf += self._topLevelDragRow()

        ctx = RenderDeckNodeContext(current_deck_id=self.mw.col.conf["curDeck"])

        for child in top.children:
            buf += self._render_deck_node(child, ctx)

        return buf

    def _render_deck_node(self, node: DeckTreeNode, ctx: RenderDeckNodeContext) -> str:
        if node.collapsed:
            prefix = "+"
        else:
            prefix = "-"

        due = node.review_count + node.learn_count

        def indent():
            return "&nbsp;" * 6 * (node.level - 1)

        if node.deck_id == ctx.current_deck_id:
            klass = "deck current"
        else:
            klass = "deck"

        buf = "<tr class='%s' id='%d'>" % (klass, node.deck_id)
        # deck link
        if node.children:
            collapse = (
                "<a class=collapse href=# onclick='return pycmd(\"collapse:%d\")'>%s</a>"
                % (node.deck_id, prefix)
            )
        else:
            collapse = "<span class=collapse></span>"
        if node.filtered:
            extraclass = "filtered"
        else:
            extraclass = ""
        buf += """

        <td class=decktd colspan=5>%s%s<a class="deck %s"
        href=# onclick="return pycmd('open:%d')">%s</a></td>""" % (
            indent(),
            collapse,
            extraclass,
            node.deck_id,
            node.name,
        )
        # due counts
        def nonzeroColour(cnt, klass):
            if not cnt:
                klass = "zero-count"
            return f'<span class="{klass}">{cnt}</span>'

        buf += "<td align=right>%s</td><td align=right>%s</td>" % (
            nonzeroColour(due, "review-count"),
            nonzeroColour(node.new_count, "new-count"),
        )
        # options
        buf += (
            "<td align=center class=opts><a onclick='return pycmd(\"opts:%d\");'>"
            "<img src='/_anki/imgs/gears.svg' class=gears></a></td></tr>" % node.deck_id
        )
        # children
        if not node.collapsed:
            for child in node.children:
                buf += self._render_deck_node(child, ctx)
        return buf

    def _topLevelDragRow(self):
        return "<tr class='top-level-drag-row'><td colspan='6'>&nbsp;</td></tr>"

    # Options
    ##########################################################################

    def _showOptions(self, did: str) -> None:
        m = QMenu(self.mw)
        a = m.addAction(tr(TR.ACTIONS_RENAME))
        qconnect(a.triggered, lambda b, did=did: self._rename(int(did)))
        a = m.addAction(tr(TR.ACTIONS_OPTIONS))
        qconnect(a.triggered, lambda b, did=did: self._options(did))
        a = m.addAction(tr(TR.ACTIONS_EXPORT))
        qconnect(a.triggered, lambda b, did=did: self._export(did))
        a = m.addAction(tr(TR.ACTIONS_DELETE))
        qconnect(a.triggered, lambda b, did=did: self._delete(int(did)))
        gui_hooks.deck_browser_will_show_options_menu(m, int(did))
        m.exec_(QCursor.pos())

    def _export(self, did):
        self.mw.onExport(did=did)

    def _rename(self, did: int) -> None:
        self.mw.checkpoint(tr(TR.ACTIONS_RENAME_DECK))
        deck = self.mw.col.decks.get(did)
        oldName = deck["name"]
        newName = getOnlyText(tr(TR.DECKS_NEW_DECK_NAME), default=oldName)
        newName = newName.replace('"', "")
        if not newName or newName == oldName:
            return
        try:
            self.mw.col.decks.rename(deck, newName)
            gui_hooks.sidebar_should_refresh_decks()
        except DeckRenameError as e:
            return showWarning(e.description)
        self.show()

    def _options(self, did):
        # select the deck first, because the dyn deck conf assumes the deck
        # we're editing is the current one
        self.mw.col.decks.select(did)
        self.mw.onDeckConf()

    def _collapse(self, did: int) -> None:
        self.mw.col.decks.collapse(did)
        node = self.mw.col.decks.find_deck_in_tree(self._dueTree, did)
        if node:
            node.collapsed = not node.collapsed
        self._renderPage(reuse=True)

    def _dragDeckOnto(self, draggedDeckDid: int, ontoDeckDid: int):
        try:
            self.mw.col.decks.renameForDragAndDrop(draggedDeckDid, ontoDeckDid)
            gui_hooks.sidebar_should_refresh_decks()
        except DeckRenameError as e:
            return showWarning(e.description)

        self.show()

    def ask_delete_deck(self, did: int) -> bool:
        deck = self.mw.col.decks.get(did)
        if deck["dyn"]:
            return True

        count = self.mw.col.decks.card_count(did, include_subdecks=True)
        if not count:
            return True

        extra = tr(TR.DECKS_IT_HAS_CARD, count=count)
        if askUser(
            tr(TR.DECKS_ARE_YOU_SURE_YOU_WISH_TO, val=deck["name"]) + " " + extra
        ):
            return True
        return False

    def _delete(self, did: int) -> None:
        if self.ask_delete_deck(did):

            def do_delete():
                return self.mw.col.decks.rem(did, True)

            def on_done(fut: Future):
                self.show()
                res = fut.result()  # Required to check for errors

            self.mw.checkpoint(tr(TR.DECKS_DELETE_DECK))
            self.mw.taskman.with_progress(do_delete, on_done)

    # Top buttons
    ######################################################################

    drawLinks = [
        ["", "shared", tr(TR.DECKS_GET_SHARED)],
        ["", "create", tr(TR.DECKS_CREATE_DECK)],
        ["Ctrl+Shift+I", "import", tr(TR.DECKS_IMPORT_FILE)],
    ]

    def _drawButtons(self):
        buf = ""
        drawLinks = deepcopy(self.drawLinks)
        for b in drawLinks:
            if b[0]:
                b[0] = tr(TR.ACTIONS_SHORTCUT_KEY, val=shortcut(b[0]))
            buf += """
<button title='%s' onclick='pycmd(\"%s\");'>%s</button>""" % tuple(
                b
            )
        self.bottom.draw(
            buf=buf,
            link_handler=self._linkHandler,
            web_context=DeckBrowserBottomBar(self),
        )

    def _onShared(self):
        openLink(aqt.appShared + "decks/")