# 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

import http.server
import re
import socket
import socketserver
import threading
from http import HTTPStatus
from typing import Optional

import aqt
from anki.collection import Collection
from anki.rsbackend import from_json_bytes
from anki.utils import devMode
from aqt.qt import *
from aqt.utils import aqt_data_folder


def _getExportFolder():
    data_folder = aqt_data_folder()
    webInSrcFolder = os.path.abspath(os.path.join(data_folder, "web"))
    if os.path.exists(webInSrcFolder):
        return webInSrcFolder
    elif isMac:
        dir = os.path.dirname(os.path.abspath(__file__))
        return os.path.abspath(dir + "/../../Resources/web")
    else:
        raise Exception("couldn't find web folder")


_exportFolder = _getExportFolder()

# webengine on windows sometimes opens a connection and fails to send a request,
# which will hang the server if unthreaded
class ThreadedHTTPServer(socketserver.ThreadingMixIn, http.server.HTTPServer):
    # allow for a flood of requests before we've started up properly
    request_queue_size = 100

    # work around python not being able to handle non-latin hostnames
    def server_bind(self):
        """Override server_bind to store the server name."""
        socketserver.TCPServer.server_bind(self)
        host, port = self.server_address[:2]
        try:
            self.server_name = socket.getfqdn(host)
        except:
            self.server_name = "server"
        self.server_port = port


class MediaServer(threading.Thread):

    _port: Optional[int] = None
    _ready = threading.Event()
    daemon = True

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

    def run(self):
        RequestHandler.mw = self.mw
        desired_port = int(os.getenv("ANKI_API_PORT", 0))
        self.server = ThreadedHTTPServer(("127.0.0.1", desired_port), RequestHandler)
        self._ready.set()
        self.server.serve_forever()

    def getPort(self):
        self._ready.wait()
        return self.server.server_port

    def shutdown(self):
        self.server.shutdown()


class RequestHandler(http.server.SimpleHTTPRequestHandler):

    timeout = 10
    mw: Optional[aqt.main.AnkiQt] = None

    def do_GET(self):
        f = self.send_head()
        if f:
            try:
                self.copyfile(f, self.wfile)
            except Exception as e:
                if devMode:
                    print("http server caught exception:", e)
                else:
                    # swallow it - user likely surfed away from
                    # review screen before an image had finished
                    # downloading
                    pass
            finally:
                f.close()

    def send_head(self):
        path = self.translate_path(self.path)
        path = self._redirectWebExports(path)
        try:
            isdir = os.path.isdir(path)
        except ValueError:
            # path too long exception on Windows
            self.send_error(HTTPStatus.NOT_FOUND, "File not found")
            return None

        if isdir:
            self.send_error(HTTPStatus.NOT_FOUND, "File not found")
            return None

        ctype = self.guess_type(path)
        try:
            f = open(path, "rb")
        except OSError:
            self.send_error(HTTPStatus.NOT_FOUND, "File not found")
            return None
        try:
            self.send_response(HTTPStatus.OK)
            self.send_header("Content-type", ctype)
            fs = os.fstat(f.fileno())
            self.send_header("Content-Length", str(fs[6]))
            self.send_header("Last-Modified", self.date_time_string(fs.st_mtime))
            self.send_header("Access-Control-Allow-Origin", "*")
            self.end_headers()
            return f
        except:
            f.close()
            raise

    def log_message(self, format, *args):
        if not devMode:
            return
        print(
            "%s - - [%s] %s"
            % (self.address_string(), self.log_date_time_string(), format % args)
        )

    def _redirectWebExports(self, path):
        # catch /_anki references and rewrite them to web export folder
        targetPath = os.path.join(os.getcwd(), "_anki", "")
        if path.startswith(targetPath):
            newPath = os.path.join(_exportFolder, path[len(targetPath) :])
            return newPath

        # catch /_addons references and rewrite them to addons folder
        targetPath = os.path.join(os.getcwd(), "_addons", "")
        if path.startswith(targetPath):
            try:
                addMgr = self.mw.addonManager
            except AttributeError:
                return path

            addonPath = path[len(targetPath) :]

            try:
                addon, subPath = addonPath.split(os.path.sep, 1)
            except ValueError:
                return path
            if not addon:
                return path

            pattern = addMgr.getWebExports(addon)
            if not pattern:
                return path

            subPath2 = subPath.replace(os.sep, "/")
            if re.fullmatch(pattern, subPath) or re.fullmatch(pattern, subPath2):
                newPath = os.path.join(addMgr.addonsFolder(), addonPath)
                return newPath

        return path

    def do_POST(self):
        if not self.path.startswith("/_anki/"):
            self.send_error(HTTPStatus.NOT_FOUND, "Method not found")
            return

        cmd = self.path[len("/_anki/") :]

        if cmd == "graphData":
            content_length = int(self.headers['Content-Length'])
            body = self.rfile.read(content_length)
            data = graph_data(self.mw.col, **from_json_bytes(body))
        else:
            self.send_error(HTTPStatus.NOT_FOUND, "Method not found")
            return

        self.send_response(HTTPStatus.OK)
        self.send_header("Content-Type", "application/binary")
        self.send_header("Content-Length", str(len(data)))
        self.send_header("Access-Control-Allow-Origin", "*")
        self.end_headers()

        self.wfile.write(data)


def graph_data(col: Collection, search: str, days: str) -> bytes:
    try:
        return col.backend.graphs(search=search, days=days)
    except Exception as e:
        # likely searching error
        print(e)
        return b''

# work around Windows machines with incorrect mime type
RequestHandler.extensions_map[".css"] = "text/css"