import os
import json
import logging
import cherrypy
from time import sleep
from queue import Queue
from threading import Thread
from urllib.parse import urlparse
from dataclasses import dataclass, field
from deluge_client import DelugeRPCClient
from jinja2 import Environment, FileSystemLoader, select_autoescape
from mediaweb import shows
from enum import Enum


APPROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), "../"))


@dataclass
class Cache:
    torrents: dict = field(default_factory=dict)
    shows: dict = field(default_factory=dict)
    moves: dict = field(default_factory=dict)


@dataclass
class Client:
    rpc: DelugeRPCClient
    pathmap: (str, str)


class SortResult(Enum):
    OK = 0
    EXISTED = 1
    FAIL = 2


class ClientCache(object):
    def __init__(self, options, libpath):
        self.options = options
        self.clients = {}
        self.data = Cache()
        self.q = Queue()
        self.inflight = False
        self.libpath = libpath

        self.background_t = Thread(target=self.background, daemon=True)
        self.timer_t = Thread(target=self.timer, daemon=True)

    def start(self):
        self.background_t.start()
        self.timer_t.start()

    def add_client(self, rpc, pathmap):  # not thread safe
        cnum = len(self.clients)
        self.data.torrents[cnum] = {}
        self.data.moves[cnum] = {}
        self.clients[cnum] = Client(rpc, pathmap)

    def refresh(self):
        if self.q.qsize() <= 1:  # guarantees a refresh after your call and also deduplicates effort
            self.q.put(None)

    def background(self):
        while True:
            self.q.get()  # block until we need to do something
            self.inflight = True
            logging.info("performing background tasks...")

            self.build_showindex()
            self.build_torrentindex()
            self.queue_sorts()

            self.q.task_done()
            self.inflight = False
            logging.info("background tasks complete")

    def timer(self):
        while True:
            self.refresh()
            logging.info("scheduling next loop")
            sleep(300)  # TODO configurable task interval

    def build_torrentindex(self):
        logging.info("refreshing torrents")
        for cid, client in self.clients.items():  # TODO parallelize
            self.data.torrents[cid] = client.rpc.core.get_torrents_status({"label": self.options["label"]},
                                                                          ['name', 'label', 'save_path', 'is_seed',
                                                                           'is_finished', 'progress', 'files',
                                                                           'paused', 'peers', 'eta'])
            newkeys = self.data.torrents[cid].keys()
            for key in list(self.data.moves[cid].keys()):
                if key not in newkeys:
                    del self.data.moves[cid][key]  # delete precomputed sort operations for torrents that went away

    def build_showindex(self):
        logging.info("updating show index")
        data = shows.create_index([self.libpath])
        self.data.shows = sorted(data, key=lambda x: x.name)

    def queue_sorts(self):
        logging.info("precomputing sorts")
        for cid, torrents in self.data.torrents.items():
            for thash, torrent in torrents.items():
                if thash not in self.data.moves[cid]:
                    matches = shows.match_episode(get_fname(torrent), self.data.shows)
                    if matches:
                        self.data.moves[cid][thash] = matches[0]

    @property
    def torrents(self):
        return {self.format_tkey(cid, thash): torrent
                for cid, torrents in self.data.torrents.items()
                for thash, torrent in torrents.items()}

    @property
    def moves(self):
        return {self.format_tkey(cid, thash): move
                for cid, moves in self.data.moves.items()
                for thash, move in moves.items()}

    def client(self, tkey):
        cid, thash = self.extract_key(tkey)
        return thash, self.clients[cid]

    @staticmethod
    def extract_key(tkey):
        cid, thash = tkey.split(":")
        return (int(cid), thash)

    @staticmethod
    def format_tkey(cid, thash):
        return f"{cid}:{thash}"


class MediaWeb(object):
    def __init__(self, cache, templater, options):
        self.tpl = templater
        self.cache = cache
        self.options = options

    def render(self, template, **kwargs):
        """
        Render a template
        """
        return self.tpl.get_template(template).render(options=self.options,
                                                      torrents=self.cache.torrents,
                                                      moves=self.cache.moves,
                                                      shows=self.cache.data.shows,
                                                      user=cherrypy.request.login,
                                                      **kwargs,
                                                      **self.get_default_vars())

    def get_default_vars(self):
        return {}

    @cherrypy.expose
    def index(self):
        return self.render("splash.html")

    @cherrypy.expose
    def home(self, action=None):
        if action:
            if action == "update":
                self.cache.refresh()
            raise cherrypy.HTTPRedirect("/home")
        return self.render("index.html", inflight=self.cache.inflight)

    @cherrypy.expose
    def move(self, tkey, dest=None, otherdest=None):
        thash, client = self.cache.client(tkey)
        torrent = client.rpc.core.get_torrent_status(thash, [])

        if cherrypy.request.method == "POST" and (dest or otherdest):  # TODO maybe support otherdest list per client
            target = os.path.join(client.pathmap[0],
                                  otherdest or dest)
            client.rpc.core.move_storage([thash], target)
            self.cache.refresh()
            raise cherrypy.HTTPRedirect("/home")

        return self.render("moveform.html", torrent=torrent, tkey=tkey)

    @cherrypy.expose
    def sort(self, tkey, score=65, dest=None):
        thash, client = self.cache.client(tkey)
        torrent = client.rpc.core.get_torrent_status(thash, [])

        # find the actual file among the torrent's files - really we just pick the biggest one
        fname = get_fname(torrent)

        # find candidate dest locations
        score = int(score)
        matches = shows.match_episode(fname, self.cache.data.shows, minscore=score)

        if cherrypy.request.method == "POST" and dest:
            # pick the candidate dest the user specified
            thematch = None
            for m in matches:
                if m.dest.dir == dest:
                    thematch = m
                    break

            result, reason = self.execute_move(tkey, torrent, thematch)
            self.cache.refresh()

            return self.render("sortform_done.html", success_torrents=[[torrent, result, reason]], failed_torrents=[])

        return self.render("sortform.html", torrent=torrent, matches=matches, tkey=tkey, score=score)

    def execute_move(self, tkey, torrent, match):
        result = SortResult.OK

        # resolve the pathmap
        thash, client = self.cache.client(tkey)

        pmap = client.pathmap
        fname = get_fname(torrent)

        in_library_path = os.path.join(match.dest.dir, match.subdest, fname)  # path relative from the library's root
        client_full_path = os.path.join(torrent["save_path"], fname)  # absolute storage path in deluge

        assert client_full_path[0:len(pmap[0])] == pmap[0]  # sanity check: deluge's path must starts with our pathmap

        local_torrent_path = os.path.join(pmap[1], client_full_path[len(pmap[0]):].lstrip("/"))  # our perspective's path to the file
        local_library_path = os.path.join(self.options["library_path"], in_library_path)  # where we will place the file in the library

        # check if the dest file already exists:
        if os.path.exists(local_library_path):
            # if the src and dest are already linked to the same file, this is a noop
            if os.stat(local_torrent_path).st_ino == os.stat(local_library_path).st_ino:
                result = SortResult.EXISTED
                logging.info("dest exists, skipping linking %s -> %s", local_torrent_path, local_library_path)
            else:
                return SortResult.FAIL, "destination file already exists and has different contents"
        else:
            # hard link into library
            showdir = os.path.dirname(local_library_path)
            if not os.path.exists(showdir):
                os.makedirs(showdir)
            os.link(local_torrent_path, local_library_path)
            logging.info("linking %s -> %s", local_torrent_path, local_library_path)

        client_stashdir = os.path.join(pmap[0],
                                       self.options["stashprefix"],
                                       get_mapped_stashdir(self.options["trackermap"], torrent["trackers"]))

        # move deluge path to stash dir
        client.rpc.core.move_storage([torrent["hash"]], client_stashdir)

        # label torrent as sorted
        client.rpc.label.set_torrent(torrent["hash"], self.options["label_done"])

        return result, None

    @cherrypy.expose
    def autosort(self, tkeys):
        if not isinstance(tkeys, list):
            tkeys = [tkeys]

        results = []

        for tkey in tkeys:
            thash, client = self.cache.client(tkey)
            torrent = client.rpc.core.get_torrent_status(thash, [])  # TODO reduce to needed fields
            res = self.execute_move(tkey, torrent, self.cache.moves[tkey])
            results.append([torrent, res[0], res[1]])

        self.cache.refresh()

        return self.render("sortform_done.html",
                           success_torrents=[r for r in results if r[1] != SortResult.FAIL],
                           failed_torrents=[r for r in results if r[1] == SortResult.FAIL])

    @cherrypy.expose
    def modify(self, action, tkey):
        thash, client = self.cache.client(tkey)
        if action == "Resume":
            client.rpc.core.resume_torrent([thash])
        elif action == "Pause":
            client.rpc.core.pause_torrent([thash])
        elif action == "Delete":
            if self.cache.torrents[tkey]["progress"] > 0:
                raise Exception("Cowardly refusing to delete a torrent with progress > 0")
            else:
                client.rpc.core.remove_torrent(thash, True)
        else:
            raise cherrypy.HTTPError(404)
        self.cache.refresh()
        raise cherrypy.HTTPRedirect("/home")


def get_fname(torrent):
    finfo = None
    fsize = 0
    for tfile in torrent["files"]:
        if tfile["size"] > fsize:
            finfo = tfile
    return finfo["path"]


def get_mapped_stashdir(mapping, trackers):
    tracker = None
    for tracker in trackers:
        for k, v in mapping.items():
            if k in tracker["url"]:
                return v
    return urlparse(tracker["url"]).hostname.lower() if tracker else "other"


def tsortbyname(dict_items):
    return sorted(dict_items, key=lambda x: x[1]["name"].lower())


def main():
    logging.basicConfig(level=logging.WARNING,
                        format="%(asctime)-15s %(levelname)-8s %(filename)s:%(lineno)d %(message)s")

    _sentry_dsn = os.environ.get("SENTRY_DSN")
    if _sentry_dsn:
        try:
            import sentry_sdk
            sentry_sdk.init(_sentry_dsn)
            logging.info("enabled error reporting via sentry")
        except ImportError as ie:
            logging.error(f"SENTRY_DSN set, but sentry_sdk unavailable: {ie}")

    import argparse
    import signal

    parser = argparse.ArgumentParser(description="mediaweb server")
    parser.add_argument("-c", "--config", required=True, help="config file path")
    parser.add_argument('--debug', action="store_true", help="enable development options")
    args = parser.parse_args()

    if args.debug:
        logging.getLogger().setLevel(logging.INFO)

    with open(args.config) as f:
        cfg = json.load(f)

    options = {  # :|
        "movedests": cfg["movedests"],
        # "pathmap": args.pathmap.split(":"),
        "library_path": cfg["library_path"],
        "stashprefix": cfg["stashprefix"],
        "trackermap": cfg["trackermap"],
        "label": cfg["label"],
        "label_done": cfg["label_done"]
    }

    tpl_dir = os.path.join(APPROOT, "templates")
    tpl = Environment(loader=FileSystemLoader(tpl_dir),
                      autoescape=select_autoescape(['html', 'xml']))
    tpl.filters.update(tsortbyname=tsortbyname,
                       len=len,
                       jsond=json.dumps)

    def validate_password(realm, user, passw):
        return user == passw  # lol

    rpc_cache = ClientCache(options, cfg["library_path"])

    for client in cfg["deluges"]:
        uri = urlparse(client["uri"])
        assert uri.scheme == "deluge"
        port = uri.port if uri.port else 58846
        rpc_cache.add_client(DelugeRPCClient(uri.hostname, port, uri.username, uri.password, decode_utf8=True),
                             tuple(client["pathmap"]))

    web = MediaWeb(rpc_cache, tpl, options)
    cherrypy.tree.mount(web, '/', {'/': {'tools.auth_basic.on': True,
                                         'tools.auth_basic.realm': 'mediaweb',
                                         'tools.auth_basic.checkpassword': validate_password, },
                                   '/index': {'tools.auth_basic.on': False},
                                   '/static': {'tools.auth_basic.on': False,
                                               'tools.staticdir.on': True,
                                               'tools.staticdir.dir': os.path.join(APPROOT, 'assets')}})

    # General config options
    cherrypy.config.update({
        'tools.sessions.on': False,
        'request.show_tracebacks': True,
        'server.show_tracebacks': True,
        'server.socket_port': cfg["port"],
        'server.thread_pool': 1 if args.debug else 5,
        'server.socket_host': '0.0.0.0',
        'log.screen': False,
        'engine.autoreload.on': args.debug
    })

    # Setup signal handling and run it.
    def signal_handler(signum, stack):
        logging.warning('Got sig {}, exiting...'.format(signum))
        cherrypy.engine.exit()

    signal.signal(signal.SIGINT, signal_handler)
    signal.signal(signal.SIGTERM, signal_handler)

    try:
        rpc_cache.start()
        cherrypy.engine.start()
        cherrypy.engine.block()
    finally:
        logging.info("API has shut down")
        cherrypy.engine.exit()


if __name__ == '__main__':
    main()


# https://github.com/deluge-torrent/deluge/blob/1.3-stable/deluge/ui/console/commands/info.py#L46
# https://deluge.readthedocs.io/en/latest/reference/api.html?highlight=rpc