"""
Copyright (C) 2021  Alexander "PapaTutuWawa"

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.
"""
# TODO: remove Alle sollte jede subscription entfernen
# TODO: Deal with weird casing and typos
# TODO: pollen hilfe <CMD> should print help per command
import asyncio
import datetime

from mira.module import BaseModule

import requests
import aioxmpp

NAME = "pollen"

API_ENDPOINT = "https://allergie.hexal.de/pollenflug/vorhersage/load_pollendaten.php"


def api_query(plz, date):
    return API_ENDPOINT + "?datum={}&plz={}".format(date, plz)


def intensity_str(intensity):
    """
    Map the intensity value to a human readable string
    """
    return ("Kein Pollenflug", "Schwach", "Mittelschwer", "Stark")[intensity]


class PollenModule(BaseModule):
    __instance = None
    _subcommand_table = {}

    _pollen_data = {}  # PLZ -> Date -> Type -> Severity
    _dates_notified = {}  # JID -> [Dates already sent out]
    _sleep_duration = 100

    @staticmethod
    def get_instance(base, **kwargs):
        if PollenModule.__instance == None:
            PollenModule(base, **kwargs)

        return PollenModule.__instance

    def __init__(self, base, **kwargs):
        if PollenModule.__instance != None:
            raise Exception("Trying to init singleton twice")

        super().__init__(base, **kwargs)
        PollenModule.__instance = self
        self._subcommand_table = {
            "subscribe": self._subscribe,
            "unsubscribe": self._unsubscribe,
            "hilfe": self._help,
            "*": self._any,
        }
        self._sleep_duration = self.get_option("sleep_duration", 12 * 3600)

        # Load data
        # NOTE: Since we request the pollen_data at start anyway, we won't
        #       need to save it. We only save dates_notified to prevent
        #       sending one notification too many.
        self._dates_notified = self._stm.get_data("dates_notified")

        loop = asyncio.get_event_loop()
        periodic = loop.create_task(self._request_pollen_data(True))

    def notification_body(self, plz, date, allergies):
        """
        Format a message that will be sent to the user
        """
        msg = "{} (*{}*)\n".format(date, plz)

        if "Alle" in [x["type"] for x in allergies]:
            allergies = list(self._pollen_data[plz][date].keys)

        count = 0
        for allergy in allergies:
            intensity = self._pollen_data[plz][date][allergy["type"]]
            if intensity >= allergy["level"]:
                msg += "{}: {}".format(allergy["type"], intensity_str(intensity))
                count += 1

        if count == 0:
            return ""
        return msg

    def _is_notified(self, jid, date):
        """
        Returns True, when the pollen data for the date of date has
        already been sent to jid.
        """
        if not jid in self._dates_notified:
            return False

        return date in self._dates_notified[jid]

    def _set_dates_notified(self, jid, new_dates):
        """
        Marks a date as being sent to a user. Also ensures that
        there are at maximum 7 days in this list
        """
        if not jid in self._dates_notified:
            self._dates_notified[jid] = new_dates
            self._stm.set_data("dates_notified", self._dates_notified)
            return

        self._dates_notified[jid] += new_dates
        self._dates_notified[jid] = self._dates_notified[jid][-7:]
        self._stm.set_data("dates_notified", self._dates_notified)

    def _broadcast_jid(self, jid, filter_allergies=[]):
        """
        Sends the pollen data to jid. If filter_allergies is set, then
        only the data for the pollen types in filter_allergies will be sent.
        """
        for plz, data in self._sum.get_subscriptions_for_jid(jid).items():
            if filter_allergies:
                allergies = filter_allergies
            else:
                allergies = data["data"]
            notified = []

            for date in self._pollen_data[plz]:
                if self._is_notified(jid, date) and not filter_allergies:
                    continue
                notified.append(date)

                msg = self.notification_body(plz, date, allergies)
                if msg:
                    self.send_message(aioxmpp.JID.fromstr(jid), msg)

            if notified:
                self._set_dates_notified(jid, notified)

    def _broadcast_all(self):
        for plz in self._pollen_data:
            for jid, data in self._sum.get_subscriptions_for_keyword(plz).items():
                notified = []

                for date in self._pollen_data[plz]:
                    if self._is_notified(jid, date):
                        continue
                    notified.append(date)

                    self.send_message(
                        aioxmpp.JID.fromstr(jid),
                        self.notification_body(plz, date, data),
                    )

                if notified:
                    self._set_dates_notified(jid, notified)

    async def _request_pollen_data(self, loop):
        while True:
            today = datetime.date.today().strftime("%Y-%m-%d")
            for plz in self._sum.get_subscription_keywords():
                req = requests.get(api_query(plz, today))
                data = req.json()["content"]
                pollen = data["pollen"]
                for date in data["values"]:
                    if not plz in self._pollen_data:
                        self._pollen_data[plz] = {}
                    if not date in self._pollen_data[plz]:
                        self._pollen_data[plz][date] = {}

                    for i in range(len(pollen)):
                        type_ = pollen[i]
                        self._pollen_data[plz][date][type_] = int(
                            data["values"][date][i]
                        )

            # For when we want to just refresh data as someone just subscribed
            if not loop:
                break

            self._broadcast_all()
            await asyncio.sleep(self._sleep_duration)

    async def _subscribe(self, cmd, msg):
        if len(cmd) < 3 or len(cmd) > 4:
            self.send_message(
                msg.from_, "Verwendung: pollen add <PLZ> <Allergen> [<Level>]"
            )
            return

        plz = cmd[1]
        allergy = cmd[2]
        jid = str(msg.from_.bare())
        level = int(cmd[3]) if len(cmd) == 4 else 0

        if self._sum.is_subscribed_to_data(jid, plz, "Alle"):
            self.send_message(msg.from_, "Du hast schon alle Allergene abonniert")
            return

        if self._sum.is_subscribed_to_data(jid, plz, allergy):
            self.send_message(msg.from_, "Du hast das schon abonniert")
            return

        if level < 0 or level > 3:
            self.send_message(msg.from_, "Das Level muss zwischen 0 und 3 liegen")
            return

        self._sum.append_subscription_data(
            jid, plz, {"type": allergy, "level": level}
        )
        self.send_message(msg.from_, "Du erhälst nun Pollenmeldungen zu %s" % allergy)

        # Just some bandwidth saving measure
        if plz not in self._pollen_data:
            await self._request_pollen_data(False)
        self._broadcast_jid(jid, [{"type": allergy, "level": level}])

    async def _unsubscribe(self, cmd, msg):
        if len(cmd) != 3:
            self.send_message(msg.from_, "Verwendung: pollen remove <PLZ> <Allergen>")
            return

        plz = cmd[1]
        allergy = cmd[2]
        jid = str(msg.from_.bare())

        if allergy == "Alle":
            self._sum.filter_subscription_data_items(jid, plz, lambda x: False)
            self.send_message(msg.from_, "Du erhälst keine Pollenmeldungen mehr")
            return

        if not self._sum.is_subscribed_to_data_one(
            jid, plz, lambda x: x["type"] == allergy
        ):
            self.send_message(msg.from_, "Du hast %s nicht abonniert" % (allergy))
            return

        self._sum.filter_subscription_data_items(
            str(msg.from_.bare()), plz, lambda x: x["type"] != allergy
        )
        self.send_message(
            msg.from_, "Du erhälst nun keine Pollenmeldungen zu %s mehr" % (allergy)
        )

    async def _help(self, cmd, msg):
        body = """Verfügbare Befehle:
pollen subscribe <PLZ> <Typ> [<Min. Level>]
pollen unsubscribe <PLZ> <Typ>
pollen hilfe

Pollentypen: Ambrosia, Ampfer, Beifuß, Birke, Buche, Eiche, Erle, Esche, Gräser, Hasel, Pappel, Roggen, Ulme, Wegerich, Weide, Alle (Alias für alle Pollentypen)
Level: 0 (Kein Pollenflug) - 3 (Starker Pollenflug)
"""
        self.send_message(msg.from_, body)

    async def _any(self, cmd, msg):
        self.send_message(msg.from_, "Unbekannter Befehl")
        await self._help(cmd, msg)


def get_instance(base, **kwargs):
    return PollenModule.get_instance(base, **kwargs)