#!/usr/bin/env python3

import asyncio
import functools
import glob
import importlib
import json

import yaml
import os
import re
import signal
import sys
import traceback
import urllib.parse
import logging
import logging.config
import datetime
import hashlib
from importlib import reload
from io import BytesIO
from PIL import Image

import requests
from nio import AsyncClient, InviteEvent, JoinError, RoomMessageText, MatrixRoom, LoginError, RoomMemberEvent, RoomVisibility, RoomPreset, RoomCreateError, RoomResolveAliasResponse, UploadError, UploadResponse, SyncError

# Couple of custom exceptions


class UploadFailed(Exception):
    pass

class CommandRequiresAdmin(Exception):
    pass


class CommandRequiresOwner(Exception):
    pass


class Bot:

    def __init__(self):
        self.appid = 'org.vranki.hemppa'
        self.version = '1.5'
        self.client = None
        self.join_on_invite = False
        self.modules = dict()
        self.module_aliases = dict()
        self.leave_empty_rooms = True
        self.uri_cache = dict()
        self.pollcount = 0
        self.poll_task = None
        self.owners = []
        self.debug = os.getenv("DEBUG", "false").lower() == "true"
        self.logger = None

        self.jointime = None  # HACKHACKHACK to avoid running old commands after join
        self.join_hack_time = 5  # Seconds

        self.initialize_logger()

    def initialize_logger(self):

        if os.path.exists('config/logging.yml'):
            with open('config/logging.yml') as f:
                config = yaml.load(f, Loader=yaml.Loader)
                logging.config.dictConfig(config)
        else:
            log_format = '%(levelname)s - %(name)s - %(message)s'
            logging.basicConfig(format=log_format)

        self.logger = logging.getLogger("hemppa")

        if self.debug:
            logging.root.setLevel(logging.DEBUG)
            self.logger.info("enabled debugging")

        self.logger.debug("Logger initialized")

    def get_uri_cache(self, url, blob=False):
        """

        :param url: Url of binary content of the image to upload
        :param blob: Flag to indicate if the second param is an url or a binary content
        :return: [matrix_uri, mimetype, w, h, size], or None
        """
        cache_key = url
        if blob:  ## url is bytes, cannot be used a key for cache
            cache_key = hashlib.md5(url).hexdigest()

        return self.uri_cache.get(cache_key)


    async def upload_and_send_image(self, room, url, text=None, blob=False, blob_content_type="image/png", no_cache=False):
        """

        :param room: A MatrixRoom the image should be send to after uploading
        :param url: Url of binary content of the image to upload
        :param text: A textual representation of the image
        :param blob: Flag to indicate if the second param is an url or a binary content
        :param blob_content_type: Content type of the image in case of binary content
        :param no_cache: Set to true if you want to bypass cache and always re-upload the file
        :return:
        """

        if not text and not blob:
            text = f"Image: {url}"

        res = self.get_uri_cache(url, blob=blob)
        if res:
            try:
                matrix_uri, mimetype, w, h, size = res
                return await self.send_image(room, matrix_uri, text, mimetype, w, h, size)
            except ValueError: # broken cache?
                self.logger.warning(f"Image cache for {url} could not be unpacked, attempting to re-upload...")
        try:
            matrix_uri, mimetype, w, h, size = await self.upload_image(url, blob=blob, no_cache=no_cache)
        except (UploadFailed, ValueError):
            return await self.send_text(room, f"Sorry. Something went wrong fetching {url} and uploading the image to matrix server :(")

        return await self.send_image(room, matrix_uri, text, mimetype, w, h, size)

    # Helper function to upload a image from URL to homeserver. Use send_image() to actually send it to room.
    # Throws exception if upload fails
    async def upload_image(self, url_or_bytes, blob=False, blob_content_type="image/png", no_cache=False):
        """
        :param url_or_bytes: Url or binary content of the image to upload
        :param blob: Flag to indicate if the first param is an url or a binary content
        :param blob_content_type: Content type of the image in case of binary content
        :param no_cache: Flag to indicate whether to cache the resulting uploaded details
        :return: A MXC-Uri https://matrix.org/docs/spec/client_server/r0.6.0#mxc-uri, Content type, Width, Height, Image size in bytes
        """

        self.client: AsyncClient
        response: UploadResponse

        cache_key = url_or_bytes
        if blob:  ## url is bytes, cannot be used a key for cache
            cache_key = hashlib.md5(url).hexdigest()

        if no_cache:
            cache_key = None

        if blob:
            i = Image.open(BytesIO(url_or_bytes))
            image_length = len(url_or_bytes)
            content_type = blob_content_type
            (response, alist) = await self.client.upload(lambda a, b: url_or_bytes, blob_content_type, filesize=image_length)
        else:
            self.logger.debug(f"start downloading image from url {url_or_bytes}")
            headers = {'User-Agent': 'Mozilla/5.0'}
            url_response = requests.get(url_or_bytes, headers=headers)
            self.logger.debug(f"response [status_code={url_response.status_code}, headers={url_response.headers}")

            if url_response.status_code == 200:
                content_type = url_response.headers.get("content-type")
                self.logger.info(f"uploading content to matrix server [size={len(url_response.content)}, content-type: {content_type}]")
                (response, alist) = await self.client.upload(lambda a, b: url_response.content, content_type)
                self.logger.debug("response: %s", response)
                i = Image.open(BytesIO(url_response.content))
                image_length = len(url_response.content)
            else:
                self.logger.error("unable to request url: %s", url_response)
                raise UploadFailed

        if isinstance(response, UploadResponse):
            self.logger.info("uploaded file to %s", response.content_uri)
            res = [response.content_uri, content_type, i.size[0], i.size[1], image_length]
            if cache_key:
                self.uri_cache[cache_key] = res
            return res
        else:
            response: UploadError
            self.logger.error("unable to upload file. msg: %s", response.message)

        raise UploadFailed

    async def send_text(self, room, body, msgtype="m.notice", bot_ignore=False):
        """

        :param room: A MatrixRoom the text should be send to
        :param body: Textual content of the message
        :param msgtype: The message type for the room https://matrix.org/docs/spec/client_server/latest#m-room-message-msgtypes
        :param bot_ignore: Flag to mark the message to be ignored by the bot
        :return: the NIO Response from room_send()
        """

        msg = {
            "body": body,
            "msgtype": msgtype,
        }
        if bot_ignore:
            msg["org.vranki.hemppa.ignore"] = "true"

        return await self.client.room_send(room.room_id, 'm.room.message', msg)

    async def send_html(self, room, html, plaintext, msgtype="m.notice", bot_ignore=False):
        """

        :param room: A MatrixRoom the html should be send to
        :param html: Html content of the message
        :param plaintext: Plaintext content of the message
        :param msgtype: The message type for the room https://matrix.org/docs/spec/client_server/latest#m-room-message-msgtypes
        :param bot_ignore: Flag to mark the message to be ignored by the bot
        :return:
        """

        msg = {
            "msgtype": msgtype,
            "format": "org.matrix.custom.html",
            "formatted_body": html,
            "body": plaintext
        }
        if bot_ignore:
            msg["org.vranki.hemppa.ignore"] = "true"
        await self.client.room_send(room.room_id, 'm.room.message', msg)

    async def send_location(self, room, body, latitude, longitude, bot_ignore=False):
        """

        :param room: A MatrixRoom the html should be send to
        :param html: Html content of the message
        :param body: Plaintext content of the message
        :param latitude: Latitude in WGS84 coordinates (float)
        :param longitude: Longitude in WGS84 coordinates (float)
        :param bot_ignore: Flag to mark the message to be ignored by the bot
        :return:
        """
        locationmsg = {
            "body": str(body),
            "geo_uri": 'geo:' + str(latitude) + ',' + str(longitude),
            "msgtype": "m.location",
            }
        await self.client.room_send(room.room_id, 'm.room.message', locationmsg)

    async def send_image(self, room, url, body, mimetype=None, width=None, height=None, size=None):
        """

        :param room: A MatrixRoom the image should be send to
        :param url: A MXC-Uri https://matrix.org/docs/spec/client_server/r0.6.0#mxc-uri
        :param body: A textual representation of the image
        :param mimetype: The mimetype of the image
        :param width: Width in pixel of the image
        :param height: Height in pixel of the image
        :param size: Size in bytes of the image
        :return:
        """
        msg = {
            "url": url,
            "body": body,
            "msgtype": "m.image",
            "info": {
                "thumbnail_info": None,
                "thumbnail_url": None,
            },
        }

        if mimetype:
            msg["info"]["mimetype"] = mimetype
        if width:
            msg["info"]["w"] = width
        if height:
            msg["info"]["h"] = height
        if size:
            msg["info"]["size"] = size

        return await self.client.room_send(room.room_id, 'm.room.message', msg)

    async def set_room_avatar(self, room, uri, mimetype=None, width=None, height=None, size=None):
        """

        :param room: A MatrixRoom the image should be send to
        :param uri: A MXC-Uri https://matrix.org/docs/spec/client_server/r0.6.0#mxc-uri
        :param mimetype: The mimetype of the image
        :param width: Width in pixel of the image
        :param height: Height in pixel of the image
        :param size: Size in bytes of the image
        :return:
        """
        msg = {
            "url": uri,
            "info": {
                "thumbnail_info": None,
                "thumbnail_url": None,
            },
        }

        if mimetype:
            msg["info"]["mimetype"] = mimetype
        if width:
            msg["info"]["w"] = width
        if height:
            msg["info"]["h"] = height
        if size:
            msg["info"]["size"] = size

        return await self.client.room_put_state(room.room_id, 'm.room.avatar', msg)

    async def send_msg(self, mxid, roomname, message):
        """

        :param mxid: A Matrix user id to send the message to
        :param roomname: A Matrix room id to send the message to
        :param message: Text to be sent as message
        :return bool: Success upon sending the message
        """
        # Sends private message to user. Returns true on success.
        msg_room = await self.find_or_create_private_msg(mxid, roomname)
        if not msg_room or (type(msg_room) is RoomCreateError):
            self.logger.error(f'Unable to create room when trying to message {mxid}')
            return False

        # Send message to the room
        await self.send_text(msg_room, message)
        return True

    async def find_or_create_private_msg(self, mxid, roomname):
        # Find if we already have a common room with user:
        msg_room = None
        for croomid in self.client.rooms:
            roomobj = self.client.rooms[croomid]
            if len(roomobj.users) == 2:
                for user in roomobj.users:
                    if user == mxid:
                        msg_room = roomobj

        # Nope, let's create one
        if not msg_room:
            msg_room = await self.client.room_create(visibility=RoomVisibility.private,
                name=roomname,
                is_direct=True,
                preset=RoomPreset.private_chat,
                invite={mxid},
            )
        return msg_room


    def remove_callback(self, callback):
        for cb_object in self.client.event_callbacks:
            if cb_object.func == callback:
                self.logger.info("remove callback")
                self.client.event_callbacks.remove(cb_object)

    def get_room_by_id(self, room_id):
        try:
            return self.client.rooms[room_id]
        except KeyError:
            return None

    async def get_room_by_alias(self, alias):
        rar = await self.client.room_resolve_alias(alias)
        if type(rar) is RoomResolveAliasResponse:
            return rar.room_id
        return None

    # Throws exception if event sender is not a room admin
    def must_be_admin(self, room, event, power_level=50):
        if not self.is_admin(room, event, power_level=power_level):
            raise CommandRequiresAdmin

    # Throws exception if event sender is not a bot owner
    def must_be_owner(self, event):
        if not self.is_owner(event):
            raise CommandRequiresOwner

    # Returns true if event's sender has PL50 or more in the room event was sent in,
    # or is bot owner
    def is_admin(self, room, event, power_level=50):
        if self.is_owner(event):
            return True
        if event.sender not in room.power_levels.users:
            return False
        return room.power_levels.users[event.sender] >= power_level

    # Returns true if event's sender is owner of the bot
    def is_owner(self, event):
        return event.sender in self.owners

    # Checks if this event should be ignored by bot, including custom property
    def should_ignore_event(self, event):
        return "org.vranki.hemppa.ignore" in event.source['content']

    def save_settings(self):
        module_settings = dict()
        for modulename, moduleobject in self.modules.items():
            try:
                module_settings[modulename] = moduleobject.get_settings()
            except Exception:
                self.logger.exception(f'unhandled exception {modulename}.get_settings')
        data = {self.appid: self.version, 'module_settings': module_settings, 'uri_cache': self.uri_cache}
        self.set_account_data(data)

    def load_settings(self, data):
        if not data:
            return
        if not data.get('module_settings'):
            return
        if data.get('uri_cache'):
            self.uri_cache = data['uri_cache']
        for modulename, moduleobject in self.modules.items():
            if data['module_settings'].get(modulename):
                try:
                    moduleobject.set_settings(
                        data['module_settings'][modulename])
                except Exception:
                    self.logger.exception(f'unhandled exception {modulename}.set_settings')

    async def message_cb(self, room, event):
        # Ignore if asked to ignore
        if self.should_ignore_event(event):
            if self.debug:
                self.logger.debug('Ignoring event!')
            return

        body = event.body
        # Figure out the command
        if not self.starts_with_command(body):
            return

        if self.owners_only and not self.is_owner(event):
            self.logger.info(f"Ignoring {event.sender}, because they're not an owner")
            await self.send_text(room, "Sorry, only bot owner can run commands.")
            return

        # HACK to ignore messages for some time after joining.
        if self.jointime:
            if (datetime.datetime.now() - self.jointime).seconds < self.join_hack_time:
                self.logger.info(f"Waiting for join delay, ignoring message: {body}")
                return
            self.jointime = None

        command = body.split().pop(0)

        # Strip away non-alphanumeric characters, including leading ! for security
        command = re.sub(r'\W+', '', command)

        # Fallback to any declared aliases
        moduleobject = self.modules.get(command) or self.modules.get(self.module_aliases.get(command))

        if moduleobject is not None:
            if moduleobject.enabled:
                try:
                    await moduleobject.matrix_message(self, room, event)
                except CommandRequiresAdmin:
                    await self.send_text(room, f'Sorry, you need admin power level in this room to run that command.')
                except CommandRequiresOwner:
                    await self.send_text(room, f'Sorry, only bot owner can run that command.')
                except Exception:
                    await self.send_text(room, f'Module {command} experienced difficulty: {sys.exc_info()[0]} - see log for details')
                    self.logger.exception(f'unhandled exception in !{command}')
        else:
            self.logger.error(f"Unknown command: {command}")
            # TODO Make this configurable
            # await self.send_text(room,
            #                     f"Sorry. I don't know what to do. Execute !help to get a list of available commands.")

    @staticmethod
    def starts_with_command(body):
        """Checks if body starts with ! and has one or more letters after it"""
        return re.match(r"^!\w.*", body) is not None

    async def invite_cb(self, room, event):
        room: MatrixRoom
        event: InviteEvent

        if self.join_on_invite or self.is_owner(event):
            for attempt in range(3):
                self.jointime = datetime.datetime.now()
                result = await self.client.join(room.room_id)
                if type(result) == JoinError:
                    self.logger.error(f"Error joining room %s (attempt %d): %s", room.room_id, attempt, result.message)
                else:
                    self.logger.info(f"joining room '{room.display_name}'({room.room_id}) invited by '{event.sender}'")
                    return
        else:
            self.logger.warning(f'Received invite event, but not joining as sender is not owner or bot not configured to join on invite. {event}')

    async def memberevent_cb(self, room, event):
        # Automatically leaves rooms where bot is alone.
        if room.member_count == 1 and event.membership=='leave' and event.sender != self.matrix_user:
            self.logger.info(f"Membership event in {room.display_name} ({room.room_id}) with {room.member_count} members by '{event.sender}' (I am {self.matrix_user})- leaving room as i don't want to be left alone!")
            await self.client.room_leave(room.room_id)

    def load_module(self, modulename):
        try:
            self.logger.info(f'Loading module: {modulename}..')
            module = importlib.import_module('modules.' + modulename)
            module = reload(module)
            cls = getattr(module, 'MatrixModule')
            return cls(modulename)
        except Exception:
            self.logger.exception(f'Module {modulename} failed to load')
            return None

    def reload_modules(self):
        for modulename in self.modules:
            self.logger.info(f'Reloading {modulename} ..')
            self.modules[modulename] = self.load_module(modulename)

        self.load_settings(self.get_account_data())

    def get_modules(self):
        modulefiles = glob.glob('./modules/*.py')

        for modulefile in modulefiles:
            modulename = os.path.splitext(os.path.basename(modulefile))[0]
            moduleobject = self.load_module(modulename)
            if moduleobject:
                self.modules[modulename] = moduleobject

    def clear_modules(self):
        self.modules = dict()

    async def poll_timer(self):
        while True:
            self.pollcount = self.pollcount + 1
            for modulename, moduleobject in self.modules.items():
                if moduleobject.enabled:
                    try:
                        await moduleobject.matrix_poll(self, self.pollcount)
                    except Exception:
                        self.logger.exception(f'unhandled exception from {modulename}.matrix_poll')
            await asyncio.sleep(10)

    def set_account_data(self, data):
        userid = urllib.parse.quote(self.matrix_user)

        ad_url = f"{self.client.homeserver}/_matrix/client/r0/user/{userid}/account_data/{self.appid}?access_token={self.client.access_token}"

        response = requests.put(ad_url, json.dumps(data))
        self.__handle_error_response(response)

        if response.status_code != 200:
            self.logger.error('Setting account data failed. response: %s json: %s', response, response.json())

    def get_account_data(self):
        userid = urllib.parse.quote(self.matrix_user)

        ad_url = f"{self.client.homeserver}/_matrix/client/r0/user/{userid}/account_data/{self.appid}?access_token={self.client.access_token}"

        response = requests.get(ad_url)
        self.__handle_error_response(response)

        if response.status_code == 200:
            return response.json()
        self.logger.error(f'Getting account data failed: {response} {response.json()} - this is normal if you have not saved any settings yet.')
        return None

    def __handle_error_response(self, response):
        if response.status_code == 401:
            self.logger.error("access token is invalid or missing")
            self.logger.info("NOTE: check MATRIX_ACCESS_TOKEN")
            sys.exit(2)

    def init(self):

        self.matrix_user = os.getenv('MATRIX_USER')
        matrix_server = os.getenv('MATRIX_SERVER')
        bot_owners = os.getenv('BOT_OWNERS')
        access_token = os.getenv('MATRIX_ACCESS_TOKEN')
        join_on_invite = os.getenv('JOIN_ON_INVITE')
        owners_only = os.getenv('OWNERS_ONLY') is not None
        leave_empty_rooms = os.getenv('LEAVE_EMPTY_ROOMS')

        if matrix_server and self.matrix_user and bot_owners and access_token:
            self.client = AsyncClient(matrix_server, self.matrix_user, ssl = matrix_server.startswith("https://"))
            self.client.access_token = access_token
            self.join_on_invite = (join_on_invite or '').lower() == 'true'
            self.leave_empty_rooms = (leave_empty_rooms or 'true').lower() == 'true'
            self.owners = bot_owners.split(',')
            self.owners_only = owners_only
            self.get_modules()

        else:
            self.logger.error("The environment variables MATRIX_SERVER, MATRIX_USER, MATRIX_ACCESS_TOKEN and BOT_OWNERS are mandatory")
            sys.exit(1)

    def start(self):
        self.load_settings(self.get_account_data())
        enabled_modules = [module for module_name, module in self.modules.items() if module.enabled]
        self.logger.info(f'Starting {len(enabled_modules)} modules..')
        for modulename, moduleobject in self.modules.items():
            if moduleobject.enabled:
                try:
                    moduleobject.matrix_start(self)
                except Exception:
                    self.logger.exception(f'unhandled exception from {modulename}.matrix_start')
        self.logger.info(f'All modules started.')

    def stop(self):
        self.logger.info(f'Stopping {len(self.modules)} modules..')
        for modulename, moduleobject in self.modules.items():
            try:
                moduleobject.matrix_stop(self)
            except Exception:
                self.logger.exception(f'unhandled exception from {modulename}.matrix_stop')
        self.logger.info(f'All modules stopped.')

    async def run(self):
        sync_response = await self.client.sync()
        if type(sync_response) == SyncError:
            self.logger.error(f"Received Sync Error when trying to do initial sync! Error message is: %s", sync_response.message)
        else:
            for roomid, room in self.client.rooms.items():
                self.logger.info(f"Bot is on '{room.display_name}'({roomid}) with {len(room.users)} users")
                if len(room.users) == 1 and self.leave_empty_rooms:
                    self.logger.info(f'Room {roomid} has no other users - leaving it.')
                    self.logger.info(await self.client.room_leave(roomid))

            if self.client.logged_in:
                self.start()
                self.poll_task = asyncio.get_event_loop().create_task(self.poll_timer())
                self.load_settings(self.get_account_data())
                self.client.add_event_callback(self.message_cb, RoomMessageText)
                self.client.add_event_callback(self.invite_cb, (InviteEvent,))
                self.client.add_event_callback(self.memberevent_cb, (RoomMemberEvent,))

                if self.join_on_invite:
                    self.logger.info('Note: Bot will join rooms if invited')
                self.logger.info('Bot running as %s, owners %s', self.client.user, self.owners)
                self.bot_task = asyncio.create_task(self.client.sync_forever(timeout=30000))
                await self.bot_task
            else:
                self.logger.error('Client was not able to log in, check env variables!')

    async def shutdown(self):
        await self.close()

    async def close(self):
        try:
            await self.client.close()
            self.logger.info("Connection closed")
        except Exception as ex:
            self.logger.error("error while closing client: %s", ex)

    def handle_exit(self, signame, loop):
        self.logger.info(f"Received signal {signame}")
        if self.poll_task:
            self.poll_task.cancel()
        self.bot_task.cancel()
        self.stop()


async def main():
    bot = Bot()
    bot.init()

    loop = asyncio.get_running_loop()

    for signame in {'SIGINT', 'SIGTERM'}:
        loop.add_signal_handler(
            getattr(signal, signame),
            functools.partial(bot.handle_exit, signame, loop))

    await bot.run()
    await bot.shutdown()


try:
    asyncio.run(main())
except Exception as e:
    traceback.print_exc(file=sys.stderr)