"""
    Copyright 2018 Alex Taber ("astronautlevel")

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
"""

from matrix_client.client import MatrixClient

import discord
import requests
import re

from config import *

matrix_client = MatrixClient(matrix_homeserver)
token = matrix_client.login(matrix_username, matrix_password)
discord_client = discord.Client()

matrix_room = matrix_client.join_room(matrix_room_id)

matrix_file_types = ('m.file', 'm.image', 'm.video', 'm.audio')

message_id_cache = {}
unmatched_messages_cache = {}

message_delete_queue = []

def prepare_matrix_content(message):
	reg = re.match(r"^<a?:\w+:(\d+)>$", message.content)

	if reg:
		return "https://cdn.discordapp.com/emojis/{}.png?size=32".format(reg.group(1))

	attachments = "\n".join([x.url for x in message.attachments])
	content = message.clean_content + ("\n" + attachments if attachments != "" else "")
	content = re.sub(r"<a?(:\w+:)\d*>", r"\g<1>", content)
	return content

guild = None
channel = None
emojis = {}

@discord_client.event
async def on_ready():
	global guild
	global emojis
	global webhook
	global channel
	channel = discord_client.get_channel(discord_channel)
	guild = channel.guild
	for emoji in guild.emojis:
		if not emoji.animated:
			emojis[":{}:".format(emoji.name)] = "<:{}:{}>".format(emoji.name, emoji.id)
		else:
			emojis[":{}:".format(emoji.name)] = "<a:{}:{}>".format(emoji.name, emoji.id)

@discord_client.event
async def on_message(message):
	for message_id in message_delete_queue:
		message_delete_queue.remove(message_id)
		message = await channel.get_message(message_id)
		await message.delete()
	if message.author.name in unmatched_messages_cache.keys():
		message_id_cache[unmatched_messages_cache[message.author.name]] = message.id
		del unmatched_messages_cache[message.author.name]
	if message.author.discriminator == "0000" or message.channel.id != discord_channel: return
	username = message.author.name[:1] + "\u200B" + message.author.name[1:] + "#" + message.author.discriminator
	content = prepare_matrix_content(message)
	matrix_message_id = matrix_room.send_text("<{}> {}".format(username, content))['event_id']
	message_id_cache[message.id] = matrix_message_id

@discord_client.event
async def on_message_edit(before, after):
	if after.author.discriminator == "0000" or after.channel.id != discord_channel: return
	if after.content == before.content: return
	after.attachments = []
	username = after.author.name[:1] + "\u200B" + after.author.name[1:] + "#" + after.author.discriminator
	content = prepare_matrix_content(after)
	matrix_room.redact_message(message_id_cache[before.id], reason="Message Edited")
	message_id_cache[after.id] = matrix_room.send_text("<{}> {} (edited)".format(username, content))['event_id']

@discord_client.event
async def on_raw_message_delete(paylod):
	if payload.message_id in message_id_cache.keys():
		matrix_room.redact_message(message_id_cache[paylod.message_id], reason="Message Deleted")

def send_webhook(username, avatar_url, content, matrix_id):
	unmatched_messages_cache[username] = matrix_id;

	payload = {}

	payload['content'] = content
	payload['avatar_url'] = avatar_url
	payload['username'] = username

	for tries in range(5):
		r = requests.post(webhook_url, data = payload)
		if r.ok:
			return
		else:
			print(r.status_code)

def prepare_discord_content(content):
	content = content.replace("@everyone", "@\u200Beveryone")
	content = content.replace("@here", "@\u200Bhere")
	content = re.sub("</?del>", "~~", content)
	mentions = re.findall("(^|\s)(@(\w*))", content)
	for mention in mentions:
		member = guild.get_member_named(mention[2])
		if not member: continue
		content = content.replace(mention[1], member.mention)
	for emoji_name, emoji_id in emojis.items():
		if emoji_name in content:
			content = content.replace(emoji_name, emoji_id)
	return content

def on_matrix_message(room, event):
	user = matrix_client.get_user(event['sender'])
	if event['type'] == "m.room.message" and not user.user_id == matrix_user_id:
		if event['content']['msgtype'] == "m.text":
			username = "{}{}".format(discord_prefix, user.get_display_name())
			avatar = user.get_avatar_url()
			content = prepare_discord_content(event['content']['body'])
			send_webhook(username, avatar, content, event['event_id'])
		if event['content']['msgtype'] in matrix_file_types:
			username = "{}{}".format(discord_prefix, user.get_display_name())
			avatar = user.get_avatar_url()
			content = matrix_homeserver + "/_matrix/media/v1/download/" + event['content']['url'][6:]
			send_webhook(username, avatar, content, event['event_id'])
	if event['type'] == "m.room.redaction" and not user.user_id == matrix_user_id:
		try:
			message_delete_queue.append(message_id_cache[event['redacts']])
		except KeyError:
			pass

matrix_room.add_listener(on_matrix_message)
matrix_client.start_listener_thread()
discord_client.run(discord_token)