# maubot - A plugin-based Matrix bot system.
# Copyright (C) 2021 Tulir Asokan
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
from typing import Optional, Type, cast
import logging.config
import importlib
import argparse
import asyncio
import os.path
import signal
import copy
import sys

from ruamel.yaml import YAML
from ruamel.yaml.comments import CommentedMap
import sqlalchemy as sql
from aiohttp import web, hdrs, ClientSession
from yarl import URL

from mautrix.util.config import RecursiveDict, BaseMissingError
from mautrix.util.db import Base
from mautrix.util.logging import TraceLogger
from mautrix.types import (Filter, RoomFilter, RoomEventFilter, StrippedStateEvent,
                           EventType, Membership, FilterID, SyncToken)

from ..plugin_base import Plugin
from ..plugin_server import PluginWebApp, PrefixResource
from ..loader import PluginMeta
from ..server import AccessLogger
from ..matrix import MaubotMatrixClient
from ..lib.store_proxy import SyncStoreProxy
from ..__meta__ import __version__
from .config import Config
from .loader import FileSystemLoader
from .database import NextBatch

crypto_import_error = None

try:
    from mautrix.crypto import OlmMachine, PgCryptoStore, PgCryptoStateStore
    from mautrix.util.async_db import Database as AsyncDatabase
except ImportError as err:
    crypto_import_error = err
    OlmMachine = AsyncDatabase = PgCryptoStateStore = PgCryptoStore = None

parser = argparse.ArgumentParser(
    description="A plugin-based Matrix bot system -- standalone mode.",
    prog="python -m maubot.standalone")
parser.add_argument("-c", "--config", type=str, default="config.yaml",
                    metavar="<path>", help="the path to your config file")
parser.add_argument("-b", "--base-config", type=str,
                    default="pkg://maubot.standalone/example-config.yaml",
                    metavar="<path>", help="the path to the example config "
                                           "(for automatic config updates)")
parser.add_argument("-m", "--meta", type=str, default="maubot.yaml",
                    metavar="<path>", help="the path to your plugin metadata file")
args = parser.parse_args()

config = Config(args.config, args.base_config)
config.load()
try:
    config.update()
except BaseMissingError:
    print("No example config found, not updating config")
except Exception as e:
    print("Failed to update config:", e)

logging.config.dictConfig(copy.deepcopy(config["logging"]))

log = logging.getLogger("maubot.init")

log.debug(f"Loading plugin metadata from {args.meta}")
yaml = YAML()
with open(args.meta, "r") as meta_file:
    meta: PluginMeta = PluginMeta.deserialize(yaml.load(meta_file.read()))

if "/" in meta.main_class:
    module, main_class = meta.main_class.split("/", 1)
else:
    module = meta.modules[0]
    main_class = meta.main_class
bot_module = importlib.import_module(module)
plugin: Type[Plugin] = getattr(bot_module, main_class)
loader = FileSystemLoader(os.path.dirname(args.meta))

log.info(f"Initializing standalone {meta.id} v{meta.version} on maubot {__version__}")

log.debug("Opening database")
db = sql.create_engine(config["database"])
Base.metadata.bind = db
Base.metadata.create_all()
NextBatch.bind(db)

user_id = config["user.credentials.id"]
device_id = config["user.credentials.device_id"]
homeserver = config["user.credentials.homeserver"]
access_token = config["user.credentials.access_token"]

crypto_store = crypto_db = state_store = None
if device_id and not OlmMachine:
    log.warning("device_id set in config, but encryption dependencies not installed",
                exc_info=crypto_import_error)
elif device_id:
    crypto_db = AsyncDatabase.create(config["database"], upgrade_table=PgCryptoStore.upgrade_table)
    crypto_store = PgCryptoStore(account_id=user_id, pickle_key="mau.crypto", db=crypto_db)
    state_store = PgCryptoStateStore(crypto_db)

nb = NextBatch.get(user_id)
if not nb:
    nb = NextBatch(user_id=user_id, next_batch=SyncToken(""), filter_id=FilterID(""))
    nb.insert()

bot_config = None
if not meta.config and "base-config.yaml" in meta.extra_files:
    log.warning("base-config.yaml in extra files, but config is not set to true. "
                "Assuming legacy plugin and loading config.")
    meta.config = True
if meta.config:
    log.debug("Loading config")
    config_class = plugin.get_config_class()


    def load() -> CommentedMap:
        return config["plugin_config"]


    def load_base() -> RecursiveDict[CommentedMap]:
        return RecursiveDict(config.load_base()["plugin_config"], CommentedMap)


    def save(data: RecursiveDict[CommentedMap]) -> None:
        config["plugin_config"] = data
        config.save()


    try:
        bot_config = config_class(load=load, load_base=load_base, save=save)
        bot_config.load_and_update()
    except Exception:
        log.fatal("Failed to load plugin config", exc_info=True)
        sys.exit(1)

if meta.webapp:
    web_app = web.Application()
    web_runner = web.AppRunner(web_app, access_log_class=AccessLogger)
    web_base_path = config["server.base_path"].rstrip("/")
    public_url = str(URL(config["server.public_url"]) / web_base_path.lstrip("/")).rstrip("/")
    plugin_webapp = PluginWebApp()

    async def _handle_plugin_request(req: web.Request) -> web.StreamResponse:
        if req.path.startswith(web_base_path):
            req = req.clone(rel_url=req.rel_url
                            .with_path(req.rel_url.path[len(web_base_path):])
                            .with_query(req.query_string))
            return await plugin_webapp.handle(req)
        return web.Response(status=404)

    resource = PrefixResource(web_base_path)
    resource.add_route(hdrs.METH_ANY, _handle_plugin_request)
    web_app.router.register_resource(resource)
else:
    web_app = web_runner = public_url = plugin_webapp = None

loop = asyncio.get_event_loop()

client: Optional[MaubotMatrixClient] = None
bot: Optional[Plugin] = None


async def main():
    http_client = ClientSession(loop=loop)

    global client, bot

    client_log = logging.getLogger("maubot.client").getChild(user_id)
    client = MaubotMatrixClient(mxid=user_id, base_url=homeserver, token=access_token,
                                client_session=http_client, loop=loop, log=client_log,
                                sync_store=SyncStoreProxy(nb), state_store=state_store,
                                device_id=device_id)
    client.ignore_first_sync = config["user.ignore_first_sync"]
    client.ignore_initial_sync = config["user.ignore_initial_sync"]
    if crypto_store:
        await crypto_db.start()
        await state_store.upgrade_table.upgrade(crypto_db)
        await crypto_store.open()

        client.crypto = OlmMachine(client, crypto_store, state_store)
        crypto_device_id = await crypto_store.get_device_id()
        if crypto_device_id and crypto_device_id != device_id:
            log.fatal("Mismatching device ID in crypto store and config "
                      f"(store: {crypto_device_id}, config: {device_id})")
            sys.exit(10)
        await client.crypto.load()
        if not crypto_device_id:
            await crypto_store.put_device_id(device_id)
        log.debug("Enabled encryption support")

    if web_runner:
        await web_runner.setup()
        site = web.TCPSite(web_runner, config["server.hostname"], config["server.port"])
        await site.start()
        log.info(f"Web server listening on {site.name}")

    while True:
        try:
            whoami = await client.whoami()
        except Exception:
            log.exception("Failed to connect to homeserver, retrying in 10 seconds...")
            await asyncio.sleep(10)
            continue
        if whoami.user_id != user_id:
            log.fatal(f"User ID mismatch: configured {user_id}, but server said {whoami.user_id}")
            sys.exit(11)
        elif whoami.device_id and device_id and whoami.device_id != device_id:
            log.fatal(f"Device ID mismatch: configured {device_id}, "
                      f"but server said {whoami.device_id}")
            sys.exit(12)
        log.debug(f"Confirmed connection as {whoami.user_id} / {whoami.device_id}")
        break

    if config["user.sync"]:
        if not nb.filter_id:
            nb.edit(filter_id=await client.create_filter(Filter(
                room=RoomFilter(timeline=RoomEventFilter(limit=50)),
            )))
        client.start(nb.filter_id)

    if config["user.autojoin"]:
        log.debug("Autojoin is enabled")

        @client.on(EventType.ROOM_MEMBER)
        async def _handle_invite(evt: StrippedStateEvent) -> None:
            if evt.state_key == client.mxid and evt.content.membership == Membership.INVITE:
                await client.join_room(evt.room_id)

    displayname, avatar_url = config["user.displayname"], config["user.avatar_url"]
    if avatar_url != "disable":
        await client.set_avatar_url(avatar_url)
    if displayname != "disable":
        await client.set_displayname(displayname)

    plugin_log = cast(TraceLogger, logging.getLogger("maubot.instance.__main__"))
    bot = plugin(client=client, loop=loop, http=http_client, instance_id="__main__",
                 log=plugin_log, config=bot_config, database=db if meta.database else None,
                 webapp=plugin_webapp, webapp_url=public_url, loader=loader)

    await bot.internal_start()


async def stop(suppress_stop_error: bool = False) -> None:
    if client:
        client.stop()
    if bot:
        try:
            await bot.internal_stop()
        except Exception:
            if not suppress_stop_error:
                log.exception("Error stopping bot")
    if crypto_db:
        await crypto_db.stop()
    if web_runner:
        await web_runner.shutdown()
        await web_runner.cleanup()


try:
    log.info("Starting plugin")
    loop.run_until_complete(main())
except Exception:
    log.fatal("Failed to start plugin", exc_info=True)
    loop.run_until_complete(stop(suppress_stop_error=True))
    loop.close()
    sys.exit(1)

signal.signal(signal.SIGINT, signal.default_int_handler)
signal.signal(signal.SIGTERM, signal.default_int_handler)

try:
    log.info("Startup completed, running forever")
    loop.run_forever()
except KeyboardInterrupt:
    log.info("Interrupt received, stopping")
    loop.run_until_complete(stop())
    loop.close()
    sys.exit(0)
except Exception:
    log.fatal("Fatal error in bot", exc_info=True)
    sys.exit(1)