# matrix-appservice-kakaotalk - A Matrix-KakaoTalk puppeting bridge.
# Copyright (C) 2022 Tulir Asokan, Andrew Ferrazzutti
#
# 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/>.
import time

from yarl import URL

from mautrix.bridge.commands import HelpSection, command_handler
from mautrix.errors import MForbidden
from mautrix.util.signed_token import sign_token

from ..kt.client import Client as KakaoTalkClient
from ..kt.client.errors import DeviceVerificationRequired, IncorrectPasscode, IncorrectPassword, CommandException

#from .. import puppet as pu
from .typehint import CommandEvent

SECTION_AUTH = HelpSection("Authentication", 10, "")

web_unsupported = (
    "This instance of the KakaoTalk bridge does not support the web-based login interface"
)
alternative_web_login = (
    "Alternatively, you may use [the web-based login interface]({url}) "
    "to prevent the bridge and homeserver from seeing your password"
)
forced_web_login = (
    "This instance of the KakaoTalk bridge does not allow in-Matrix login. "
    "Please use [the web-based login interface]({url})."
)
send_password = "Please send your password here to log in"
missing_email = "Please use `$cmdprefix+sp login <email>` to log in here"
try_again_or_cancel = "Try again, or say `$cmdprefix+sp cancel` to give up."


@command_handler(
    needs_auth=False,
    management_only=True,
    help_section=SECTION_AUTH,
    help_text="Log in to KakaoTalk",
    help_args="[_email_]",
)
async def login(evt: CommandEvent) -> None:
    if evt.sender.client:
        await evt.reply("You're already logged in")
        return

    email = evt.args[0] if len(evt.args) > 0 else None

    if email:
        evt.sender.command_status = {
            "action": "Login",
            "room_id": evt.room_id,
            "next": enter_password,
            "email": evt.args[0],
        }

    if evt.bridge.public_website:
        external_url = URL(evt.config["appservice.public.external"])
        token = sign_token(
            evt.bridge.public_website.secret_key,
            {
                "mxid": evt.sender.mxid,
                "expiry": int(time.time()) + 30 * 60,
            },
        )
        url = (external_url / "login.html").with_fragment(token)
        if not evt.config["appservice.public.allow_matrix_login"]:
            await evt.reply(forced_web_login.format(url=url))
        elif email:
            await evt.reply(f"{send_password}. {alternative_web_login.format(url=url)}.")
        else:
            await evt.reply(f"{missing_email}. {alternative_web_login.format(url=url)}.")
    elif not email:
        await evt.reply(f"{missing_email}. {web_unsupported}.")
    else:
        await evt.reply(f"{send_password}. {web_unsupported}.")


async def enter_password(evt: CommandEvent) -> None:
    try:
        await evt.az.intent.redact(evt.room_id, evt.event_id)
    except MForbidden:
        pass

    assert(evt.sender.command_status)
    req = {
        "uuid": await evt.sender.get_uuid(),
        "form": {
            "email": evt.sender.command_status["email"],
            "password": evt.content.body,
        }
    }
    try:
        await _do_login(evt, req)
    except DeviceVerificationRequired:
        await evt.reply(
            "Open KakaoTalk on your smartphone. It should show a device registration passcode. "
            "Enter that passcode here."
        )
        evt.sender.command_status = {
            "action": "Login",
            "room_id": evt.room_id,
            "next": enter_dv_code,
            "req": req,
        }
    except IncorrectPassword:
        await evt.reply(f"Incorrect password. {try_again_or_cancel}")
    #except OAuthException as e:
    #    await evt.reply(f"Error from KakaoTalk:\n\n> {e}")
    except Exception as e:
        await _handle_login_failure(evt, e)


async def enter_dv_code(evt: CommandEvent) -> None:
    assert(evt.sender.command_status)
    req: dict = evt.sender.command_status["req"]
    passcode = evt.content.body
    try:
        await KakaoTalkClient.register_device(passcode, **req)
        await _do_login(evt, req)
    except IncorrectPasscode:
        await evt.reply(f"Incorrect device registration passcode. {try_again_or_cancel}")
    #except OAuthException as e:
    #    await evt.reply(f"Error from KakaoTalk:\n\n> {e}")
    except Exception as e:
        await _handle_login_failure(evt, e)


async def _do_login(evt: CommandEvent, req: dict) -> None:
    oauth_credential = await KakaoTalkClient.login(**req)
    await evt.sender.on_logged_in(oauth_credential)
    evt.sender.command_status = None
    await evt.reply("Successfully logged in")

async def _handle_login_failure(evt: CommandEvent, e: Exception) -> None:
    evt.sender.command_status = None
    if isinstance(e, CommandException):
        message = "Failed to log in"
        evt.log.error(message)
    else:
        message = "Error while logging in"
        evt.log.exception(message)
    await evt.reply(f"{message}: {e}")


@command_handler(needs_auth=True, help_section=SECTION_AUTH, help_text="Log out of KakaoTalk")
async def logout(evt: CommandEvent) -> None:
    #puppet = await pu.Puppet.get_by_ktid(evt.sender.ktid)
    await evt.sender.logout()
    #if puppet.is_real_user:
    #    await puppet.switch_mxid(None, None)
    await evt.reply("Successfully logged out")