# mautrix-telegram - A Matrix-Telegram puppeting bridge
# 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 __future__ import annotations

from telethon.errors import (
    AboutTooLongError,
    AuthKeyError,
    FirstNameInvalidError,
    HashInvalidError,
    UsernameInvalidError,
    UsernameNotModifiedError,
    UsernameOccupiedError,
)
from telethon.tl.functions.account import (
    GetAuthorizationsRequest,
    ResetAuthorizationRequest,
    UpdateProfileRequest,
    UpdateUsernameRequest,
)
from telethon.tl.types import Authorization

from mautrix.types import EventID

from .. import SECTION_AUTH, CommandEvent, command_handler


@command_handler(
    needs_auth=True,
    help_section=SECTION_AUTH,
    help_args="<_new username_>",
    help_text="Change your Telegram username.",
)
async def username(evt: CommandEvent) -> EventID:
    if len(evt.args) == 0:
        return await evt.reply("**Usage:** `$cmdprefix+sp username <new username>`")
    if evt.sender.is_bot:
        return await evt.reply("Bots can't set their own username.")
    new_name = evt.args[0]
    if new_name == "-":
        new_name = ""
    try:
        await evt.sender.client(UpdateUsernameRequest(username=new_name))
    except UsernameInvalidError:
        return await evt.reply(
            "Invalid username. Usernames must be between 5 and 30 alphanumeric characters."
        )
    except UsernameNotModifiedError:
        return await evt.reply("That is your current username.")
    except UsernameOccupiedError:
        return await evt.reply("That username is already in use.")
    await evt.sender.update_info()
    if not evt.sender.tg_username:
        await evt.reply("Username removed")
    else:
        await evt.reply(f"Username changed to {evt.sender.tg_username}")


@command_handler(
    needs_auth=True,
    help_section=SECTION_AUTH,
    help_args="<_new about_>",
    help_text="Change your Telegram about section.",
)
async def about(evt: CommandEvent) -> EventID:
    if len(evt.args) == 0:
        return await evt.reply("**Usage:** `$cmdprefix+sp about <new about>`")
    if evt.sender.is_bot:
        return await evt.reply("Bots can't set their own about section.")
    new_about = " ".join(evt.args)
    if new_about == "-":
        new_about = ""
    try:
        await evt.sender.client(UpdateProfileRequest(about=new_about))
    except AboutTooLongError:
        return await evt.reply("The provided about section is too long")
    return await evt.reply("About section updated")


@command_handler(
    needs_auth=True,
    help_section=SECTION_AUTH,
    help_args="<_new displayname_>",
    help_text="Change your Telegram displayname.",
)
async def displayname(evt: CommandEvent) -> EventID:
    if len(evt.args) == 0:
        return await evt.reply("**Usage:** `$cmdprefix+sp displayname <new displayname>`")
    if evt.sender.is_bot:
        return await evt.reply("Bots can't set their own displayname.")

    first_name, last_name = (
        (evt.args[0], "") if len(evt.args) == 1 else (" ".join(evt.args[:-1]), evt.args[-1])
    )
    try:
        await evt.sender.client(UpdateProfileRequest(first_name=first_name, last_name=last_name))
    except FirstNameInvalidError:
        return await evt.reply("Invalid first name")
    await evt.sender.update_info()
    return await evt.reply("Displayname updated")


def _format_session(sess: Authorization) -> str:
    return (
        f"**{sess.app_name} {sess.app_version}**  \n"
        f"  **Platform:** {sess.device_model} {sess.platform} {sess.system_version}  \n"
        f"  **Active:** {sess.date_active} (created {sess.date_created})  \n"
        f"  **From:** {sess.ip} - {sess.region}, {sess.country}"
    )


@command_handler(
    needs_auth=True,
    help_section=SECTION_AUTH,
    help_args="<`list`|`terminate`> [_hash_]",
    help_text="View or delete other Telegram sessions.",
)
async def session(evt: CommandEvent) -> EventID:
    if len(evt.args) == 0:
        return await evt.reply("**Usage:** `$cmdprefix+sp session <list|terminate> [hash]`")
    elif evt.sender.is_bot:
        return await evt.reply("Bots can't manage their sessions")
    cmd = evt.args[0].lower()
    if cmd == "list":
        res = await evt.sender.client(GetAuthorizationsRequest())
        session_list = res.authorizations
        current = [s for s in session_list if s.current][0]
        current_text = _format_session(current)
        other_text = "\n".join(
            f"* {_format_session(sess)}  \n  **Hash:** {sess.hash}"
            for sess in session_list
            if not sess.current
        )
        return await evt.reply(
            f"### Current session\n"
            f"{current_text}\n"
            f"\n"
            f"### Other active sessions\n"
            f"{other_text}"
        )
    elif cmd == "terminate" and len(evt.args) > 1:
        try:
            session_hash = int(evt.args[1])
        except ValueError:
            return await evt.reply("Hash must be an integer")
        try:
            ok = await evt.sender.client(ResetAuthorizationRequest(hash=session_hash))
        except HashInvalidError:
            return await evt.reply("Invalid session hash.")
        except AuthKeyError as e:
            if e.message == "FRESH_RESET_AUTHORISATION_FORBIDDEN":
                return await evt.reply(
                    "New sessions can't terminate other sessions. Please wait a while."
                )
            raise
        if ok:
            return await evt.reply("Session terminated successfully.")
        else:
            return await evt.reply("Session not found.")
    else:
        return await evt.reply("**Usage:** `$cmdprefix+sp session <list|terminate> [hash]`")