# 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/>.
from __future__ import annotations

from typing import TYPE_CHECKING, Awaitable
import asyncio

from mautrix.bridge.commands import HelpSection, command_handler
from mautrix.util import utf16_surrogate
from mautrix.util.formatter import (
    EntityString,
    EntityType,
    MarkdownString,
    MatrixParser,
    SimpleEntity,
)

from ..kt.types.api.struct import ApiUserType
from ..rpc.types import RPCError

from .. import puppet as pu, user as u
from .typehint import CommandEvent

from ..kt.client.errors import CommandException

SECTION_ACCOUNT = HelpSection("Account management", 35, "")
SECTION_FRIENDS = HelpSection("Friends management", 40, "")
SECTION_CHANNELS = HelpSection("Channel management", 45, "")

if TYPE_CHECKING:
    from mautrix.types import UserID

    from ..kt.types.api.struct import FriendStruct
    from ..kt.types.bson import Long


_CMD_CONFIRM_CHANGE_ID = "confirm-change-id"

@command_handler(
    needs_auth=True,
    management_only=False,
    help_section=SECTION_ACCOUNT,
    help_text="Set or change your KakaoTalk ID",
    help_args="<_KakaoTalk ID_>",
    aliases=["set-id"],
)
async def change_id(evt: CommandEvent) -> None:
    if len(evt.args) != 1:
        await evt.reply(f"**Usage:** `$cmdprefix+sp {evt.command} <KakaoTalk ID>`")
        return
    new_id = evt.args[0]
    if len(new_id) > 20:
        await evt.reply("ID must not exceed 20 characters. Please choose a shorter ID.")
        return
    await evt.mark_read()
    if await evt.sender.client.can_change_uuid(new_id):
        await evt.reply(
            "Once set, your KakaoTalk ID can be changed only once! "
           f"If you are sure that you want to change it, type `$cmdprefix+sp {_CMD_CONFIRM_CHANGE_ID}`. "
            "Otherwise, type `$cmdprefix+sp cancel`."
        )
        evt.sender.command_status = {
            "action": "ID change",
            "room_id": evt.room_id,
            "next": _confirm_change_id,
            "new_id": new_id,
        }
    else:
        await evt.reply(
           f"Cannot change KakaoTalk ID to `{new_id}`. "
            "That ID might already be in use or have restricted characters. "
            "Either try a different ID, or try again later."
        )

async def _confirm_change_id(evt: CommandEvent) -> None:
    assert evt.sender.command_status
    new_id = evt.sender.command_status.pop("new_id")
    evt.sender.command_status = None
    await evt.mark_read()
    try:
        await evt.sender.client.change_uuid(new_id)
    except CommandException:
        await evt.reply(f"Failed to change KakaoTalk ID to `{new_id}`. Try again later.")
    else:
        await evt.reply(f"Successfully changed ID to `{new_id}`")


@command_handler(
    needs_auth=True,
    management_only=False,
    help_section=SECTION_ACCOUNT,
    help_text="Allow others to search by your KakaoTalk ID",
)
def make_id_searchable(evt: CommandEvent) -> Awaitable[None]:
    return _set_id_searchable(evt, True)

@command_handler(
    needs_auth=True,
    management_only=False,
    help_section=SECTION_ACCOUNT,
    help_text="Prevent others from searching by your KakaoTalk ID",
)
def make_id_hidden(evt: CommandEvent) -> Awaitable[None]:
    return _set_id_searchable(evt, False)

async def _set_id_searchable(evt: CommandEvent, searchable: bool) -> None:
    await evt.mark_read()
    try:
        await evt.sender.client.set_uuid_searchable(searchable)
    except RPCError as e:
        await evt.reply(str(e))
    else:
        await evt.reply(f"Successfully made KakaoTalk ID {'searchable' if searchable else 'hidden'}")

async def _get_search_result_puppet(source: u.User, friend_struct: FriendStruct) -> pu.Puppet:
    puppet = await pu.Puppet.get_by_ktid(friend_struct.userId)
    if not puppet.name_set:
        await puppet.update_info_from_friend(source, friend_struct)
    return puppet


@command_handler(
    needs_auth=True,
    management_only=False,
    help_section=SECTION_FRIENDS,
    help_text="List all KakaoTalk friends",
)
async def list_friends(evt: CommandEvent) -> None:
    try:
        resp = await evt.sender.client.list_friends()
        await evt.mark_read()
    except CommandException as e:
        await evt.reply(f"Error while listing friends: {e!s}")
        return
    puppets = await asyncio.gather(
        *[
            _get_search_result_puppet(evt.sender, friend_struct)
            for friend_struct in resp.friends if friend_struct.userType == ApiUserType.NORMAL
            # NOTE Using NORMAL to avoid listing KakaoTalk bots, which are apparently PLUS users
        ]
    )
    results = "".join(
        f"* [{puppet.name}](https://matrix.to/#/{puppet.default_mxid})\n" for puppet in puppets
    )
    if results:
        await evt.reply(f"{results}")
    else:
        await evt.reply("No friends found.")


class MentionFormatString(EntityString[SimpleEntity, EntityType], MarkdownString):
    def format(self, entity_type: EntityType, **kwargs) -> MentionFormatString:
        if entity_type == EntityType.USER_MENTION:
            self.entities.append(
                SimpleEntity(
                    type=entity_type,
                    offset=0,
                    length=len(self.text),
                    extra_info={"user_id": kwargs["user_id"]},
                )
            )
        return self

class MentionParser(MatrixParser[MentionFormatString]):
    fs = MentionFormatString

async def _get_id_from_mxid(mxid: UserID) -> Long | None:
    user = await u.User.get_by_mxid(mxid, create=False)
    if user and user.ktid:
        return user.ktid
    puppet = await pu.Puppet.get_by_mxid(mxid, create=False)
    return puppet.ktid if puppet else None


@command_handler(
    needs_auth=True,
    management_only=False,
    help_section=SECTION_FRIENDS,
    help_text="Add a KakaoTalk user to your KakaoTalk friends list",
    help_args="<_KakaoTalk ID_|_Matrix user ID_>",
)
async def add_friend(evt: CommandEvent) -> None:
    await _edit_friend(evt, True)

@command_handler(
    needs_auth=True,
    management_only=False,
    help_section=SECTION_FRIENDS,
    help_text="Remove a KakaoTalk user from your KakaoTalk friends list",
    help_args="<_KakaoTalk ID_|_Matrix user ID_>",
)
async def remove_friend(evt: CommandEvent) -> None:
    await _edit_friend(evt, False)

async def _edit_friend(evt: CommandEvent, add: bool) -> None:
    if not evt.args:
        await evt.reply(f"**Usage:** `$cmdprefix+sp {evt.command} <KakaoTalk ID|Matrix user ID>`")
        return
    formatted_body = evt.content.get("formatted_body")
    if formatted_body:
        arg = formatted_body[len(evt.command):].strip()
        parsed = await MentionParser().parse(utf16_surrogate.add(arg))
        if not parsed.entities:
            await evt.reply("No user found")
            return
        if (
            len(parsed.entities) > 1 or
            parsed.entities[0].offset != 0 or
            parsed.entities[0].length != len(utf16_surrogate.remove(parsed.text))
        ):
            await evt.reply("Can add only one friend at a time")
            return
        mxid = parsed.entities[0].extra_info["user_id"]
        ktid = await _get_id_from_mxid(mxid)
        if not ktid:
            await evt.reply("No KakaoTalk user found for this Matrix ID")
        else:
            await _edit_friend_by_ktid(evt, ktid, add)
    else:
        arg = evt.content.body[len(evt.command):].strip()
        ktid = await _get_id_from_mxid(arg)
        if ktid:
            await _edit_friend_by_ktid(evt, ktid, add)
        else:
            await _edit_friend_by_uuid(evt, arg, add)

async def _edit_friend_by_ktid(evt: CommandEvent, ktid: Long, add: bool) -> None:
    try:
        friend_struct = await evt.sender.client.edit_friend(ktid, add)
    except RPCError as e:
        await evt.reply(str(e))
    else:
        await _on_friend_edited(evt, friend_struct, add)

async def _edit_friend_by_uuid(evt: CommandEvent, uuid: str, add: bool) -> None:
    try:
        friend_struct = await evt.sender.client.edit_friend_by_uuid(uuid, add)
    except RPCError as e:
        await evt.reply(str(e))
    except CommandException as e:
        if e.status == -1002:
            await evt.reply(
                f"Failed to {'add' if add else 'remove'} friend. Ensure their ID is spelled correctly."
            )
        else:
            raise
    else:
        await _on_friend_edited(evt, friend_struct, add)

async def _on_friend_edited(evt: CommandEvent, friend_struct: FriendStruct | None, add: bool):
    await evt.reply(f"Friend {'added' if add else 'removed'}")
    if friend_struct:
        puppet = await pu.Puppet.get_by_ktid(friend_struct.userId)
        await puppet.update_info_from_friend(evt.sender, friend_struct)


@command_handler(
    needs_auth=True,
    management_only=False,
    help_section=SECTION_CHANNELS,
    help_text="Leave this KakaoTalk channel",
)
async def leave(evt: CommandEvent) -> None:
    if not evt.sender.is_connected:
        await evt.reply("You are not connected to KakaoTalk chats")
        return
    if not evt.is_portal:
        await evt.reply("This command may only be used in a KakaoTalk channel portal room")
        return
    await evt.mark_read()
    await evt.sender.client.leave_channel(evt.portal.channel_props)
    await evt.sender.on_channel_left(evt.portal.ktid, evt.portal.kt_type)