# 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 NamedTuple

from mautrix.types import Format, MessageEventContent, RelationType, RoomID, UserID
from mautrix.util import utf16_surrogate
from mautrix.util.formatter import (
    EntityString,
    EntityType,
    MarkdownString,
    MatrixParser,
    SimpleEntity,
)
from mautrix.util.logging import TraceLogger

from ..kt.types.bson import Long
from ..kt.types.chat import KnownChatType
from ..kt.types.chat.attachment import ReplyAttachment, MentionStruct

from ..kt.client.types import TO_MSGTYPE_MAP

from .. import portal as po, puppet as pu, user as u
from ..db import Message as DBMessage


class SendParams(NamedTuple):
    text: str
    mentions: list[MentionStruct] | None
    reply_to: ReplyAttachment


class KakaoTalkFormatString(EntityString[SimpleEntity, EntityType], MarkdownString):
    def format(self, entity_type: EntityType, **kwargs) -> KakaoTalkFormatString:
        prefix = suffix = ""
        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
        elif entity_type == EntityType.BOLD:
            prefix = suffix = "*"
        elif entity_type == EntityType.ITALIC:
            prefix = suffix = "_"
        elif entity_type == EntityType.STRIKETHROUGH:
            prefix = suffix = "~"
        elif entity_type == EntityType.URL:
            if kwargs["url"] != self.text:
                suffix = f" ({kwargs['url']})"
        elif entity_type == EntityType.PREFORMATTED:
            prefix = f"```{kwargs['language']}\n"
            suffix = "\n```"
        elif entity_type == EntityType.INLINE_CODE:
            prefix = suffix = "`"
        elif entity_type == EntityType.BLOCKQUOTE:
            children = self.trim().split("\n")
            children = [child.prepend("> ") for child in children]
            return self.join(children, "\n")
        elif entity_type == EntityType.HEADER:
            prefix = "#" * kwargs["size"] + " "
        else:
            return self

        self._offset_entities(len(prefix))
        self.text = f"{prefix}{self.text}{suffix}"
        return self


class ToKakaoTalkParser(MatrixParser[KakaoTalkFormatString]):
    fs = KakaoTalkFormatString


async def _get_id_from_mxid(mxid: UserID, portal: po.Portal) -> Long | None:
    orig_sender = await u.User.get_by_mxid(mxid, create=False)
    if orig_sender and orig_sender.ktid:
        return orig_sender.ktid
    elif orig_sender:
        sender, _ = await portal.get_relay_sender(orig_sender, "relation")
        if sender and sender.ktid:
            return sender.ktid
    puppet = await pu.Puppet.get_by_mxid(mxid, create=False)
    return puppet.ktid if puppet else None


async def matrix_to_kakaotalk(
    content: MessageEventContent,
    room_id: RoomID,
    log: TraceLogger,
    portal: po.Portal,
    skip_reply: bool = False
) -> SendParams:
    # NOTE By design, this *throws* if user intent can't be matched (i.e. if a reply can't be created)
    if content.relates_to.rel_type == RelationType.REPLY and not skip_reply:
        message = await DBMessage.get_by_mxid(content.relates_to.event_id, room_id)
        if not message or not message.ktid:
            raise ValueError(
                f"Couldn't find reply target {content.relates_to.event_id}"
                " to bridge text message reply metadata to KakaoTalk"
            )
        try:
            src_event = await portal.main_intent.get_event(room_id, message.mxid)
        except:
            log.exception(f"Failed to find Matrix event for reply target {message.mxid}")
            raise
        src_kt_sender = await _get_id_from_mxid(src_event.sender, portal)
        if src_kt_sender is None:
            raise ValueError(
                f"Found no KakaoTalk user ID for reply target sender {src_event.sender}"
            )
        content.trim_reply_fallback()
        src_converted = await matrix_to_kakaotalk(src_event.content, room_id, log, portal, skip_reply=True)
        if src_event.content.relates_to.rel_type == RelationType.REPLY:
            src_type = KnownChatType.REPLY
            src_message = src_converted.text
        else:
            src_type = TO_MSGTYPE_MAP[src_event.content.msgtype]
            if src_type == KnownChatType.FILE:
                src_message = _media_type_reply_body_map[KnownChatType.FILE] + src_converted.text
            else:
                src_message = _media_type_reply_body_map.get(src_type, src_converted.text)
        reply_to = ReplyAttachment(
            # NOTE mentions will be merged into this later
            # TODO Set this for emoticon reply, but must first support them
            attach_only=False,
            # TODO If replying with media works, must set type AND all attachment properties
            #      But then, the reply object must be an intersection of a ReplyAttachment and something else
            #attach_type=TO_MSGTYPE_MAP.get(content.msgtype),
            # TODO Confirm why official client sets this to 0, and whether this should be left as None instead
            attach_type=0,
            src_logId=message.ktid,
            src_mentions=src_converted.mentions or [],
            src_message=src_message,
            src_type=src_type,
            src_userId=src_kt_sender,
        )
    else:
        reply_to = None
    if (
        content.get("format", None) == Format.HTML and content["formatted_body"] and 
        content.msgtype.is_text and
        not portal.is_direct
    ):
        parsed = await ToKakaoTalkParser().parse(utf16_surrogate.add(content["formatted_body"]))
        text = utf16_surrogate.remove(parsed.text)
        mentions_by_user: dict[Long, MentionStruct] = {}
        # Make sure to not create remote mentions for any remote user not in the room
        if parsed.entities:
            joined_members = set(await portal.main_intent.get_room_members(room_id))
            last_offset = 0
            at = 0
            for mention in sorted(parsed.entities, key=lambda entity: entity.offset):
                mxid = mention.extra_info["user_id"]
                if mxid not in joined_members:
                    continue
                ktid = await _get_id_from_mxid(mxid, portal)
                if ktid is None:
                    continue
                at += text[last_offset:mention.offset+1].count("@")
                last_offset = mention.offset+1
                mention_by_user = mentions_by_user.setdefault(ktid, MentionStruct(
                    at=[],
                    len=mention.length,
                    user_id=ktid,
                ))
                mention_by_user.at.append(at)
        mentions = list(mentions_by_user.values()) if mentions_by_user else None
    else:
        text = content.body
        mentions = None
    return SendParams(text=text, mentions=mentions, reply_to=reply_to)


_media_type_reply_body_map: dict[KnownChatType, str] = {
    KnownChatType.PHOTO: "Photo",
    KnownChatType.VIDEO: "Video",
    KnownChatType.AUDIO: "Voice Note",
    KnownChatType.FILE: "File: ",
}