import asyncio
import re

from library.telegram.base import RequestContext
from nexus.translations import t
from telethon import (
    events,
    functions,
)
from telethon.errors import MessageIdInvalidError

from .base import BaseHandler


class ViewHandler(BaseHandler):
    filter = events.NewMessage(incoming=True, pattern='^/v([abcm])([sr])?_([A-Za-z0-9]+)_([0-9]+)_([0-9]+)_'
                                                      '([0-9]+)')
    should_reset_last_widget = False

    async def handler(self, event: events.ChatAction, request_context: RequestContext):
        short_schema = event.pattern_match.group(1)
        parent_view_type = event.pattern_match.group(2) or 's'
        schema = self.short_schema_to_schema(short_schema)
        session_id = event.pattern_match.group(3)
        old_message_id = int(event.pattern_match.group(4))
        document_id = int(event.pattern_match.group(5))
        position = int(event.pattern_match.group(6))

        page = int(position / self.application.config['application']['page_size'])

        request_context.add_default_fields(mode='view', session_id=session_id)
        request_context.statbox(action='view', query=str(document_id), position=position)
        found_old_widget = old_message_id == self.application.user_manager.last_widget.get(request_context.chat.id)

        try:
            if found_old_widget:
                message_id = old_message_id
                link_preview = None
            else:
                old_message = (await self.application.telegram_client(
                    functions.messages.GetMessagesRequest(id=[old_message_id])
                )).messages[0]
                prefetch_message = await self.application.telegram_client.send_message(
                    request_context.chat.id,
                    t("SEARCHING", language=request_context.chat.language),
                    reply_to=old_message.reply_to_msg_id,
                )
                self.application.user_manager.last_widget[request_context.chat.id] = prefetch_message.id
                message_id = prefetch_message.id
                link_preview = True

            document_view = await self.resolve_document(
                schema,
                document_id,
                position,
                session_id,
                request_context,
            )

            back_command = None
            if parent_view_type == 's':
                back_command = f'/search_{session_id}_{message_id}_{page}'
            elif parent_view_type == 'r':
                messages = (await self.application.telegram_client(
                    functions.messages.GetMessagesRequest(id=[old_message_id])
                )).messages
                if not messages:
                    return await event.respond(
                        t('REPLY_MESSAGE_HAS_BEEN_DELETED', language=request_context.chat.language),
                    )
                message = messages[0]
                referencing_to = re.search(r'Linked to: ([0-9]+)', message.raw_text).group(1)
                back_command = f'/rp_{session_id}_{message_id}_{referencing_to}_{page}'

            view, buttons = document_view.get_view(
                language=request_context.chat.language,
                session_id=session_id,
                bot_external_name=self.application.config['telegram']['bot_external_name'],
                position=position,
                back_command=back_command,
            )
            actions = [
                self.application.telegram_client.edit_message(
                    request_context.chat.id,
                    message_id,
                    view,
                    buttons=buttons,
                    link_preview=link_preview,
                ),
                event.delete(),
            ]
            if not found_old_widget:
                actions.append(
                    self.application.telegram_client.delete_messages(
                        request_context.chat.id,
                        [old_message_id],
                    )
                )
            return await asyncio.gather(*actions)
        except MessageIdInvalidError:
            await event.reply(t("VIEWS_CANNOT_BE_SHARED", language=request_context.chat.language))