from __future__ import annotations

import typing
import datetime

from .. import operator, entities, cmdmgr, errors


@operator.operator_class(
    name="list",
    help="列出此会话中的所有历史对话",
    usage='!list\n!list <页码>'
)
class ListOperator(operator.CommandOperator):

    async def execute(
        self,
        context: entities.ExecuteContext
    ) -> typing.AsyncGenerator[entities.CommandReturn, None]:
        
        page = 0

        if len(context.crt_params) > 0:
            try:
                page = int(context.crt_params[0]-1)
            except:
                yield entities.CommandReturn(error=errors.CommandOperationError('页码应为整数'))
                return

        record_per_page = 10

        content = ''

        index = 0

        using_conv_index = 0

        for conv in context.session.conversations[::-1]:
            time_str =  conv.create_time.strftime("%Y-%m-%d %H:%M:%S")

            if conv == context.session.using_conversation:
                using_conv_index = index

            if index >= page * record_per_page and index < (page + 1) * record_per_page:
                content += f"{index} {time_str}: {conv.messages[0].content if len(conv.messages) > 0 else '无内容'}\n"
            index += 1

        if content == '':
            content = '无'
        else:
            if context.session.using_conversation is None:
                content += "\n当前处于新会话"
            else:
                content += f"\n当前会话: {using_conv_index} {context.session.using_conversation.create_time.strftime('%Y-%m-%d %H:%M:%S')}: {context.session.using_conversation.messages[0].content if len(context.session.using_conversation.messages) > 0 else '无内容'}"
        
        yield entities.CommandReturn(text=f"第 {page + 1} 页 (时间倒序):\n{content}")