from __future__ import annotations

import typing

from .. import operator, entities, cmdmgr, errors


@operator.operator_class(
    name="resend",
    help="重发当前会话的最后一条消息",
    usage='!resend'
)
class ResendOperator(operator.CommandOperator):

    async def execute(
        self,
        context: entities.ExecuteContext
    ) -> typing.AsyncGenerator[entities.CommandReturn, None]:
        # 回滚到最后一条用户message前
        if context.session.using_conversation is None:
            yield entities.CommandReturn(error=errors.CommandError("当前没有对话"))
        else:
            conv_msg = context.session.using_conversation.messages
            
            # 倒序一直删到最后一条用户message
            while len(conv_msg) > 0 and conv_msg[-1].role != 'user':
                conv_msg.pop()

            if len(conv_msg) > 0:
                # 删除最后一条用户message
                conv_msg.pop()

            # 不重发了，提示用户已删除就行了
            yield entities.CommandReturn(text="已删除最后一次请求记录")