from typing import Dict, Any, Optional, List, cast
from enum import Enum
from config import CONVERSATION_ENABLE_MULTI_TURN
from agent.agents.conversation import ConversationAgent
from agent.agents.tool import ToolAgent
from services.common.app_errors import AppError, ErrorCode
from services.common.datetime_utils import DateTimeGenerator


class WorkflowType(Enum):
    """可用的工作流类型"""
    CONVERSATION = "conversation"
    TOOL_USING = "tool_using"
    

class WorkflowManager:
    """管理不同工作流类型及其执行"""
    
    def __init__(self, default_model_section: Optional[str] = None, enable_multi_turn: Optional[bool] = None):
        self.workflows = {
            WorkflowType.CONVERSATION: ConversationAgent(model_section=default_model_section),
            WorkflowType.TOOL_USING: ToolAgent(model_section=default_model_section)
        }
        self.active_sessions: Dict[str, Any] = {}
        self.enable_multi_turn = CONVERSATION_ENABLE_MULTI_TURN if enable_multi_turn is None else bool(enable_multi_turn)
    
    def get_workflow(self, workflow_type: WorkflowType):
        """获取工作流实例"""
        return self.workflows.get(workflow_type)

    @staticmethod
    def _validate_user_input(user_input: Any) -> str:
        if not isinstance(user_input, str) or not user_input.strip():
            raise AppError(
                code=ErrorCode.INVALID_REQUEST,
                message="user_input 不能为空",
                status_code=400,
                detail={"field": "user_input", "reason": "missing_or_blank"},
            )
        return user_input

    def execute_workflow(self, workflow_type: WorkflowType, user_input: str, 
                        session_id: Optional[str] = None, **kwargs) -> Dict[str, Any]:
        """执行指定工作流"""
        user_input = self._validate_user_input(user_input)
        workflow = self.get_workflow(workflow_type)
        
        if not workflow:
            return {"error": f"Workflow {workflow_type.value} not found"}
        
        # 未提供会话 ID 时生成
        if not session_id:
            session_id = f"session_{len(self.active_sessions) + 1}"

        existing_session: Optional[Dict[str, Any]] = self.active_sessions.get(session_id)
        if existing_session and existing_session.get("workflow_type") != workflow_type:
            raise ValueError(
                f"Session '{session_id}' is already bound to workflow '{existing_session['workflow_type'].value}'"
            )

        run_kwargs: Dict[str, Any] = dict(kwargs)
        if "conversation_id" not in run_kwargs:
            run_kwargs["conversation_id"] = session_id
        if workflow_type == WorkflowType.CONVERSATION and self.enable_multi_turn:
            if "conversation_history" not in run_kwargs:
                history_value = cast(Any, list((existing_session or {}).get("conversation_history") or []))
                run_kwargs["conversation_history"] = history_value
            if "last_context" not in run_kwargs:
                context_value = cast(Any, dict((existing_session or {}).get("last_context") or {}))
                run_kwargs["last_context"] = context_value
        
        # 执行工作流
        result = workflow.run(user_input, **run_kwargs)

        session_record: Dict[str, Any] = {
            "workflow_type": workflow_type,
            "last_result": result,
            "timestamp": self._get_timestamp()
        }

        if workflow_type == WorkflowType.CONVERSATION and self.enable_multi_turn:
            context = (result or {}).get("context") or {}
            session_record["conversation_history"] = list(
                (result or {}).get("conversation_history") or context.get("conversation_history") or []
            )
            session_record["last_context"] = dict(context.get("last_context") or {})

        # 存储会话数据
        self.active_sessions[session_id] = session_record
        
        return {
            "session_id": session_id,
            "workflow_type": workflow_type.value,
            "result": result
        }
    
    def get_available_workflows(self) -> List[str]:
        """获取可用工作流列表"""
        return [workflow.value for workflow in WorkflowType]
    
    def _get_timestamp(self) -> str:
        """获取当前时间戳"""
        return DateTimeGenerator.now().iso_str
    
    def get_session_info(self, session_id: str) -> Optional[Dict[str, Any]]:
        """获取会话信息"""
        return self.active_sessions.get(session_id)
    
    def cleanup_sessions(self, older_than_hours: int = 24):
        """清理过期会话"""
        from datetime import timedelta
        
        cutoff_time = DateTimeGenerator.now().dt - timedelta(hours=older_than_hours)
        
        sessions_to_remove = []
        for session_id, session_data in self.active_sessions.items():
            session_time = DateTimeGenerator.parse(session_data["timestamp"], default_to_now=False)
            if session_time < cutoff_time:
                sessions_to_remove.append(session_id)
        
        for session_id in sessions_to_remove:
            del self.active_sessions[session_id]
        
        return len(sessions_to_remove)