"""
Advanced Mode 实验服务

处理专家模式分阶段训练的业务逻辑
"""

import uuid
from datetime import datetime
from typing import AsyncGenerator, Dict, List, Optional, Any

from ..core.adapters import (
    get_database_adapter,
    get_task_queue_adapter,
    get_progress_adapter,
)
from ..models.schemas.experiment import (
    ExperimentCreate,
    ExperimentUpdate,
    ExperimentResponse,
    ExperimentListResponse,
    StageStatus,
    StageExecuteResponse,
    StagesListResponse,
    STAGE_DEPENDENCIES,
)


# 阶段类型列表（按执行顺序）
STAGE_TYPES = [
    "audio_slice",
    "asr",
    "text_feature",
    "hubert_feature",
    "semantic_token",
    "sovits_train",
    "gpt_train",
]


class ExperimentService:
    """
    Advanced Mode 实验服务
    
    提供专家模式的分阶段训练管理：
    - 创建实验
    - 查询实验/阶段状态
    - 执行/取消单个阶段
    - 检查阶段依赖
    
    Example:
        >>> service = ExperimentService()
        >>> exp = await service.create_experiment(request)
        >>> await service.execute_stage(exp.id, "audio_slice", {})
        >>> stages = await service.get_all_stages(exp.id)
    """
    
    def __init__(self):
        """初始化服务"""
        self._db = None
        self._queue = None
        self._progress = None
    
    @property
    def db(self):
        """延迟获取数据库适配器"""
        if self._db is None:
            self._db = get_database_adapter()
        return self._db
    
    @property
    def queue(self):
        """延迟获取任务队列适配器"""
        if self._queue is None:
            self._queue = get_task_queue_adapter()
        return self._queue
    
    @property
    def progress_adapter(self):
        """延迟获取进度适配器"""
        if self._progress is None:
            self._progress = get_progress_adapter()
        return self._progress
    
    async def create_experiment(self, request: ExperimentCreate) -> ExperimentResponse:
        """
        创建实验
        
        创建实验但不立即执行，用户可以逐阶段控制训练流程。
        
        Args:
            request: 创建实验请求
            
        Returns:
            ExperimentResponse
        """
        exp_id = f"exp-{uuid.uuid4().hex[:8]}"
        
        experiment_data = {
            "id": exp_id,
            "exp_name": request.exp_name,
            "version": request.version,
            "gpu_numbers": request.gpu_numbers,
            "is_half": request.is_half,
            "audio_file_id": request.audio_file_id,
            "status": "created",
        }
        
        # 创建实验（会自动创建所有阶段）
        experiment = await self.db.create_experiment(experiment_data)
        
        return self._experiment_to_response(experiment)
    
    async def get_experiment(self, exp_id: str) -> Optional[ExperimentResponse]:
        """
        获取实验详情
        
        Args:
            exp_id: 实验ID
            
        Returns:
            ExperimentResponse 或 None
        """
        experiment = await self.db.get_experiment(exp_id)
        if not experiment:
            return None
        return self._experiment_to_response(experiment)
    
    async def list_experiments(
        self,
        status: Optional[str] = None,
        limit: int = 50,
        offset: int = 0
    ) -> ExperimentListResponse:
        """
        获取实验列表
        
        Args:
            status: 按状态筛选
            limit: 每页数量
            offset: 偏移量
            
        Returns:
            ExperimentListResponse
        """
        experiments = await self.db.list_experiments(
            status=status, limit=limit, offset=offset
        )
        
        # 获取每个实验的完整信息（包含 stages）
        full_experiments = []
        for exp in experiments:
            full_exp = await self.db.get_experiment(exp["id"])
            if full_exp:
                full_experiments.append(full_exp)
        
        return ExperimentListResponse(
            items=[self._experiment_to_response(e) for e in full_experiments],
            total=len(experiments),  # TODO: 添加 count 方法
            limit=limit,
            offset=offset,
        )
    
    async def update_experiment(
        self,
        exp_id: str,
        request: ExperimentUpdate
    ) -> Optional[ExperimentResponse]:
        """
        更新实验基础配置
        
        Args:
            exp_id: 实验ID
            request: 更新请求
            
        Returns:
            ExperimentResponse 或 None
        """
        updates = {}
        if request.exp_name is not None:
            updates["exp_name"] = request.exp_name
        if request.gpu_numbers is not None:
            updates["gpu_numbers"] = request.gpu_numbers
        if request.is_half is not None:
            updates["is_half"] = request.is_half
        
        if not updates:
            return await self.get_experiment(exp_id)
        
        experiment = await self.db.update_experiment(exp_id, updates)
        if not experiment:
            return None
        
        return self._experiment_to_response(experiment)
    
    async def delete_experiment(self, exp_id: str) -> bool:
        """
        删除实验
        
        Args:
            exp_id: 实验ID
            
        Returns:
            是否成功删除
        """
        # 先取消所有运行中的阶段
        stages = await self.db.get_all_stages(exp_id)
        for stage in stages:
            if stage.get("status") == "running" and stage.get("job_id"):
                await self.queue.cancel(stage["job_id"])
        
        return await self.db.delete_experiment(exp_id)
    
    async def check_stage_dependencies(
        self,
        exp_id: str,
        stage_type: str
    ) -> Dict[str, Any]:
        """
        检查阶段依赖是否满足
        
        Args:
            exp_id: 实验ID
            stage_type: 阶段类型
            
        Returns:
            {"satisfied": bool, "missing": List[str]}
        """
        experiment = await self.db.get_experiment(exp_id)
        if not experiment:
            return {"satisfied": False, "missing": [], "error": "实验不存在"}
        
        dependencies = STAGE_DEPENDENCIES.get(stage_type, [])
        stages = experiment.get("stages", {})
        
        missing = []
        for dep in dependencies:
            dep_stage = stages.get(dep, {})
            if dep_stage.get("status") != "completed":
                missing.append(dep)
        
        return {
            "satisfied": len(missing) == 0,
            "missing": missing,
        }
    
    async def execute_stage(
        self,
        exp_id: str,
        stage_type: str,
        params: Dict[str, Any]
    ) -> Optional[StageExecuteResponse]:
        """
        执行指定阶段
        
        Args:
            exp_id: 实验ID
            stage_type: 阶段类型
            params: 阶段参数
            
        Returns:
            StageExecuteResponse 或 None
        """
        # 获取实验
        experiment = await self.db.get_experiment(exp_id)
        if not experiment:
            return None
        
        stages = experiment.get("stages", {})
        current_stage = stages.get(stage_type, {})
        
        # 检查是否是重新执行
        is_rerun = current_stage.get("status") == "completed"
        previous_run = None
        if is_rerun:
            previous_run = {
                "completed_at": current_stage.get("completed_at"),
                "outputs": current_stage.get("outputs"),
            }
        
        # 构建阶段配置
        stage_config = {
            "exp_id": exp_id,
            "exp_name": experiment["exp_name"],
            "version": experiment.get("version", "v2"),
            "gpu_numbers": experiment.get("gpu_numbers", "0"),
            "is_half": experiment.get("is_half", True),
            "audio_file_id": experiment.get("audio_file_id"),
            "stage_type": stage_type,
            "params": params,
            # 只执行单个阶段
            "stages": [stage_type],
        }
        
        # 生成任务ID（用于进度追踪）
        task_id = f"{exp_id}-{stage_type}-{uuid.uuid4().hex[:4]}"
        
        # 入队执行
        job_id = await self.queue.enqueue(task_id, stage_config)
        
        # 更新阶段状态
        now = datetime.utcnow()
        await self.db.update_stage(exp_id, stage_type, {
            "status": "running",
            "config": params,
            "job_id": job_id,
            "started_at": now,
            "completed_at": None,
            "error_message": None,
            "outputs": None,
            "progress": 0.0,
        })
        
        # 更新实验状态为运行中
        await self.db.update_experiment(exp_id, {"status": "running"})
        
        return StageExecuteResponse(
            exp_id=exp_id,
            stage_type=stage_type,
            status="running",
            job_id=job_id,
            config=params,
            rerun=is_rerun,
            previous_run=previous_run,
            started_at=now,
        )
    
    async def get_stage(
        self,
        exp_id: str,
        stage_type: str
    ) -> Optional[StageStatus]:
        """
        获取阶段状态
        
        Args:
            exp_id: 实验ID
            stage_type: 阶段类型
            
        Returns:
            StageStatus 或 None
        """
        stage = await self.db.get_stage(exp_id, stage_type)
        if not stage:
            return None
        return self._stage_to_status(stage)
    
    async def get_all_stages(self, exp_id: str) -> Optional[StagesListResponse]:
        """
        获取所有阶段状态
        
        Args:
            exp_id: 实验ID
            
        Returns:
            StagesListResponse 或 None
        """
        stages = await self.db.get_all_stages(exp_id)
        if not stages:
            # 检查实验是否存在
            experiment = await self.db.get_experiment(exp_id)
            if not experiment:
                return None
            stages = []
        
        return StagesListResponse(
            exp_id=exp_id,
            stages=[self._stage_to_status(s) for s in stages],
        )
    
    async def cancel_stage(self, exp_id: str, stage_type: str) -> bool:
        """
        取消正在执行的阶段
        
        Args:
            exp_id: 实验ID
            stage_type: 阶段类型
            
        Returns:
            是否成功取消
        """
        stage = await self.db.get_stage(exp_id, stage_type)
        if not stage:
            return False
        
        # 只有运行中的阶段可以取消
        if stage.get("status") != "running":
            return False
        
        # 取消任务
        job_id = stage.get("job_id")
        if job_id:
            await self.queue.cancel(job_id)
        
        # 更新状态
        await self.db.update_stage(exp_id, stage_type, {
            "status": "cancelled",
            "completed_at": datetime.utcnow(),
            "message": "阶段已取消",
        })
        
        return True
    
    async def subscribe_stage_progress(
        self,
        exp_id: str,
        stage_type: str
    ) -> AsyncGenerator[Dict[str, Any], None]:
        """
        订阅阶段进度（SSE 流）
        
        Args:
            exp_id: 实验ID
            stage_type: 阶段类型
            
        Yields:
            进度信息字典
        """
        # 获取阶段信息
        stage = await self.db.get_stage(exp_id, stage_type)
        if not stage:
            yield {"type": "error", "message": "阶段不存在"}
            return
        
        # 如果阶段已结束，直接返回最终状态
        if stage.get("status") in ("completed", "failed", "cancelled"):
            yield {
                "type": "final",
                "status": stage.get("status"),
                "message": stage.get("message") or stage.get("error_message"),
                "progress": stage.get("progress", 0.0),
                "outputs": stage.get("outputs"),
            }
            return
        
        # 如果阶段未开始
        if stage.get("status") == "pending":
            yield {"type": "info", "message": "阶段尚未开始"}
            return
        
        # 使用任务ID订阅进度
        # 任务ID格式: {exp_id}-{stage_type}-{random}
        # 由于我们不知道确切的任务ID，使用 job_id
        job_id = stage.get("job_id")
        if not job_id:
            yield {"type": "error", "message": "无法获取任务ID"}
            return
        
        # 订阅进度
        # 注意：这里需要根据实际的进度适配器实现来调整
        # 当前使用 task_id 格式为 "{exp_id}-{stage_type}"
        task_id = f"{exp_id}-{stage_type}"
        
        async for progress in self.progress_adapter.subscribe(task_id):
            yield progress
            
            # 检查是否为终态
            if progress.get("status") in ("completed", "failed", "cancelled"):
                break
    
    def _experiment_to_response(self, experiment: Dict[str, Any]) -> ExperimentResponse:
        """将实验数据转换为响应模型"""
        stages_data = experiment.get("stages", {})
        stages = {}
        
        for stage_type, stage_info in stages_data.items():
            stages[stage_type] = self._stage_to_status(stage_info)
        
        # 解析日期时间
        created_at = experiment.get("created_at")
        if isinstance(created_at, str):
            created_at = datetime.fromisoformat(created_at)
        elif created_at is None:
            created_at = datetime.utcnow()
        
        updated_at = experiment.get("updated_at")
        if isinstance(updated_at, str):
            updated_at = datetime.fromisoformat(updated_at)
        
        return ExperimentResponse(
            id=experiment["id"],
            exp_name=experiment["exp_name"],
            version=experiment.get("version", "v2"),
            status=experiment.get("status", "created"),
            gpu_numbers=experiment.get("gpu_numbers", "0"),
            is_half=experiment.get("is_half", True),
            audio_file_id=experiment.get("audio_file_id", ""),
            stages=stages,
            created_at=created_at,
            updated_at=updated_at,
        )
    
    def _stage_to_status(self, stage: Dict[str, Any]) -> StageStatus:
        """将阶段数据转换为状态模型"""
        # 解析日期时间
        started_at = stage.get("started_at")
        if isinstance(started_at, str):
            started_at = datetime.fromisoformat(started_at)
        
        completed_at = stage.get("completed_at")
        if isinstance(completed_at, str):
            completed_at = datetime.fromisoformat(completed_at)
        
        return StageStatus(
            stage_type=stage.get("stage_type", ""),
            status=stage.get("status", "pending"),
            progress=stage.get("progress"),
            message=stage.get("message"),
            started_at=started_at,
            completed_at=completed_at,
            config=stage.get("config"),
            outputs=stage.get("outputs"),
            error_message=stage.get("error_message"),
        )