"""
任务管理器

提供统一的任务状态查询和管理功能
"""
import logging
from typing import Optional, List, Dict, Any
from datetime import datetime
from sqlalchemy.orm import Session
from sqlalchemy import desc, or_
from fastapi import HTTPException
from decimal import Decimal

from app.models.audio import (
    ASRRecognitionV2,
    AudioSynthesisV2,
    VoiceCloneV2,
    LongTextAudio
)
from app.schemas.audio_v2 import (
    TaskStatusResponse,
    TaskStatistics,
    UserAudioStatisticsResponse
)

logger = logging.getLogger(__name__)


class TaskManager:
    """任务管理器"""
    
    def __init__(self, db: Session, user_id: str):
        """
        初始化任务管理器
        
        Args:
            db: 数据库会话
            user_id: 用户ID
        """
        self.db = db
        self.user_id = user_id
    
    def get_task_status(self, task_id: str) -> TaskStatusResponse:
        """
        查询任务状态（跨所有任务类型）
        
        Args:
            task_id: 任务ID
            
        Returns:
            任务状态响应
            
        Raises:
            HTTPException: 任务不存在
        """
        # 依次查询各个表
        task = None
        task_type = None
        
        # 查询语音识别任务
        task = self.db.query(ASRRecognitionV2).filter(
            ASRRecognitionV2.task_id == task_id,
            ASRRecognitionV2.user_id == self.user_id
        ).first()
        if task:
            task_type = "asr_recognition"
        
        # 查询语音合成任务
        if not task:
            task = self.db.query(AudioSynthesisV2).filter(
                AudioSynthesisV2.task_id == task_id,
                AudioSynthesisV2.user_id == self.user_id
            ).first()
            if task:
                task_type = "audio_synthesis"
        
        # 查询声音克隆任务
        if not task:
            task = self.db.query(VoiceCloneV2).filter(
                VoiceCloneV2.task_id == task_id,
                VoiceCloneV2.user_id == self.user_id
            ).first()
            if task:
                task_type = "voice_clone"
        
        # 查询长文本转音频任务
        if not task:
            task = self.db.query(LongTextAudio).filter(
                LongTextAudio.task_id == task_id,
                LongTextAudio.user_id == self.user_id
            ).first()
            if task:
                task_type = "long_text_audio"
        
        if not task:
            raise HTTPException(status_code=404, detail="任务不存在")
        
        # 构建响应
        progress = None
        if task_type == "long_text_audio":
            progress = task.progress
        
        return TaskStatusResponse(
            task_id=task.task_id,
            status=task.status,
            progress=progress,
            error_message=task.error_message,
            created_at=task.created_at,
            updated_at=task.updated_at,
            completed_at=task.completed_at
        )
    
    def cancel_task(self, task_id: str) -> bool:
        """
        取消任务（仅PENDING状态可取消）
        
        Args:
            task_id: 任务ID
            
        Returns:
            是否成功取消
            
        Raises:
            HTTPException: 任务不存在或无法取消
        """
        # 查找任务
        task = None
        task_type = None
        
        for model, type_name in [
            (ASRRecognitionV2, "asr_recognition"),
            (AudioSynthesisV2, "audio_synthesis"),
            (VoiceCloneV2, "voice_clone"),
            (LongTextAudio, "long_text_audio")
        ]:
            task = self.db.query(model).filter(
                model.task_id == task_id,
                model.user_id == self.user_id
            ).first()
            if task:
                task_type = type_name
                break
        
        if not task:
            raise HTTPException(status_code=404, detail="任务不存在")
        
        # 检查状态
        if task.status != "PENDING":
            raise HTTPException(
                status_code=400,
                detail=f"任务状态为{task.status}，无法取消"
            )
        
        # 更新状态为FAILED
        task.status = "FAILED"
        task.error_message = "用户取消"
        task.updated_at = datetime.now()
        task.completed_at = datetime.now()
        
        self.db.commit()
        
        return True
    
    def delete_task(self, task_id: str) -> bool:
        """
        删除任务记录
        
        Args:
            task_id: 任务ID
            
        Returns:
            是否成功删除
            
        Raises:
            HTTPException: 任务不存在
        """
        # 查找并删除任务
        deleted = False
        
        for model in [ASRRecognitionV2, AudioSynthesisV2, VoiceCloneV2, LongTextAudio]:
            task = self.db.query(model).filter(
                model.task_id == task_id,
                model.user_id == self.user_id
            ).first()
            
            if task:
                self.db.delete(task)
                self.db.commit()
                deleted = True
                break
        
        if not deleted:
            raise HTTPException(status_code=404, detail="任务不存在")
        
        return True
    
    def batch_delete_tasks(self, task_ids: List[str]) -> Dict[str, Any]:
        """
        批量删除任务
        
        Args:
            task_ids: 任务ID列表
            
        Returns:
            删除结果统计
        """
        success_count = 0
        failed_tasks = []
        
        for task_id in task_ids:
            try:
                self.delete_task(task_id)
                success_count += 1
            except Exception as e:
                failed_tasks.append({
                    "task_id": task_id,
                    "error": str(e)
                })
        
        return {
            "success_count": success_count,
            "failed_count": len(failed_tasks),
            "failed_tasks": failed_tasks
        }
    
    def get_user_statistics(self) -> UserAudioStatisticsResponse:
        """
        获取用户语音统计信息
        
        Returns:
            用户语音统计响应
        """
        # 语音识别统计
        asr_stats = self._get_task_statistics(ASRRecognitionV2)
        
        # 语音合成统计
        tts_stats = self._get_task_statistics(AudioSynthesisV2)
        
        # 声音克隆统计
        voice_clone_stats = self._get_task_statistics(VoiceCloneV2)
        
        # 长文本转音频统计
        long_text_stats = self._get_task_statistics(LongTextAudio)
        
        return UserAudioStatisticsResponse(
            asr_stats=asr_stats,
            tts_stats=tts_stats,
            voice_clone_stats=voice_clone_stats,
            long_text_stats=long_text_stats
        )
    
    def _get_task_statistics(self, model) -> TaskStatistics:
        """
        获取指定模型的任务统计
        
        Args:
            model: ORM模型类
            
        Returns:
            任务统计信息
        """
        query = self.db.query(model).filter(model.user_id == self.user_id)
        
        total = query.count()
        pending = query.filter(model.status == "PENDING").count()
        processing = query.filter(model.status == "PROCESSING").count()
        succeeded = query.filter(model.status == "SUCCEEDED").count()
        failed = query.filter(model.status == "FAILED").count()
        
        # 计算总费用
        total_bill = self.db.query(
            func.sum(model.bill)
        ).filter(
            model.user_id == self.user_id
        ).scalar() or Decimal('0')
        
        # 计算总时长（如果有duration字段）
        total_duration = None
        if hasattr(model, 'duration'):
            total_duration = self.db.query(
                func.sum(model.duration)
            ).filter(
                model.user_id == self.user_id,
                model.status == "SUCCEEDED"
            ).scalar()
        
        return TaskStatistics(
            total=total,
            pending=pending,
            processing=processing,
            succeeded=succeeded,
            failed=failed,
            total_bill=total_bill,
            total_duration=total_duration
        )