"""
Queue Manager
Redis 기반 큐 관리 시스템
"""
import redis.asyncio as redis
import json
import logging
from typing import Optional, Dict, Any, List
from datetime import datetime

from .models import PipelineJob, QueueMessage

logger = logging.getLogger(__name__)

class QueueManager:
    """Redis 기반 큐 매니저"""
    
    QUEUES = {
        "keyword_processing": "queue:keyword",
        "rss_collection": "queue:rss",
        "search_enrichment": "queue:search", 
        "ai_summarization": "queue:summarize",
        "translation": "queue:translate",
        "image_generation": "queue:image",
        "article_assembly": "queue:assembly",
        "failed": "queue:failed",
        "scheduled": "queue:scheduled"
    }
    
    def __init__(self, redis_url: str = "redis://redis:6379"):
        self.redis_url = redis_url
        self.redis_client: Optional[redis.Redis] = None
        
    async def connect(self):
        """Redis 연결"""
        if not self.redis_client:
            self.redis_client = await redis.from_url(
                self.redis_url,
                encoding="utf-8",
                decode_responses=True
            )
            logger.info("Connected to Redis")
    
    async def disconnect(self):
        """Redis 연결 해제"""
        if self.redis_client:
            await self.redis_client.close()
            self.redis_client = None
            
    async def enqueue(self, queue_name: str, job: PipelineJob, priority: int = 0) -> str:
        """작업을 큐에 추가"""
        try:
            queue_key = self.QUEUES.get(queue_name, f"queue:{queue_name}")
            
            message = QueueMessage(
                queue_name=queue_name,
                job=job
            )
            
            # 우선순위에 따라 추가
            if priority > 0:
                await self.redis_client.lpush(queue_key, message.json())
            else:
                await self.redis_client.rpush(queue_key, message.json())
            
            # 통계 업데이트
            await self.redis_client.hincrby("stats:queues", queue_name, 1)
            
            logger.info(f"Job {job.job_id} enqueued to {queue_name}")
            return job.job_id
            
        except Exception as e:
            logger.error(f"Failed to enqueue job: {e}")
            raise
    
    async def dequeue(self, queue_name: str, timeout: int = 0) -> Optional[PipelineJob]:
        """큐에서 작업 가져오기"""
        try:
            queue_key = self.QUEUES.get(queue_name, f"queue:{queue_name}")
            
            if timeout > 0:
                result = await self.redis_client.blpop(queue_key, timeout=timeout)
                if result:
                    _, data = result
                else:
                    return None
            else:
                data = await self.redis_client.lpop(queue_key)
                
            if data:
                message = QueueMessage.parse_raw(data)
                
                # 처리 중 목록에 추가
                processing_key = f"processing:{queue_name}"
                await self.redis_client.hset(
                    processing_key,
                    message.job.job_id,
                    message.json()
                )
                
                return message.job
            
            return None
            
        except Exception as e:
            logger.error(f"Failed to dequeue job: {e}")
            return None
    
    async def mark_completed(self, queue_name: str, job_id: str):
        """작업 완료 표시"""
        try:
            processing_key = f"processing:{queue_name}"
            await self.redis_client.hdel(processing_key, job_id)
            
            # 통계 업데이트
            await self.redis_client.hincrby("stats:completed", queue_name, 1)
            
            logger.info(f"Job {job_id} completed in {queue_name}")
            
        except Exception as e:
            logger.error(f"Failed to mark job as completed: {e}")
    
    async def mark_failed(self, queue_name: str, job: PipelineJob, error: str):
        """작업 실패 처리"""
        try:
            processing_key = f"processing:{queue_name}"
            await self.redis_client.hdel(processing_key, job.job_id)
            
            # 재시도 확인
            if job.retry_count < job.max_retries:
                job.retry_count += 1
                await self.enqueue(queue_name, job)
                logger.info(f"Job {job.job_id} requeued (retry {job.retry_count}/{job.max_retries})")
            else:
                # 실패 큐로 이동
                job.data["error"] = error
                job.data["failed_stage"] = queue_name
                await self.enqueue("failed", job)
                
                # 통계 업데이트
                await self.redis_client.hincrby("stats:failed", queue_name, 1)
                logger.error(f"Job {job.job_id} failed: {error}")
                
        except Exception as e:
            logger.error(f"Failed to mark job as failed: {e}")
    
    async def get_queue_stats(self) -> Dict[str, Any]:
        """큐 통계 조회"""
        try:
            stats = {}
            
            for name, key in self.QUEUES.items():
                stats[name] = {
                    "pending": await self.redis_client.llen(key),
                    "processing": await self.redis_client.hlen(f"processing:{name}"),
                }
            
            # 완료/실패 통계
            stats["completed"] = await self.redis_client.hgetall("stats:completed") or {}
            stats["failed"] = await self.redis_client.hgetall("stats:failed") or {}
            
            return stats
            
        except Exception as e:
            logger.error(f"Failed to get queue stats: {e}")
            return {}
    
    async def clear_queue(self, queue_name: str):
        """큐 초기화 (테스트용)"""
        queue_key = self.QUEUES.get(queue_name, f"queue:{queue_name}")
        await self.redis_client.delete(queue_key)
        await self.redis_client.delete(f"processing:{queue_name}")
        logger.info(f"Queue {queue_name} cleared")