import time
import json
import pickle
import os
from typing import Any, Optional, Dict
from datetime import datetime, timedelta
from pathlib import Path
from config import Config

try:
    from upstash_redis import Redis
except ImportError:
    Redis = None

class CacheManager:
    def __init__(self):
        self.storage_type = None
        self.cache_dir = None
        self.redis = None
        
        # 尝试初始化存储（优先级：Redis > Disk > Memory）
        self._init_storage()
        
        # 初始化内存缓存
        self.epg: Dict[str, Dict[str, Any]] = {}
        self.cid: Optional[str] = None
        self.cid_time: float = 0
        self.auth: Optional[Dict[str, Any]] = None
        self.auth_time: float = 0
        self.channels: Optional[list] = None
        self.channels_time: float = 0
        self.stream_info: Dict[str, Dict[str, Any]] = {}
        
        # 加载已有缓存
        self._load_cache()
    
    def _init_storage(self):
        """初始化存储（Redis > Disk > Memory）"""
        
        # 1. 尝试 Redis
        redis_url = os.getenv('REDIS_URL', '')
        redis_token = os.getenv('REDIS_TOKEN', '')
        
        if Redis and redis_url and redis_token:
            try:
                self.redis = Redis(url=redis_url, token=redis_token)
                self.redis.ping()
                self.storage_type = 'redis'
                print("✅ 使用 Redis 持久化存储")
                return
            except Exception as e:
                print(f"⚠️ Redis 连接失败: {e}")
                self.redis = None
        
        # 2. 尝试本地磁盘
        cache_dir = Path(os.getenv('CACHE_DIR', '/tmp/cache'))
        
        try:
            cache_dir.mkdir(parents=True, exist_ok=True)
            (cache_dir / 'epg').mkdir(exist_ok=True)
            
            # 测试写入权限
            test_file = cache_dir / '.test'
            test_file.write_text('test')
            test_file.unlink()
            
            self.cache_dir = cache_dir
            self.storage_type = 'disk'
            print(f"✅ 使用本地磁盘缓存: {cache_dir}")
            print(f"   缓存将在容器运行期间保留")
            return
            
        except Exception as e:
            print(f"⚠️ 磁盘缓存不可用: {e}")
        
        # 3. 降级到内存
        self.storage_type = 'memory'
        print("⚠️ 使用内存缓存（容器重启后丢失）")
    
    def _load_cache(self):
        """启动时加载缓存"""
        if self.storage_type == 'redis':
            self._load_from_redis()
        elif self.storage_type == 'disk':
            self._load_from_disk()
    
    def _load_from_redis(self):
        """从 Redis 加载缓存"""
        try:
            # 加载 CID
            cid_data = self.redis.get('cache:cid')
            if cid_data:
                data = json.loads(cid_data)
                self.cid = data['value']
                self.cid_time = data['time']
            
            # 加载 Auth
            auth_data = self.redis.get('cache:auth')
            if auth_data:
                data = json.loads(auth_data)
                self.auth = data['value']
                self.auth_time = data['time']
            
            # 加载 Channels
            channels_data = self.redis.get('cache:channels')
            if channels_data:
                data = json.loads(channels_data)
                self.channels = data['value']
                self.channels_time = data['time']
            
            print("✅ Redis 缓存加载完成")
        except Exception as e:
            print(f"⚠️ Redis 缓存加载失败: {e}")
    
    def _load_from_disk(self):
        """从磁盘加载缓存"""
        try:
            # 加载 EPG 缓存
            epg_file = self.cache_dir / 'epg_cache.pkl'
            if epg_file.exists():
                with open(epg_file, 'rb') as f:
                    self.epg = pickle.load(f)
                print(f"✅ 从磁盘加载 {len(self.epg)} 条 EPG 缓存")
            
            # 加载元数据缓存
            meta_file = self.cache_dir / 'meta_cache.json'
            if meta_file.exists():
                with open(meta_file, 'r') as f:
                    meta = json.load(f)
                    if 'cid' in meta:
                        self.cid = meta['cid'].get('value')
                        self.cid_time = meta['cid'].get('time', 0)
                    if 'auth' in meta:
                        self.auth = meta['auth'].get('value')
                        self.auth_time = meta['auth'].get('time', 0)
                    if 'channels' in meta:
                        self.channels = meta['channels'].get('value')
                        self.channels_time = meta['channels'].get('time', 0)
                print("✅ 从磁盘加载元数据缓存")
                
        except Exception as e:
            print(f"⚠️ 磁盘缓存加载失败: {e}")
    
    def _save_to_disk(self, force=False):
        """保存缓存到磁盘"""
        if self.storage_type != 'disk' or not self.cache_dir:
            return
        
        try:
            # 保存 EPG（使用 pickle，快速）
            epg_file = self.cache_dir / 'epg_cache.pkl'
            with open(epg_file, 'wb') as f:
                pickle.dump(self.epg, f, protocol=pickle.HIGHEST_PROTOCOL)
            
            # 保存元数据（使用 JSON，可读）
            meta_file = self.cache_dir / 'meta_cache.json'
            meta = {
                'cid': {'value': self.cid, 'time': self.cid_time},
                'auth': {'value': self.auth, 'time': self.auth_time},
                'channels': {'value': self.channels, 'time': self.channels_time}
            }
            with open(meta_file, 'w') as f:
                json.dump(meta, f)
            
            if force:
                print(f"💾 磁盘缓存已保存 ({len(self.epg)} 条 EPG)")
        except Exception as e:
            print(f"⚠️ 磁盘缓存保存失败: {e}")
    
    # ==================== CID 缓存 ====================
    
    def get_cid(self) -> Optional[str]:
        if self.cid and (time.time() - self.cid_time < Config.CACHE_TTL['CID']):
            return self.cid
        
        if self.storage_type == 'redis':
            try:
                cid_data = self.redis.get('cache:cid')
                if cid_data:
                    data = json.loads(cid_data)
                    if time.time() - data['time'] < Config.CACHE_TTL['CID']:
                        self.cid = data['value']
                        self.cid_time = data['time']
                        return self.cid
            except:
                pass
        
        return None
    
    def set_cid(self, cid: str):
        self.cid = cid
        self.cid_time = time.time()
        
        if self.storage_type == 'redis':
            try:
                data = {'value': cid, 'time': self.cid_time}
                self.redis.set('cache:cid', json.dumps(data), ex=Config.CACHE_TTL['CID'])
            except:
                pass
        elif self.storage_type == 'disk':
            self._save_to_disk()
    
    # ==================== Auth 缓存 ====================
    
    def get_auth(self) -> Optional[Dict[str, Any]]:
        if self.auth and (time.time() - self.auth_time < Config.CACHE_TTL['AUTH']):
            return self.auth
        
        if self.storage_type == 'redis':
            try:
                auth_data = self.redis.get('cache:auth')
                if auth_data:
                    data = json.loads(auth_data)
                    if time.time() - data['time'] < Config.CACHE_TTL['AUTH']:
                        self.auth = data['value']
                        self.auth_time = data['time']
                        return self.auth
            except:
                pass
        
        return None
    
    def set_auth(self, auth: Dict[str, Any]):
        self.auth = auth
        self.auth_time = time.time()
        
        if self.storage_type == 'redis':
            try:
                data = {'value': auth, 'time': self.auth_time}
                self.redis.set('cache:auth', json.dumps(data), ex=Config.CACHE_TTL['AUTH'])
            except:
                pass
        elif self.storage_type == 'disk':
            self._save_to_disk()
    
    # ==================== Channels 缓存 ====================
    
    def get_channels(self) -> Optional[list]:
        if self.channels and (time.time() - self.channels_time < Config.CACHE_TTL['CHANNELS']):
            return self.channels
        
        if self.storage_type == 'redis':
            try:
                channels_data = self.redis.get('cache:channels')
                if channels_data:
                    data = json.loads(channels_data)
                    if time.time() - data['time'] < Config.CACHE_TTL['CHANNELS']:
                        self.channels = data['value']
                        self.channels_time = data['time']
                        return self.channels
            except:
                pass
        
        return None
    
    def set_channels(self, channels: list):
        self.channels = channels
        self.channels_time = time.time()
        
        if self.storage_type == 'redis':
            try:
                data = {'value': channels, 'time': self.channels_time}
                self.redis.set('cache:channels', json.dumps(data), ex=Config.CACHE_TTL['CHANNELS'])
            except:
                pass
        elif self.storage_type == 'disk':
            self._save_to_disk()
    
    # ==================== Stream 缓存 ====================
    
    def get_stream(self, key: str) -> Optional[str]:
        if key in self.stream_info:
            cached = self.stream_info[key]
            if time.time() - cached['time'] < Config.CACHE_TTL['STREAM']:
                return cached['url']
        return None
    
    def set_stream(self, key: str, url: str):
        self.stream_info[key] = {'url': url, 'time': time.time()}
        
        if len(self.stream_info) > Config.MAX_STREAM_CACHE:
            oldest_key = min(self.stream_info.keys(), 
                           key=lambda k: self.stream_info[k]['time'])
            del self.stream_info[oldest_key]
    
    # ==================== EPG 缓存 ====================
    
    def get_epg(self, vid: str, date: str) -> Optional[any]:
        key = f"{vid}_{date}"
        
        # 检查内存缓存
        if key in self.epg:
            cached = self.epg[key]
            
            if vid == '_all_' and date == 'full':
                if time.time() - cached['time'] < Config.CACHE_TTL['EPG_FULL']:
                    return cached['data']
            else:
                today = self._get_jst_date()
                ttl = Config.CACHE_TTL['EPG_TODAY'] if date == today else Config.CACHE_TTL['EPG_OTHER']
                
                if time.time() - cached['time'] < ttl:
                    return cached['data']
        
        # 如果使用磁盘缓存，尝试从单独文件加载
        if self.storage_type == 'disk' and vid != '_all_':
            try:
                epg_file = self.cache_dir / 'epg' / f"{key}.pkl"
                if epg_file.exists():
                    with open(epg_file, 'rb') as f:
                        cached = pickle.load(f)
                    
                    today = self._get_jst_date()
                    ttl = Config.CACHE_TTL['EPG_TODAY'] if date == today else Config.CACHE_TTL['EPG_OTHER']
                    
                    if time.time() - cached['time'] < ttl:
                        # 加载到内存
                        self.epg[key] = cached
                        return cached['data']
            except:
                pass
        
        return None
    
    def set_epg(self, vid: str, date: str, data: any):
        key = f"{vid}_{date}"
        self.epg[key] = {
            'data': data,
            'time': time.time(),
            'date': date,
            'vid': vid
        }
        
        # Redis 存储
        if self.storage_type == 'redis':
            # Redis 代码保持不变...
            pass
        
        # 磁盘存储
        elif self.storage_type == 'disk':
            # 单独保存每个 EPG 文件（避免频繁写入大文件）
            try:
                epg_file = self.cache_dir / 'epg' / f"{key}.pkl"
                with open(epg_file, 'wb') as f:
                    pickle.dump(self.epg[key], f, protocol=pickle.HIGHEST_PROTOCOL)
            except:
                pass
            
            # 每 20 条更新一次主缓存文件
            if len(self.epg) % 20 == 0:
                self._save_to_disk()
        
        # 清理过期缓存
        if len(self.epg) > Config.MAX_EPG_CACHE:
            self._clean_old_epg()
    
    def _clean_old_epg(self):
        """清理过期 EPG"""
        cutoff_date = (datetime.now() - timedelta(days=Config.CACHE_TTL['EPG_MAX_DAYS'])).strftime('%Y-%m-%d')
        to_delete = [k for k, v in self.epg.items() 
                    if v.get('date', '') < cutoff_date and not k.startswith('_all_')]
        
        for k in to_delete:
            del self.epg[k]
            
            # 删除磁盘文件
            if self.storage_type == 'disk':
                try:
                    epg_file = self.cache_dir / 'epg' / f"{k}.pkl"
                    if epg_file.exists():
                        epg_file.unlink()
                except:
                    pass
    
    def _get_jst_date(self) -> str:
        from datetime import timezone
        jst = timezone(timedelta(hours=9))
        now = datetime.now(jst)
        return now.strftime('%Y-%m-%d')
    
    # ==================== 缓存管理 ====================
    
    def clear_cache(self, cache_type: str = 'all'):
        if cache_type in ['cid', 'all']:
            self.cid = None
            self.cid_time = 0
            if self.storage_type == 'redis':
                try:
                    self.redis.delete('cache:cid')
                except:
                    pass
        
        if cache_type in ['auth', 'all']:
            self.auth = None
            self.auth_time = 0
            if self.storage_type == 'redis':
                try:
                    self.redis.delete('cache:auth')
                except:
                    pass
        
        if cache_type in ['channels', 'all']:
            self.channels = None
            self.channels_time = 0
            if self.storage_type == 'redis':
                try:
                    self.redis.delete('cache:channels')
                except:
                    pass
        
        if cache_type in ['streams', 'all']:
            self.stream_info.clear()
        
        if cache_type in ['epg', 'all']:
            self.epg.clear()
            
            # 清理磁盘文件
            if self.storage_type == 'disk' and self.cache_dir:
                try:
                    for epg_file in (self.cache_dir / 'epg').glob('*.pkl'):
                        epg_file.unlink()
                    (self.cache_dir / 'epg_cache.pkl').unlink(missing_ok=True)
                except:
                    pass
        
        # 保存更改
        if self.storage_type == 'disk':
            self._save_to_disk()
    
    def get_stats(self) -> dict:
        return {
            'storage_type': self.storage_type,
            'cid': {
                'cached': self.cid is not None,
                'value': self.cid if self.cid else None,
                'age': f"{int(time.time() - self.cid_time)}s" if self.cid else None,
                'ttl': f"{Config.CACHE_TTL['CID'] - int(time.time() - self.cid_time)}s" if self.cid else None,
                'storage': self.storage_type
            },
            'auth': {
                'cached': self.auth is not None,
                'token': self.auth['access_token'] if self.auth and 'access_token' in self.auth else None,
                'age': f"{int(time.time() - self.auth_time)}s" if self.auth else None,
                'ttl': f"{Config.CACHE_TTL['AUTH'] - int(time.time() - self.auth_time)}s" if self.auth else None,
                'storage': self.storage_type
            },
            'channels': self.channels is not None,
            'streams': len(self.stream_info),
            'epg': len(self.epg),
            'epg_detail': self.get_epg_cache_info() if self.epg else None
        }
    
    def get_epg_cache_info(self) -> dict:
        """获取 EPG 缓存详细信息"""
        info = {
            'total_entries': len(self.epg),
            'by_channel': {},
            'by_date': {},
            'full_cache_available': False
        }
        
        # 检查全量缓存
        if '_all__full' in self.epg:
            info['full_cache_available'] = True
            full_cache = self.epg['_all__full']
            info['full_cache_time'] = datetime.fromtimestamp(full_cache['time']).strftime('%Y-%m-%d %H:%M:%S')
            info['full_cache_age'] = f"{int(time.time() - full_cache['time'])}s"
        
        # 统计各频道和日期
        for key, value in self.epg.items():
            if key == '_all__full':
                continue
            
            vid = value.get('vid', 'unknown')
            date = value.get('date', 'unknown')
            
            if vid not in info['by_channel']:
                info['by_channel'][vid] = {'dates': [], 'program_count': 0}
            info['by_channel'][vid]['dates'].append(date)
            info['by_channel'][vid]['program_count'] += len(value.get('data', []))
            
            if date not in info['by_date']:
                info['by_date'][date] = {'channels': [], 'program_count': 0}
            info['by_date'][date]['channels'].append(vid)
            info['by_date'][date]['program_count'] += len(value.get('data', []))
        
        info['summary'] = {
            'total_channels': len(info['by_channel']),
            'total_dates': len(info['by_date']),
            'total_programs': sum(ch['program_count'] for ch in info['by_channel'].values())
        }
        
        return info
    
    def __del__(self):
        """程序退出时保存缓存"""
        if self.storage_type == 'disk':
            self._save_to_disk(force=True)
            print("💾 缓存已保存到磁盘")


# 全局单例
cache = CacheManager()