import logging
import os
from datetime import datetime, timedelta
from logging.handlers import RotatingFileHandler
from extensions import redis_client, db
import json
from flask import request, has_request_context, g

# 创建日志目录
LOG_DIR = os.path.join(os.path.dirname(os.path.dirname(__file__)), 'logs')
os.makedirs(LOG_DIR, exist_ok=True)

class SystemLogger:
    def __init__(self):
        self.logger = logging.getLogger('vision_ai')
        self.logger.setLevel(logging.INFO)
        
        # 文件处理器 (自动轮转，最大10MB，保留5个备份)
        file_handler = RotatingFileHandler(
            os.path.join(LOG_DIR, 'system.log'),
            maxBytes=10*1024*1024,
            backupCount=5,
            encoding='utf-8'
        )
        file_handler.setLevel(logging.INFO)
        
        # 控制台处理器
        console_handler = logging.StreamHandler()
        console_handler.setLevel(logging.INFO)
        
        # 格式化
        formatter = logging.Formatter(
            '[%(asctime)s] %(levelname)s - %(message)s',
            datefmt='%Y-%m-%d %H:%M:%S'
        )
        file_handler.setFormatter(formatter)
        console_handler.setFormatter(formatter)
        
        self.logger.addHandler(file_handler)
        self.logger.addHandler(console_handler)
    
    def _push_to_redis(self, level, message, extra=None):
        """推送到 Redis 并保留 30 天数据"""
        try:
            now = datetime.utcnow()
            bj_now = now + timedelta(hours=8)
            user_id = None
            if has_request_context():
                user_id = g.get('user_id') or (getattr(g, 'user', None).id if hasattr(g, 'user') and g.user else None)
            
            log_entry = {
                "time": bj_now.strftime('%Y-%m-%d %H:%M:%S'),
                "level": level,
                "message": message,
                "user_id": user_id,
                "extra": extra or {}
            }
            # 使用有序集合 (ZSET)，分数为时间戳，方便按时间清理
            timestamp = now.timestamp()
            redis_client.zadd('system_logs_zset', {json.dumps(log_entry, ensure_ascii=False): timestamp})
            
            # 清理 30 天之前的日志 (30 * 24 * 3600 秒)
            thirty_days_ago = timestamp - (30 * 24 * 3600)
            redis_client.zremrangebyscore('system_logs_zset', 0, thirty_days_ago)
        except:
            pass

    def _write_to_db(self, level, message, module=None, extra=None):
        """写入数据库"""
        try:
            from models import SystemLog
            
            log_data = {
                'level': level,
                'message': message,
                'module': module,
                'user_id': extra.get('user_id') if extra else None,
                'extra': json.dumps(extra, ensure_ascii=False) if extra else None,
                'created_at': datetime.utcnow()
            }
            
            # 捕获请求上下文信息
            if has_request_context():
                log_data.update({
                    'ip': request.remote_addr,
                    'path': request.path,
                    'method': request.method,
                    'user_agent': request.headers.get('User-Agent')
                })
                # 如果 log_data 还没 user_id，尝试从 context 获取
                if not log_data['user_id']:
                    log_data['user_id'] = getattr(g, 'user_id', None) or (getattr(g.user, 'id', None) if hasattr(g, 'user') and g.user else None)
            
            new_log = SystemLog(**log_data)
            db.session.add(new_log)
            db.session.commit()
        except Exception as e:
            # 避免日志错误导致程序崩溃
            self.logger.error(f"Failed to write log to DB: {str(e)}")

    def info(self, message, module=None, **kwargs):
        self.logger.info(message)
        self._push_to_redis('INFO', message, kwargs)
        self._write_to_db('INFO', message, module, kwargs)
    
    def warning(self, message, module=None, **kwargs):
        self.logger.warning(message)
        self._push_to_redis('WARNING', message, kwargs)
        self._write_to_db('WARNING', message, module, kwargs)
    
    def error(self, message, module=None, **kwargs):
        self.logger.error(message)
        self._push_to_redis('ERROR', message, kwargs)
        self._write_to_db('ERROR', message, module, kwargs)
    
    def debug(self, message, module=None, **kwargs):
        self.logger.debug(message)
        self._push_to_redis('DEBUG', message, kwargs)
        self._write_to_db('DEBUG', message, module, kwargs)

# 全局日志实例
system_logger = SystemLogger()