"""
请求日志中间件

自动将所有请求记录到数据库 platform_logs 表
"""
import time
import logging
from typing import Optional, Set
from starlette.middleware.base import BaseHTTPMiddleware
from starlette.requests import Request
from starlette.responses import Response

from .trace import get_trace_id
from ..database import SessionLocal
from ..models.logs import PlatformLog

logger = logging.getLogger(__name__)


class RequestLoggerMiddleware(BaseHTTPMiddleware):
    """请求日志中间件
    
    自动记录所有请求到数据库，便于后续查询和分析
    
    使用示例:
        app.add_middleware(RequestLoggerMiddleware, app_code="000-platform")
    """
    
    # 默认排除的路径（不记录这些请求）
    DEFAULT_EXCLUDE_PATHS: Set[str] = {
        "/",
        "/docs",
        "/redoc",
        "/openapi.json",
        "/api/health",
        "/api/health/",
        "/favicon.ico",
    }
    
    def __init__(
        self,
        app,
        app_code: str = "platform",
        exclude_paths: Optional[Set[str]] = None,
        log_request_body: bool = False,
        log_response_body: bool = False,
        max_body_length: int = 1000
    ):
        """初始化中间件
        
        Args:
            app: FastAPI应用
            app_code: 应用代码，记录到日志中
            exclude_paths: 排除的路径集合，这些路径不记录日志
            log_request_body: 是否记录请求体
            log_response_body: 是否记录响应体
            max_body_length: 记录体的最大长度
        """
        super().__init__(app)
        self.app_code = app_code
        self.exclude_paths = exclude_paths or self.DEFAULT_EXCLUDE_PATHS
        self.log_request_body = log_request_body
        self.log_response_body = log_response_body
        self.max_body_length = max_body_length
    
    async def dispatch(self, request: Request, call_next) -> Response:
        path = request.url.path
        
        # 检查是否排除
        if self._should_exclude(path):
            return await call_next(request)
        
        trace_id = get_trace_id()
        method = request.method
        start_time = time.time()
        
        # 获取客户端IP
        client_ip = self._get_client_ip(request)
        
        # 获取租户ID（从查询参数）
        tenant_id = request.query_params.get("tid") or request.query_params.get("tenant_id")
        
        # 执行请求
        response = None
        error_message = None
        status_code = 500
        
        try:
            response = await call_next(request)
            status_code = response.status_code
        except Exception as e:
            error_message = str(e)
            raise
        finally:
            duration_ms = int((time.time() - start_time) * 1000)
            
            # 异步写入数据库（不阻塞响应）
            try:
                self._save_log(
                    trace_id=trace_id,
                    method=method,
                    path=path,
                    status_code=status_code,
                    duration_ms=duration_ms,
                    ip_address=client_ip,
                    tenant_id=tenant_id,
                    error_message=error_message
                )
            except Exception as e:
                logger.error(f"Failed to save request log: {e}")
        
        return response
    
    def _should_exclude(self, path: str) -> bool:
        """检查路径是否应排除"""
        # 精确匹配
        if path in self.exclude_paths:
            return True
        
        # 前缀匹配（静态文件等）
        exclude_prefixes = ["/static/", "/assets/", "/_next/"]
        for prefix in exclude_prefixes:
            if path.startswith(prefix):
                return True
        
        return False
    
    def _get_client_ip(self, request: Request) -> str:
        """获取客户端真实IP"""
        # 优先从代理头获取
        forwarded = request.headers.get("X-Forwarded-For")
        if forwarded:
            return forwarded.split(",")[0].strip()
        
        real_ip = request.headers.get("X-Real-IP")
        if real_ip:
            return real_ip
        
        # 直连IP
        if request.client:
            return request.client.host
        
        return "unknown"
    
    def _save_log(
        self,
        trace_id: str,
        method: str,
        path: str,
        status_code: int,
        duration_ms: int,
        ip_address: str,
        tenant_id: Optional[str] = None,
        error_message: Optional[str] = None
    ):
        """保存日志到数据库"""
        from datetime import datetime
        
        # 使用独立的数据库会话
        db = SessionLocal()
        try:
            # 转换 tenant_id 为整数（如果是数字字符串）
            tenant_id_int = None
            if tenant_id:
                try:
                    tenant_id_int = int(tenant_id)
                except (ValueError, TypeError):
                    tenant_id_int = None
            
            log_entry = PlatformLog(
                log_type="request",
                level="error" if status_code >= 500 else ("warn" if status_code >= 400 else "info"),
                app_code=self.app_code,
                tenant_id=tenant_id_int,
                trace_id=trace_id,
                message=f"{method} {path}" + (f" - {error_message}" if error_message else ""),
                path=path,
                method=method,
                status_code=status_code,
                duration_ms=duration_ms,
                log_time=datetime.now(),  # 必须设置 log_time
                context={"ip": ip_address}  # ip_address 放到 context 中
            )
            db.add(log_entry)
            db.commit()
        except Exception as e:
            logger.error(f"Database error saving log: {e}")
            db.rollback()
        finally:
            db.close()