package middleware

import (
	"time"
	"github.com/gin-gonic/gin"
	"go.uber.org/zap"
)

// LoggerMiddleware 日志中间件
func LoggerMiddleware(logger *zap.Logger) gin.HandlerFunc {
	return func(c *gin.Context) {
		start := time.Now()
		path := c.Request.URL.Path
		raw := c.Request.URL.RawQuery
		
		// 处理请求
		c.Next()
		
		// 计算延迟
		latency := time.Since(start)
		
		// 获取请求信息
		clientIP := c.ClientIP()
		method := c.Request.Method
		statusCode := c.Writer.Status()
		bodySize := c.Writer.Size()
		
		if raw != "" {
			path = path + "?" + raw
		}
		
		// 记录日志
		logger.Info("HTTP Request",
			zap.String("method", method),
			zap.String("path", path),
			zap.String("client_ip", clientIP),
			zap.Int("status_code", statusCode),
			zap.Int("body_size", bodySize),
			zap.Duration("latency", latency),
			zap.String("user_agent", c.Request.UserAgent()),
		)
	}
}

// RequestIDMiddleware 请求ID中间件
func RequestIDMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		requestID := c.GetHeader("X-Request-ID")
		if requestID == "" {
			requestID = generateRequestID()
		}
		
		c.Set("request_id", requestID)
		c.Header("X-Request-ID", requestID)
		
		c.Next()
	}
}

// generateRequestID 生成请求ID
func generateRequestID() string {
	// 简单实现，实际应用中可能需要更复杂的ID生成逻辑
	return time.Now().Format("20060102150405") + "-" + randomString(8)
}

// randomString 生成随机字符串
func randomString(length int) string {
	const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
	b := make([]byte, length)
	for i := range b {
		b[i] = charset[time.Now().UnixNano()%int64(len(charset))]
	}
	return string(b)
}