package middleware

import (
	"log"
	"time"

	"github.com/gin-gonic/gin"
)

// Logger 结构化日志中间件，记录请求 ID、方法、路径、状态码、耗时、客户端 IP
func Logger() gin.HandlerFunc {
	return func(c *gin.Context) {
		start := time.Now()
		path := c.Request.URL.Path
		if raw := c.Request.URL.RawQuery; raw != "" {
			path = path + "?" + raw
		}

		c.Next()

		cost := time.Since(start)
		rid := GetRequestID(c)
		status := c.Writer.Status()

		// 根据状态码选择日志级别标记
		level := "INFO"
		if status >= 500 {
			level = "ERROR"
		} else if status >= 400 {
			level = "WARN"
		}

		log.Printf("[%s] req_id=%s | %s %s | %d | %s | ip=%s | size=%d",
			level,
			rid,
			c.Request.Method,
			path,
			status,
			cost.String(),
			c.ClientIP(),
			c.Writer.Size(),
		)
	}
}