package middleware

import (
	"time"

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

// GinLogger 用结构化日志（slog，由 main 设为 JSON handler）记录每个请求，
// 替代 gin 默认的 text logger，便于生产环境集中采集与检索。
func GinLogger() gin.HandlerFunc {
	return func(c *gin.Context) {
		start := time.Now()
		path := c.Request.URL.Path
		raw := c.Request.URL.RawQuery

		c.Next()

		// 跳过健康检查等高频噪声路径
		if path == "/api/health" || path == "/api/v1/health" {
			return
		}

		latency := time.Since(start)
		status := c.Writer.Status()
		clientIP := c.ClientIP()
		method := c.Request.Method
		if raw != "" {
			path = path + "?" + raw
		}

		attrs := []slog.Attr{
			slog.String("method", method),
			slog.String("path", path),
			slog.Int("status", status),
			slog.String("ip", clientIP),
			slog.Duration("latency", latency),
		}
		if len(c.Errors) > 0 {
			attrs = append(attrs, slog.String("error", c.Errors.ByType(gin.ErrorTypePrivate).String()))
		}

		switch {
		case status >= 500:
			slog.LogAttrs(c.Request.Context(), slog.LevelError, "request", attrs...)
		case status >= 400:
			slog.LogAttrs(c.Request.Context(), slog.LevelWarn, "request", attrs...)
		default:
			slog.LogAttrs(c.Request.Context(), slog.LevelInfo, "request", attrs...)
		}
	}
}