package api

import (
	"log/slog"
	"net/http"
	"time"

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

// requestLogger returns a Gin middleware that logs each request via slog.
// Requests to /healthz are skipped to avoid health-check noise.
func requestLogger(lg *slog.Logger) gin.HandlerFunc {
	if lg == nil {
		lg = slog.Default()
	}
	return func(c *gin.Context) {
		if c.FullPath() == "/healthz" || c.Request.URL.Path == "/healthz" {
			c.Next()
			return
		}

		start := time.Now()
		c.Next()

		status := c.Writer.Status()
		path := c.FullPath()
		if path == "" {
			path = c.Request.URL.Path
		}

		attrs := []any{
			"method", c.Request.Method,
			"path", path,
			"status", status,
			"latency_ms", time.Since(start).Milliseconds(),
			"client_ip", c.ClientIP(),
		}
		if len(c.Errors) > 0 {
			attrs = append(attrs, "error", c.Errors.String())
		}

		switch {
		case status >= http.StatusInternalServerError:
			lg.Error("http request completed", attrs...)
		case status >= http.StatusBadRequest:
			lg.Warn("http request completed", attrs...)
		default:
			lg.Info("http request completed", attrs...)
		}
	}
}