package middleware

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"log/slog"
	"time"

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

func GinLogger() gin.HandlerFunc {
	return func(c *gin.Context) {
		var body []byte
		if c.Request.Body != nil {
			body, _ = io.ReadAll(c.Request.Body)
			c.Request.Body = io.NopCloser(bytes.NewBuffer(body))
		}

		headerJSON, _ := json.Marshal(c.Request.Header)

		startTime := time.Now()

		c.Next()

		ctx := c.Request.Context()

		var errorMessage string
		if len(c.Errors) > 0 {
			errorMessage = c.Errors.String()
		}

		fields := []any{
			"status", c.Writer.Status(),
			"method", c.Request.Method,
			"uri", c.Request.RequestURI,
			"ip", c.ClientIP(),
			"latency", time.Since(startTime).String(),
			"user_agent", c.Request.UserAgent(),
			"headers", string(headerJSON),
			"request_body", string(body),
			"errors", errorMessage,
		}

		status := c.Writer.Status()
		if len(c.Errors) > 0 || status >= 500 {
			slog.ErrorContext(ctx, fmt.Sprintf("%d %s %s", c.Writer.Status(), c.Request.Method, c.Request.RequestURI), fields...)
		} else if status >= 400 {
			slog.WarnContext(ctx, fmt.Sprintf("%d %s %s", c.Writer.Status(), c.Request.Method, c.Request.RequestURI), fields...)
		} else {
			slog.InfoContext(ctx, fmt.Sprintf("%d %s %s", c.Writer.Status(), c.Request.Method, c.Request.RequestURI), fields...)
		}
	}
}