package middleware

import (
	"bytes"
	"fmt"

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

// 原理是创建的时候注入了一个方法处理响应的信息

func ResponseFilterMiddleware(c *gin.Context) {

	fmt.Println(c.Writer)
	blw := &bodyLogWriter{
		body:           bytes.NewBufferString(""),
		ResponseWriter: c.Writer,
	}
	c.Writer = blw
	c.Next()

	statusCode := c.Writer.Status()

	fmt.Println(statusCode)
	fmt.Println("拦截输出")
}

type bodyLogWriter struct {
	gin.ResponseWriter
	body *bytes.Buffer
}

// 真正输出的时候，它会调用这个输出方法
func (w bodyLogWriter) Write(b []byte) (int, error) {
	// b = []byte(`{"code":0}`)
	w.body.Write(b)
	return w.ResponseWriter.Write(b)
}