package httputil

// Copy from https://github.com/samber/slog-gin/blob/main/dump.go

import (
	"bytes"
	"io"
	"net/http"

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

var _ http.ResponseWriter = (*bodyWriter)(nil)
var _ http.Flusher = (*bodyWriter)(nil)
var _ http.Hijacker = (*bodyWriter)(nil)

type bodyWriter struct {
	gin.ResponseWriter

	body    *bytes.Buffer
	maxSize int
	bytes   int
}

// implements gin.ResponseWriter
func (w *bodyWriter) Write(b []byte) (int, error) {
	if w.body != nil {
		if w.body.Len()+len(b) > w.maxSize {
			w.body.Write(b[:w.maxSize-w.body.Len()])
		} else {
			w.body.Write(b)
		}
	}

	w.bytes += len(b)
	return w.ResponseWriter.Write(b)
}

func newBodyWriter(writer gin.ResponseWriter, maxSize int) *bodyWriter {
	body := bytes.NewBufferString("")

	return &bodyWriter{
		ResponseWriter: writer,
		body:           body,
		maxSize:        maxSize,
		bytes:          0,
	}
}

type bodyReader struct {
	io.ReadCloser

	body    *bytes.Buffer
	maxSize int
	bytes   int
}

// implements io.Reader
func (r *bodyReader) Read(b []byte) (int, error) {
	n, err := r.ReadCloser.Read(b)
	if r.body != nil {
		if r.body.Len()+n > r.maxSize {
			r.body.Write(b[:r.maxSize-r.body.Len()])
		} else {
			r.body.Write(b[:n])
		}
	}
	r.bytes += n
	return n, err
}

func newBodyReader(reader io.ReadCloser, maxSize int) *bodyReader {
	body := bytes.NewBufferString("")

	return &bodyReader{
		ReadCloser: reader,
		body:       body,
		maxSize:    maxSize,
		bytes:      0,
	}
}