rest/response.go

package rest

import (
	"bytes"
	"encoding/json"
	"io"
	"log"
	"mime/multipart"
	"net/http"
	"net/textproto"

	mjson "git.ali33.ru/fcg-xvii/go-tools/json"
)

func NewResponse() *Response {
	return &Response{
		data:  make(mjson.Map),
		files: make(map[string]io.ReadCloser),
	}
}

type Response struct {
	data    mjson.Map
	files   map[string]io.ReadCloser
	err     error
	errArgs mjson.Map
	code    int
}

func (s *Response) KeySet(key string, val any) {
	s.data[key] = val
}

func (s *Response) FileSet(name string, file io.ReadCloser) {
	s.files[name] = file
}

func (s *Response) SetError(code int, err error) {
	s.code = code
	s.err = err
}

func (s *Response) Close() {
	for _, file := range s.files {
		file.Close()
	}
}

func (s *Response) Send(w http.ResponseWriter) error {
	log.Println("SEND...")
	defer s.Close()
	if s.err != nil {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(s.code)
		body := mjson.Map{
			"error": s.err.Error(),
			"args":  s.errArgs,
		}
		w.Write(body.JSON())
		return nil
	}
	// Если есть файлы, то используем multipart
	if len(s.files) > 0 {
		var b bytes.Buffer
		writer := multipart.NewWriter(&b)

		// Добавляем JSON-данные как часть
		partHeader := make(textproto.MIMEHeader)
		partHeader.Set("Content-Type", "application/json")
		partHeader.Set("Content-Disposition", `form-data; name="data"`)
		dataPart, err := writer.CreatePart(partHeader)
		if err != nil {
			return err
		}
		if err := json.NewEncoder(dataPart).Encode(s.data); err != nil {
			return err
		}

		// Добавляем файлы
		for filename, file := range s.files {
			part, err := writer.CreateFormFile("file", filename)
			if err != nil {
				return err
			}
			if _, err := io.Copy(part, file); err != nil {
				return err
			}
		}

		// Закрываем multipart writer
		if err := writer.Close(); err != nil {
			return err
		}

		// Отправляем multipart response
		w.Header().Set("Content-Type", writer.FormDataContentType())
		w.Write(b.Bytes())
	} else {
		// Если нет файлов, просто отправляем JSON
		w.Header().Set("Content-Type", "application/json")
		return json.NewEncoder(w).Encode(s.data)
	}

	return nil
}

///////////////////////////////////////////

func ResponseError(err error, args mjson.Map, code int) *Response {
	return &Response{
		code:    code,
		err:     err,
		errArgs: args,
	}
}

///////////////////////////////////////////

func ResponseErrKeyNotExists(key string) *Response {
	return ResponseError(
		ErrKeyNotExists,
		mjson.Map{
			"key": key,
		},
		500,
	)
}

func ResponseErrKeyInvalidType(key, kType string) *Response {
	return ResponseError(
		ErrKeyInvalidType,
		mjson.Map{
			"key":  key,
			"type": kType,
		},
		500,
	)
}

func ResponseNotFound(data mjson.Map) *Response {
	return &Response{
		code:    404,
		err:     ErrNotFound,
		errArgs: data,
	}
}