package pb

import (
	"bytes"
	"io/fs"
	"io/ioutil"
	"mime/multipart"
	"strconv"

	"git.0cd.xyz/michael/request"
	"google.golang.org/protobuf/proto"
	"google.golang.org/protobuf/reflect/protoreflect"
)

// Read protocol buffer from file
func ReadFile(path string, message protoreflect.ProtoMessage) error {
	file, err := ioutil.ReadFile(path)
	if err != nil {
		return err
	}
	if err := proto.Unmarshal(file, message); err != nil {
		return err
	}
	return nil
}

// Write protocol buffer to file
func WriteFile(path string, message protoreflect.ProtoMessage, perm fs.FileMode) error {
	msg, err := proto.Marshal(message)
	if err != nil {
		return err
	}
	if err := ioutil.WriteFile(path, msg, perm); err != nil {
		return err
	}
	return nil
}

// SendFile protocol buffer as multipart file to http address
func SendFile(filename, url string, headers map[string]string, message protoreflect.ProtoMessage) (req *request.Response, err error) {
	body, err := proto.Marshal(message)
	if err != nil {
		return nil, err
	}

	buf := &bytes.Buffer{}
	writer := multipart.NewWriter(buf)
	part, err := writer.CreateFormFile("file", filename)
	if err != nil {
		return nil, err
	}

	part.Write(body)
	for key, val := range map[string]string{
		"type":        "upload",
		"synchronous": "true",
	} {
		writer.WriteField(key, val)
	}
	writer.Close()

	headers["Content-Length"] = strconv.Itoa(buf.Len())
	headers["Content-Type"] = writer.FormDataContentType()

	req, err = request.Post(url,
		headers, buf)
	if err != nil {
		return nil, err
	}
	return req, nil
}