golang dropbox upload

dropbox.go

package dropbox

import (
	"bytes"
	"encoding/json"
	"errors"
	"io/ioutil"
	"log"
	"net/http"
)

const (
	oauth2AccessToken = ""
)

type UploadInfo struct {
	Data     []byte
	FullPath string
}

type ResponseInfo struct {
	Response string
	Err      error
}

func UploadFile(uploadInfo UploadInfo) ResponseInfo {
	client := &http.Client{}
	req, err := http.NewRequest("POST", "https://content.dropboxapi.com/2/files/upload", bytes.NewReader(uploadInfo.Data))
	if err != nil {
		return ResponseInfo{"", err}
	}
	req.Header.Set("Content-Type", "application/octet-stream")
	req.Header.Set("Authorization", "Bearer "+oauth2AccessToken)
	req.Header.Set("Dropbox-API-Arg", "{\"path\":\""+uploadInfo.FullPath+"\"}")
	resp, err := client.Do(req)
	if err != nil {
		return ResponseInfo{"", err}
	}
	defer resp.Body.Close()
	respByte, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Println("fail to read response data")
		return ResponseInfo{"", err}
	}
	var mapObject = make(map[string]interface{})
	err = json.Unmarshal(respByte, &mapObject)
	if err != nil {
		return ResponseInfo{"", errors.New(string(respByte))}
	}
	fileName, check := mapObject["path_display"].(string)
	if !check {
		return ResponseInfo{"", errors.New(string(respByte))}
	}
	responseInfo := getLinkFile(client, fileName)
	if responseInfo.Err != nil {
		return ResponseInfo{"", err}
	}
	return ResponseInfo{responseInfo.Response, nil}
}

func getLinkFile(client *http.Client, fileName string) ResponseInfo {
	req, err := http.NewRequest("POST", "https://api.dropboxapi.com/2/files/get_temporary_link",
		bytes.NewReader([]byte("{\"path\":\""+fileName+"\"}")))
	if err != nil {
		return ResponseInfo{"", err}
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+oauth2AccessToken)
	resp, err := client.Do(req)
	if err != nil {
		return ResponseInfo{"", err}
	}
	defer resp.Body.Close()
	respByte, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return ResponseInfo{"", err}
	}
	var mapObject = make(map[string]interface{})
	err = json.Unmarshal(respByte, &mapObject)
	if err != nil {
		return ResponseInfo{"", errors.New(string(respByte))}
	}
	link, check := mapObject["link"].(string)
	if !check {
		return ResponseInfo{"", errors.New(string(respByte))}
	}
	return ResponseInfo{link, nil}
}