metarare_api-main/auth/google.go

package auth

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

type GoogleUser struct {
	ID    string `json:"id,omitempty"`
	Email string `json:"email,omitempty"`
	Name  string `json:"name,omitempty"`
}

const InfoURL = "https://www.googleapis.com/oauth2/v2/userinfo"

func GetGoogleSignInURL() string {
	return fmt.Sprintf(
		"%s?client_id=%s&redirect_uri=%s&response_type=code&scope=openid email profile",
		googleConfig.Endpoint.AuthURL,
		googleConfig.ClientID,
		googleConfig.RedirectURL,
	)
}

func GetGoogleAccessToken(code string) (string, error) {
	getTokenURL := fmt.Sprintf(
		"%s?client_id=%s&client_secret=%s&grant_type=authorization_code&redirect_uri=%s&code=%s",
		googleConfig.Endpoint.TokenURL, googleConfig.ClientID, googleConfig.ClientSecret, googleConfig.RedirectURL, code,
	)
	fmt.Println(getTokenURL)
	tokenRequest, err := http.NewRequest("POST", getTokenURL, nil)
	if err != nil {
		return "", err
	}
	tokenClient := &http.Client{}
	tokenResponse, err := tokenClient.Do(tokenRequest)
	if err != nil {
		return "", err
	}
	defer tokenResponse.Body.Close()

	tokenBody, _ := ioutil.ReadAll(tokenResponse.Body)
	var tokenObject map[string]interface{}
	json.Unmarshal(tokenBody, &tokenObject)

	return tokenObject["access_token"].(string), nil
}

func GetGoogleUserInfo(code string) (*GoogleUser, error) {
	if len(code) <= 0 {
		return nil, errors.New("invalid parameter value")
	}

	token, err := GetGoogleAccessToken(code)
	if err != nil {
		return nil, err
	}

	//GET USER INFO
	getUserInfoURL := fmt.Sprintf(
		"%s?access_token=%s",
		InfoURL,
		token,
	)
	userInfoRequest, err := http.NewRequest("GET", getUserInfoURL, nil)
	if err != nil {
		return nil, err
	}
	userInfoClient := &http.Client{}
	userInfoResponse, err := userInfoClient.Do(userInfoRequest)
	if err != nil {
		return nil, err
	}
	defer userInfoResponse.Body.Close()

	userInfoBody, _ := ioutil.ReadAll(userInfoResponse.Body)
	var userInfoObject map[string]interface{}
	json.Unmarshal(userInfoBody, &userInfoObject)
	if userInfoResponse.StatusCode != 200 {
		return nil, errors.New("invalid access token")
	}

	return &GoogleUser{
		ID:    userInfoObject["id"].(string),
		Name:  userInfoObject["name"].(string),
		Email: userInfoObject["email"].(string),
	}, nil
}