make oauth as a service

server/services/oauth/oauth.go

@@ -0,0 +1,105 @@
+package oauth
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"os"
+	"recipe-manager/config"
+	"recipe-manager/models"
+
+	"golang.org/x/oauth2"
+)
+
+type OAuthService interface {
+	AuthURL(state string, stateMap map[string]string) string
+	GetState(state string) (map[string]string, bool)
+	RemoveState(state string)
+	Exchange(ctx context.Context, code string) (*oauth2.Token, error)
+	GetUserInfo(ctx context.Context, token *oauth2.Token) (*models.User, error)
+	RefreshToken(ctx context.Context, token *oauth2.Token) (*oauth2.Token, error)
+}
+
+type oauthService struct {
+	cfg     *config.ServerConfig
+	gConfig *oauth2.Config
+	nonce   map[string]map[string]string
+}
+
+func NewOAuthService(cfg *config.ServerConfig) OAuthService {
+
+	file, err := os.Open("client_secret.json")
+	if err != nil {
+		panic(err)
+	}
+	defer file.Close()
+
+	var clientSecret map[string]interface{}
+	json.NewDecoder(file).Decode(&clientSecret)
+
+	return &oauthService{
+		cfg: cfg,
+		gConfig: &oauth2.Config{
+			ClientID:     clientSecret["web"].(map[string]interface{})["client_id"].(string),
+			ClientSecret: clientSecret["web"].(map[string]interface{})["client_secret"].(string),
+			RedirectURL:  cfg.ServerDomain + "/auth/google/callback",
+			Scopes:       []string{"https://www.googleapis.com/auth/userinfo.email", "https://www.googleapis.com/auth/userinfo.profile"},
+			Endpoint: oauth2.Endpoint{
+				AuthURL:  clientSecret["web"].(map[string]interface{})["auth_uri"].(string),
+				TokenURL: clientSecret["web"].(map[string]interface{})["token_uri"].(string),
+			},
+		},
+		nonce: make(map[string]map[string]string),
+	}
+}
+
+func (o *oauthService) AuthURL(state string, stateMap map[string]string) string {
+
+	if stateMap != nil {
+		o.nonce[state] = stateMap
+	} else {
+		o.nonce[state] = make(map[string]string)
+	}
+
+	return o.gConfig.AuthCodeURL(state, oauth2.SetAuthURLParam("hd", "forth.co.th"), oauth2.SetAuthURLParam("include_granted_scopes", "true"), oauth2.AccessTypeOffline)
+}
+
+func (o *oauthService) GetState(state string) (map[string]string, bool) {
+	val, ok := o.nonce[state]
+	return val, ok
+}
+
+func (o *oauthService) RemoveState(state string) {
+	delete(o.nonce, state)
+}
+
+func (o *oauthService) Exchange(ctx context.Context, code string) (*oauth2.Token, error) {
+
+	return o.gConfig.Exchange(ctx, code)
+}
+
+func (o *oauthService) GetUserInfo(ctx context.Context, token *oauth2.Token) (*models.User, error) {
+	client := o.gConfig.Client(ctx, token)
+	resp, err := client.Get("https://www.googleapis.com/oauth2/v3/userinfo")
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var userInfo map[string]interface{}
+	json.NewDecoder(resp.Body).Decode(&userInfo)
+
+	if userInfo["error"] != nil {
+		return nil, errors.New("Error getting user info")
+	}
+
+	return &models.User{
+		Name:    userInfo["name"].(string),
+		Email:   userInfo["email"].(string),
+		Picture: userInfo["picture"].(string),
+	}, nil
+}
+
+func (o *oauthService) RefreshToken(ctx context.Context, token *oauth2.Token) (*oauth2.Token, error) {
+	return o.gConfig.TokenSource(ctx, token).Token()
+}