support Nextcloud OAuth 2.0 authentication

pkg/auth/oauth2/oauth2_provider.go

@@ -0,0 +1,22 @@
+package oauth2
+
+import (
+	"net/http"
+
+	"github.com/mayswind/ezbookkeeping/pkg/core"
+)
+
+// OAuth2Provider defines the structure of OAuth 2.0 provider
+type OAuth2Provider interface {
+	// GetAuthUrl returns the authentication url of the provider
+	GetAuthUrl() string
+
+	// GetTokenUrl returns the token url of the provider
+	GetTokenUrl() string
+
+	// GetUserInfo returns the user info
+	GetUserInfo(c core.Context, oauth2Client *http.Client) (*OAuth2UserInfo, error)
+
+	// GetScopes returns the scopes required by the provider
+	GetScopes() []string
+}