Move oauth2 error to oauth2 service package (#17603)

services/auth/source/oauth2/source_register.go

@@ -5,7 +5,7 @@
 package oauth2
 
 import (
-	"code.gitea.io/gitea/models"
+	"fmt"
 )
 
 // RegisterSource causes an OAuth2 configuration to be registered
@@ -20,11 +20,28 @@ func (source *Source) UnregisterSource() error {
 	return nil
 }
 
+// ErrOpenIDConnectInitialize represents a "OpenIDConnectInitialize" kind of error.
+type ErrOpenIDConnectInitialize struct {
+	OpenIDConnectAutoDiscoveryURL string
+	ProviderName                  string
+	Cause                         error
+}
+
+// IsErrOpenIDConnectInitialize checks if an error is a ExternalLoginUserAlreadyExist.
+func IsErrOpenIDConnectInitialize(err error) bool {
+	_, ok := err.(ErrOpenIDConnectInitialize)
+	return ok
+}
+
+func (err ErrOpenIDConnectInitialize) Error() string {
+	return fmt.Sprintf("Failed to initialize OpenID Connect Provider with name '%s' with url '%s': %v", err.ProviderName, err.OpenIDConnectAutoDiscoveryURL, err.Cause)
+}
+
 // wrapOpenIDConnectInitializeError is used to wrap the error but this cannot be done in modules/auth/oauth2
 // inside oauth2: import cycle not allowed models -> modules/auth/oauth2 -> models
 func wrapOpenIDConnectInitializeError(err error, providerName string, source *Source) error {
 	if err != nil && source.Provider == "openidConnect" {
-		err = models.ErrOpenIDConnectInitialize{ProviderName: providerName, OpenIDConnectAutoDiscoveryURL: source.OpenIDConnectAutoDiscoveryURL, Cause: err}
+		err = ErrOpenIDConnectInitialize{ProviderName: providerName, OpenIDConnectAutoDiscoveryURL: source.OpenIDConnectAutoDiscoveryURL, Cause: err}
 	}
 	return err
 }