2 files changed, 137 insertions, 0 deletions
diff --git a/services/externalaccount/link.go b/services/externalaccount/link.go
new file mode 100644
index 0000000..d6e2ea7
--- /dev/null
+++ b/services/externalaccount/link.go
@@ -0,0 +1,30 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package externalaccount
+
+import (
+	"context"
+	"fmt"
+
+	user_model "code.gitea.io/gitea/models/user"
+
+	"github.com/markbates/goth"
+)
+
+// Store represents a thing that stores things
+type Store interface {
+	Get(any) any
+	Set(any, any) error
+	Release() error
+}
+
+// LinkAccountFromStore links the provided user with a stored external user
+func LinkAccountFromStore(ctx context.Context, store Store, user *user_model.User) error {
+	gothUser := store.Get("linkAccountGothUser")
+	if gothUser == nil {
+		return fmt.Errorf("not in LinkAccount session")
+	}
+
+	return LinkAccountToUser(ctx, user, gothUser.(goth.User))
+}
diff --git a/services/externalaccount/user.go b/services/externalaccount/user.go
new file mode 100644
index 0000000..3cfd8c8
--- /dev/null
+++ b/services/externalaccount/user.go
@@ -0,0 +1,107 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package externalaccount
+
+import (
+	"context"
+	"strconv"
+	"strings"
+
+	"code.gitea.io/gitea/models/auth"
+	issues_model "code.gitea.io/gitea/models/issues"
+	repo_model "code.gitea.io/gitea/models/repo"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/structs"
+
+	"github.com/markbates/goth"
+)
+
+func toExternalLoginUser(ctx context.Context, user *user_model.User, gothUser goth.User) (*user_model.ExternalLoginUser, error) {
+	authSource, err := auth.GetActiveOAuth2SourceByName(ctx, gothUser.Provider)
+	if err != nil {
+		return nil, err
+	}
+	return &user_model.ExternalLoginUser{
+		ExternalID:        gothUser.UserID,
+		UserID:            user.ID,
+		LoginSourceID:     authSource.ID,
+		RawData:           gothUser.RawData,
+		Provider:          gothUser.Provider,
+		Email:             gothUser.Email,
+		Name:              gothUser.Name,
+		FirstName:         gothUser.FirstName,
+		LastName:          gothUser.LastName,
+		NickName:          gothUser.NickName,
+		Description:       gothUser.Description,
+		AvatarURL:         gothUser.AvatarURL,
+		Location:          gothUser.Location,
+		AccessToken:       gothUser.AccessToken,
+		AccessTokenSecret: gothUser.AccessTokenSecret,
+		RefreshToken:      gothUser.RefreshToken,
+		ExpiresAt:         gothUser.ExpiresAt,
+	}, nil
+}
+
+// LinkAccountToUser link the gothUser to the user
+func LinkAccountToUser(ctx context.Context, user *user_model.User, gothUser goth.User) error {
+	externalLoginUser, err := toExternalLoginUser(ctx, user, gothUser)
+	if err != nil {
+		return err
+	}
+
+	if err := user_model.LinkExternalToUser(ctx, user, externalLoginUser); err != nil {
+		return err
+	}
+
+	externalID := externalLoginUser.ExternalID
+
+	var tp structs.GitServiceType
+	for _, s := range structs.SupportedFullGitService {
+		if strings.EqualFold(s.Name(), gothUser.Provider) {
+			tp = s
+			break
+		}
+	}
+
+	if tp.Name() != "" {
+		return UpdateMigrationsByType(ctx, tp, externalID, user.ID)
+	}
+
+	return nil
+}
+
+// UpdateExternalUser updates external user's information
+func UpdateExternalUser(ctx context.Context, user *user_model.User, gothUser goth.User) error {
+	externalLoginUser, err := toExternalLoginUser(ctx, user, gothUser)
+	if err != nil {
+		return err
+	}
+
+	return user_model.UpdateExternalUserByExternalID(ctx, externalLoginUser)
+}
+
+// UpdateMigrationsByType updates all migrated repositories' posterid from gitServiceType to replace originalAuthorID to posterID
+func UpdateMigrationsByType(ctx context.Context, tp structs.GitServiceType, externalUserID string, userID int64) error {
+	// Skip update if externalUserID is not a valid numeric ID or exceeds int64
+	if _, err := strconv.ParseInt(externalUserID, 10, 64); err != nil {
+		return nil
+	}
+
+	if err := issues_model.UpdateIssuesMigrationsByType(ctx, tp, externalUserID, userID); err != nil {
+		return err
+	}
+
+	if err := issues_model.UpdateCommentsMigrationsByType(ctx, tp, externalUserID, userID); err != nil {
+		return err
+	}
+
+	if err := repo_model.UpdateReleasesMigrationsByType(ctx, tp, externalUserID, userID); err != nil {
+		return err
+	}
+
+	if err := issues_model.UpdateReactionsMigrationsByType(ctx, tp, externalUserID, userID); err != nil {
+		return err
+	}
+	return issues_model.UpdateReviewsMigrationsByType(ctx, tp, externalUserID, userID)
+}