snapshot of https://github.com/mattermost/mattermost.git (master, 2026-09-16; blobs > 131072B omitted)

server/platform/services/sharedchannel/util.go

@@ -0,0 +1,139 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package sharedchannel
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/mattermost/mattermost/server/public/model"
+	"github.com/mattermost/mattermost/server/v8/channels/store"
+)
+
+// fixMention transforms @username:remotename mentions to @username format
+// Used when syncing posts to a user's home cluster
+func fixMention(post *model.Post, mentionMap model.UserMentionMap, user *model.User) {
+	if post == nil || len(mentionMap) == 0 {
+		return
+	}
+
+	realUsername, ok := user.GetProp(model.UserPropsKeyRemoteUsername)
+	if !ok {
+		return
+	}
+
+	for mention, id := range mentionMap {
+		// Only process mentions with colons that match this user's ID
+		if id == user.Id && strings.Contains(mention, ":") {
+			post.Message = strings.ReplaceAll(post.Message, "@"+mention, "@"+realUsername)
+		}
+	}
+}
+
+func sanitizeUserForSync(user *model.User) *model.User {
+	user.Password = model.NewId()
+	user.AuthData = nil
+	user.AuthService = ""
+	user.Roles = "system_user"
+	user.AllowMarketing = false
+	user.NotifyProps = model.StringMap{}
+	user.LastPasswordUpdate = 0
+	user.LastPictureUpdate = 0
+	user.FailedAttempts = 0
+	user.MfaActive = false
+	user.MfaSecret = ""
+
+	return user
+}
+
+const MungUsernameSeparator = "-"
+
+// mungUsername creates a new username by combining username and remote cluster name, plus
+// a suffix to create uniqueness. If the resulting username exceeds the max length then
+// it is truncated and ellipses added.
+func mungUsername(username string, remotename string, suffix string, maxLen int) string {
+	if suffix != "" {
+		suffix = MungUsernameSeparator + suffix
+	}
+
+	// If the username already contains a colon then another server already munged it.
+	// In that case we can split on the colon and use the existing remote name.
+	// We still need to re-mung with suffix in case of collision.
+	comps := strings.Split(username, ":")
+	if len(comps) >= 2 {
+		username = comps[0]
+		remotename = strings.Join(comps[1:], "")
+	}
+
+	var userEllipses string
+	var remoteEllipses string
+
+	// The remotename is allowed to use up to half the maxLen, and the username gets the remaining space.
+	// Username might have a suffix to account for, and remotename always has a preceding colon.
+	half := maxLen / 2
+
+	// If the remotename is less than half the maxLen, then the left over space can be given to
+	// the username.
+	extra := max(half-(len(remotename)+1), 0)
+
+	truncUser := (len(username) + len(suffix)) - (half + extra)
+	if truncUser > 0 {
+		username = username[:len(username)-truncUser-3]
+		userEllipses = "..."
+	}
+
+	truncRemote := (len(remotename) + 1) - (maxLen - (len(username) + len(userEllipses) + len(suffix)))
+	if truncRemote > 0 {
+		remotename = remotename[:len(remotename)-truncRemote-3]
+		remoteEllipses = "..."
+	}
+
+	return fmt.Sprintf("%s%s%s:%s%s", username, suffix, userEllipses, remotename, remoteEllipses)
+}
+
+func isConflictError(err error) (string, bool) {
+	if err == nil {
+		return "", false
+	}
+
+	var errConflict *store.ErrConflict
+	if errors.As(err, &errConflict) {
+		return strings.ToLower(errConflict.Resource), true
+	}
+
+	var errInput *store.ErrInvalidInput
+	if errors.As(err, &errInput) {
+		_, field, _ := errInput.InvalidInputInfo()
+		return strings.ToLower(field), true
+	}
+	return "", false
+}
+
+func isNotFoundError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	var errNotFound *store.ErrNotFound
+	return errors.As(err, &errNotFound)
+}
+
+func postsSliceToMap(posts []*model.Post) map[string]*model.Post {
+	m := make(map[string]*model.Post, len(posts))
+	for _, p := range posts {
+		m[p.Id] = p
+	}
+	return m
+}
+
+func reducePostsSliceInCache(posts []*model.Post, cache map[string]*model.Post) []*model.Post {
+	reduced := make([]*model.Post, 0, len(posts))
+	for _, p := range posts {
+		if _, ok := cache[p.Id]; !ok {
+			reduced = append(reduced, p)
+		}
+	}
+	return reduced
+}