Adds Remote Cluster related API endpoints (#27432)

* Adds Remote Cluster related API endpoints

New endpoints for the following routes are added:

- Get Remote Clusters at `GET /api/v4/remotecluster`
- Create Remote Cluster at `POST /api/v4/remotecluster`
- Accept Remote Cluster invite at `POST
/api/v4/remotecluster/accept_invite`
- Generate Remote Cluster invite at `POST
/api/v4/remotecluster/{remote_id}/generate_invite`
- Get Remote Cluster at `GET /api/v4/remotecluster/{remote_id}`
- Patch Remote Cluster at `PATCH /api/v4/remotecluster/{remote_id}`
- Delete Remote Cluster at `DELETE /api/v4/remotecluster/{remote_id}`

These endpoints are planned to be used from the system console, and
gated through the `manage_secure_connections` permission.

* Update server/channels/api4/remote_cluster_test.go

Co-authored-by: Doug Lauder <wiggin77@warpmail.net>

* Fix AppError names

---------

Co-authored-by: Doug Lauder <wiggin77@warpmail.net>
Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/app/slashcommands/command_remote.go

@@ -4,7 +4,6 @@
 package slashcommands
 
 import (
-	"encoding/base64"
 	"errors"
 	"fmt"
 	"strings"
@@ -144,19 +143,13 @@ func (rp *RemoteProvider) doCreate(a *app.App, args *model.CommandArgs, margs ma
 	}
 
 	// Display the encrypted invitation
-	invite := &model.RemoteClusterInvite{
-		RemoteId: rcSaved.RemoteId,
-		SiteURL:  url,
-		Token:    rcSaved.Token,
-	}
-	encrypted, err := invite.Encrypt(password)
+	inviteCode, err := a.CreateRemoteClusterInvite(rcSaved.RemoteId, url, rcSaved.Token, password)
 	if err != nil {
 		return responsef(args.T("api.command_remote.encrypt_invitation.error", map[string]any{"Error": err.Error()}))
 	}
-	encoded := base64.URLEncoding.EncodeToString(encrypted)
 
 	return responsef("##### " + args.T("api.command_remote.invitation_created") + "\n" +
-		args.T("api.command_remote.invite_summary", map[string]any{"Command": "/secure-connection accept", "Invitation": encoded, "SiteURL": invite.SiteURL}))
+		args.T("api.command_remote.invite_summary", map[string]any{"Command": "/secure-connection accept", "Invitation": inviteCode, "SiteURL": url}))
 }
 
 // doAccept accepts an invitation generated by a remote site.
@@ -182,14 +175,9 @@ func (rp *RemoteProvider) doAccept(a *app.App, args *model.CommandArgs, margs ma
 	}
 
 	// invite is encoded as base64 and encrypted
-	decoded, err := base64.URLEncoding.DecodeString(blob)
-	if err != nil {
-		return responsef(args.T("api.command_remote.decode_invitation.error", map[string]any{"Error": err.Error()}))
-	}
-	invite := &model.RemoteClusterInvite{}
-	err = invite.Decrypt(decoded, password)
-	if err != nil {
-		return responsef(args.T("api.command_remote.incorrect_password.error", map[string]any{"Error": err.Error()}))
+	invite, dErr := a.DecryptRemoteClusterInvite(blob, password)
+	if dErr != nil {
+		return responsef(args.T("api.command_remote.decode_invitation.error", map[string]any{"Error": dErr.Error()}))
 	}
 
 	rcs, _ := a.GetRemoteClusterService()
@@ -202,7 +190,7 @@ func (rp *RemoteProvider) doAccept(a *app.App, args *model.CommandArgs, margs ma
 		return responsef(args.T("api.command_remote.site_url_not_set"))
 	}
 
-	rc, err := rcs.AcceptInvitation(invite, name, displayname, args.UserId, args.TeamId, url)
+	rc, err := rcs.AcceptInvitation(invite, name, displayname, args.UserId, url)
 	if err != nil {
 		return responsef(args.T("api.command_remote.accept_invitation.error", map[string]any{"Error": err.Error()}))
 	}
@@ -231,7 +219,7 @@ func (rp *RemoteProvider) doRemove(a *app.App, args *model.CommandArgs, margs ma
 
 // doStatus displays connection status for all remote clusters.
 func (rp *RemoteProvider) doStatus(a *app.App, args *model.CommandArgs, _ map[string]string) *model.CommandResponse {
-	list, err := a.GetAllRemoteClusters(model.RemoteClusterQueryFilter{})
+	list, err := a.GetAllRemoteClusters(0, 999999, model.RemoteClusterQueryFilter{})
 	if err != nil {
 		responsef(args.T("api.command_remote.fetch_status.error", map[string]any{"Error": err.Error()}))
 	}
@@ -263,7 +251,7 @@ func getRemoteClusterAutocompleteListItems(a *app.App, includeOffline bool) ([]m
 	filter := model.RemoteClusterQueryFilter{
 		ExcludeOffline: !includeOffline,
 	}
-	clusters, err := a.GetAllRemoteClusters(filter)
+	clusters, err := a.GetAllRemoteClusters(0, 999999, filter)
 	if err != nil || len(clusters) == 0 {
 		return []model.AutocompleteListItem{}, nil
 	}
@@ -284,7 +272,7 @@ func getRemoteClusterAutocompleteListItemsNotInChannel(a *app.App, channelID str
 		ExcludeOffline: !includeOffline,
 		NotInChannel:   channelID,
 	}
-	all, err := a.GetAllRemoteClusters(filter)
+	all, err := a.GetAllRemoteClusters(0, 999999, filter)
 	if err != nil || len(all) == 0 {
 		return []model.AutocompleteListItem{}, nil
 	}