Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/boards/ws/plugin_adapter_client.go

@@ -0,0 +1,89 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package ws
+
+import (
+	"sync"
+	"sync/atomic"
+	"time"
+
+	mm_model "github.com/mattermost/mattermost-server/v6/model"
+)
+
+type PluginAdapterClient struct {
+	inactiveAt int64
+	webConnID  string
+	userID     string
+	teams      []string
+	blocks     []string
+	mu         sync.RWMutex
+}
+
+func (pac *PluginAdapterClient) isActive() bool {
+	return atomic.LoadInt64(&pac.inactiveAt) == 0
+}
+
+func (pac *PluginAdapterClient) hasExpired(threshold time.Duration) bool {
+	return !mm_model.GetTimeForMillis(atomic.LoadInt64(&pac.inactiveAt)).Add(threshold).After(time.Now())
+}
+
+func (pac *PluginAdapterClient) subscribeToTeam(teamID string) {
+	pac.mu.Lock()
+	defer pac.mu.Unlock()
+
+	pac.teams = append(pac.teams, teamID)
+}
+
+func (pac *PluginAdapterClient) unsubscribeFromTeam(teamID string) {
+	pac.mu.Lock()
+	defer pac.mu.Unlock()
+
+	newClientTeams := []string{}
+	for _, id := range pac.teams {
+		if id != teamID {
+			newClientTeams = append(newClientTeams, id)
+		}
+	}
+	pac.teams = newClientTeams
+}
+
+func (pac *PluginAdapterClient) unsubscribeFromBlock(blockID string) {
+	pac.mu.Lock()
+	defer pac.mu.Unlock()
+
+	newClientBlocks := []string{}
+	for _, id := range pac.blocks {
+		if id != blockID {
+			newClientBlocks = append(newClientBlocks, id)
+		}
+	}
+	pac.blocks = newClientBlocks
+}
+
+func (pac *PluginAdapterClient) isSubscribedToTeam(teamID string) bool {
+	pac.mu.RLock()
+	defer pac.mu.RUnlock()
+
+	for _, id := range pac.teams {
+		if id == teamID {
+			return true
+		}
+	}
+
+	return false
+}
+
+//nolint:unused
+func (pac *PluginAdapterClient) isSubscribedToBlock(blockID string) bool {
+	pac.mu.RLock()
+	defer pac.mu.RUnlock()
+
+	for _, id := range pac.blocks {
+		if id == blockID {
+			return true
+		}
+	}
+
+	return false
+}