2 files changed, 54 insertions, 4 deletions

diff --git a/server/lib/plugins/plugin-manager.ts b/server/lib/plugins/plugin-manager.ts
index 7cbfa8569..8496979f8 100644
--- a/server/lib/plugins/plugin-manager.ts
+++ b/server/lib/plugins/plugin-manager.ts
@@ -11,6 +11,7 @@ import { PLUGIN_GLOBAL_CSS_PATH } from '../../initializers/constants'
 import { PluginType } from '../../../shared/models/plugins/plugin.type'
 import { installNpmPlugin, installNpmPluginFromDisk, removeNpmPlugin } from './yarn'
 import { outputFile } from 'fs-extra'
+import { ServerConfigPlugin } from '../../../shared/models/server'
 
 export interface RegisteredPlugin {
   name: string
@@ -47,7 +48,7 @@ export class PluginManager {
   private constructor () {
   }
 
-  async registerPlugins () {
+  async registerPluginsAndThemes () {
     await this.resetCSSGlobalFile()
 
     const plugins = await PluginModel.listEnabledPluginsAndThemes()
@@ -63,12 +64,20 @@ export class PluginManager {
     this.sortHooksByPriority()
   }
 
+  getRegisteredPluginOrTheme (name: string) {
+    return this.registeredPlugins[name]
+  }
+
   getRegisteredPlugin (name: string) {
-    return this.registeredPlugins[ name ]
+    const registered = this.getRegisteredPluginOrTheme(name)
+
+    if (!registered || registered.type !== PluginType.PLUGIN) return undefined
+
+    return registered
   }
 
   getRegisteredTheme (name: string) {
-    const registered = this.getRegisteredPlugin(name)
+    const registered = this.getRegisteredPluginOrTheme(name)
 
     if (!registered || registered.type !== PluginType.THEME) return undefined
 
@@ -76,7 +85,11 @@ export class PluginManager {
   }
 
   getRegisteredPlugins () {
-    return this.registeredPlugins
+    return this.getRegisteredPluginsOrThemes(PluginType.PLUGIN)
+  }
+
+  getRegisteredThemes () {
+    return this.getRegisteredPluginsOrThemes(PluginType.THEME)
   }
 
   async runHook (hookName: string, param?: any) {
@@ -309,6 +322,19 @@ export class PluginManager {
     }
   }
 
+  private getRegisteredPluginsOrThemes (type: PluginType) {
+    const plugins: RegisteredPlugin[] = []
+
+    for (const pluginName of Object.keys(this.registeredPlugins)) {
+      const plugin = this.registeredPlugins[ pluginName ]
+      if (plugin.type !== type) continue
+
+      plugins.push(plugin)
+    }
+
+    return plugins
+  }
+
   static get Instance () {
     return this.instance || (this.instance = new this())
   }
diff --git a/server/lib/plugins/theme-utils.ts b/server/lib/plugins/theme-utils.ts
new file mode 100644
index 000000000..066339e65
--- /dev/null
+++ b/server/lib/plugins/theme-utils.ts
@@ -0,0 +1,24 @@
+import { DEFAULT_THEME } from '../../initializers/constants'
+import { PluginManager } from './plugin-manager'
+import { CONFIG } from '../../initializers/config'
+
+function getThemeOrDefault (name: string) {
+  if (isThemeRegistered(name)) return name
+
+  // Fallback to admin default theme
+  if (name !== CONFIG.THEME.DEFAULT) return getThemeOrDefault(CONFIG.THEME.DEFAULT)
+
+  return DEFAULT_THEME
+}
+
+function isThemeRegistered (name: string) {
+  if (name === DEFAULT_THEME) return true
+
+  return !!PluginManager.Instance.getRegisteredThemes()
+                        .find(r => r.name === name)
+}
+
+export {
+  getThemeOrDefault,
+  isThemeRegistered
+}