Introduce generic video constant manager for plugins

Allow a plugin developer to get back constants values,
and reset constants deletions or additions.

1 files changed, 139 insertions, 0 deletions

diff --git a/server/lib/plugins/video-constant-manager-factory.ts b/server/lib/plugins/video-constant-manager-factory.ts
new file mode 100644
index 000000000..f04dde29f
--- /dev/null
+++ b/server/lib/plugins/video-constant-manager-factory.ts
@@ -0,0 +1,139 @@
+import { logger } from '@server/helpers/logger'
+import {
+  VIDEO_CATEGORIES,
+  VIDEO_LANGUAGES,
+  VIDEO_LICENCES,
+  VIDEO_PLAYLIST_PRIVACIES,
+  VIDEO_PRIVACIES
+} from '@server/initializers/constants'
+import { ConstantManager } from '@shared/models/plugins/server/plugin-constant-manager.model'
+
+type AlterableVideoConstant = 'language' | 'licence' | 'category' | 'privacy' | 'playlistPrivacy'
+type VideoConstant = Record<number | string, string>
+
+type UpdatedVideoConstant = {
+  [name in AlterableVideoConstant]: {
+    [ npmName: string]: {
+      added: VideoConstant[]
+      deleted: VideoConstant[]
+    }
+  }
+}
+
+const constantsHash: { [key in AlterableVideoConstant]: VideoConstant } = {
+  language: VIDEO_LANGUAGES,
+  licence: VIDEO_LICENCES,
+  category: VIDEO_CATEGORIES,
+  privacy: VIDEO_PRIVACIES,
+  playlistPrivacy: VIDEO_PLAYLIST_PRIVACIES
+}
+
+export class VideoConstantManagerFactory {
+  private readonly updatedVideoConstants: UpdatedVideoConstant = {
+    playlistPrivacy: { },
+    privacy: { },
+    language: { },
+    licence: { },
+    category: { }
+  }
+
+  constructor (
+    private readonly npmName: string
+  ) {}
+
+  public resetVideoConstants (npmName: string) {
+    const types: AlterableVideoConstant[] = [ 'language', 'licence', 'category', 'privacy', 'playlistPrivacy' ]
+    for (const type of types) {
+      this.resetConstants({ npmName, type })
+    }
+  }
+
+  private resetConstants (parameters: { npmName: string, type: AlterableVideoConstant }) {
+    const { npmName, type } = parameters
+    const updatedConstants = this.updatedVideoConstants[type][npmName]
+
+    if (!updatedConstants) return
+
+    for (const added of updatedConstants.added) {
+      delete constantsHash[type][added.key]
+    }
+
+    for (const deleted of updatedConstants.deleted) {
+      constantsHash[type][deleted.key] = deleted.label
+    }
+
+    delete this.updatedVideoConstants[type][npmName]
+  }
+
+  public createVideoConstantManager<K extends number | string>(type: AlterableVideoConstant): ConstantManager<K> {
+    const { npmName } = this
+    return {
+      addConstant: (key: K, label: string) => this.addConstant({ npmName, type, key, label }),
+      deleteConstant: (key: K) => this.deleteConstant({ npmName, type, key }),
+      getConstantValue: (key: K) => constantsHash[type][key],
+      getConstants: () => constantsHash[type] as Record<K, string>,
+      resetConstants: () => this.resetConstants({ npmName, type })
+    }
+  }
+
+  private addConstant<T extends string | number> (parameters: {
+    npmName: string
+    type: AlterableVideoConstant
+    key: T
+    label: string
+  }) {
+    const { npmName, type, key, label } = parameters
+    const obj = constantsHash[type]
+
+    if (obj[key]) {
+      logger.warn('Cannot add %s %s by plugin %s: key already exists.', type, npmName, key)
+      return false
+    }
+
+    if (!this.updatedVideoConstants[type][npmName]) {
+      this.updatedVideoConstants[type][npmName] = {
+        added: [],
+        deleted: []
+      }
+    }
+
+    this.updatedVideoConstants[type][npmName].added.push({ key: key, label } as VideoConstant)
+    obj[key] = label
+
+    return true
+  }
+
+  private deleteConstant<T extends string | number> (parameters: {
+    npmName: string
+    type: AlterableVideoConstant
+    key: T
+  }) {
+    const { npmName, type, key } = parameters
+    const obj = constantsHash[type]
+
+    if (!obj[key]) {
+      logger.warn('Cannot delete %s by plugin %s: key %s does not exist.', type, npmName, key)
+      return false
+    }
+
+    if (!this.updatedVideoConstants[type][npmName]) {
+      this.updatedVideoConstants[type][npmName] = {
+        added: [],
+        deleted: []
+      }
+    }
+
+    const updatedConstants = this.updatedVideoConstants[type][npmName]
+
+    const alreadyAdded = updatedConstants.added.find(a => a.key === key)
+    if (alreadyAdded) {
+      updatedConstants.added.filter(a => a.key !== key)
+    } else if (obj[key]) {
+      updatedConstants.deleted.push({ key, label: obj[key] } as VideoConstant)
+    }
+
+    delete obj[key]
+
+    return true
+  }
+}