WIP plugins: add ability to register plugins

1 files changed, 169 insertions, 0 deletions

diff --git a/server/lib/plugins/plugin-manager.ts b/server/lib/plugins/plugin-manager.ts
new file mode 100644
index 000000000..b48ecc991
--- /dev/null
+++ b/server/lib/plugins/plugin-manager.ts
@@ -0,0 +1,169 @@
+import { PluginModel } from '../../models/server/plugin'
+import { logger } from '../../helpers/logger'
+import { RegisterHookOptions } from '../../../shared/models/plugins/register.model'
+import { join } from 'path'
+import { CONFIG } from '../../initializers/config'
+import { isLibraryCodeValid, isPackageJSONValid } from '../../helpers/custom-validators/plugins'
+import { PluginPackageJson } from '../../../shared/models/plugins/plugin-package-json.model'
+import { PluginLibrary } from '../../../shared/models/plugins/plugin-library.model'
+import { createReadStream, createWriteStream } from 'fs'
+import { PLUGIN_GLOBAL_CSS_PATH } from '../../initializers/constants'
+import { PluginType } from '../../../shared/models/plugins/plugin.type'
+
+export interface RegisteredPlugin {
+  name: string
+  version: string
+  description: string
+  peertubeEngine: string
+
+  type: PluginType
+
+  path: string
+
+  staticDirs: { [name: string]: string }
+
+  css: string[]
+
+  // Only if this is a plugin
+  unregister?: Function
+}
+
+export interface HookInformationValue {
+  pluginName: string
+  handler: Function
+  priority: number
+}
+
+export class PluginManager {
+
+  private static instance: PluginManager
+
+  private registeredPlugins: { [ name: string ]: RegisteredPlugin } = {}
+  private hooks: { [ name: string ]: HookInformationValue[] } = {}
+
+  private constructor () {
+  }
+
+  async registerPlugins () {
+    const plugins = await PluginModel.listEnabledPluginsAndThemes()
+
+    for (const plugin of plugins) {
+      try {
+        await this.registerPluginOrTheme(plugin)
+      } catch (err) {
+        logger.error('Cannot register plugin %s, skipping.', plugin.name, { err })
+      }
+    }
+
+    this.sortHooksByPriority()
+  }
+
+  getRegisteredPlugin (name: string) {
+    return this.registeredPlugins[ name ]
+  }
+
+  getRegisteredTheme (name: string) {
+    const registered = this.getRegisteredPlugin(name)
+
+    if (!registered || registered.type !== PluginType.THEME) return undefined
+
+    return registered
+  }
+
+  async unregister (name: string) {
+    const plugin = this.getRegisteredPlugin(name)
+
+    if (!plugin) {
+      throw new Error(`Unknown plugin ${name} to unregister`)
+    }
+
+    if (plugin.type === PluginType.THEME) {
+      throw new Error(`Cannot unregister ${name}: this is a theme`)
+    }
+
+    await plugin.unregister()
+  }
+
+  private async registerPluginOrTheme (plugin: PluginModel) {
+    logger.info('Registering plugin or theme %s.', plugin.name)
+
+    const pluginPath = join(CONFIG.STORAGE.PLUGINS_DIR, plugin.name, plugin.version)
+    const packageJSON: PluginPackageJson = require(join(pluginPath, 'package.json'))
+
+    if (!isPackageJSONValid(packageJSON, plugin.type)) {
+      throw new Error('Package.JSON is invalid.')
+    }
+
+    let library: PluginLibrary
+    if (plugin.type === PluginType.PLUGIN) {
+      library = await this.registerPlugin(plugin, pluginPath, packageJSON)
+    }
+
+    this.registeredPlugins[ plugin.name ] = {
+      name: plugin.name,
+      type: plugin.type,
+      version: plugin.version,
+      description: plugin.description,
+      peertubeEngine: plugin.peertubeEngine,
+      path: pluginPath,
+      staticDirs: packageJSON.staticDirs,
+      css: packageJSON.css,
+      unregister: library ? library.unregister : undefined
+    }
+  }
+
+  private async registerPlugin (plugin: PluginModel, pluginPath: string, packageJSON: PluginPackageJson) {
+    const registerHook = (options: RegisterHookOptions) => {
+      if (!this.hooks[options.target]) this.hooks[options.target] = []
+
+      this.hooks[options.target].push({
+        pluginName: plugin.name,
+        handler: options.handler,
+        priority: options.priority || 0
+      })
+    }
+
+    const library: PluginLibrary = require(join(pluginPath, packageJSON.library))
+    if (!isLibraryCodeValid(library)) {
+      throw new Error('Library code is not valid (miss register or unregister function)')
+    }
+
+    library.register({ registerHook })
+
+    logger.info('Add plugin %s CSS to global file.', plugin.name)
+
+    await this.addCSSToGlobalFile(pluginPath, packageJSON.css)
+
+    return library
+  }
+
+  private sortHooksByPriority () {
+    for (const hookName of Object.keys(this.hooks)) {
+      this.hooks[hookName].sort((a, b) => {
+        return b.priority - a.priority
+      })
+    }
+  }
+
+  private async addCSSToGlobalFile (pluginPath: string, cssRelativePaths: string[]) {
+    for (const cssPath of cssRelativePaths) {
+      await this.concatFiles(join(pluginPath, cssPath), PLUGIN_GLOBAL_CSS_PATH)
+    }
+  }
+
+  private concatFiles (input: string, output: string) {
+    return new Promise<void>((res, rej) => {
+      const outputStream = createWriteStream(input)
+      const inputStream = createReadStream(output)
+
+      inputStream.pipe(outputStream)
+
+      inputStream.on('end', () => res())
+      inputStream.on('error', err => rej(err))
+    })
+  }
+
+  static get Instance () {
+    return this.instance || (this.instance = new this())
+  }
+}