feature: initial syndication feeds support

Provides rss 2.0, atom 1.0 and json 1.0 feeds for videos (instance and account-wide) on listings and video-watch views.

* still lacks redis caching
* still lacks lastBuildDate support
* still lacks channel-wide support
* still lacks semantic annotation (for licenses, NSFW warnings, etc.)
* still lacks love ( ˘ ³˘)

* RSS: has MRSS support for torrent lists!
* RSS: includes the first torrent in an enclosure
* JSON: lists all torrents in the 'attachments' object
* ATOM: lacking torrent listing support

Advances #23
Partial implementation for the accountId generation in the client, which will need a hotfix to add a way to get the proper account id.

7 files changed, 298 insertions, 74 deletions

diff --git a/server/controllers/feeds.ts b/server/controllers/feeds.ts
new file mode 100644
index 000000000..b9d4c5d50
--- /dev/null
+++ b/server/controllers/feeds.ts
@@ -0,0 +1,136 @@
+import * as express from 'express'
+import { CONFIG } from '../initializers'
+import { asyncMiddleware, feedsValidator } from '../middlewares'
+import { VideoModel } from '../models/video/video'
+import * as Feed from 'pfeed'
+import { ResultList } from '../../shared/models'
+import { AccountModel } from '../models/account/account'
+
+const feedsRouter = express.Router()
+
+feedsRouter.get('/feeds/videos.:format',
+  asyncMiddleware(feedsValidator),
+  asyncMiddleware(generateFeed)
+)
+
+// ---------------------------------------------------------------------------
+
+export {
+  feedsRouter
+}
+
+// ---------------------------------------------------------------------------
+
+async function generateFeed (req: express.Request, res: express.Response, next: express.NextFunction) {
+  let feed = initFeed()
+  let feedStart = 0
+  let feedCount = 10
+  let feedSort = '-createdAt'
+
+  let resultList: ResultList<VideoModel>
+  const account: AccountModel = res.locals.account
+
+  if (account) {
+    resultList = await VideoModel.listUserVideosForApi(
+      account.id,
+      feedStart,
+      feedCount,
+      feedSort,
+      true
+    )
+  } else {
+    resultList = await VideoModel.listForApi(
+      feedStart,
+      feedCount,
+      feedSort,
+      req.query.filter,
+      true
+    )
+  }
+
+  // Adding video items to the feed, one at a time
+  resultList.data.forEach(video => {
+    const formattedVideoFiles = video.getFormattedVideoFilesJSON()
+    const torrents = formattedVideoFiles.map(videoFile => ({
+      title: video.name,
+      url: videoFile.torrentUrl,
+      size_in_bytes: videoFile.size
+    }))
+
+    feed.addItem({
+      title: video.name,
+      id: video.url,
+      link: video.url,
+      description: video.getTruncatedDescription(),
+      content: video.description,
+      author: [
+        {
+          name: video.VideoChannel.Account.getDisplayName(),
+          link: video.VideoChannel.Account.Actor.url
+        }
+      ],
+      date: video.publishedAt,
+      language: video.language,
+      nsfw: video.nsfw,
+      torrent: torrents
+    })
+  })
+
+  // Now the feed generation is done, let's send it!
+  return sendFeed(feed, req, res)
+}
+
+function initFeed () {
+  const webserverUrl = CONFIG.WEBSERVER.URL
+
+  return new Feed({
+    title: CONFIG.INSTANCE.NAME,
+    description: CONFIG.INSTANCE.SHORT_DESCRIPTION,
+    // updated: TODO: somehowGetLatestUpdate, // optional, default = today
+    id: webserverUrl,
+    link: webserverUrl,
+    image: webserverUrl + '/client/assets/images/icons/icon-96x96.png',
+    favicon: webserverUrl + '/client/assets/images/favicon.png',
+    copyright: `All rights reserved, unless otherwise specified in the terms specified at ${webserverUrl}/about` +
+    ` and potential licenses granted by each content's rightholder.`,
+    generator: `Toraifōsu`, // ^.~
+    feedLinks: {
+      json: `${webserverUrl}/feeds/videos.json`,
+      atom: `${webserverUrl}/feeds/videos.atom`,
+      rss: `${webserverUrl}/feeds/videos.xml`
+    },
+    author: {
+      name: 'instance admin of ' + CONFIG.INSTANCE.NAME,
+      email: CONFIG.ADMIN.EMAIL,
+      link: `${webserverUrl}/about`
+    }
+  })
+}
+
+function sendFeed (feed, req: express.Request, res: express.Response) {
+  const format = req.params.format
+
+  if (format === 'atom' || format === 'atom1') {
+    res.set('Content-Type', 'application/atom+xml')
+    return res.send(feed.atom1()).end()
+  }
+
+  if (format === 'json' || format === 'json1') {
+    res.set('Content-Type', 'application/json')
+    return res.send(feed.json1()).end()
+  }
+
+  if (format === 'rss' || format === 'rss2') {
+    res.set('Content-Type', 'application/rss+xml')
+    return res.send(feed.rss2()).end()
+  }
+
+  // We're in the ambiguous '.xml' case and we look at the format query parameter
+  if (req.query.format === 'atom' || req.query.format === 'atom1') {
+    res.set('Content-Type', 'application/atom+xml')
+    return res.send(feed.atom1()).end()
+  }
+
+  res.set('Content-Type', 'application/rss+xml')
+  return res.send(feed.rss2()).end()
+}
diff --git a/server/controllers/index.ts b/server/controllers/index.ts
index 457d0a12e..ff7928312 100644
--- a/server/controllers/index.ts
+++ b/server/controllers/index.ts
@@ -1,6 +1,7 @@
 export * from './activitypub'
-export * from './static'
+export * from './api'
 export * from './client'
+export * from './feeds'
 export * from './services'
-export * from './api'
+export * from './static'
 export * from './webfinger'
diff --git a/server/helpers/custom-validators/feeds.ts b/server/helpers/custom-validators/feeds.ts
new file mode 100644
index 000000000..638e814f0
--- /dev/null
+++ b/server/helpers/custom-validators/feeds.ts
@@ -0,0 +1,23 @@
+import { exists } from './misc'
+
+function isValidRSSFeed (value: string) {
+  if (!exists(value)) return false
+
+  const feedExtensions = [
+    'xml',
+    'json',
+    'json1',
+    'rss',
+    'rss2',
+    'atom',
+    'atom1'
+  ]
+
+  return feedExtensions.indexOf(value) !== -1
+}
+
+// ---------------------------------------------------------------------------
+
+export {
+  isValidRSSFeed
+}
diff --git a/server/middlewares/validators/feeds.ts b/server/middlewares/validators/feeds.ts
new file mode 100644
index 000000000..6a8cfce86
--- /dev/null
+++ b/server/middlewares/validators/feeds.ts
@@ -0,0 +1,35 @@
+import * as express from 'express'
+import { param, query } from 'express-validator/check'
+import { isAccountIdExist, isAccountNameValid, isLocalAccountNameExist } from '../../helpers/custom-validators/accounts'
+import { join } from 'path'
+import { isIdOrUUIDValid } from '../../helpers/custom-validators/misc'
+import { logger } from '../../helpers/logger'
+import { areValidationErrors } from './utils'
+import { isValidRSSFeed } from '../../helpers/custom-validators/feeds'
+
+const feedsValidator = [
+  param('format').optional().custom(isValidRSSFeed).withMessage('Should have a valid format (rss, atom, json)'),
+  query('format').optional().custom(isValidRSSFeed).withMessage('Should have a valid format (rss, atom, json)'),
+  query('accountId').optional().custom(isIdOrUUIDValid),
+  query('accountName').optional().custom(isAccountNameValid),
+
+  async (req: express.Request, res: express.Response, next: express.NextFunction) => {
+    logger.debug('Checking feeds parameters', { parameters: req.query })
+
+    if (areValidationErrors(req, res)) return
+
+    if (req.query.accountId) {
+      if (!await isAccountIdExist(req.query.accountId, res)) return
+    } else if (req.query.accountName) {
+      if (!await isLocalAccountNameExist(req.query.accountName, res)) return
+    }
+
+    return next()
+  }
+]
+
+// ---------------------------------------------------------------------------
+
+export {
+  feedsValidator
+}
diff --git a/server/middlewares/validators/index.ts b/server/middlewares/validators/index.ts
index 9840e8f65..b69e1f14b 100644
--- a/server/middlewares/validators/index.ts
+++ b/server/middlewares/validators/index.ts
@@ -3,6 +3,7 @@ export * from './oembed'
 export * from './activitypub'
 export * from './pagination'
 export * from './follows'
+export * from './feeds'
 export * from './sort'
 export * from './users'
 export * from './videos'
diff --git a/server/models/account/account.ts b/server/models/account/account.ts
index c5955ef3b..3ff59887d 100644
--- a/server/models/account/account.ts
+++ b/server/models/account/account.ts
@@ -246,7 +246,7 @@ export class AccountModel extends Model<AccountModel> {
     const actor = this.Actor.toFormattedJSON()
     const account = {
       id: this.id,
-      displayName: this.name,
+      displayName: this.getDisplayName(),
       description: this.description,
       createdAt: this.createdAt,
       updatedAt: this.updatedAt
@@ -266,4 +266,8 @@ export class AccountModel extends Model<AccountModel> {
   isOwned () {
     return this.Actor.isOwned()
   }
+
+  getDisplayName () {
+    return this.name
+  }
 }
diff --git a/server/models/video/video.ts b/server/models/video/video.ts
index 54fe54535..240a2b5a2 100644
--- a/server/models/video/video.ts
+++ b/server/models/video/video.ts
@@ -95,14 +95,15 @@ enum ScopeNames {
 }
 
 @Scopes({
-  [ScopeNames.AVAILABLE_FOR_LIST]: (actorId: number, filter?: VideoFilter) => ({
-    where: {
-      id: {
-        [Sequelize.Op.notIn]: Sequelize.literal(
-          '(SELECT "videoBlacklist"."videoId" FROM "videoBlacklist")'
-        ),
-        [ Sequelize.Op.in ]: Sequelize.literal(
-          '(' +
+  [ScopeNames.AVAILABLE_FOR_LIST]: (actorId: number, filter?: VideoFilter, withFiles?: boolean) => {
+    const query: IFindOptions<VideoModel> = {
+      where: {
+        id: {
+          [Sequelize.Op.notIn]: Sequelize.literal(
+            '(SELECT "videoBlacklist"."videoId" FROM "videoBlacklist")'
+          ),
+          [ Sequelize.Op.in ]: Sequelize.literal(
+            '(' +
             'SELECT "videoShare"."videoId" AS "id" FROM "videoShare" ' +
             'INNER JOIN "actorFollow" ON "actorFollow"."targetActorId" = "videoShare"."actorId" ' +
             'WHERE "actorFollow"."actorId" = ' + parseInt(actorId.toString(), 10) +
@@ -113,45 +114,55 @@ enum ScopeNames {
             'INNER JOIN "actor" ON "account"."actorId" = "actor"."id" ' +
             'LEFT JOIN "actorFollow" ON "actorFollow"."targetActorId" = "actor"."id" ' +
             'WHERE "actor"."serverId" IS NULL OR "actorFollow"."actorId" = ' + parseInt(actorId.toString(), 10) +
-          ')'
-        )
+            ')'
+          )
+        },
+        privacy: VideoPrivacy.PUBLIC
       },
-      privacy: VideoPrivacy.PUBLIC
-    },
-    include: [
-      {
-        attributes: [ 'name', 'description' ],
-        model: VideoChannelModel.unscoped(),
-        required: true,
-        include: [
-          {
-            attributes: [ 'name' ],
-            model: AccountModel.unscoped(),
-            required: true,
-            include: [
-              {
-                attributes: [ 'preferredUsername', 'url', 'serverId' ],
-                model: ActorModel.unscoped(),
-                required: true,
-                where: VideoModel.buildActorWhereWithFilter(filter),
-                include: [
-                  {
-                    attributes: [ 'host' ],
-                    model: ServerModel.unscoped(),
-                    required: false
-                  },
-                  {
-                    model: AvatarModel.unscoped(),
-                    required: false
-                  }
-                ]
-              }
-            ]
-          }
-        ]
-      }
-    ]
-  }),
+      include: [
+        {
+          attributes: [ 'name', 'description' ],
+          model: VideoChannelModel.unscoped(),
+          required: true,
+          include: [
+            {
+              attributes: [ 'name' ],
+              model: AccountModel.unscoped(),
+              required: true,
+              include: [
+                {
+                  attributes: [ 'preferredUsername', 'url', 'serverId', 'avatarId' ],
+                  model: ActorModel.unscoped(),
+                  required: true,
+                  where: VideoModel.buildActorWhereWithFilter(filter),
+                  include: [
+                    {
+                      attributes: [ 'host' ],
+                      model: ServerModel.unscoped(),
+                      required: false
+                    },
+                    {
+                      model: AvatarModel.unscoped(),
+                      required: false
+                    }
+                  ]
+                }
+              ]
+            }
+          ]
+        }
+      ]
+    }
+
+    if (withFiles === true) {
+      query.include.push({
+        model: VideoFileModel.unscoped(),
+        required: true
+      })
+    }
+
+    return query
+  },
   [ScopeNames.WITH_ACCOUNT_DETAILS]: {
     include: [
       {
@@ -629,8 +640,8 @@ export class VideoModel extends Model<VideoModel> {
     })
   }
 
-  static listUserVideosForApi (userId: number, start: number, count: number, sort: string) {
-    const query = {
+  static listUserVideosForApi (userId: number, start: number, count: number, sort: string, withFiles = false) {
+    const query: IFindOptions<VideoModel> = {
       offset: start,
       limit: count,
       order: getSort(sort),
@@ -651,6 +662,13 @@ export class VideoModel extends Model<VideoModel> {
       ]
     }
 
+    if (withFiles === true) {
+      query.include.push({
+        model: VideoFileModel.unscoped(),
+        required: true
+      })
+    }
+
     return VideoModel.findAndCountAll(query).then(({ rows, count }) => {
       return {
         data: rows,
@@ -659,7 +677,7 @@ export class VideoModel extends Model<VideoModel> {
     })
   }
 
-  static async listForApi (start: number, count: number, sort: string, filter?: VideoFilter) {
+  static async listForApi (start: number, count: number, sort: string, filter?: VideoFilter, withFiles = false) {
     const query = {
       offset: start,
       limit: count,
@@ -668,7 +686,7 @@ export class VideoModel extends Model<VideoModel> {
 
     const serverActor = await getServerActor()
 
-    return VideoModel.scope({ method: [ ScopeNames.AVAILABLE_FOR_LIST, serverActor.id, filter ] })
+    return VideoModel.scope({ method: [ ScopeNames.AVAILABLE_FOR_LIST, serverActor.id, filter, withFiles ] })
       .findAndCountAll(query)
       .then(({ rows, count }) => {
         return {
@@ -707,7 +725,8 @@ export class VideoModel extends Model<VideoModel> {
     const serverActor = await getServerActor()
 
     return VideoModel.scope({ method: [ ScopeNames.AVAILABLE_FOR_LIST, serverActor.id ] })
-      .findAndCountAll(query).then(({ rows, count }) => {
+      .findAndCountAll(query)
+      .then(({ rows, count }) => {
         return {
           data: rows,
           total: count
@@ -1006,29 +1025,34 @@ export class VideoModel extends Model<VideoModel> {
     }
 
     // Format and sort video files
+    detailsJson.files = this.getFormattedVideoFilesJSON()
+
+    return Object.assign(formattedJson, detailsJson)
+  }
+
+  getFormattedVideoFilesJSON (): VideoFile[] {
     const { baseUrlHttp, baseUrlWs } = this.getBaseUrls()
-    detailsJson.files = this.VideoFiles
-      .map(videoFile => {
-        let resolutionLabel = videoFile.resolution + 'p'
 
-        return {
-          resolution: {
-            id: videoFile.resolution,
-            label: resolutionLabel
-          },
-          magnetUri: this.generateMagnetUri(videoFile, baseUrlHttp, baseUrlWs),
-          size: videoFile.size,
-          torrentUrl: this.getTorrentUrl(videoFile, baseUrlHttp),
-          fileUrl: this.getVideoFileUrl(videoFile, baseUrlHttp)
-        } as VideoFile
-      })
-      .sort((a, b) => {
-        if (a.resolution.id < b.resolution.id) return 1
-        if (a.resolution.id === b.resolution.id) return 0
-        return -1
-      })
+    return this.VideoFiles
+        .map(videoFile => {
+          let resolutionLabel = videoFile.resolution + 'p'
 
-    return Object.assign(formattedJson, detailsJson)
+          return {
+            resolution: {
+              id: videoFile.resolution,
+              label: resolutionLabel
+            },
+            magnetUri: this.generateMagnetUri(videoFile, baseUrlHttp, baseUrlWs),
+            size: videoFile.size,
+            torrentUrl: this.getTorrentUrl(videoFile, baseUrlHttp),
+            fileUrl: this.getVideoFileUrl(videoFile, baseUrlHttp)
+          } as VideoFile
+        })
+        .sort((a, b) => {
+          if (a.resolution.id < b.resolution.id) return 1
+          if (a.resolution.id === b.resolution.id) return 0
+          return -1
+        })
   }
 
   toActivityPubObject (): VideoTorrentObject {