Add ability for an administrator to remove any video (#61)

* Add ability for an admin to remove every video on the pod.

* Server: add BlacklistedVideos relation.

* Server: Insert in BlacklistedVideos relation upon deletion of a video.

* Server: Modify BlacklistedVideos schema to add Pod id information.

* Server: Moving insertion of a blacklisted video from the `afterDestroy` hook into the process of deletion of a video.

To avoid inserting a video when it is removed on its origin pod.
When a video is removed on its origin pod, the `afterDestroy` hook is fire, but no request is made on the delete('/:videoId') interface.
Hence, we insert into `BlacklistedVideos` only on request on delete('/:videoId') (if requirements for insertion are met).

* Server: Add removeVideoFromBlacklist hook on deletion of a video.

We are going to proceed in another way :).
We will add a new route : /:videoId/blacklist to blacklist a video.
We do not blacklist a video upon its deletion now (to distinguish a video blacklist from a regular video delete)
When we blacklist a video, the video remains in the DB, so we don't have any concern about its update. It just doesn't appear in the video list.
When we remove a video, we then have to remove it from the blacklist too.
We could also remove a video from the blacklist to 'unremove' it and make it appear again in the video list (will be another feature).

* Server: Add handler for new route post(/:videoId/blacklist)

* Client: Add isBlacklistable method

* Client: Update isRemovableBy method.

* Client: Move 'Delete video' feature from the video-list to the video-watch module.

* Server: Exclude blacklisted videos from the video list

* Server: Use findAll() in BlacklistedVideos.list() method

* Server: Fix addVideoToBlacklist function.

* Client: Add blacklist feature.

* Server: Use JavaScript Standard Style.

* Server: In checkUserCanDeleteVideo, move the callback call inside the db callback function

* Server: Modify BlacklistVideo relation

* Server: Modifiy Videos methods.

* Server: Add checkVideoIsBlacklistable method

* Server: Rewrite addVideoToBlacklist method

* Server: Fix checkVideoIsBlacklistable method

* Server: Add return to addVideoToBlacklist method

3 files changed, 134 insertions, 11 deletions

diff --git a/server/models/user.js b/server/models/user.js
index e64bab8ab..8f9c2bf65 100644
--- a/server/models/user.js
+++ b/server/models/user.js
@@ -79,7 +79,8 @@ module.exports = function (sequelize, DataTypes) {
       },
       instanceMethods: {
         isPasswordMatch,
-        toFormatedJSON
+        toFormatedJSON,
+        isAdmin
       },
       hooks: {
         beforeCreate: beforeCreateOrUpdate,
@@ -117,6 +118,11 @@ function toFormatedJSON () {
     createdAt: this.createdAt
   }
 }
+
+function isAdmin () {
+  return this.role === constants.USER_ROLES.ADMIN
+}
+
 // ------------------------------ STATICS ------------------------------
 
 function associate (models) {
diff --git a/server/models/video-blacklist.js b/server/models/video-blacklist.js
new file mode 100644
index 000000000..02ea15760
--- /dev/null
+++ b/server/models/video-blacklist.js
@@ -0,0 +1,89 @@
+'use strict'
+
+const modelUtils = require('./utils')
+
+// ---------------------------------------------------------------------------
+
+module.exports = function (sequelize, DataTypes) {
+  const BlacklistedVideo = sequelize.define('BlacklistedVideo',
+    {},
+    {
+      indexes: [
+        {
+          fields: [ 'videoId' ],
+          unique: true
+        }
+      ],
+      classMethods: {
+        associate,
+
+        countTotal,
+        list,
+        listForApi,
+        loadById,
+        loadByVideoId
+      },
+      instanceMethods: {
+        toFormatedJSON
+      },
+      hooks: {}
+    }
+  )
+
+  return BlacklistedVideo
+}
+
+// ------------------------------ METHODS ------------------------------
+
+function toFormatedJSON () {
+  return {
+    id: this.id,
+    videoId: this.videoId,
+    createdAt: this.createdAt
+  }
+}
+
+// ------------------------------ STATICS ------------------------------
+
+function associate (models) {
+  this.belongsTo(models.Video, {
+    foreignKey: 'videoId',
+    onDelete: 'cascade'
+  })
+}
+
+function countTotal (callback) {
+  return this.count().asCallback(callback)
+}
+
+function list (callback) {
+  return this.findAll().asCallback(callback)
+}
+
+function listForApi (start, count, sort, callback) {
+  const query = {
+    offset: start,
+    limit: count,
+    order: [ modelUtils.getSort(sort) ]
+  }
+
+  return this.findAndCountAll(query).asCallback(function (err, result) {
+    if (err) return callback(err)
+
+    return callback(null, result.rows, result.count)
+  })
+}
+
+function loadById (id, callback) {
+  return this.findById(id).asCallback(callback)
+}
+
+function loadByVideoId (id, callback) {
+  const query = {
+    where: {
+      videoId: id
+    }
+  }
+
+  return this.find(query).asCallback(callback)
+}
diff --git a/server/models/video.js b/server/models/video.js
index 39eb28ed9..1addfa682 100644
--- a/server/models/video.js
+++ b/server/models/video.js
@@ -16,6 +16,7 @@ const logger = require('../helpers/logger')
 const friends = require('../lib/friends')
 const modelUtils = require('./utils')
 const customVideosValidators = require('../helpers/custom-validators').videos
+const db = require('../initializers/database')
 
 // ---------------------------------------------------------------------------
 
@@ -201,7 +202,8 @@ module.exports = function (sequelize, DataTypes) {
         isOwned,
         toFormatedJSON,
         toAddRemoteJSON,
-        toUpdateRemoteJSON
+        toUpdateRemoteJSON,
+        removeFromBlacklist
       },
       hooks: {
         beforeValidate,
@@ -528,6 +530,7 @@ function list (callback) {
 }
 
 function listForApi (start, count, sort, callback) {
+  // Exclude Blakclisted videos from the list
   const query = {
     offset: start,
     limit: count,
@@ -540,7 +543,12 @@ function listForApi (start, count, sort, callback) {
       },
 
       this.sequelize.models.Tag
-    ]
+    ],
+    where: {
+      id: { $notIn: this.sequelize.literal(
+        '(SELECT "BlacklistedVideos"."videoId" FROM "BlacklistedVideos")'
+      )}
+    }
   }
 
   return this.findAndCountAll(query).asCallback(function (err, result) {
@@ -648,7 +656,11 @@ function searchAndPopulateAuthorAndPodAndTags (value, field, start, count, sort,
   }
 
   const query = {
-    where: {},
+    where: {
+      id: { $notIn: this.sequelize.literal(
+        '(SELECT "BlacklistedVideos"."videoId" FROM "BlacklistedVideos")'
+      )}
+    },
     offset: start,
     limit: count,
     distinct: true, // For the count, a video can have many tags
@@ -661,13 +673,9 @@ function searchAndPopulateAuthorAndPodAndTags (value, field, start, count, sort,
     query.where.infoHash = infoHash
   } else if (field === 'tags') {
     const escapedValue = this.sequelize.escape('%' + value + '%')
-    query.where = {
-      id: {
-        $in: this.sequelize.literal(
-          '(SELECT "VideoTags"."videoId" FROM "Tags" INNER JOIN "VideoTags" ON "Tags"."id" = "VideoTags"."tagId" WHERE name LIKE ' + escapedValue + ')'
-        )
-      }
-    }
+    query.where.id.$in = this.sequelize.literal(
+      '(SELECT "VideoTags"."videoId" FROM "Tags" INNER JOIN "VideoTags" ON "Tags"."id" = "VideoTags"."tagId" WHERE name LIKE ' + escapedValue + ')'
+    )
   } else if (field === 'host') {
     // FIXME: Include our pod? (not stored in the database)
     podInclude.where = {
@@ -755,3 +763,23 @@ function generateImage (video, videoPath, folder, imageName, size, callback) {
     })
     .thumbnail(options)
 }
+
+function removeFromBlacklist (video, callback) {
+  // Find the blacklisted video
+  db.BlacklistedVideo.loadByVideoId(video.id, function (err, video) {
+    // If an error occured, stop here
+    if (err) {
+      logger.error('Error when fetching video from blacklist.', { error: err })
+
+      return callback(err)
+    }
+
+    // If we found the video, remove it from the blacklist
+    if (video) {
+      video.destroy().asCallback(callback)
+    } else {
+      // If haven't found it, simply ignore it and do nothing
+      return callback()
+    }
+  })
+}