add best trending strategy based on Reddit's best

inspired from https://www.reddit.com/r/changelog/comments/7spgg0/best_is_the_new_hotness/
this implementation only adds freshness, and doesn't personalize based
on subscribed communities yet.

15 files changed, 57 insertions, 22 deletions

diff --git a/client/src/app/+admin/config/edit-custom-config/edit-custom-config.component.html b/client/src/app/+admin/config/edit-custom-config/edit-custom-config.component.html
index 796aa12ed..48678a194 100644
--- a/client/src/app/+admin/config/edit-custom-config/edit-custom-config.component.html
+++ b/client/src/app/+admin/config/edit-custom-config/edit-custom-config.component.html
@@ -271,6 +271,7 @@
                   <option i18n value="/videos/overview">Discover videos</option>
                   <optgroup i18n-label label="Trending pages">
                     <option i18n value="/videos/trending">Default trending page</option>
+                    <option i18n value="/videos/trending?alg=best" [disabled]="!trendingVideosAlgorithmsEnabledIncludes('best')">Best videos</option>
                     <option i18n value="/videos/trending?alg=hot" [disabled]="!trendingVideosAlgorithmsEnabledIncludes('hot')">Hot videos</option>
                     <option i18n value="/videos/trending?alg=most-viewed" [disabled]="!trendingVideosAlgorithmsEnabledIncludes('most-viewed')">Most viewed videos</option>
                     <option i18n value="/videos/trending?alg=most-liked" [disabled]="!trendingVideosAlgorithmsEnabledIncludes('most-liked')">Most liked videos</option>
@@ -288,6 +289,7 @@
                   <label i18n for="trendingVideosAlgorithmsDefault">Default trending page</label>
                   <div class="peertube-select-container">
                     <select id="trendingVideosAlgorithmsDefault" formControlName="default" class="form-control">
+                      <option i18n value="best">Best videos</option>
                       <option i18n value="hot">Hot videos</option>
                       <option i18n value="most-viewed">Most viewed videos</option>
                       <option i18n value="most-liked">Most liked videos</option>
diff --git a/client/src/app/+videos/video-list/trending/video-trending-header.component.ts b/client/src/app/+videos/video-list/trending/video-trending-header.component.ts
index 33eaa2c1e..a4a1e358f 100644
--- a/client/src/app/+videos/video-list/trending/video-trending-header.component.ts
+++ b/client/src/app/+videos/video-list/trending/video-trending-header.component.ts
@@ -36,6 +36,13 @@ export class VideoTrendingHeaderComponent extends VideoListHeaderComponent imple
 
     this.buttons = [
       {
+        label: $localize`:A variant of Trending videos based on the number of recent interactions, minus user history:Best`,
+        iconName: 'award',
+        value: 'best',
+        tooltip: $localize`Videos totalizing the most interactions for recent videos, minus user history`,
+        hidden: true
+      },
+      {
         label: $localize`:A variant of Trending videos based on the number of recent interactions:Hot`,
         iconName: 'flame',
         value: 'hot',
diff --git a/client/src/app/core/server/server.service.ts b/client/src/app/core/server/server.service.ts
index 39739afd0..11288fc54 100644
--- a/client/src/app/core/server/server.service.ts
+++ b/client/src/app/core/server/server.service.ts
@@ -131,7 +131,7 @@ export class ServerService {
       videos: {
         intervalDays: 0,
         algorithms: {
-          enabled: [ 'hot', 'most-viewed', 'most-liked' ],
+          enabled: [ 'best', 'hot', 'most-viewed', 'most-liked' ],
           default: 'most-viewed'
         }
       }
diff --git a/client/src/app/shared/shared-icons/global-icon.component.ts b/client/src/app/shared/shared-icons/global-icon.component.ts
index def488df0..3af517927 100644
--- a/client/src/app/shared/shared-icons/global-icon.component.ts
+++ b/client/src/app/shared/shared-icons/global-icon.component.ts
@@ -71,7 +71,8 @@ const icons = {
   'live': require('!!raw-loader?!../../../assets/images/feather/live.svg').default,
   'repeat': require('!!raw-loader?!../../../assets/images/feather/repeat.svg').default,
   'message-circle': require('!!raw-loader?!../../../assets/images/feather/message-circle.svg').default,
-  'codesandbox': require('!!raw-loader?!../../../assets/images/feather/codesandbox.svg').default
+  'codesandbox': require('!!raw-loader?!../../../assets/images/feather/codesandbox.svg').default,
+  'award': require('!!raw-loader?!../../../assets/images/feather/award.svg').default
 }
 
 export type GlobalIconName = keyof typeof icons
diff --git a/client/src/assets/images/feather/award.svg b/client/src/assets/images/feather/award.svg
new file mode 100644
index 000000000..be70d5a13
--- /dev/null
+++ b/client/src/assets/images/feather/award.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-award"><circle cx="12" cy="8" r="7"></circle><polyline points="8.21 13.89 7 23 12 20 17 23 15.79 13.88"></polyline></svg>
\ No newline at end of file
diff --git a/config/default.yaml b/config/default.yaml
index 22488da99..95df2e06c 100644
--- a/config/default.yaml
+++ b/config/default.yaml
@@ -110,7 +110,8 @@ trending:
     interval_days: 7 # Compute trending videos for the last x days
     algorithms:
       enabled:
-        - 'hot' # adaptation of the Reddit 'Hot' algorithm
+        - 'best' # adaptation of Reddit's 'Best' algorithm (Hot minus History)
+        - 'hot' # adaptation of Reddit's 'Hot' algorithm
         - 'most-viewed' # default, used initially by PeerTube as the trending page
         - 'most-liked'
       default: 'most-viewed'
diff --git a/config/production.yaml.example b/config/production.yaml.example
index 66c981dd5..13a646918 100644
--- a/config/production.yaml.example
+++ b/config/production.yaml.example
@@ -108,7 +108,8 @@ trending:
     interval_days: 7 # Compute trending videos for the last x days
     algorithms:
       enabled:
-        - 'hot' # adaptation of the Reddit 'Hot' algorithm
+        - 'best' # adaptation of Reddit's 'Best' algorithm (Hot minus History)
+        - 'hot' # adaptation of Reddit's 'Hot' algorithm
         - 'most-viewed' # default, used initially by PeerTube as the trending page
         - 'most-liked'
       default: 'most-viewed'
diff --git a/server/initializers/constants.ts b/server/initializers/constants.ts
index 0fab872a9..9d9b3966c 100644
--- a/server/initializers/constants.ts
+++ b/server/initializers/constants.ts
@@ -72,7 +72,7 @@ const SORTABLE_COLUMNS = {
   FOLLOWERS: [ 'createdAt', 'state', 'score' ],
   FOLLOWING: [ 'createdAt', 'redundancyAllowed', 'state' ],
 
-  VIDEOS: [ 'name', 'duration', 'createdAt', 'publishedAt', 'originallyPublishedAt', 'views', 'likes', 'trending', 'hot' ],
+  VIDEOS: [ 'name', 'duration', 'createdAt', 'publishedAt', 'originallyPublishedAt', 'views', 'likes', 'trending', 'hot', 'best' ],
 
   // Don't forget to update peertube-search-index with the same values
   VIDEOS_SEARCH: [ 'name', 'duration', 'createdAt', 'publishedAt', 'originallyPublishedAt', 'views', 'likes', 'match' ],
diff --git a/server/models/video/video-query-builder.ts b/server/models/video/video-query-builder.ts
index e2145fb9a..822d0c89b 100644
--- a/server/models/video/video-query-builder.ts
+++ b/server/models/video/video-query-builder.ts
@@ -31,8 +31,8 @@ export type BuildVideosQueryOptions = {
 
   videoPlaylistId?: number
 
+  trendingAlgorithm?: string // best, hot, or any other algorithm implemented
   trendingDays?: number
-  hot?: boolean
 
   user?: MUserAccountId
   historyOfUser?: MUserId
@@ -252,7 +252,7 @@ function buildListQuery (model: typeof Model, options: BuildVideosQueryOptions)
       attributes.push('COALESCE(SUM("videoView"."views"), 0) AS "score"')
 
       group = 'GROUP BY "video"."id"'
-    } else if (options.hot) {
+    } else if ([ 'best', 'hot' ].includes(options.trendingAlgorithm)) {
       /**
        * "Hotness" is a measure based on absolute view/comment/like/dislike numbers,
        * with fixed weights only applied to their log values.
@@ -269,28 +269,39 @@ function buildListQuery (model: typeof Model, options: BuildVideosQueryOptions)
        */
       const weights = {
         like: 3,
-        dislike: 3,
+        dislike: -3,
         view: 1 / 12,
-        comment: 2 // a comment takes more time than a like to do, but can be done multiple times
+        comment: 2, // a comment takes more time than a like to do, but can be done multiple times
+        history: -2
       }
 
       joins.push('LEFT JOIN "videoComment" ON "video"."id" = "videoComment"."videoId"')
 
-      attributes.push(
+      let attribute =
         `LOG(GREATEST(1, "video"."likes" - 1)) * ${weights.like} ` + // likes (+)
-        `- LOG(GREATEST(1, "video"."dislikes" - 1)) * ${weights.dislike} ` + // dislikes (-)
+        `+ LOG(GREATEST(1, "video"."dislikes" - 1)) * ${weights.dislike} ` + // dislikes (-)
         `+ LOG("video"."views" + 1) * ${weights.view} ` + // views (+)
         `+ LOG(GREATEST(1, COUNT(DISTINCT "videoComment"."id"))) * ${weights.comment} ` + // comments (+)
-        '+ (SELECT EXTRACT(epoch FROM "video"."publishedAt") / 47000) ' + // base score (in number of half-days)
-        'AS "score"'
-      )
+        '+ (SELECT EXTRACT(epoch FROM "video"."publishedAt") / 47000) ' // base score (in number of half-days)
+
+      if (options.trendingAlgorithm === 'best' && options.user) {
+        joins.push(
+          'LEFT JOIN "userVideoHistory" ON "video"."id" = "userVideoHistory"."videoId" AND "userVideoHistory"."userId" = :bestUser'
+        )
+        replacements.bestUser = options.user.id
+
+        attribute += `+ POWER(COUNT(DISTINCT "userVideoHistory"."id"), 2.0) * ${weights.history} `
+      }
+
+      attribute += 'AS "score"'
+      attributes.push(attribute)
 
       group = 'GROUP BY "video"."id"'
     }
   }
 
   if (options.historyOfUser) {
-    joins.push('INNER JOIN "userVideoHistory" on "video"."id" = "userVideoHistory"."videoId"')
+    joins.push('INNER JOIN "userVideoHistory" ON "video"."id" = "userVideoHistory"."videoId"')
 
     and.push('"userVideoHistory"."userId" = :historyOfUser')
     replacements.historyOfUser = options.historyOfUser.id
@@ -410,7 +421,7 @@ function buildOrder (value: string) {
 
   if (field.toLowerCase() === 'random') return 'ORDER BY RANDOM()'
 
-  if ([ 'trending', 'hot' ].includes(field.toLowerCase())) { // Sort by aggregation
+  if ([ 'trending', 'hot', 'best' ].includes(field.toLowerCase())) { // Sort by aggregation
     return `ORDER BY "score" ${direction}, "video"."views" ${direction}`
   }
 
diff --git a/server/models/video/video.ts b/server/models/video/video.ts
index ea6c9d44b..0ecb8d600 100644
--- a/server/models/video/video.ts
+++ b/server/models/video/video.ts
@@ -1090,7 +1090,9 @@ export class VideoModel extends Model {
     const trendingDays = options.sort.endsWith('trending')
       ? CONFIG.TRENDING.VIDEOS.INTERVAL_DAYS
       : undefined
-    const hot = options.sort.endsWith('hot')
+    let trendingAlgorithm
+    if (options.sort.endsWith('hot')) trendingAlgorithm = 'hot'
+    if (options.sort.endsWith('best')) trendingAlgorithm = 'best'
 
     const serverActor = await getServerActor()
 
@@ -1120,7 +1122,7 @@ export class VideoModel extends Model {
       user: options.user,
       historyOfUser: options.historyOfUser,
       trendingDays,
-      hot,
+      trendingAlgorithm,
       search: options.search
     }
 
diff --git a/server/tests/api/check-params/config.ts b/server/tests/api/check-params/config.ts
index e6309b5f7..d6c20f7af 100644
--- a/server/tests/api/check-params/config.ts
+++ b/server/tests/api/check-params/config.ts
@@ -141,7 +141,7 @@ describe('Test config API validators', function () {
     trending: {
       videos: {
         algorithms: {
-          enabled: [ 'hot', 'most-viewed', 'most-liked' ],
+          enabled: [ 'best', 'hot', 'most-viewed', 'most-liked' ],
           default: 'most-viewed'
         }
       }
diff --git a/server/tests/api/server/config.ts b/server/tests/api/server/config.ts
index e5bab0b77..26df8373e 100644
--- a/server/tests/api/server/config.ts
+++ b/server/tests/api/server/config.ts
@@ -375,7 +375,7 @@ describe('Test config', function () {
       trending: {
         videos: {
           algorithms: {
-            enabled: [ 'hot', 'most-viewed', 'most-liked' ],
+            enabled: [ 'best', 'hot', 'most-viewed', 'most-liked' ],
             default: 'hot'
           }
         }
diff --git a/server/tests/api/videos/single-server.ts b/server/tests/api/videos/single-server.ts
index 52c6800c1..da90223b8 100644
--- a/server/tests/api/videos/single-server.ts
+++ b/server/tests/api/videos/single-server.ts
@@ -363,6 +363,14 @@ describe('Test a single server', function () {
     expect(videos.length).to.equal(2)
   })
 
+  it('Should list and sort by best in descending order', async function () {
+    const res = await getVideosListPagination(server.url, 0, 2, '-best')
+
+    const videos = res.body.data
+    expect(res.body.total).to.equal(6)
+    expect(videos.length).to.equal(2)
+  })
+
   it('Should update a video', async function () {
     const attributes = {
       name: 'my super video updated',
diff --git a/shared/extra-utils/server/config.ts b/shared/extra-utils/server/config.ts
index 8998da8b6..db5a473ca 100644
--- a/shared/extra-utils/server/config.ts
+++ b/shared/extra-utils/server/config.ts
@@ -164,7 +164,7 @@ function updateCustomSubConfig (url: string, token: string, newConfig: DeepParti
     trending: {
       videos: {
         algorithms: {
-          enabled: [ 'hot', 'most-viewed', 'most-liked' ],
+          enabled: [ 'best', 'hot', 'most-viewed', 'most-liked' ],
           default: 'hot'
         }
       }
diff --git a/shared/models/videos/video-sort-field.type.ts b/shared/models/videos/video-sort-field.type.ts
index 97687f84b..5073848b8 100644
--- a/shared/models/videos/video-sort-field.type.ts
+++ b/shared/models/videos/video-sort-field.type.ts
@@ -8,4 +8,5 @@ export type VideoSortField =
 
   // trending sorts
   'trending' | '-trending' |
-  'hot' | '-hot'
+  'hot' | '-hot' |
+  'best' | '-best'