Fix Ameba error

src/invidious/hashtag.cr

@@ -1,42 +1,89 @@
 module Invidious::Hashtag
   extend self
 
-  def fetch(hashtag : String, page : Int, region : String? = nil) : Array(SearchItem)
+  struct HashtagPage
+    include DB::Serializable
+
+    property videos : Array(SearchItem) | Array(Video)
+    property header : SearchHashtag?
+    property has_next_continuation : Bool
+
+    def to_json(locale : String?, json : JSON::Builder)
+      json.object do
+        json.field "type", "hashtagPage"
+        if self.header != nil
+          json.field "header" do
+            self.header.try &.as(SearchHashtag).to_json(locale, json)
+          end
+        end
+        json.field "results" do
+          json.array do
+            self.videos.each do |item|
+              item.to_json(locale, json)
+            end
+          end
+        end
+        json.field "hasNextPage", self.has_next_continuation
+      end
+    end
+  end
+
+  def fetch(hashtag : String, page : Int, region : String? = nil) : HashtagPage
     cursor = (page - 1) * 60
-    ctoken = generate_continuation(hashtag, cursor)
-
+    header = nil
     client_config = YoutubeAPI::ClientConfig.new(region: region)
-    response = YoutubeAPI.browse(continuation: ctoken, client_config: client_config)
+    item = generate_continuation(hashtag, cursor)
+    # item is a ctoken
+    if cursor > 0
+      response = YoutubeAPI.browse(continuation: item, client_config: client_config)
+    else
+      # item browses the first page (including metadata)
+      response = YoutubeAPI.browse("FEhashtag", params: item, client_config: client_config)
+      if item_contents = response.dig?("header")
+        header = parse_item(item_contents).try &.as(SearchHashtag)
+      end
+    end
 
-    items, _ = extract_items(response)
-    return items
+    items, next_continuation = extract_items(response)
+    return HashtagPage.new({
+      videos:                items,
+      header:                header,
+      has_next_continuation: next_continuation != nil,
+    })
   end
 
   def generate_continuation(hashtag : String, cursor : Int)
     object = {
-      "80226972:embedded" => {
-        "2:string" => "FEhashtag",
-        "3:base64" => {
-          "1:varint"  => 60_i64, # result count
-          "15:base64" => {
-            "1:varint" => cursor.to_i64,
-            "2:varint" => 0_i64,
-          },
-          "93:2:embedded" => {
-            "1:string" => hashtag,
-            "2:varint" => 0_i64,
-            "3:varint" => 1_i64,
-          },
-        },
-        "35:string" => "browse-feedFEhashtag",
+      "93:2:embedded" => {
+        "1:string" => hashtag,
+        "2:varint" => 0_i64,
+        "3:varint" => 1_i64,
       },
     }
+    if cursor > 0
+      object = {
+        "80226972:embedded" => {
+          "2:string" => "FEhashtag",
+          "3:base64" => {
+            "1:varint"  => 60_i64, # result count
+            "15:base64" => {
+              "1:varint" => cursor.to_i64,
+              "2:varint" => 0_i64,
+            },
+            "93:2:embedded" => {
+              "1:string" => hashtag,
+              "2:varint" => 0_i64,
+              "3:varint" => 1_i64,
+            },
+          },
+          "35:string" => "browse-feedFEhashtag",
+        },
+      }
+    end
 
-    continuation = object.try { |i| Protodec::Any.cast_json(i) }
+    return object.try { |i| Protodec::Any.cast_json(i) }
       .try { |i| Protodec::Any.from_json(i) }
       .try { |i| Base64.urlsafe_encode(i) }
       .try { |i| URI.encode_www_form(i) }
-
-    return continuation
   end
 end

src/invidious/routes/api/v1/search.cr

@@ -69,21 +69,13 @@ module Invidious::Routes::API::V1::Search
     env.response.content_type = "application/json"
 
     begin
-      results = Invidious::Hashtag.fetch(hashtag, page, region)
+      hashtag_page = Invidious::Hashtag.fetch(hashtag, page, region)
     rescue ex
       return error_json(400, ex)
     end
 
     JSON.build do |json|
-      json.object do
-        json.field "results" do
-          json.array do
-            results.each do |item|
-              item.to_json(locale, json)
-            end
-          end
-        end
-      end
+      hashtag_page.to_json(locale, json)
     end
   end
 end

src/invidious/routes/search.cr

@@ -101,7 +101,8 @@ module Invidious::Routes::Search
     end
 
     begin
-      items = Invidious::Hashtag.fetch(hashtag, page)
+      hashtag_page = Invidious::Hashtag.fetch(hashtag, page)
+      items = hashtag_page.videos
     rescue ex
       return error_template(500, ex)
     end
@@ -111,7 +112,7 @@ module Invidious::Routes::Search
     page_nav_html = Frontend::Pagination.nav_numeric(locale,
       base_url: "/hashtag/#{hashtag_encoded}",
       current_page: page,
-      show_next: (items.size >= 60)
+      show_next: hashtag_page.has_next_continuation
     )
 
     templated "hashtag"

src/invidious/yt_backend/extractors.cr

@@ -217,15 +217,18 @@ private module Parsers
   #
   # A `hashtagTileRenderer` is a kind of search result.
   # It can be found when searching for any hashtag (e.g "#hi" or "#shorts")
+  #
+  # A `hashtagHeaderRenderer` is displayed on the first page of the hashtag page.
   module HashtagRendererParser
     def self.process(item : JSON::Any, author_fallback : AuthorFallback)
-      if item_contents = item["hashtagTileRenderer"]?
+      if item_contents = (item["hashtagTileRenderer"]? || item["hashtagHeaderRenderer"]? || item["pageHeaderRenderer"]?)
         return self.parse(item_contents)
       end
     end
 
     private def self.parse(item_contents)
-      title = extract_text(item_contents["hashtag"]).not_nil! # E.g "#hi"
+      title = item_contents.dig?("pageTitle").try &.as_s
+      title ||= extract_text(item_contents["hashtag"]).not_nil! # E.g "#hi"
 
       # E.g "/hashtag/hi"
       url = item_contents.dig?("onTapCommand", "commandMetadata", "webCommandMetadata", "url").try &.as_s
@@ -236,8 +239,10 @@ private module Parsers
 
       # Fallback for video/channel counts
       if channel_count_txt.nil? || video_count_txt.nil?
+        info_text = (item_contents.dig?("content", "pageHeaderViewModel", "metadata", "contentMetadataViewModel", "metadataRows", 0, "metadataParts", 0, "text", "content").try &.as_s ||
+                     extract_text(item_contents.dig?("hashtagInfoText"))).try &.split(" • ")
+
         # E.g: "203K videos • 81K channels"
-        info_text = extract_text(item_contents["hashtagInfoText"]?).try &.split(" • ")
 
         if info_text && info_text.size == 2
           video_count_txt ||= info_text[0]