finished youtube searcher

src/search/spotify.cr

@@ -1,7 +1,7 @@
+require "http"
+require "json"
 require "base64"
 
-require "spotify"
-
 
 class SpotifySearcher
   @root_url = Path["https://api.spotify.com/v1/"]
@@ -74,7 +74,8 @@ class SpotifySearcher
 
   end
   
-  # Generates url to run a GET request against
+  # Generates url to run a GET request against to the Spotify open API
+  # Returns a `String.`
   private def __generate_query(item_type : String, item_parameters : Hash,
   offset : Int32, limit : Int32)
     query = ""
@@ -106,6 +107,7 @@ class SpotifySearcher
 
   # Ranks the given items based off of the info from parameters.
   # Meant to find the item that the user desires.
+  # Returns an `Array` of `Array(Int32)` or [[3, 1], [...], ...]
   private def __rank_items(items : Array, parameters : Hash)
     points = [] of Array(Int32)
     index = 0
@@ -163,7 +165,7 @@ class SpotifySearcher
     end
   end
 
-  # Returns a parameter encoded for the spotify api
+  # Returns a `String` encoded for the spotify api
   #
   # ```
   # __query_encode("album", "A Night At The Opera")
@@ -176,10 +178,10 @@ class SpotifySearcher
 end
 
 
-puts SpotifySearcher.new()
-  .authorize("e4198f6a3f7b48029366f22528b5dc66", 
-             "ba057d0621a5496bbb64edccf758bde5")
-  .find_item("track", {
-    "name" => "Bohemian Rhapsody",
-    "artist" => "Queen"
-  })
+# puts SpotifySearcher.new()
+#   .authorize("e4198f6a3f7b48029366f22528b5dc66", 
+#              "ba057d0621a5496bbb64edccf758bde5")
+#   .find_item("album", {
+#     "name" => "A Night At The Opera",
+#     "artist" => "Queen"
+#   })

src/search/youtube.cr

@@ -0,0 +1,119 @@
+require "http"
+require "xml"
+
+
+module Youtube
+
+  extend self
+
+  VALID_LINK_CLASSES = [
+    "yt-simple-endpoint style-scope ytd-video-renderer",
+    "yt-uix-tile-link yt-ui-ellipsis yt-ui-ellipsis-2 yt-uix-sessionlink      spf-link "
+  ]
+
+  # Finds a youtube url based off of the given information.
+  # The query to youtube is constructed like this:
+  #   "<song_name> <artist_name> <search terms>"
+  # If *download_first* is provided, the first link found will be downloaded.
+  #
+  # ```
+  # Youtube.find_url("Bohemian Rhapsody", "Queen")
+  # => "https://www.youtube.com/watch?v=dQw4w9WgXcQ"
+  # ```
+  def find_url(song_name : String, artist_name : String, search_terms = "", download_first = false)
+    query = (song_name + " " + artist_name + " " + search_terms).strip.gsub(" ", "+")
+
+    url = "https://www.youtube.com/results?search_query=" + query 
+
+    response = HTTP::Client.get(url)
+
+    valid_nodes = __get_video_link_nodes(response.body)
+
+    if valid_nodes.size == 0
+      puts "There were no results for that query."
+      return nil
+    end
+
+    root = "https://youtube.com"
+
+    return root + valid_nodes[0]["href"] if download_first
+
+    ranked = __rank_videos(song_name, artist_name, valid_nodes)
+
+    return root + valid_nodes[ranked[0][1]]["href"]
+  end
+
+  # Will rank videos according to their title and the user input
+  # Returns an `Array` of Arrays each layed out like 
+  # [<points>, <original index>].
+  private def __rank_videos(song_name, artist_name, nodes : Array(XML::Node))
+    points = [] of Array(Int32)
+    index = 0
+
+    nodes.each do |node|
+      pts = 0
+
+      pts += __points_compare(song_name, node["title"])
+      pts += __points_compare(artist_name, node["title"])
+
+      points.push([pts, index])
+      index += 1
+    end
+
+    points.sort!{ |a, b| b[0] <=> a[0] }
+
+    return points
+  end
+
+  # Returns an `Int` based off the number of points worth assigning to the 
+  # matchiness of the string. First the strings are downcased and then all
+  # nonalphanumeric characters are stripped.
+  # If *item1* includes *item2*, return 3 pts.
+  # If after the items have been blanked, *item1* includes *item2*, 
+  #   return 1 pts.
+  # Else, return 0 pts.
+  private def __points_compare(item1 : String, item2 : String)
+    if item1.includes?(item2)
+      return 3
+    end
+
+    item1 = item1.downcase.gsub(/[^a-z0-9]/, "")
+    item2 = item2.downcase.gsub(/[^a-z0-9]/, "")
+
+    if item1.includes?(item2)
+      return 1
+    else
+      return 0
+    end
+  end
+
+  # Finds valid video links from a `HTTP::Client.get` request
+  # Returns an `Array` of `XML::Node`
+  private def __get_video_link_nodes(doc : String)
+    nodes = XML.parse(doc).xpath_nodes("//a")
+    valid_nodes = [] of XML::Node
+
+    nodes.each do |node|
+      if __video_link_node?(node)
+        valid_nodes.push(node)
+      end
+    end
+
+    return valid_nodes
+  end
+
+  # Tests if the provided `XML::Node` has a valid link to a video
+  # Returns a `Bool`
+  private def __video_link_node?(node : XML::Node)
+    # If this passes, then the node links to a playlist, not a video
+    if node["href"]?
+      return false if node["href"].includes?("&list=")
+    end
+
+    VALID_LINK_CLASSES.each do |valid_class|
+      if node["class"]?
+        return true if node["class"].includes?(valid_class)
+      end
+    end
+  end
+end