refactor: move bulk transcript retrieval to YoutubeTranscriptApi, cleanup code

Author: trldvix

README.md

@@ -282,10 +282,8 @@ TranscriptContent transcriptContent = youtubeTranscriptApi.getTranscriptWithCook
 
 ### Bulk Transcript Retrieval
 
-All bulk transcript retrieval operations are done via the `PlaylistsTranscriptApi` interface. Same as with the
-`YoutubeTranscriptApi`,
-you can create a new instance of the PlaylistsTranscriptApi by calling the `createDefaultPlaylistsApi` method of the
-`TranscriptApiFactory`.
+There are a few methods for bulk transcript retrieval in `YoutubeTranscriptApi` 
+
 Playlists and channels information is retrieved from
 the [YouTube V3 API](https://developers.google.com/youtube/v3/docs/),
 so you will need to provide API key for all methods.
@@ -304,30 +302,30 @@ All methods return a map which contains the video ID as a key and the correspond
 
 ```java
 // Create a new default PlaylistsTranscriptApi instance
-PlaylistsTranscriptApi playlistsTranscriptApi = TranscriptApiFactory.createDefaultPlaylistsApi();
+YoutubeTranscriptApi youtubeTranscriptApi = TranscriptApiFactory.createDefault();
 
 //Create request object
 TranscriptRequest request = new TranscriptRequest("apiKey");
 
 // Retrieve all available transcripts for a given playlist
-Map<String, TranscriptList> transcriptLists = playlistsTranscriptApi.listTranscriptsForPlaylist("playlistId", request);
+Map<String, TranscriptList> transcriptLists = youtubeTranscriptApi.listTranscriptsForPlaylist("playlistId", request);
 
 // Retrieve all available transcripts for a given channel
-Map<String, TranscriptList> transcriptLists = playlistsTranscriptApi.listTranscriptsForChannel("channelName", request);
+Map<String, TranscriptList> transcriptLists = youtubeTranscriptApi.listTranscriptsForChannel("channelName", request);
 ```
 
-Same as with the `YoutubeTranscriptApi`, you can also fetch transcript content directly
+Same as with the `getTranscript` method, you can also fetch transcript content directly
 using [fallback languages](#use-fallback-language) if needed.
 
 ```java
 //Create request object
 TranscriptRequest request = new TranscriptRequest("apiKey");
 
 // Retrieve transcript content for all videos in a playlist
-Map<String, TranscriptContent> transcriptLists = playlistsTranscriptApi.getTranscriptsForPlaylist("playlistId", request);
+Map<String, TranscriptContent> transcriptLists = youtubeTranscriptApi.getTranscriptsForPlaylist("playlistId", request);
 
 // Retrieve transcript content for all videos in a channel
-Map<String, TranscriptContent> transcriptLists = playlistsTranscriptApi.getTranscriptsForChannel("channelName", request, "en", "de");
+Map<String, TranscriptContent> transcriptLists = youtubeTranscriptApi.getTranscriptsForChannel("channelName", request, "en", "de");
 ```
 
 > **Note:** If you want to get transcript content in a different format, refer

lib/src/main/java/io/github/thoroldvix/api/PlaylistsTranscriptApi.java

@@ -2,10 +2,12 @@
 
 import io.github.thoroldvix.internal.TranscriptApiFactory;
 
+import java.util.Map;
+
 /**
  * This is the main interface for the YouTube Transcript API.
  * <p>
- * It provides functionality for retrieving all available transcripts or retrieving actual transcript content from YouTube.
+ * It provides functionality for retrieving all available transcripts or retrieving actual transcript content for a single video, playlist, or channel.
  * </p>
  * <p>
  * To instantiate this API, you should use {@link TranscriptApiFactory}.
@@ -94,4 +96,61 @@ public interface YoutubeTranscriptApi {
      * @throws IllegalArgumentException     If the video ID is invalid
      */
     TranscriptContent getTranscript(String videoId, String... languageCodes) throws TranscriptRetrievalException;
+
+    /**
+     * Retrieves transcript lists for all videos in the specified playlist.
+     *
+     * @param playlistId The ID of the playlist
+     * @param request    {@link TranscriptRequest} request object containing API key, cookies file path, and stop on error flag
+     * @return A map of video IDs to {@link TranscriptList} objects
+     * @throws TranscriptRetrievalException If the retrieval of the transcript lists fails
+     */
+    Map<String, TranscriptList> listTranscriptsForPlaylist(String playlistId, TranscriptRequest request) throws TranscriptRetrievalException;
+
+
+    /**
+     * Retrieves transcript lists for all videos for the specified channel.
+     *
+     * @param channelName The name of the channel
+     * @param request     {@link TranscriptRequest} request object containing API key, cookies file path, and stop on error flag
+     * @return A map of video IDs to {@link TranscriptList} objects
+     * @throws TranscriptRetrievalException If the retrieval of the transcript lists fails
+     */
+    Map<String, TranscriptList> listTranscriptsForChannel(String channelName, TranscriptRequest request) throws TranscriptRetrievalException;
+
+
+    /**
+     * Retrieves transcript content for all videos in the specified playlist.
+     *
+     * @param playlistId    The ID of the playlist
+     * @param request       {@link TranscriptRequest} request object containing API key, cookies file path, and stop on error flag
+     * @param languageCodes A varargs list of language codes in descending priority.
+     *                      <p>
+     *                      For example:
+     *                      </p>
+     *                      If this is set to {@code ("de", "en")}, it will first attempt to fetch the German transcript ("de"), and then fetch the English
+     *                      transcript ("en") if the former fails. If no language code is provided, it uses English as the default language.
+     * @return A map of video IDs to {@link TranscriptContent} objects
+     * @throws TranscriptRetrievalException If the retrieval of the transcript fails
+     */
+    Map<String, TranscriptContent> getTranscriptsForPlaylist(String playlistId,
+                                                             TranscriptRequest request,
+                                                             String... languageCodes) throws TranscriptRetrievalException;
+
+
+    /**
+     * Retrieves transcript content for all videos for the specified channel.
+     *
+     * @param channelName   The name of the channel
+     * @param request       {@link TranscriptRequest} request object containing API key, cookies file path, and stop on error flag
+     * @param languageCodes A varargs list of language codes in descending priority.
+     *                      <p>
+     *                      For example:
+     *                      </p>
+     *                      If this is set to {@code ("de", "en")}, it will first attempt to fetch the German transcript ("de"), and then fetch the English
+     *                      transcript ("en") if the former fails. If no language code is provided, it uses English as the default language.
+     * @return A map of video IDs to {@link TranscriptContent} objects
+     * @throws TranscriptRetrievalException If the retrieval of the transcript fails
+     */
+    Map<String, TranscriptContent> getTranscriptsForChannel(String channelName, TranscriptRequest request, String... languageCodes) throws TranscriptRetrievalException;
 }