feat: add logic to synthesize audio

Author: Sidsector9

includes/Classifai/Features/TextToSpeech.php

@@ -5,6 +5,7 @@
 use Classifai\Services\LanguageProcessing;
 use Classifai\Providers\Azure\Speech;
 use Classifai\Providers\OpenAI\TextToSpeech as OpenAITTS;
+use Classifai\Normalizer;
 use WP_REST_Server;
 use WP_REST_Request;
 use WP_Error;
@@ -44,6 +45,14 @@ class TextToSpeech extends Feature {
 	 */
 	const DISPLAY_GENERATED_AUDIO = '_classifai_display_generated_audio';
 
+	/**
+	 * Meta key to get/set the audio hash that helps to indicate if there is any need
+	 * for the audio file to be regenerated or not.
+	 *
+	 * @var string
+	 */
+	const AUDIO_HASH_KEY = '_classifai_post_audio_hash';
+
 	/**
 	 * Constructor.
 	 */
@@ -802,6 +811,21 @@ public function get_audio_generation_subsequent_state( $post = null ): bool {
 		return apply_filters( 'classifai_audio_generation_subsequent_state', false, get_post( $post ) );
 	}
 
+	/**
+	 * Normalizes the post content for text to speech generation.
+	 *
+	 * @param int $post_id The post ID.
+	 *
+	 * @return string The normalized post content.
+	 */
+	public function normalize_post_content( int $post_id ): string {
+		$normalizer   = new Normalizer();
+		$post         = get_post( $post_id );
+		$post_content = $normalizer->normalize_content( $post->post_content, $post->post_title, $post_id );
+
+		return $post_content;
+	}
+
 	/**
 	 * Generates feature setting data required for migration from
 	 * ClassifAI < 3.0.0 to 3.0.0

includes/Classifai/Providers/Azure/Speech.php

@@ -6,7 +6,6 @@
 namespace Classifai\Providers\Azure;
 
 use Classifai\Providers\Provider;
-use Classifai\Normalizer;
 use Classifai\Features\TextToSpeech;
 use stdClass;
 use WP_Http;
@@ -30,14 +29,6 @@ class Speech extends Provider {
 	 */
 	const API_PATH = 'cognitiveservices/v1';
 
-	/**
-	 * Meta key to get/set the audio hash that helps to indicate if there is any need
-	 * for the audio file to be regenerated or not.
-	 *
-	 * @var string
-	 */
-	const AUDIO_HASH_KEY = '_classifai_post_audio_hash';
-
 	/**
 	 * Azure Text to Speech constructor.
 	 *
@@ -337,12 +328,10 @@ public function synthesize_speech( int $post_id ) {
 			);
 		}
 
-		$normalizer          = new Normalizer();
 		$feature             = new TextToSpeech();
 		$settings            = $feature->get_settings();
-		$post                = get_post( $post_id );
-		$post_content        = $normalizer->normalize_content( $post->post_content, $post->post_title, $post_id );
-		$content_hash        = get_post_meta( $post_id, self::AUDIO_HASH_KEY, true );
+		$post_content        = $feature->normalize_post_content( $post_id );
+		$content_hash        = get_post_meta( $post_id, TextToSpeech::AUDIO_HASH_KEY, true );
 		$saved_attachment_id = (int) get_post_meta( $post_id, $feature::AUDIO_ID_KEY, true );
 
 		// Don't regenerate the audio file it it already exists and the content hasn't changed.
@@ -415,7 +404,7 @@ public function synthesize_speech( int $post_id ) {
 			);
 		}
 
-		update_post_meta( $post_id, self::AUDIO_HASH_KEY, md5( $post_content ) );
+		update_post_meta( $post_id, TextToSpeech::AUDIO_HASH_KEY, md5( $post_content ) );
 
 		return $response_body;
 	}

includes/Classifai/Providers/OpenAI/TextToSpeech.php

@@ -7,11 +7,12 @@
 
 use Classifai\Providers\Provider;
 use Classifai\Features\TextToSpeech as FeatureTextToSpeech;
+use WP_Error;
 
 class TextToSpeech extends Provider {
 	use OpenAI;
 
-	const ID = 'openai_text-to-speech';
+	const ID = 'openai_text_to_speech';
 
 	/**
 	 * OpenAI Text to Speech URL.
@@ -209,4 +210,112 @@ public function sanitize_settings( array $new_settings ): array {
 
 		return $new_settings;
 	}
+
+	/**
+	 * Common entry point for all REST endpoints for this provider.
+	 *
+	 * @param int    $post_id       The post ID we're processing.
+	 * @param string $route_to_call The name of the route we're going to be processing.
+	 * @param array  $args          Optional arguments to pass to the route.
+	 * @return array|string|WP_Error
+	 */
+	public function rest_endpoint_callback( $post_id, string $route_to_call = '', array $args = [] ) {
+		if ( ! $post_id || ! get_post( $post_id ) ) {
+			return new WP_Error( 'post_id_required', esc_html__( 'A valid post ID is required.', 'classifai' ) );
+		}
+
+		$route_to_call = strtolower( $route_to_call );
+		$return        = '';
+
+		// Handle all of our routes.
+		switch ( $route_to_call ) {
+			case 'synthesize':
+				$return = $this->synthesize_speech( $post_id, $args );
+				break;
+		}
+
+		return $return;
+	}
+
+	/**
+	 * Synthesizes speech from a post item.
+	 *
+	 * @param int $post_id Post ID.
+	 * @return string|WP_Error
+	 */
+	public function synthesize_speech( int $post_id ) {
+		if ( empty( $post_id ) ) {
+			return new WP_Error(
+				'openai_text_to_speech_post_id_missing',
+				esc_html__( 'Post ID missing.', 'classifai' )
+			);
+		}
+
+		// We skip the user cap check if running under WP-CLI.
+		if ( ! current_user_can( 'edit_post', $post_id ) && ( ! defined( 'WP_CLI' ) || ! WP_CLI ) ) {
+			return new WP_Error(
+				'openai_text_to_speech_user_not_authorized',
+				esc_html__( 'Unauthorized user.', 'classifai' )
+			);
+		}
+
+		$feature             = new FeatureTextToSpeech();
+		$settings            = $feature->get_settings();
+		$post_content        = $feature->normalize_post_content( $post_id );
+		$content_hash        = get_post_meta( $post_id, FeatureTextToSpeech::AUDIO_HASH_KEY, true );
+		$saved_attachment_id = (int) get_post_meta( $post_id, $feature::AUDIO_ID_KEY, true );
+
+		// Don't regenerate the audio file it it already exists and the content hasn't changed.
+		if ( $saved_attachment_id ) {
+
+			// Check if the audio file exists.
+			$audio_attachment_url = wp_get_attachment_url( $saved_attachment_id );
+
+			if ( $audio_attachment_url && ! empty( $content_hash ) && ( md5( $post_content ) === $content_hash ) ) {
+				return $saved_attachment_id;
+			}
+		}
+
+		// Create the request body to synthesize speech from text.
+		$request_body = array(
+			'model' => $settings[ static::ID ]['tts_model'],
+			'voice' => $settings[ static::ID ]['voice'],
+			'input' => $post_content,
+		);
+
+		// Request parameters.
+		$request_params = array(
+			'method'  => 'POST',
+			'body'    => wp_json_encode( $request_body ),
+			'timeout' => 60, // phpcs:ignore WordPressVIPMinimum.Performance.RemoteRequestTimeout.timeout_timeout
+			'headers' => array(
+				'Authorization' => 'Bearer ' . $settings[ static::ID ]['api_key'],
+				'Content-Type'  => 'application/json',
+			),
+		);
+
+		$response = wp_remote_post( $this->api_url, $request_params );
+
+		if ( is_wp_error( $response ) ) {
+			return new WP_Error(
+				'openai_text_to_speech_http_error',
+				esc_html( $response->get_error_message() )
+			);
+		}
+
+		$code          = wp_remote_retrieve_response_code( $response );
+		$response_body = wp_remote_retrieve_body( $response );
+
+		// return error if HTTP status code is not 200.
+		if ( \WP_Http::OK !== $code ) {
+			return new WP_Error(
+				'openai_text_to_speech_unsuccessful_request',
+				esc_html__( 'HTTP request unsuccessful.', 'classifai' )
+			);
+		}
+
+		update_post_meta( $post_id, FeatureTextToSpeech::AUDIO_HASH_KEY, md5( $post_content ) );
+
+		return $response_body;
+	}
 }