Prototype : Implement slug generation feature with UI and tests

includes/Abilities/Slug_Generation/Slug_Generation.php

@@ -0,0 +1,299 @@
+<?php
+/**
+ * Slug generation WordPress Ability implementation.
+ *
+ * @package WordPress\AI
+ */
+
+declare( strict_types=1 );
+
+namespace WordPress\AI\Abilities\Slug_Generation;
+
+use WP_Error;
+use WordPress\AI\Abstracts\Abstract_Ability;
+use WordPress\AI\Experiments\Slug_Generation\Slug_Generation as Slug_Generation_Experiment;
+
+use function WordPress\AI\get_post_context;
+use function WordPress\AI\normalize_content;
+
+/**
+ * Slug generation WordPress Ability.
+ *
+ * @since x.x.x
+ */
+class Slug_Generation extends Abstract_Ability {
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @since x.x.x
+	 */
+	protected function guideline_categories(): array {
+		return array( 'site', 'copy' );
+	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @since x.x.x
+	 */
+	protected function input_schema(): array {
+		return array(
+			'type'       => 'object',
+			'properties' => array(
+				'title'                 => array(
+					'type'              => 'string',
+					'sanitize_callback' => 'sanitize_text_field',
+					'description'       => esc_html__( 'Title to generate slug suggestions for.', 'ai' ),
+				),
+				'content'               => array(
+					'type'              => 'string',
+					'sanitize_callback' => 'sanitize_text_field',
+					'description'       => esc_html__( 'Content to generate slug suggestions for.', 'ai' ),
+				),
+				'context'               => array(
+					'type'              => 'string',
+					'sanitize_callback' => 'sanitize_text_field',
+					'description'       => esc_html__( 'Additional context or post ID.', 'ai' ),
+				),
+				'number_of_suggestions' => array(
+					'type'              => 'integer',
+					'sanitize_callback' => 'absint',
+					'default'           => 3,
+					'description'       => esc_html__( 'Number of slug suggestions to return.', 'ai' ),
+				),
+			),
+		);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @since x.x.x
+	 */
+	protected function output_schema(): array {
+		return array(
+			'type'       => 'object',
+			'properties' => array(
+				'slugs' => array(
+					'type'        => 'array',
+					'items'       => array(
+						'type' => 'string',
+					),
+					'description' => esc_html__( 'Generated slug suggestions.', 'ai' ),
+				),
+			),
+		);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @since x.x.x
+	 */
+	protected function execute_callback( $input ) {
+		$args = wp_parse_args(
+			$input,
+			array(
+				'title'                 => null,
+				'content'               => null,
+				'context'               => null,
+				'number_of_suggestions' => 3,
+			)
+		);
+
+		$post_id = null;
+		if ( is_numeric( $args['context'] ) ) {
+			$post_id = (int) $args['context'];
+			$post    = get_post( $post_id );
+
+			if ( ! $post ) {
+				return new WP_Error(
+					'post_not_found',
+					/* translators: %d: Post ID. */
+					sprintf( esc_html__( 'Post with ID %d not found.', 'ai' ), $post_id )
+				);
+			}
+
+			// Fetch the post context when a numeric post ID is provided.
+			$context      = get_post_context( $post->ID );
+			$post_content = $context['content'] ?? '';
+			$post_title   = $post->post_title;
+			unset( $context['content'] );
+
+			// Override with explicitly passed title or content if available.
+			if ( $args['title'] ) {
+				$post_title = sanitize_text_field( $args['title'] );
+			}
+			if ( $args['content'] ) {
+				$post_content = normalize_content( $args['content'] );
+			}
+		} else {
+			$post_content = normalize_content( $args['content'] ?? '' );
+			$post_title   = sanitize_text_field( $args['title'] ?? '' );
+			$context      = $args['context'] ?? '';
+		}
+
+		if ( empty( $post_title ) && empty( $post_content ) ) {
+			return new WP_Error(
+				'insufficient_data',
+				esc_html__( 'Post title or content is required to generate slug suggestions.', 'ai' )
+			);
+		}
+
+		// Build the prompt input with structured XML tags for title, content, and context.
+		$prompt_input = '';
+		if ( ! empty( $post_title ) ) {
+			$prompt_input .= "<title>{$post_title}</title>\n\n";
+		}
+		if ( ! empty( $post_content ) ) {
+			$prompt_input .= "<content>{$post_content}</content>";
+		}
+		if ( ! empty( $context ) ) {
+			if ( is_array( $context ) ) {
+				$context = implode( "\n", $context );
+			}
+			$prompt_input .= "\n\n<additional-context>{$context}</additional-context>";
+		}
+
+		$number_of_suggestions = (int) apply_filters( 'wpai_slug_generation_number_of_suggestions', (int) $args['number_of_suggestions'] );
+
+		// Generate the raw slug suggestion text from the AI model.
+		$result = $this->generate_slugs( $prompt_input, $context, $number_of_suggestions );
+
+		if ( is_wp_error( $result ) ) {
+			return $result;
+		}
+
+		if ( empty( $result ) ) {
+			return new WP_Error(
+				'no_results',
+				esc_html__( 'No slug suggestion was generated.', 'ai' )
+			);
+		}
+
+		// Parse the output lines into clean, sanitized WordPress slugs.
+		$lines = explode( "\n", $result );
+		$slugs = array();
+		foreach ( $lines as $line ) {
+			$line = trim( $line, " \t\n\r\0\x0B\"'" );
+			if ( empty( $line ) ) {
+				continue;
+			}
+
+			$slugs[] = sanitize_title( $line );
+		}
+
+		$slugs = array_slice( array_unique( array_filter( $slugs ) ), 0, $number_of_suggestions );
+
+		if ( empty( $slugs ) ) {
+			return new WP_Error(
+				'no_results',
+				esc_html__( 'No slug suggestion was generated.', 'ai' )
+			);
+		}
+
+		return array(
+			'slugs' => $slugs,
+		);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @since x.x.x
+	 */
+	protected function permission_callback( $args ) {
+		$post_id = isset( $args['context'] ) && is_numeric( $args['context'] ) ? absint( $args['context'] ) : null;
+
+		if ( $post_id ) {
+			$post = get_post( $post_id );
+
+			if ( ! $post ) {
+				return new WP_Error(
+					'post_not_found',
+					/* translators: %d: Post ID. */
+					sprintf( esc_html__( 'Post with ID %d not found.', 'ai' ), $post_id )
+				);
+			}
+
+			if ( ! current_user_can( 'edit_post', $post_id ) ) {
+				return new WP_Error(
+					'insufficient_capabilities',
+					esc_html__( 'You do not have permission to generate slugs for this post.', 'ai' )
+				);
+			}
+
+			$post_type = get_post_type( $post_id );
+			if ( ! $post_type ) {
+				return false;
+			}
+
+			$post_type_obj = get_post_type_object( $post_type );
+			if ( ! $post_type_obj || empty( $post_type_obj->show_in_rest ) ) {
+				return false;
+			}
+		} elseif ( ! current_user_can( 'edit_posts' ) ) {
+			return new WP_Error(
+				'insufficient_capabilities',
+				esc_html__( 'You do not have permission to generate slugs.', 'ai' )
+			);
+		}
+
+		return true;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @since x.x.x
+	 */
+	protected function meta(): array {
+		return array(
+			'show_in_rest' => true,
+		);
+	}
+
+	/**
+	 * Generates slug suggestions from the prompt.
+	 *
+	 * @since x.x.x
+	 *
+	 * @param string $prompt                The prompt.
+	 * @param mixed  $context               The context.
+	 * @param int    $number_of_suggestions The number of suggestions.
+	 * @return string|\WP_Error The generated suggestions, or WP_Error.
+	 */
+	protected function generate_slugs( string $prompt, $context, int $number_of_suggestions ) {
+		$prompt         = $this->filter_prompt( $prompt, $context );
+		$prompt_builder = $this->get_prompt_builder( $prompt, $number_of_suggestions );
+
+		if ( is_wp_error( $prompt_builder ) ) {
+			return $prompt_builder;
+		}
+
+		return $prompt_builder->generate_text();
+	}
+
+	/**
+	 * Gets a prompt builder for generating slugs.
+	 *
+	 * @since x.x.x
+	 *
+	 * @param string $prompt                The prompt.
+	 * @param int    $number_of_suggestions The number of suggestions.
+	 * @return \WP_AI_Client_Prompt_Builder|\WP_Error The prompt builder, or WP_Error.
+	 */
+	private function get_prompt_builder( string $prompt, int $number_of_suggestions ) {
+		$prompt_builder = wp_ai_client_prompt( $prompt )
+			->using_system_instruction( $this->get_system_instruction( null, array( 'number_of_suggestions' => $number_of_suggestions ) ) )
+			->using_temperature( 0.5 );
+
+		$prompt_builder = $this->filter_prompt_builder( $prompt_builder, Slug_Generation_Experiment::class, array(), $prompt );
+
+		return $this->ensure_text_generation_supported(
+			$prompt_builder,
+			esc_html__( 'Slug generation failed. Please ensure you have a connected provider that supports text generation.', 'ai' )
+		);
+	}
+}

includes/Abilities/Slug_Generation/system-instruction.php

@@ -0,0 +1,29 @@
+<?php
+/**
+ * System instruction for the Slug Generation ability.
+ *
+ * @package WordPress\AI\Abilities\Slug_Generation
+ */
+
+// Exit if accessed directly.
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+$wpai_slug_num = isset( $number_of_suggestions ) ? (int) $number_of_suggestions : 3;
+
+return sprintf(
+	'You are an editorial assistant that generates permalink slug suggestions for online articles and pages.
+
+Goal: You will be provided with a title and/or content, and optionally some additional context. You should generate a list of url-safe, concise, keyword-relevant permalink slug options (separated by newlines) that represent the content.
+
+The slug suggestions should follow these requirements:
+- Be concise (typically 2 to 5 words) and optimized for SEO.
+- Focus on key concepts and relevant keywords.
+- Use only lowercase letters, numbers, and hyphens.
+- Do not include any file extensions (e.g., .html, .php).
+- Output exactly %d suggestions, one per line.
+- Do not include any markdown, bullets, numbering, or formatting.
+- Output only the raw slug text. Respond directly without preamble. Do not wrap the output in quotes. Do not add closing remarks or follow-up questions.',
+	$wpai_slug_num
+);

includes/Experiments/Experiments.php

@@ -43,6 +43,7 @@ final class Experiments {
 		\WordPress\AI\Experiments\Meta_Description\Meta_Description::class,
 		\WordPress\AI\Experiments\Title_Generation\Title_Generation::class,
 		\WordPress\AI\Experiments\Type_Ahead\Type_Ahead::class,
+		\WordPress\AI\Experiments\Slug_Generation\Slug_Generation::class,
 	);
 
 	/**