Implement main AI store functionality.

src/ai-store/generative-ai-service.js

@@ -0,0 +1,131 @@
+/**
+ * WordPress dependencies
+ */
+import apiFetch from '@wordpress/api-fetch';
+import { __ } from '@wordpress/i18n';
+
+/**
+ * Service class.
+ *
+ * @since n.e.x.t
+ */
+export class GenerativeAiService {
+	/**
+	 * Constructor.
+	 *
+	 * @since n.e.x.t
+	 *
+	 * @param {Object} service                  Service object.
+	 * @param {string} service.slug             Service slug.
+	 * @param {string} service.name             Service name.
+	 * @param {Array}  service.available_models Available models.
+	 */
+	constructor( { slug, name, available_models: models } ) {
+		if ( ! models || ! models.length ) {
+			throw new Error(
+				`No models available for the service ${ slug }. Is it available?`
+			);
+		}
+
+		this.slug = slug;
+		this.name = name;
+		this.models = models;
+	}
+
+	/**
+	 * Gets the service slug.
+	 *
+	 * @since n.e.x.t
+	 *
+	 * @return {string} Service name.
+	 */
+	getServiceSlug() {
+		return this.slug;
+	}
+
+	/**
+	 * Lists the available generative model slugs.
+	 *
+	 * @since n.e.x.t
+	 *
+	 * @return {string[]} The available model slugs.
+	 */
+	listModels() {
+		return this.models;
+	}
+
+	/**
+	 * Generates content using the service.
+	 *
+	 * @since n.e.x.t
+	 *
+	 * @param {Object}                 args             Arguments for generating content.
+	 * @param {string|Object|Object[]} args.content     Content data to pass to the model, including the prompt and optional history.
+	 * @param {string}                 args.model       Model slug.
+	 * @param {Object}                 args.modelParams Model parameters.
+	 * @return {Promise<Object[]>} Model response candidates with the generated content.
+	 */
+	async generateContent( { content, model, modelParams } ) {
+		// Do some very basic validation.
+		if ( ! content ) {
+			throw new Error(
+				__(
+					'The content argument is required to generate content.',
+					'wp-starter-plugin'
+				)
+			);
+		}
+		if ( ! Array.isArray( content ) ) {
+			if ( typeof content === 'object' ) {
+				if ( ! content.role || ! content.parts ) {
+					throw new Error(
+						__(
+							'The content object must have a role and parts properties.',
+							'wp-starter-plugin'
+						)
+					);
+				}
+			} else if ( typeof content !== 'string' ) {
+				throw new Error(
+					__(
+						'The content argument must be a string, an object, or an array of objects.',
+						'wp-starter-plugin'
+					)
+				);
+			}
+		}
+
+		return await apiFetch( {
+			path: `/wp-starter-plugin/v1/services/${ this.slug }:generate-content`,
+			method: 'POST',
+			data: {
+				content,
+				model: model || '',
+				modelParams: modelParams || {},
+			},
+		} );
+	}
+}
+
+const services = {};
+
+/**
+ * Gets the generative AI service instance for the given service data.
+ *
+ * The service data must be an object received from the services REST endpoint.
+ *
+ * @since n.e.x.t
+ *
+ * @param {Object}   serviceData                  Service data.
+ * @param {string}   serviceData.slug             Service slug.
+ * @param {string}   serviceData.name             Service name.
+ * @param {string[]} serviceData.available_models Available models.
+ * @return {GenerativeAiService} Generative AI service instance.
+ */
+export function getGenerativeAiService( serviceData ) {
+	if ( ! services[ serviceData.slug ] ) {
+		services[ serviceData.slug ] = new GenerativeAiService( serviceData );
+	}
+
+	return services[ serviceData.slug ];
+}

src/ai-store/services.js

@@ -8,6 +8,7 @@ import { createRegistrySelector } from '@wordpress/data';
  * Internal dependencies
  */
 import { STORE_NAME } from './name';
+import { getGenerativeAiService } from './generative-ai-service';
 
 const RECEIVE_SERVICES = 'RECEIVE_SERVICES';
 
@@ -85,18 +86,67 @@ const selectors = {
 		return state.services;
 	},
 
-	getService: createRegistrySelector( ( select ) => ( state, slug ) => {
-		const services = select( STORE_NAME ).getServices();
-		if ( services === undefined ) {
-			return undefined;
+	isServiceRegistered: createRegistrySelector(
+		( select ) => ( state, slug ) => {
+			const services = select( STORE_NAME ).getServices();
+			if ( services === undefined ) {
+				return undefined;
+			}
+			return services[ slug ] !== undefined;
 		}
-		if ( services[ slug ] === undefined ) {
-			// eslint-disable-next-line no-console
-			console.error( `Invalid service ${ slug }.` );
-			return undefined;
+	),
+
+	isServiceAvailable: createRegistrySelector(
+		( select ) => ( state, slug ) => {
+			const services = select( STORE_NAME ).getServices();
+			if ( services === undefined ) {
+				return undefined;
+			}
+			return (
+				services[ slug ] !== undefined && services[ slug ].is_available
+			);
+		}
+	),
+
+	hasAvailableServices: createRegistrySelector(
+		( select ) => ( state, slugs ) => {
+			const services = select( STORE_NAME ).getServices();
+			if ( services === undefined ) {
+				return undefined;
+			}
+			if ( ! slugs ) {
+				slugs = Object.keys( services );
+			}
+			return slugs.some(
+				( slug ) =>
+					services[ slug ] !== undefined &&
+					services[ slug ].is_available
+			);
+		}
+	),
+
+	getAvailableService: createRegistrySelector(
+		( select ) => ( state, slugs ) => {
+			const services = select( STORE_NAME ).getServices();
+			if ( services === undefined ) {
+				return undefined;
+			}
+			if ( typeof slugs === 'string' ) {
+				slugs = [ slugs ];
+			} else if ( ! slugs ) {
+				slugs = Object.keys( services );
+			}
+			const availableSlug = slugs.find(
+				( slug ) =>
+					services[ slug ] !== undefined &&
+					services[ slug ].is_available
+			);
+			if ( ! availableSlug ) {
+				return null;
+			}
+			return getGenerativeAiService( services[ availableSlug ] );
 		}
-		return services[ slug ];
-	} ),
+	),
 };
 
 const storeConfig = {