<?php
/**
 * Class Google\Site_Kit\Modules\Idea_Hub
 *
 * @package   Google\Site_Kit
 * @copyright 2021 Google LLC
 * @license   https://www.apache.org/licenses/LICENSE-2.0 Apache License 2.0
 * @link      https://sitekit.withgoogle.com
 */

namespace Google\Site_Kit\Modules;

use Exception;
use Google\Site_Kit\Context;
use Google\Site_Kit\Core\Admin\Notice;
use Google\Site_Kit\Core\Assets\Asset;
use Google\Site_Kit\Core\Assets\Assets;
use Google\Site_Kit\Core\Authentication\Authentication;
use Google\Site_Kit\Core\Authentication\Clients\Google_Site_Kit_Client;
use Google\Site_Kit\Core\Dismissals\Dismissed_Items;
use Google\Site_Kit\Core\Modules\Module;
use Google\Site_Kit\Core\Modules\Module_Settings;
use Google\Site_Kit\Core\Modules\Module_With_Deactivation;
use Google\Site_Kit\Core\Modules\Module_With_Debug_Fields;
use Google\Site_Kit\Core\Modules\Module_With_Assets;
use Google\Site_Kit\Core\Modules\Module_With_Assets_Trait;
use Google\Site_Kit\Core\Modules\Module_With_Owner;
use Google\Site_Kit\Core\Modules\Module_With_Owner_Trait;
use Google\Site_Kit\Core\Modules\Module_With_Persistent_Registration;
use Google\Site_Kit\Core\Modules\Module_With_Scopes;
use Google\Site_Kit\Core\Modules\Module_With_Scopes_Trait;
use Google\Site_Kit\Core\Modules\Module_With_Settings;
use Google\Site_Kit\Core\Modules\Module_With_Settings_Trait;
use Google\Site_Kit\Core\Assets\Script;
use Google\Site_Kit\Core\Assets\Script_Data;
use Google\Site_Kit\Core\REST_API\Exception\Invalid_Datapoint_Exception;
use Google\Site_Kit\Core\REST_API\Data_Request;
use Google\Site_Kit\Core\Storage\Options;
use Google\Site_Kit\Core\Storage\Post_Meta;
use Google\Site_Kit\Core\Storage\Transients;
use Google\Site_Kit\Core\Storage\User_Options;
use Google\Site_Kit\Core\Util\Feature_Flags;
use Google\Site_Kit\Modules\Idea_Hub\Idea_Interaction_Count;
use Google\Site_Kit\Modules\Idea_Hub\Post_Idea_Name;
use Google\Site_Kit\Modules\Idea_Hub\Post_Idea_Text;
use Google\Site_Kit\Modules\Idea_Hub\Post_Idea_Topics;
use Google\Site_Kit\Modules\Idea_Hub\Settings;
use Google\Site_Kit_Dependencies\Google\Model as Google_Model;
use Google\Site_Kit_Dependencies\Google\Service\Ideahub as Google_Service_Ideahub;
use Google\Site_Kit_Dependencies\Google\Service\Ideahub\GoogleSearchIdeahubV1betaIdeaActivity as Google_Service_Ideahub_GoogleSearchIdeahubV1betaIdeaActivity;
use Google\Site_Kit_Dependencies\Google\Service\Ideahub\GoogleSearchIdeahubV1betaIdeaState as Google_Service_Ideahub_GoogleSearchIdeahubV1betaIdeaState;
use Google\Site_Kit_Dependencies\Psr\Http\Message\RequestInterface;
use Google\Site_Kit\Core\Util\Method_Proxy_Trait;
use InvalidArgumentException;
use RuntimeException;
use WP_Error;
use WP_Post;

/**
 * Class representing the Idea Hub module.
 *
 * @since 1.32.0
 * @access private
 * @ignore
 */
final class Idea_Hub extends Module
	implements Module_With_Scopes, Module_With_Settings, Module_With_Debug_Fields, Module_With_Assets, Module_With_Deactivation, Module_With_Owner, Module_With_Persistent_Registration {

	use Module_With_Assets_Trait;
	use Module_With_Owner_Trait;
	use Module_With_Scopes_Trait;
	use Module_With_Settings_Trait;
	use Method_Proxy_Trait;

	/**
	 * Module slug name.
	 */
	const MODULE_SLUG = 'idea-hub';

	/**
	 * Saved ideas cache key.
	 */
	const TRANSIENT_SAVED_IDEAS = 'googlesitekit_idea_hub_saved_ideas';

	/**
	 * New ideas cache key.
	 */
	const TRANSIENT_NEW_IDEAS = 'googlesitekit_idea_hub_new_ideas';

	/**
	 * New ideas notice slug and dismissible item key.
	 */
	const SLUG_NEW_IDEAS = 'idea-hub_new-ideas';

	/**
	 * Saved ideas notice slug and dismissible item key.
	 */
	const SLUG_SAVED_IDEAS = 'idea-hub_saved-ideas';

	/**
	 * Last changed cache key.
	 */
	const IDEA_HUB_LAST_CHANGED = 'googlesitekit_idea_hub_last_changed';

	/**
	 * Idea activity types.
	 */
	const ACTIVITY_POST_PUBLISHED   = 'POST_PUBLISHED';
	const ACTIVITY_POST_UNPUBLISHED = 'POST_UNPUBLISHED';
	const ACTIVITY_POST_DRAFTED     = 'POST_DRAFTED';
	const ACTIVITY_POST_DELETED     = 'POST_DELETED';

	/**
	 * Map of ideas datapoint to transient key.
	 */
	const DATAPOINT_TRANSIENT_MAP = array(
		'new-ideas'   => self::TRANSIENT_NEW_IDEAS,
		'saved-ideas' => self::TRANSIENT_SAVED_IDEAS,
	);

	/**
	 * Post_Idea_Name instance.
	 *
	 * @since 1.32.0
	 * @var Post_Idea_Name
	 */
	private $post_name_setting;

	/**
	 * Post_Idea_Text instance.
	 *
	 * @since 1.32.0
	 * @var Post_Idea_Text
	 */
	private $post_text_setting;

	/**
	 * Post_Idea_Topics instance.
	 *
	 * @since 1.32.0
	 * @var Post_Idea_Topics
	 */
	private $post_topic_setting;

	/**
	 * Transients instance.
	 *
	 * @since 1.40.0
	 * @var Transients
	 */
	private $transients;

	/**
	 * Idea_Interaction_Count instance.
	 *
	 * @since 1.42.0
	 * @var Idea_Interaction_Count
	 */
	private $interaction_count;

	/**
	 * Constructor.
	 *
	 * @since 1.38.0
	 *
	 * @param Context        $context        Plugin context.
	 * @param Options        $options        Optional. Option API instance. Default is a new instance.
	 * @param User_Options   $user_options   Optional. User Option API instance. Default is a new instance.
	 * @param Authentication $authentication Optional. Authentication instance. Default is a new instance.
	 * @param Assets         $assets         Optional. Assets API instance. Default is a new instance.
	 */
	public function __construct(
		Context $context,
		Options $options = null,
		User_Options $user_options = null,
		Authentication $authentication = null,
		Assets $assets = null
	) {
		parent::__construct( $context, $options, $user_options, $authentication, $assets );

		$post_meta                = new Post_Meta();
		$this->post_name_setting  = new Post_Idea_Name( $post_meta );
		$this->post_text_setting  = new Post_Idea_Text( $post_meta );
		$this->post_topic_setting = new Post_Idea_Topics( $post_meta );
		$this->transients         = new Transients( $this->context );
		$this->interaction_count  = new Idea_Interaction_Count( $this->user_options );
	}

	/**
	 * Registers functionality through WordPress hooks.
	 *
	 * @since 1.38.0
	 */
	public function register_persistent() {
		/**
		 * Changes the posts view to have a custom label in place of Draft for Idea Hub Drafts.
		 */
		add_filter(
			'display_post_states',
			function( $post_states, $post ) {
				if ( ! $this->is_idea_post( $post->ID ) ) {
					return $post_states;
				}
				$idea = $this->get_post_idea( $post->ID );
				if ( '' === $post->post_title && 'draft' === $post->post_status ) {
					/* translators: %s: Idea Hub Idea Title */
					$post_states['draft'] = sprintf( __( 'Idea Hub Draft “%s”', 'google-site-kit' ), $idea['text'] );
				} else {
					$post_states['idea-hub'] = __( 'inspired by Idea Hub', 'google-site-kit' );
				}
				return $post_states;
			},
			10,
			2
		);

		/**
		 * Allows us to trash / modify empty idea posts.
		 */
		add_filter(
			'wp_insert_post_empty_content',
			function( $maybe_empty, $postarr ) {
				if ( isset( $postarr['ID'] ) && $this->is_idea_post( $postarr['ID'] ) ) {
					return false;
				}
				return $maybe_empty;
			},
			10,
			2
		);
	}

	/**
	 * Registers functionality through WordPress hooks.
	 *
	 * @since 1.32.0
	 */
	public function register() {
		$this->register_scopes_hook();

		if ( $this->is_connected() ) {
			/**
			 * Show admin notices on the posts page if we have saved / new ideas.
			 */
			add_filter( 'googlesitekit_admin_notices', $this->get_method_proxy( 'admin_notice_idea_hub_ideas' ) );

			/**
			 * Adds a special class name to idea posts.
			 */
			add_filter( 'post_class', $this->get_method_proxy( 'update_post_classes' ), 10, 3 );

			add_action(
				'admin_footer-edit.php',
				function() {
					$screen = get_current_screen();
					if ( ! is_null( $screen ) && 'post' === $screen->post_type ) {
						echo '<div id="js-googlesitekit-post-list" class="googlesitekit-plugin"></div>';
					}
				}
			);

			add_action(
				'before_delete_post',
				function( $post_id ) {
					$this->track_idea_activity( $post_id, self::ACTIVITY_POST_DELETED );
				}
			);

			/**
			 * Watches for Idea Hub post state changes.
			 */
			add_action( 'transition_post_status', $this->get_method_proxy( 'on_idea_hub_post_status_transition' ), 10, 3 );
		}

		$this->post_name_setting->register();
		$this->post_text_setting->register();
		$this->post_topic_setting->register();

		$this->interaction_count->register();
	}

	/**
	 * Shows admin notification for idea hub ideas on post list screen.
	 *
	 * @since 1.38.0
	 *
	 * @param array $notices Array of admin notices.
	 * @return array Array of admin notices.
	 */
	private function admin_notice_idea_hub_ideas( $notices ) {
		$screen = get_current_screen();
		if ( is_null( $screen ) || 'edit-post' !== $screen->id || 'post' !== $screen->post_type ) {
			return $notices;
		}

		$dismissed_items                = new Dismissed_Items( $this->user_options );
		$escape_and_wrap_notice_content = function( $message ) {
			$message = wp_kses(
				$message,
				array(
					'a' => array(
						'href' => array(),
					),
				)
			);

			return '<p>' . $message . '</p>';
		};

		$notices[] = new Notice(
			self::SLUG_SAVED_IDEAS,
			array(
				'content'         => function() use ( $escape_and_wrap_notice_content ) {
					$message_body = sprintf(
						/* translators: %s: URL to saved ideas */
						__( 'Want some inspiration for a new post? <a href="%s">Revisit your saved ideas</a> in Site Kit.', 'google-site-kit' ),
						esc_url( $this->context->admin_url( 'dashboard', array( 'idea-hub-tab' => 'saved-ideas' ) ) )
					);

					$message = sprintf(
						/* translators: 1: Plugin name. 2: Message. */
						__( '%1$s: %2$s', 'google-site-kit' ),
						__( 'Site Kit by Google', 'google-site-kit' ),
						$message_body
					);

					return $escape_and_wrap_notice_content( $message );
				},
				'type'            => Notice::TYPE_INFO,
				'active_callback' => function() use ( $dismissed_items ) {
					try {
						$saved_ideas = $this->get_cached_ideas( 'saved-ideas' );
						$has_saved_ideas = ! empty( $saved_ideas );

						if ( ! $has_saved_ideas && $dismissed_items->is_dismissed( self::SLUG_SAVED_IDEAS ) ) {
							// Saved items no longer need to be dismissed as there are none currently.
							$dismissed_items->add( self::SLUG_SAVED_IDEAS, -1 );
						}

						if ( $dismissed_items->is_dismissed( self::SLUG_SAVED_IDEAS ) ) {
							return false;
						}

						return $has_saved_ideas;
					} catch ( Exception $exception ) {
						return false;
					}
				},
				'dismissible'     => true,
			)
		);

		$notices[] = new Notice(
			self::SLUG_NEW_IDEAS,
			array(
				'content'         => function() use ( $escape_and_wrap_notice_content ) {
					$message_body = sprintf(
						/* translators: %s: URL to saved ideas */
						__( 'Want some inspiration for a new post? <a href="%s">Review your new ideas</a> in Site Kit.', 'google-site-kit' ),
						esc_url( $this->context->admin_url( 'dashboard', array( 'idea-hub-tab' => 'new-ideas' ) ) )
					);

					$message = sprintf(
						/* translators: 1: Plugin name. 2: Message. */
						__( '%1$s: %2$s', 'google-site-kit' ),
						__( 'Site Kit by Google', 'google-site-kit' ),
						$message_body
					);

					return $escape_and_wrap_notice_content( $message );
				},
				'type'            => Notice::TYPE_INFO,
				'active_callback' => function() use ( $dismissed_items ) {
					if (
						$dismissed_items->is_dismissed( self::SLUG_NEW_IDEAS )
						|| $dismissed_items->is_dismissed( self::SLUG_SAVED_IDEAS )
					) {
						return false;
					}

					try {
						$saved_ideas = $this->get_cached_ideas( 'saved-ideas' );

						if ( ! empty( $saved_ideas ) ) {
							// Don't show new ideas notice if there are saved ideas,
							// irrespective of whether we show them the saved ideas notice.
							return false;
						}

						$new_ideas = $this->get_cached_ideas( 'new-ideas' );

						return ! empty( $new_ideas );
					} catch ( Exception $exception ) {
						return false;
					}
				},
				'dismissible'     => true,
			)
		);

		return $notices;
	}

	/**
	 * Gets ideas from cache.
	 *
	 * If cache has expired, ideas will be fetched and cached if successful.
	 *
	 * @since 1.50.0
	 *
	 * @param string $datapoint The datapoint to fetch ideas from.
	 * @return array Cached or freshly cached ideas.
	 * @throws InvalidArgumentException Thrown if invalid datapoint is given.
	 * @throws RuntimeException Thrown if get_data returns a WP_Error.
	 */
	protected function get_cached_ideas( $datapoint ) {
		if ( empty( self::DATAPOINT_TRANSIENT_MAP[ $datapoint ] ) ) {
			throw new InvalidArgumentException( "Invalid datapoint $datapoint" );
		}

		$transient = self::DATAPOINT_TRANSIENT_MAP[ $datapoint ];
		$ideas     = $this->transients->get( $transient );

		if ( is_array( $ideas ) ) {
			return $ideas;
		}

		$ideas = $this->get_data( $datapoint );

		if ( is_wp_error( $ideas ) ) {
			throw new RuntimeException( $ideas->get_error_message() );
		}

		$this->transients->set( $transient, $ideas, HOUR_IN_SECONDS );

		return $ideas;
	}

	/**
	 * Gets required Google OAuth scopes for the module.
	 *
	 * @since 1.32.0
	 *
	 * @return array List of Google OAuth scopes.
	 */
	public function get_scopes() {
		return array(
			'https://www.googleapis.com/auth/ideahub.read',
			'https://www.googleapis.com/auth/ideahub.full',
		);
	}

	/**
	 * Checks whether the module is connected.
	 *
	 * A module being connected means that all steps required as part of its activation are completed.
	 *
	 * @since 1.32.0
	 *
	 * @return bool True if module is connected, false otherwise.
	 */
	public function is_connected() {
		$required_keys = array( 'tosAccepted' );

		$options = $this->get_settings()->get();
		foreach ( $required_keys as $required_key ) {
			if ( empty( $options[ $required_key ] ) ) {
				return false;
			}
		}

		return parent::is_connected();
	}

	/**
	 * Cleans up when the module is deactivated.
	 *
	 * @since 1.32.0
	 */
	public function on_deactivation() {
		$this->get_settings()->delete();
		$this->transients->delete( self::TRANSIENT_NEW_IDEAS );
		$this->transients->delete( self::TRANSIENT_SAVED_IDEAS );
	}

	/**
	 * Gets an array of debug field definitions.
	 *
	 * @since 1.32.0
	 *
	 * @return array
	 */
	public function get_debug_fields() {
		$settings = $this->get_settings()->get();

		return array();
	}

	/**
	 * Gets map of datapoint to definition data for each.
	 *
	 * @since 1.32.0
	 *
	 * @return array Map of datapoints to their definitions.
	 */
	protected function get_datapoint_definitions() {
		return array(
			'POST:create-idea-draft-post' => array( 'service' => '' ),
			'GET:draft-post-ideas'        => array(
				'service'   => '',
				'shareable' => Feature_Flags::enabled( 'dashboardSharing' ),
			),
			'GET:new-ideas'               => array(
				'service'   => 'ideahub',
				'shareable' => Feature_Flags::enabled( 'dashboardSharing' ),
			),
			'GET:published-post-ideas'    => array(
				'service'   => '',
				'shareable' => Feature_Flags::enabled( 'dashboardSharing' ),
			),
			'GET:saved-ideas'             => array(
				'service'   => 'ideahub',
				'shareable' => Feature_Flags::enabled( 'dashboardSharing' ),
			),
			'POST:update-idea-state'      => array( 'service' => 'ideahub' ),
		);
	}

	/**
	 * Creates a request object for the given datapoint.
	 *
	 * @since 1.32.0
	 *
	 * @param Data_Request $data Data request object.
	 * @return RequestInterface|callable|WP_Error Request object or callable on success, or WP_Error on failure.
	 *
	 * @throws Invalid_Datapoint_Exception Thrown if the datapoint does not exist.
	 */
	protected function create_data_request( Data_Request $data ) {
		switch ( "{$data->method}:{$data->datapoint}" ) {
			case 'POST:create-idea-draft-post':
				$expected_parameters = array(
					'name'   => 'string',
					'text'   => 'string',
					'topics' => 'array',
				);
				if ( ! isset( $data['idea'] ) ) {
					return new WP_Error(
						'missing_required_param',
						/* translators: %s: Missing parameter name */
						sprintf( __( 'Request parameter is empty: %s.', 'google-site-kit' ), 'idea' ),
						array( 'status' => 400 )
					);
				}
				$idea = $data['idea'];
				foreach ( $expected_parameters as $parameter_name => $expected_parameter_type ) {
					if ( ! isset( $idea[ $parameter_name ] ) ) {
						return new WP_Error(
							'missing_required_param',
							/* translators: %s: Missing parameter name */
							sprintf( __( 'Request idea parameter is empty: %s.', 'google-site-kit' ), $parameter_name ),
							array( 'status' => 400 )
						);
					}
					$parameter_type = gettype( $idea[ $parameter_name ] );
					if ( $parameter_type !== $expected_parameter_type ) {
						return new WP_Error(
							'wrong_parameter_type',
							sprintf(
								/* translators: %1$s: parameter name, %2$s expected type, %3$s received type */
								__( 'Wrong parameter type for %1$s, expected %2$s, received %3$s', 'google-site-kit' ),
								$parameter_name,
								$expected_parameter_type,
								$parameter_type
							),
							array( 'status' => 400 )
						);
					}
				}

				return function() use ( $idea ) {
					// Allows us to create a blank post.
					add_filter( 'wp_insert_post_empty_content', '__return_false' );
					$post_id = wp_insert_post( array(), false );
					remove_filter( 'wp_insert_post_empty_content', '__return_false' );

					if ( 0 === $post_id ) {
						return new WP_Error(
							'unable_to_draft_post',
							__( 'Unable to draft post.', 'google-site-kit' ),
							array( 'status' => 400 )
						);
					}

					$this->set_post_idea( $post_id, $idea );
					$this->track_idea_activity( $post_id, self::ACTIVITY_POST_DRAFTED );

					$this->transients->delete( self::TRANSIENT_SAVED_IDEAS );
					$this->transients->delete( self::TRANSIENT_NEW_IDEAS );

					return $post_id;
				};
			case 'GET:draft-post-ideas':
				return function() {
					return $this->query_idea_posts( 'draft' );
				};
			case 'GET:new-ideas':
				return $this->fetch_ideas( 'new' );
			case 'GET:published-post-ideas':
				return function() {
					$statuses = array( 'publish', 'future', 'private' );
					return $this->query_idea_posts( $statuses );
				};
			case 'GET:saved-ideas':
				return $this->fetch_ideas( 'saved' );
			case 'POST:update-idea-state':
				if ( ! isset( $data['name'] ) ) {
					return new WP_Error(
						'missing_required_param',
						/* translators: %s: Missing parameter name */
						sprintf( __( 'Request parameter is empty: %s.', 'google-site-kit' ), 'name' ),
						array( 'status' => 400 )
					);
				}

				if ( ! isset( $data['saved'] ) && ! isset( $data['dismissed'] ) ) {
					return new WP_Error(
						'missing_required_param',
						__( 'Either "saved" or "dismissed" parameter must be provided.', 'google-site-kit' ),
						array( 'status' => 400 )
					);
				}

				$idea_name       = $data['name'];
				$idea_name_parts = explode( '/', $data['name'] );

				$parent = $this->get_parent_slug();
				$parent = sprintf(
					'%s/ideaStates/%s',
					untrailingslashit( $parent ),
					array_pop( $idea_name_parts )
				);

				$update_mask = array();

				$body = new Google_Service_Ideahub_GoogleSearchIdeahubV1betaIdeaState();
				$body->setName( $idea_name );

				if ( isset( $data['saved'] ) ) {
					$body->setSaved( filter_var( $data['saved'], FILTER_VALIDATE_BOOLEAN ) );
					$update_mask[] = 'saved';
				}

				if ( isset( $data['dismissed'] ) ) {
					$body->setDismissed( filter_var( $data['dismissed'], FILTER_VALIDATE_BOOLEAN ) );
					$update_mask[] = 'dismissed';
				}

				$params = array(
					'updateMask' => implode( ',', $update_mask ),
				);

				return $this->get_service( 'ideahub' )->platforms_properties_ideaStates->patch( $parent, $body, $params );
		}

		return parent::create_data_request( $data );
	}

	/**
	 * Parses a response for the given datapoint.
	 *
	 * @since 1.34.0
	 *
	 * @param Data_Request $data     Data request object.
	 * @param mixed        $response Request response.
	 *
	 * @return mixed Parsed response data on success, or WP_Error on failure.
	 */
	protected function parse_data_response( Data_Request $data, $response ) {
		$filter_draft_post_response = function( $post_id ) {
			return array_merge(
				array(
					'postID'      => $post_id,
					'postEditURL' => get_edit_post_link( $post_id, null ),
				),
				$this->get_post_idea( $post_id )
			);
		};

		switch ( "{$data->method}:{$data->datapoint}" ) {
			case 'POST:create-idea-draft-post':
				$this->interaction_count->increment();

				return $filter_draft_post_response( $response );
			case 'GET:draft-post-ideas':
				return array_filter(
					array_map(
						$filter_draft_post_response,
						is_array( $response ) ? $response : array( $response )
					)
				);
			case 'GET:new-ideas':
				$ideas = $this->filter_out_ideas_with_posts( $response->getIdeas() );
				return array_map( array( self::class, 'filter_idea_with_id' ), $ideas );
			case 'GET:published-post-ideas':
				return array_filter(
					array_map(
						function( $post_id ) {
							return array_merge(
								array(
									'postID'      => $post_id,
									'postEditURL' => get_edit_post_link( $post_id ),
									'postURL'     => get_permalink( $post_id ),
								),
								$this->get_post_idea( $post_id )
							);
						},
						is_array( $response ) ? $response : array( $response )
					)
				);
			case 'GET:saved-ideas':
				$ideas = $this->filter_out_ideas_with_posts( $response->getIdeas() );
				return array_map( array( self::class, 'filter_idea_with_id' ), $ideas );
			case 'POST:update-idea-state':
				$this->interaction_count->increment();

				$this->transients->delete( self::TRANSIENT_SAVED_IDEAS );
				$this->transients->delete( self::TRANSIENT_NEW_IDEAS );

				return self::filter_idea_state_with_id( $response );
		}

		return parent::parse_data_response( $data, $response );
	}

	/**
	 * Sets up information about the module.
	 *
	 * @since 1.32.0
	 *
	 * @return array Associative array of module info.
	 */
	protected function setup_info() {
		return array(
			'slug'        => self::MODULE_SLUG,
			'name'        => _x( 'Idea Hub', 'Service name', 'google-site-kit' ),
			'description' => __( 'Idea Hub suggests what you can write about next, from actual questions people asked on Google Search', 'google-site-kit' ),
			'order'       => 7,
		);
	}

	/**
	 * Sets up the module's settings instance.
	 *
	 * @since 1.32.0
	 *
	 * @return Module_Settings
	 */
	protected function setup_settings() {
		return new Settings( $this->options );
	}

	/**
	 * Sets up the module's assets to register.
	 *
	 * @since 1.32.0
	 *
	 * @return Asset[] List of Asset objects.
	 */
	protected function setup_assets() {
		$base_url = $this->context->url( 'dist/assets/' );

		return array(
			new Script(
				'googlesitekit-modules-idea-hub',
				array(
					'src'          => $base_url . 'js/googlesitekit-modules-idea-hub.js',
					'dependencies' => array(
						'googlesitekit-vendor',
						'googlesitekit-api',
						'googlesitekit-data',
						'googlesitekit-modules',
					),
				)
			),
			new Script(
				'googlesitekit-idea-hub-post-list',
				array(
					'src'           => $base_url . 'js/googlesitekit-idea-hub-post-list.js',
					'load_contexts' => array( Asset::CONTEXT_ADMIN_POSTS ),
					'dependencies'  => array(
						'googlesitekit-i18n',
						'googlesitekit-datastore-location',
						'googlesitekit-datastore-ui',
						'googlesitekit-datastore-user',
						'googlesitekit-modules',
					),
				)
			),
			new Script(
				'googlesitekit-idea-hub-notice',
				array(
					'src'           => $base_url . 'js/googlesitekit-idea-hub-notice.js',
					'dependencies'  => array(
						'googlesitekit-i18n',
						'wp-data',
						'wp-api-fetch',
						'wp-polyfill',
						'wp-url',
					),
					'load_contexts' => array( Asset::CONTEXT_ADMIN_POST_EDITOR ),
				)
			),
			new Script_Data(
				'googlesitekit-idea-hub-data',
				array(
					'global'        => '_googlesitekitIdeaHub',
					'data_callback' => function () {
						return array(
							'lastIdeaPostUpdatedAt' => $this->transients->get( self::IDEA_HUB_LAST_CHANGED ),
							'interactionCount'      => $this->interaction_count->get(),
						);
					},
				)
			),
		);
	}

	/**
	 * Sets up the Google services the module should use.
	 *
	 * This method is invoked once by {@see Module::get_service()} to lazily set up the services when one is requested
	 * for the first time.
	 *
	 * @since 1.40.0
	 *
	 * @param Google_Site_Kit_Client $client Google client instance.
	 * @return array Google services as $identifier => $service_instance pairs.
	 */
	protected function setup_services( Google_Site_Kit_Client $client ) {
		return array(
			'ideahub' => new Google_Service_Ideahub( $client ),
		);
	}

	/**
	 * Saves post idea settings.
	 *
	 * @since 1.33.0
	 *
	 * @param int   $post_id Post ID.
	 * @param array $idea    Idea settings.
	 */
	public function set_post_idea( $post_id, array $idea ) {
		$idea = wp_parse_args(
			$idea,
			array(
				'name'   => '',
				'text'   => '',
				'topics' => array(),
			)
		);

		$this->post_name_setting->set( $post_id, $idea['name'] );
		$this->post_text_setting->set( $post_id, $idea['text'] );
		$this->post_topic_setting->set( $post_id, $idea['topics'] );
	}

	/**
	 * Parses an idea ID, adds it to the model object and returns updated model.
	 *
	 * @since 1.40.0
	 *
	 * @param Google_Model $idea Idea model.
	 * @return \stdClass Updated model with _id attribute.
	 */
	public static function filter_idea_with_id( $idea ) {
		$obj = $idea->toSimpleObject();

		$matches = array();
		if ( preg_match( '#ideas/([^/]+)#', $idea['name'], $matches ) ) {
			$obj->_id = $matches[1];
		}

		return $obj;
	}

	/**
	 * Parses an idea state ID, adds it to the model object and returns updated model.
	 *
	 * @since 1.40.0
	 *
	 * @param Google_Model $idea_state Idea state model.
	 * @return \stdClass Updated model with _id attribute.
	 */
	public static function filter_idea_state_with_id( $idea_state ) {
		$obj = $idea_state->toSimpleObject();

		$matches = array();
		if ( preg_match( '#platforms/([^/]+)/properties/([^/]+)/ideaStates/([^/]+)#', $idea_state['name'], $matches ) ) {
			$obj->_id = $matches[3];
		}

		return $obj;
	}

	/**
	 * Gets post idea settings.
	 *
	 * @since 1.33.0
	 *
	 * @param int $post_id Post ID.
	 * @return array|null Post idea settings array. Returns NULL if a post doesn't have an associated idea.
	 */
	public function get_post_idea( $post_id ) {
		$name   = $this->post_name_setting->get( $post_id );
		$text   = $this->post_text_setting->get( $post_id );
		$topics = $this->post_topic_setting->get( $post_id );
		if ( empty( $name ) || empty( $text ) || empty( $topics ) ) {
			return null;
		}

		return array(
			'name'   => $name,
			'text'   => $text,
			'topics' => $topics,
		);
	}

	/**
	 * Checks whether the post is an Idea Hub post.
	 *
	 * @since 1.36.0
	 *
	 * @param int $post_id Post ID.
	 * @return bool True if the post with supplied ID is an Idea Hub post.
	 */
	private function is_idea_post( $post_id ) {
		return is_array( $this->get_post_idea( $post_id ) );
	}

	/**
	 * Hook to check whether an Idea Hub post status has changed.
	 *
	 * @since 1.40.0
	 *
	 * @param string  $new_status Updated post status.
	 * @param string  $old_status Previous post status.
	 * @param WP_Post $post The post in question.
	 */
	private function on_idea_hub_post_status_transition( $new_status, $old_status, $post ) {
		if ( $new_status === $old_status || ! $this->is_idea_post( $post->ID ) ) {
			return;
		}

		$this->transients->set( self::IDEA_HUB_LAST_CHANGED, time() );

		if ( 'publish' === $new_status ) {
			$this->track_idea_activity( $post->ID, self::ACTIVITY_POST_PUBLISHED );
		} elseif ( 'publish' === $old_status ) {
			$this->track_idea_activity( $post->ID, self::ACTIVITY_POST_UNPUBLISHED );
		}
	}

	/**
	 * Adds .googlesitekit-idea-hub__draft class to idea posts on the posts page.
	 *
	 * @since 1.40.0
	 *
	 * @param array $classes An array of post class names.
	 * @param array $class An array of additional class names added to the post.
	 * @param int   $post_id The post ID.
	 * @return array An array of post class names.
	 */
	private function update_post_classes( $classes, $class, $post_id ) {
		// Do nothing on the frontend.
		if ( ! is_admin() ) {
			return $classes;
		}

		$screen = get_current_screen();
		if ( is_null( $screen ) || 'edit-post' !== $screen->id || 'post' !== $screen->post_type ) {
			return $classes;
		}

		if ( $this->is_idea_post( $post_id ) ) {
			$classes[] = 'googlesitekit-idea-hub__post';

			if ( ! wp_style_is( 'googlesitekit-admin-css' ) ) {
				$this->assets->enqueue_asset( 'googlesitekit-admin-css' );
			}
		}

		return $classes;
	}

	/**
	 * Gets the parent slug to use for Idea Hub API requests.
	 *
	 * @since 1.40.0
	 *
	 * @return string Parent slug.
	 */
	private function get_parent_slug() {
		$reference_url = $this->context->get_reference_site_url();
		$reference_url = rawurlencode( $reference_url );

		return "platforms/sitekit/properties/{$reference_url}";
	}

	/**
	 * Pulls posts created for an idea from the database.
	 *
	 * @since 1.40.0
	 *
	 * @param string|array $post_status Post status or statuses.
	 * @return array An array of post IDs.
	 */
	private function query_idea_posts( $post_status ) {
		$wp_query = new \WP_Query();

		return $wp_query->query(
			array(
				'fields'                 => 'ids',
				'post_status'            => $post_status,
				'posts_per_page'         => 500, // phpcs:ignore WordPress.WP.PostsPerPage.posts_per_page_posts_per_page
				'no_found_rows'          => true,
				'update_post_term_cache' => false,
				'order'                  => 'DESC',
				'orderby'                => 'ID',
				'meta_query'             => array( // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
					array(
						'key'     => Post_Idea_Name::META_KEY,
						'compare' => 'EXISTS',
					),
				),
			)
		);
	}

	/**
	 * Fetches ideas from the Idea Hub API.
	 *
	 * @since 1.40.0
	 *
	 * @param string $type Ideas type. Valid values "saved", "new" or an empty string which means all ideas.
	 * @return mixed List ideas request.
	 */
	private function fetch_ideas( $type ) {
		$parent = $this->get_parent_slug();
		$params = array(
			'pageSize' => 100,
		);

		if ( 'saved' === $type ) {
			$params['filter'] = 'saved(true)';
		} elseif ( 'new' === $type ) {
			$params['filter'] = 'saved(false)';
		}

		return $this->get_service( 'ideahub' )
			->platforms_properties_ideas
			->listPlatformsPropertiesIdeas( $parent, $params );
	}

	/**
	 * Filters out ideas for which we have already created a post.
	 *
	 * @since 1.40.0
	 *
	 * @param array $ideas Ideas list to filter.
	 * @return array Filtered ideas list.
	 */
	private function filter_out_ideas_with_posts( $ideas ) {
		if ( empty( $ideas ) ) {
			return $ideas;
		}

		$names = wp_list_pluck( $ideas, 'name' );

		$statuses = array( 'publish', 'pending', 'draft', 'future', 'private' );
		$posts    = $this->query_idea_posts( $statuses );
		if ( empty( $posts ) ) {
			return $ideas;
		}

		$ideas_with_posts = array();
		foreach ( $posts as $post_id ) {
			$idea = $this->get_post_idea( $post_id );
			if ( ! empty( $idea['name'] ) ) {
				$ideas_with_posts[] = $idea['name'];
			}
		}

		$ideas = array_filter(
			$ideas,
			function( $idea ) use ( $ideas_with_posts ) {
				return ! in_array( $idea->getName(), $ideas_with_posts, true );
			}
		);

		return array_values( $ideas );
	}

	/**
	 * Tracks an idea activity.
	 *
	 * @since 1.42.0
	 *
	 * @param int    $post_id Post ID.
	 * @param string $type    Activity type.
	 */
	private function track_idea_activity( $post_id, $type ) {
		$post = get_post( $post_id );
		$name = $this->post_name_setting->get( $post->ID );
		if ( empty( $name ) ) {
			return;
		}

		$parent   = $this->get_parent_slug();
		$activity = new Google_Service_Ideahub_GoogleSearchIdeahubV1betaIdeaActivity();

		$activity->setIdeas( array( $name ) );
		$activity->setTopics( array() );
		$activity->setType( $type );

		if ( 'publish' === $post->post_status ) {
			$uri = get_permalink( $post );
			if ( ! empty( $uri ) ) {
				$activity->setUri( $uri );
			}
		}

		try {
			$this->get_service( 'ideahub' )
				->platforms_properties_ideaActivities
				->create( $parent, $activity );
		} catch ( Exception $e ) { // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedCatch
			// Do nothing.
		}
	}

}
