<?php
/**
 * The admin screen.
 *
 * @package SharelyAI
 */

namespace SharelyAI;

defined( 'ABSPATH' ) || exit;

/**
 * Settings → Sharely.AI: two tabs, Status and Settings.
 *
 * One page with WordPress's own tab bar rather than two menu entries. This
 * class owns the menu, the tabs and the settings form; `Status` renders the
 * other tab's body, and `Connect` owns connecting and disconnecting.
 *
 * There are no credential fields. An administrator should not have to find a
 * workspace id or mint a key by hand — that is what Connect is for — and
 * `wp-config.php` constants remain the path for a scripted install.
 */
final class Settings {

	public const PAGE = 'sharelyai';

	/**
	 * The handle the stylesheet is registered under.
	 */
	public const STYLE = 'sharelyai-admin';

	/**
	 * The handle the progress script is registered under.
	 */
	public const SCRIPT = 'sharelyai-admin';

	/**
	 * WordPress's own name for this screen, as add_options_page() returns it.
	 *
	 * Kept so the stylesheet loads on this screen and nowhere else: comparing
	 * the hook suffix is the only reliable way to say "my page", and a plugin
	 * that restyles the whole admin is a plugin nobody keeps.
	 *
	 * @var string
	 */
	private string $hook = '';

	/**
	 * Constructor.
	 *
	 * @param Connection $connection The connection being configured.
	 */
	public function __construct( private Connection $connection ) {}

	/**
	 * Hooks the screen up.
	 */
	public function register(): void {
		add_action( 'admin_menu', array( $this, 'add_page' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue' ) );
		add_action( 'admin_post_sharelyai_save', array( $this, 'handle_save' ) );
		add_action( 'admin_post_sharelyai_disconnect', array( $this, 'handle_disconnect' ) );
		add_action( 'admin_post_sharelyai_stats_clear', array( $this, 'handle_stats_clear' ) );
		add_action( 'admin_post_sharelyai_sync', array( $this, 'handle_sync' ) );
	}

	/**
	 * The screen's URL, optionally on a tab.
	 *
	 * @param string $tab Tab slug; the Status tab has none.
	 */
	public static function page_url( string $tab = '' ): string {
		$args = array( 'page' => self::PAGE );
		if ( '' !== $tab ) {
			$args['tab'] = $tab;
		}
		return add_query_arg( $args, admin_url( 'options-general.php' ) );
	}

	/**
	 * Adds the options page.
	 */
	public function add_page(): void {
		$this->hook = (string) add_options_page(
			__( 'Sharely.AI', 'sharelyai' ),
			__( 'Sharely.AI', 'sharelyai' ),
			'manage_options',
			self::PAGE,
			array( $this, 'render' )
		);
	}

	/**
	 * WordPress's id for this screen, once `add_page()` has run.
	 *
	 * Empty before then. It is not a constant: WordPress derives the id from
	 * the parent menu, and that derivation is its business, not ours — which
	 * is exactly why `enqueue()` compares against this rather than a literal.
	 */
	public function screen_id(): string {
		return $this->hook;
	}

	/**
	 * Loads the stylesheet, on this screen only.
	 *
	 * @param string $hook The screen WordPress is about to render.
	 */
	public function enqueue( string $hook ): void {
		if ( '' === $this->hook || $hook !== $this->hook ) {
			return;
		}
		wp_enqueue_style(
			self::STYLE,
			PLUGIN_URL . 'assets/css/admin.css',
			array(),
			Assets::version( 'assets/css/admin.css' )
		);

		// The poller, and only while there is something to poll. A screen with
		// no sync running has nothing to ask about, and asking anyway would be
		// a request every few seconds for the life of the tab.
		if ( ! ( new Sync( $this->connection ) )->is_running() ) {
			return;
		}

		wp_enqueue_script(
			self::SCRIPT,
			PLUGIN_URL . 'assets/js/admin.js',
			array(),
			Assets::version( 'assets/js/admin.js' ),
			true
		);
		wp_add_inline_script(
			self::SCRIPT,
			'window.sharelyaiProgress = ' . wp_json_encode(
				array(
					'url'     => admin_url( 'admin-ajax.php' ),
					'action'  => Progress::ACTION,
					'nonce'   => wp_create_nonce( Progress::ACTION ),
					'running' => true,
				)
			) . ';',
			'before'
		);
	}

	/**
	 * Renders whichever tab is asked for.
	 */
	public function render(): void {
		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}

		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- choosing a tab to read is not a change.
		$tab = isset( $_GET['tab'] ) && 'settings' === $_GET['tab'] ? 'settings' : 'status';
		?>
		<div class="wrap">
			<h1><?php esc_html_e( 'Sharely.AI', 'sharelyai' ); ?></h1>
			<?php $this->render_notice(); ?>

			<h2 class="nav-tab-wrapper sai-tabs">
				<a href="<?php echo esc_url( self::page_url() ); ?>"
					class="nav-tab <?php echo 'status' === $tab ? 'nav-tab-active' : ''; ?>">
					<?php esc_html_e( 'Status', 'sharelyai' ); ?>
				</a>
				<a href="<?php echo esc_url( self::page_url( 'settings' ) ); ?>"
					class="nav-tab <?php echo 'settings' === $tab ? 'nav-tab-active' : ''; ?>">
					<?php esc_html_e( 'Settings', 'sharelyai' ); ?>
				</a>
			</h2>

			<div class="sai">
				<?php
				if ( 'settings' === $tab ) {
					$this->render_settings();
				} else {
					( new Status( $this->connection ) )->render();
				}
				?>
			</div>
		</div>
		<?php
	}

	/**
	 * Whatever the last action left to say.
	 */
	private function render_notice(): void {
		$notice = get_transient( 'sharelyai_notice' );
		if ( ! is_array( $notice ) ) {
			return;
		}
		delete_transient( 'sharelyai_notice' );
		?>
		<div class="notice notice-<?php echo esc_attr( (string) $notice['type'] ); ?> is-dismissible">
			<p><?php echo esc_html( (string) $notice['message'] ); ?></p>
		</div>
		<?php
	}

	/**
	 * The Settings tab.
	 *
	 * Only settings something already reads. A switch for a feature that does
	 * not exist yet is worse than no switch: it looks like it works.
	 */
	private function render_settings(): void {
		$selected  = $this->connection->post_types();
		$retention = (int) $this->connection->get( 'stats_retention_days', 30 );

		// Which workspace this is configuring, before the settings that
		// configure it. It used to come after, which left Save Changes stranded
		// between the form and a card it had nothing to do with.
		$this->render_connection_readout();
		?>
		<form class="sai-form" method="post" action="<?php echo esc_url( admin_url( 'admin-post.php' ) ); ?>">
			<?php wp_nonce_field( 'sharelyai_save' ); ?>
			<input type="hidden" name="action" value="sharelyai_save">

			<div class="sai__card">
				<h3><?php esc_html_e( 'Content', 'sharelyai' ); ?></h3>
				<table class="form-table" role="presentation">
					<tbody>
						<tr>
							<th scope="row"><?php esc_html_e( 'Post types Sharely reads', 'sharelyai' ); ?></th>
							<td>
								<fieldset>
									<legend class="screen-reader-text"><?php esc_html_e( 'Post types Sharely reads', 'sharelyai' ); ?></legend>
									<?php foreach ( Connection::public_post_types() as $type ) : ?>
										<?php $object = get_post_type_object( $type ); ?>
										<label class="sai__choice">
											<input type="checkbox" name="post_types[]"
												value="<?php echo esc_attr( $type ); ?>"
												<?php checked( in_array( $type, $selected, true ) ); ?>>
											<?php echo esc_html( (string) ( $object->labels->name ?? $type ) ); ?>
											<code><?php echo esc_html( $type ); ?></code>
										</label>
									<?php endforeach; ?>
								</fieldset>
								<p class="description">
									<?php esc_html_e( 'Published entries of these types are sent to Sharely. Unticking a type stops it being sent from the next sync; entries already there are removed by that sync.', 'sharelyai' ); ?>
								</p>
							</td>
						</tr>
						<tr>
							<th scope="row"><?php esc_html_e( 'Private entries', 'sharelyai' ); ?></th>
							<td>
								<label class="sai__choice">
									<input type="checkbox" name="sync_private" value="1"
										<?php checked( (bool) $this->connection->get( 'sync_private', false ) ); ?>>
									<?php esc_html_e( 'Send private entries too, tagged with the roles that may read them', 'sharelyai' ); ?>
								</label>
								<p class="description">
									<?php esc_html_e( 'Off by default, because it changes what leaves your site. With it on, a private entry is sent tagged with the roles holding the capability to read it, and only a signed-in visitor holding one of those roles finds it. Password-protected entries are never sent either way: a password is not a role, so there is no honest way to describe who may read one.', 'sharelyai' ); ?>
								</p>
								<?php if ( ! (bool) $this->connection->get( 'rbac_enabled' ) ) : ?>
									<p class="description">
										<strong><?php esc_html_e( 'Visitor permissions are off for this workspace.', 'sharelyai' ); ?></strong>
										<?php esc_html_e( 'Until they are on, every entry is visible to everyone — so private entries stay here.', 'sharelyai' ); ?>
									</p>
								<?php endif; ?>
							</td>
						</tr>
					</tbody>
				</table>
			</div>

			<div class="sai__card">
				<h3><?php esc_html_e( 'Search', 'sharelyai' ); ?></h3>
				<table class="form-table" role="presentation">
					<tbody>
						<tr>
							<th scope="row"><?php esc_html_e( 'Answer site search with Sharely', 'sharelyai' ); ?></th>
							<td>
								<label class="sai__choice">
									<input type="checkbox" name="search_enabled" value="1"
										<?php checked( (bool) $this->connection->get( 'search_enabled', true ) ); ?>>
									<?php esc_html_e( 'Use Sharely for this site’s search results', 'sharelyai' ); ?>
								</label>
								<p class="description">
									<?php esc_html_e( 'Your theme’s own search page, with results ranked by meaning rather than by keyword. WordPress answers instead whenever Sharely cannot — if it is unreachable, slow, or has nothing synced yet — so the search box never breaks.', 'sharelyai' ); ?>
								</p>
							</td>
						</tr>
						<tr>
							<th scope="row"><?php esc_html_e( 'Answer questions', 'sharelyai' ); ?></th>
							<td>
								<label class="sai__choice">
									<input type="checkbox" name="ask_enabled" value="1"
										<?php checked( (bool) $this->connection->get( 'ask_enabled', true ) ); ?>>
									<?php esc_html_e( 'Offer an Ask panel', 'sharelyai' ); ?>
								</label>
								<label class="sai__choice">
									<input type="checkbox" name="ask_on_search" value="1"
										<?php checked( (bool) $this->connection->get( 'ask_on_search', true ) ); ?>>
									<?php esc_html_e( 'Show it above the search results', 'sharelyai' ); ?>
								</label>
								<p class="description">
									<?php
									printf(
										/* translators: %s: the shortcode, already escaped. */
										esc_html__( 'An answer written only from this site’s pages, with links to them. Place it anywhere with %s.', 'sharelyai' ),
										'<code>[' . esc_html( Ask::SHORTCODE ) . ']</code>'
									);
									?>
								</p>
							</td>
						</tr>
					</tbody>
				</table>
			</div>

			<div class="sai__card">
				<h3><?php esc_html_e( 'Statistics', 'sharelyai' ); ?></h3>
				<table class="form-table" role="presentation">
					<tbody>
						<tr>
							<th scope="row"><?php esc_html_e( 'Record what visitors search for', 'sharelyai' ); ?></th>
							<td>
								<label class="sai__choice">
									<input type="checkbox" name="stats_enabled" value="1"
										<?php checked( (bool) $this->connection->get( 'stats_enabled', true ) ); ?>>
									<?php esc_html_e( 'Keep a local count of searches', 'sharelyai' ); ?>
								</label>
								<p class="description">
									<?php esc_html_e( 'The words typed, how many results came back and which engine answered — on this site, in this database. No visitor is identified: no user, no IP, no session.', 'sharelyai' ); ?>
								</p>
							</td>
						</tr>
						<tr>
							<th scope="row">
								<label for="sharelyai-retention"><?php esc_html_e( 'Days of statistics kept', 'sharelyai' ); ?></label>
							</th>
							<td>
								<input type="number" id="sharelyai-retention" name="stats_retention_days"
									min="1" max="365" step="1" class="small-text"
									value="<?php echo esc_attr( (string) $retention ); ?>">
								<p class="description">
									<?php esc_html_e( 'Older rows are deleted daily.', 'sharelyai' ); ?>
								</p>
							</td>
						</tr>
					</tbody>
				</table>
			</div>

			<?php submit_button(); ?>
		</form>

		<?php
	}

	/**
	 * The connection, read-only, so this tab can answer "which workspace?".
	 */
	private function render_connection_readout(): void {
		if ( ! $this->connection->is_connected() ) {
			return;
		}
		?>
		<div class="sai__card sai__card--narrow">
			<h3><?php esc_html_e( 'Connection', 'sharelyai' ); ?></h3>
			<p>
				<?php
				printf(
					/* translators: 1: workspace name or id, 2: last four characters of the API key. */
					esc_html__( 'Connected to %1$s with key ····%2$s.', 'sharelyai' ),
					'<strong>' . esc_html( $this->workspace_label() ) . '</strong>',
					esc_html( (string) $this->connection->get( 'key_last4' ) )
				);
				?>
			</p>
			<p class="description">
				<?php
				printf(
					'<a href="%s">%s</a>',
					esc_url( self::page_url() ),
					esc_html__( 'Status and disconnect are on the Status tab.', 'sharelyai' )
				);
				?>
			</p>
		</div>
		<?php
	}

	/**
	 * The workspace's name, or its id when Sharely did not send a name.
	 */
	private function workspace_label(): string {
		$name = (string) $this->connection->get( 'workspace_name' );
		return '' !== $name ? $name : $this->connection->workspace_id();
	}

	/**
	 * Saves the settings.
	 */
	public function handle_save(): void {
		$this->guard( 'sharelyai_save' );

		// phpcs:disable WordPress.Security.NonceVerification.Missing -- guard() calls check_admin_referer() above; the sniff cannot see through it.
		// Sanitized on the next line, per value: sanitize_key() is what applies to
		// a post type name, and it cannot be applied to the array itself.
		$posted = isset( $_POST['post_types'] ) ? (array) wp_unslash( $_POST['post_types'] ) : array(); // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
		$types  = array_values(
			array_intersect(
				Connection::public_post_types(),
				array_map( 'sanitize_key', array_map( 'strval', $posted ) )
			)
		);

		$retention = isset( $_POST['stats_retention_days'] ) ? (int) $_POST['stats_retention_days'] : 30;
		$enabled   = isset( $_POST['stats_enabled'] );
		$search    = isset( $_POST['search_enabled'] );
		$ask       = isset( $_POST['ask_enabled'] );
		// Private entries need the workspace to be filtering by role at all.
		// Letting this be ticked on a workspace with permissions off would
		// publish members-only content to every visitor.
		$private    = isset( $_POST['sync_private'] ) && (bool) $this->connection->get( 'rbac_enabled' );
		$ask_search = isset( $_POST['ask_on_search'] );
		// phpcs:enable WordPress.Security.NonceVerification.Missing

		$this->connection->save(
			array(
				// An array, even an empty one: that is what "none, deliberately"
				// looks like, as against the null of never having been asked.
				'post_types'           => $types,
				'search_enabled'       => $search,
				'sync_private'         => $private,
				'ask_enabled'          => $ask,
				'ask_on_search'        => $ask_search,
				'stats_enabled'        => $enabled,
				'stats_retention_days' => min( 365, max( 1, $retention ) ),
			)
		);

		$this->redirect_with( 'success', __( 'Settings saved.', 'sharelyai' ), 'settings' );
	}

	/**
	 * Starts a sync.
	 */
	public function handle_sync(): void {
		$this->guard( 'sharelyai_sync' );

		$started = ( new Sync( $this->connection ) )->start_full();
		if ( ! $started['ok'] ) {
			$this->redirect_with( 'error', $started['message'] );
		}

		if ( 0 === $started['total'] ) {
			$this->redirect_with(
				'error',
				__( 'Nothing to send: no published entry is in scope. Check the post types under Settings.', 'sharelyai' )
			);
		}

		$this->redirect_with(
			'success',
			sprintf(
				/* translators: %s: number of entries. */
				_n(
					'Sending %s entry to Sharely. This page shows the progress.',
					'Sending %s entries to Sharely. This page shows the progress.',
					$started['total'],
					'sharelyai'
				),
				number_format_i18n( $started['total'] )
			)
		);
	}

	/**
	 * Clears the credentials. Nothing in Sharely is touched.
	 *
	 * The local record of what was sent goes too: without credentials those
	 * knowledge ids cannot be used for anything, and keeping them would make a
	 * later reconnection believe the workspace already holds this site.
	 */
	public function handle_disconnect(): void {
		$this->guard( 'sharelyai_disconnect' );

		// First, while the credentials are still here to authenticate with:
		// tell Sharely, so the site stops showing as connected there too.
		$announced = ( new Connect( $this->connection ) )->announce_disconnect();

		( new Queue() )->cancel_all();
		( new Sync( $this->connection ) )->forget_all();
		( new Stats( $this->connection ) )->clear();
		// Before the connection goes, because both of these are keyed by the
		// workspace it names. A bearer and a set of role ids belong to one
		// workspace and are meaningless — or wrong — in the next.
		( new Credentials( $this->connection ) )->forget();
		( new Roles( $this->connection ) )->forget();
		$this->connection->forget();

		$this->redirect_with(
			'success',
			$announced
				? __( 'Disconnected. Sharely has been told, and your workspace and its content are untouched.', 'sharelyai' )
				: __( 'Disconnected here. Sharely could not be reached, so the site may still be listed there — remove it from Connected sites in Sharely. Your workspace and its content are untouched.', 'sharelyai' )
		);
	}

	/**
	 * Forgets the recorded searches, keeping the connection.
	 */
	public function handle_stats_clear(): void {
		$this->guard( 'sharelyai_stats_clear' );
		( new Stats( $this->connection ) )->clear();
		$this->redirect_with( 'success', __( 'Search statistics cleared.', 'sharelyai' ) );
	}

	/**
	 * Only an administrator, only from this screen.
	 *
	 * @param string $action Nonce action.
	 */
	private function guard( string $action ): void {
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'You are not allowed to do that.', 'sharelyai' ), 403 );
		}
		check_admin_referer( $action );
	}

	/**
	 * Back to the screen with a message.
	 *
	 * @param string $type    success|error.
	 * @param string $message What to say.
	 * @param string $tab     Which tab to return to.
	 */
	private function redirect_with( string $type, string $message, string $tab = '' ): void {
		set_transient(
			'sharelyai_notice',
			array(
				'type'    => $type,
				'message' => $message,
			),
			60
		);
		wp_safe_redirect( self::page_url( $tab ) );
		exit;
	}
}