<?php
/**
 * Settings → Mapsemble admin page.
 *
 * @package Mapsemble
 */

namespace Mapsemble\Admin;

use Mapsemble\Api\Client;
use Mapsemble\Capabilities;
use Mapsemble\Connect;

/**
 * Registers the Mapsemble credentials screen.
 */
class SettingsPage {

	public const PAGE_SLUG = 'mapsemble-settings';

	/**
	 * Query flag the connect-finish redirect carries, so the page knows to
	 * pick up the notice the handler left behind. Public: both the manual
	 * finish and the polling script's redirect land on it.
	 */
	public const CONNECT_FLAG = 'mapsemble-connect';

	/**
	 * The screen's URL.
	 */
	public static function url(): string {
		return add_query_arg( 'page', self::PAGE_SLUG, admin_url( 'admin.php' ) );
	}

	/**
	 * API client.
	 *
	 * @var Client
	 */
	private Client $api;

	/**
	 * The connect handshake.
	 *
	 * @var Connect
	 */
	private Connect $connect;

	/**
	 * Hook suffix of this screen, as handed back by add_submenu_page().
	 *
	 * @var string
	 */
	private string $hook_suffix = '';

	/**
	 * Constructor.
	 *
	 * @param Client  $api     API client.
	 * @param Connect $connect The connect handshake.
	 */
	public function __construct( Client $api, Connect $connect ) {
		$this->api     = $api;
		$this->connect = $connect;
	}

	/**
	 * Hooks the page into the admin.
	 */
	public function register(): void {
		// Priority 13: after the parent menu (11) and Maps (12), so
		// Settings sits last.
		add_action( 'admin_menu', array( $this, 'add_menu' ), 13 );
		add_action( 'admin_init', array( $this, 'register_settings' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue' ) );
		add_action( 'admin_post_mapsemble_connect_finish', array( $this, 'handle_connect_finish' ) );
		add_action( 'wp_ajax_mapsemble_connect_check', array( $this, 'ajax_connect_check' ) );
		// Dropped from the address bar after the notice shows, like
		// settings-updated, so a reload cannot repeat it.
		add_filter(
			'removable_query_args',
			static function ( array $args ): array {
				$args[] = self::CONNECT_FLAG;
				return $args;
			}
		);
	}

	/**
	 * Adds the screen under the Mapsemble menu.
	 */
	public function add_menu(): void {
		$this->hook_suffix = (string) add_submenu_page(
			Menu::SLUG,
			__( 'Mapsemble settings', 'mapsemble' ),
			__( 'Settings', 'mapsemble' ),
			Capabilities::MANAGE,
			self::PAGE_SLUG,
			array( $this, 'render_page' )
		);
	}

	/**
	 * Loads the connect script and styles, on this screen only.
	 *
	 * The script whenever the connect section renders — a connected site
	 * can reconnect, and that promises the same automation. A site
	 * configured through constants cannot be connected from here at all.
	 *
	 * @param string $hook_suffix Current admin page.
	 */
	public function enqueue( string $hook_suffix ): void {
		if ( '' === $this->hook_suffix || $hook_suffix !== $this->hook_suffix ) {
			return;
		}

		// The stylesheet also lays out the collapsed sections, so it is
		// wanted whatever the state; the script only while there is
		// something to poll for.
		wp_enqueue_style(
			'mapsemble-admin-connect',
			plugins_url( 'assets/css/admin-connect.css', MAPSEMBLE_PLUGIN_FILE ),
			array(),
			MAPSEMBLE_VERSION
		);
		if ( $this->connect->credentials_are_constants() ) {
			return;
		}
		wp_enqueue_script(
			'mapsemble-admin-connect',
			plugins_url( 'assets/js/admin-connect.js', MAPSEMBLE_PLUGIN_FILE ),
			array( 'wp-i18n' ),
			MAPSEMBLE_VERSION,
			true
		);
		wp_set_script_translations( 'mapsemble-admin-connect', 'mapsemble', MAPSEMBLE_PLUGIN_DIR . '/languages' );
		wp_localize_script(
			'mapsemble-admin-connect',
			'mapsembleConnect',
			array(
				'ajaxUrl' => admin_url( 'admin-ajax.php' ),
				'nonce'   => wp_create_nonce( 'mapsemble_connect_check' ),
			)
		);
	}

	/**
	 * Finishes a connect attempt by hand: the no-JavaScript path.
	 *
	 * With scripting on, the page polls ajax_connect_check() and follows
	 * it to the same notice, and the button posting here is hidden — but the script puts it
	 * back if it gives up waiting, so there is always a way to finish.
	 */
	public function handle_connect_finish(): void {
		check_admin_referer( 'mapsemble_connect_finish' );
		if ( ! current_user_can( Capabilities::MANAGE ) ) {
			wp_die( esc_html__( 'You are not allowed to change the Mapsemble settings.', 'mapsemble' ) );
		}

		if ( $this->connect->collect() ) {
			$this->park_connected_notice();
		} else {
			add_settings_error(
				'mapsemble',
				'mapsemble_not_connected',
				__( 'Nothing authenticated yet. Open "Authenticate on Mapsemble", press Connect there, then try again.', 'mapsemble' ),
				'warning'
			);
			$this->park_notices();
		}

		wp_safe_redirect( add_query_arg( self::CONNECT_FLAG, '1', self::url() ) );
		exit;
	}

	/**
	 * Reports whether the approval has landed yet, collecting it if so.
	 *
	 * Polled by the settings page while an admin approves on Mapsemble, so
	 * the approval completes on its own. Nothing the caller supplies is
	 * trusted, because the caller supplies nothing: the state is read from
	 * this site's own option.
	 */
	public function ajax_connect_check(): void {
		check_ajax_referer( 'mapsemble_connect_check', 'nonce' );
		if ( ! current_user_can( Capabilities::MANAGE ) ) {
			wp_send_json_error( array( 'message' => __( 'You are not allowed to change the Mapsemble settings.', 'mapsemble' ) ), 403 );
		}

		// While an attempt is pending the honest answer is whether *it* has
		// landed — a connected site reconnecting must not be told "yes" for
		// the credentials it is trying to replace. Without one (rare: every
		// render of the section starts one) there is nothing to collect.
		$pending   = $this->connect->has_pending_attempt();
		$connected = $pending ? $this->connect->collect() : $this->connect->is_connected();

		// An approval that landed on this very poll gets the same success
		// notice as the manual finish, and the script is sent to the URL
		// that shows it. Otherwise there is nothing new to announce.
		$redirect = '';
		if ( $pending && $connected ) {
			$this->park_connected_notice();
			$redirect = add_query_arg( self::CONNECT_FLAG, '1', self::url() );
		}
		wp_send_json(
			array(
				'connected' => $connected,
				'redirect'  => $redirect,
			)
		);
	}

	/**
	 * Queues the "connected" success notice and parks it for the next page.
	 */
	private function park_connected_notice(): void {
		add_settings_error(
			'mapsemble',
			'mapsemble_connected',
			__( 'Connected to Mapsemble. Your maps are now listed when you place a map block.', 'mapsemble' ),
			'success'
		);
		$this->park_notices();
	}

	/**
	 * Parks the queued settings notices for the page the flag leads to.
	 *
	 * The same hand-off core's options.php uses: the notices ride a
	 * short-lived transient across the redirect, and render_page() picks
	 * them up when it sees the flag.
	 */
	private function park_notices(): void {
		set_transient( 'settings_errors', get_settings_errors(), 30 );
	}

	/**
	 * Registers the mapsemble_settings option.
	 */
	public function register_settings(): void {
		register_setting(
			'mapsemble',
			'mapsemble_settings',
			array(
				'type'              => 'array',
				'sanitize_callback' => array( $this, 'sanitize_settings' ),
				'default'           => array(),
			)
		);
	}

	/**
	 * Sanitizes submitted settings; blank secret keeps the saved one, and so
	 * does an absent client ID.
	 *
	 * @param mixed $input Raw submitted value.
	 * @return array Clean settings array.
	 */
	public function sanitize_settings( $input ): array {
		$input = is_array( $input ) ? $input : array();
		$saved = get_option( 'mapsemble_settings', array() );
		$saved = is_array( $saved ) ? $saved : array();

		$secret = trim( (string) ( $input['client_secret'] ?? '' ) );
		if ( '' === $secret ) {
			$secret = (string) ( $saved['client_secret'] ?? '' );
		}

		// Absent is not empty: a disabled input (MAPSEMBLE_CLIENT_ID defined)
		// does not submit, and saving the uninstall choice then must not
		// blank the saved ID behind the constant. A field sent empty is a
		// deliberate clear and still clears.
		$client_id = array_key_exists( 'client_id', $input )
			? sanitize_text_field( (string) $input['client_id'] )
			: (string) ( $saved['client_id'] ?? '' );

		// Fresh credentials invalidate everything derived from the old ones;
		// see forget_account_caches() for what and why. Only fresh ones: a
		// save that just flips the uninstall choice leaves the token and the
		// map list valid, and dropping them would cost the next screen a
		// round trip for nothing. Credentials set through the
		// MAPSEMBLE_CLIENT_ID / MAPSEMBLE_CLIENT_SECRET constants never pass
		// through here; see readme.txt for the transients to delete by hand
		// in that case.
		if ( (string) ( $saved['client_id'] ?? '' ) !== $client_id
			|| (string) ( $saved['client_secret'] ?? '' ) !== $secret ) {
			Client::forget_account_caches();
		}

		return array(
			'client_id'                => $client_id,
			'client_secret'            => $secret,
			'delete_data_on_uninstall' => ! empty( $input['delete_data_on_uninstall'] ),
		);
	}

	/**
	 * Renders the screen.
	 */
	public function render_page(): void {
		if ( ! current_user_can( Capabilities::MANAGE ) ) {
			return;
		}

		// This screen hangs off a custom admin.php menu, and core only renders
		// settings notices on its own options-*.php screens — so without this,
		// options.php redirects back here with ?settings-updated=true and the
		// page shows nothing, leaving a completed save looking like a no-op.
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- display-only read of the redirect marker.
		if ( isset( $_GET['settings-updated'] ) ) {
			add_settings_error( 'mapsemble', 'mapsemble_settings_updated', __( 'Settings saved.', 'mapsemble' ), 'success' );
		}
		// The connect-finish handler parks its notice the way options.php
		// does; core only reads that transient back under
		// ?settings-updated, which would also announce "Settings saved."
		// for a connect that found nothing. So it is read back here, under
		// the handler's own flag.
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- display-only read of the redirect marker.
		if ( isset( $_GET[ self::CONNECT_FLAG ] ) ) {
			$parked = get_transient( 'settings_errors' );
			delete_transient( 'settings_errors' );
			foreach ( is_array( $parked ) ? $parked : array() as $error ) {
				if ( 'mapsemble' === ( $error['setting'] ?? '' ) ) {
					add_settings_error( 'mapsemble', (string) $error['code'], (string) $error['message'], (string) $error['type'] );
				}
			}
		}
		// Unconditional, so any validation errors registered against the
		// 'mapsemble' setting surface here too, not just the saved notice.
		settings_errors( 'mapsemble' );

		echo '<div class="wrap">';
		echo '<h1>' . esc_html__( 'Mapsemble settings', 'mapsemble' ) . '</h1>';
		$this->render_credentials_form();
		echo '</div>';
	}

	/**
	 * Renders the credentials form and connection status.
	 */
	private function render_credentials_form(): void {
		$settings           = $this->api->get_settings();
		$id_is_constant     = defined( 'MAPSEMBLE_CLIENT_ID' );
		$secret_is_constant = defined( 'MAPSEMBLE_CLIENT_SECRET' );

		// Constants outrank the option the connect flow writes, so on such a
		// site the button could only "succeed" invisibly. The fields below
		// already say where the credentials come from.
		if ( ! $this->connect->credentials_are_constants() ) {
			$this->render_connect_section();
		}
		?>
		<form method="post" action="options.php">
			<?php settings_fields( 'mapsemble' ); ?>
			<?php
			// One form, so one Save covers both sections. The credential
			// inputs still submit while their details is closed — a closed
			// details hides its content, it does not remove it — so saving
			// the uninstall choice alone resubmits the ID unchanged and leaves
			// the secret blank, which keeps the saved one.
			?>
			<details class="mapsemble-manual-details">
				<summary><?php esc_html_e( 'Enter credentials manually', 'mapsemble' ); ?></summary>
				<table class="form-table" role="presentation">
					<tr>
						<th scope="row">
							<label for="mapsemble-client-id"><?php esc_html_e( 'Client ID', 'mapsemble' ); ?></label>
						</th>
						<td>
							<input name="mapsemble_settings[client_id]" type="text" id="mapsemble-client-id" autocomplete="off"
								value="<?php echo esc_attr( $id_is_constant ? '' : $settings['client_id'] ); ?>"
								class="regular-text" <?php disabled( $id_is_constant ); ?> />
							<?php if ( $id_is_constant ) : ?>
								<p class="description"><?php esc_html_e( 'Defined as MAPSEMBLE_CLIENT_ID in wp-config.php.', 'mapsemble' ); ?></p>
							<?php else : ?>
								<p class="description"><?php esc_html_e( 'From your Mapsemble account (Settings → API).', 'mapsemble' ); ?></p>
							<?php endif; ?>
						</td>
					</tr>
					<tr>
						<th scope="row">
							<label for="mapsemble-client-secret"><?php esc_html_e( 'Client secret', 'mapsemble' ); ?></label>
						</th>
						<td>
							<input name="mapsemble_settings[client_secret]" type="password" id="mapsemble-client-secret"
								value="" autocomplete="new-password" class="regular-text"
								placeholder="<?php echo esc_attr( '' !== $settings['client_secret'] ? '••••••••••••' : '' ); ?>"
								<?php disabled( $secret_is_constant ); ?> />
							<?php if ( $secret_is_constant ) : ?>
								<p class="description"><?php esc_html_e( 'Defined as MAPSEMBLE_CLIENT_SECRET in wp-config.php.', 'mapsemble' ); ?></p>
							<?php elseif ( '' !== $settings['client_secret'] ) : ?>
								<p class="description"><?php esc_html_e( 'A secret is saved. Leave blank to keep it.', 'mapsemble' ); ?></p>
							<?php endif; ?>
						</td>
					</tr>
				</table>
			</details>
			<?php
			// A data-retention choice, not a credentials one: out of the
			// folded manual fields, where a connected site never looks.
			?>
			<h2><?php esc_html_e( 'Data', 'mapsemble' ); ?></h2>
			<table class="form-table" role="presentation">
				<tr>
					<th scope="row"><?php esc_html_e( 'Uninstall', 'mapsemble' ); ?></th>
					<td>
						<label for="mapsemble-delete-data">
							<input name="mapsemble_settings[delete_data_on_uninstall]" type="checkbox"
								id="mapsemble-delete-data" value="1"
								<?php checked( $settings['delete_data_on_uninstall'] ); ?> />
							<?php esc_html_e( 'Also delete stored coordinates (post meta) when the plugin is uninstalled.', 'mapsemble' ); ?>
						</label>
						<p class="description">
							<?php
							// The checkbox only governs the post meta; everything
							// the plugin owns outright goes regardless (see
							// uninstall.php). Said here, because a checkbox about
							// deleting reads as *the* switch and leaving the
							// unconditional part unsaid would let someone
							// uninstall expecting their configuration to survive.
							esc_html_e( 'Uninstalling always deletes the site-fed maps\' settings, the credentials and the plugin\'s capabilities; the maps on your Mapsemble account are not touched. This checkbox additionally deletes the stored coordinates and "hidden" flags from your posts.', 'mapsemble' );
							?>
						</p>
					</td>
				</tr>
			</table>
			<?php submit_button(); ?>
		</form>
		<?php $this->render_connection_status(); ?>
		<?php
	}

	/**
	 * Renders the one-click connect section: a link to approve this site on
	 * Mapsemble, and the manual way to finish when the page cannot watch.
	 *
	 * Its own form, outside the settings form: forms do not nest, and a
	 * collection has nothing to validate.
	 */
	private function render_connect_section(): void {
		$connected = $this->connect->is_connected();

		echo '<h2>' . esc_html__( 'Connect to Mapsemble', 'mapsemble' ) . '</h2>';
		if ( $connected ) {
			echo '<p>' . esc_html__( 'This site is connected. Reconnect only if you have revoked the credentials on Mapsemble or switched accounts.', 'mapsemble' ) . '</p>';
			// Collapsed once it has done its job: the controls below are then
			// for the rare reconnect, not for reading.
			echo '<details class="mapsemble-connect-details">';
			echo '<summary>' . esc_html__( 'Reconnect', 'mapsemble' ) . '</summary>';
		}
		?>
		<p><?php esc_html_e( 'Authenticate this site on Mapsemble and the credentials fill themselves in. Nothing to copy, and the secret never travels through your browser.', 'mapsemble' ); ?></p>
		<?php
		// Describes the Authenticate button, so it leads it.
		?>
		<p class="description"><?php esc_html_e( 'The button opens Mapsemble in a new tab. Approve the connection there and this page finishes on its own.', 'mapsemble' ); ?></p>
		<p>
			<a class="button button-primary mapsemble-connect-start" target="_blank" rel="noopener"
				href="<?php echo esc_url( $this->connect->approval_url( home_url() ) ); ?>"><?php esc_html_e( 'Authenticate on Mapsemble', 'mapsemble' ); ?></a>
		</p>
		<div class="mapsemble-connect-progress" data-mapsemble-connect-progress role="status" aria-live="polite"></div>
		<form method="post" action="<?php echo esc_url( admin_url( 'admin-post.php' ) ); ?>" class="mapsemble-connect-fallback">
			<input type="hidden" name="action" value="mapsemble_connect_finish" />
			<?php wp_nonce_field( 'mapsemble_connect_finish' ); ?>
			<?php submit_button( __( 'Finish connecting', 'mapsemble' ), 'secondary', 'submit', false ); ?>
		</form>
		<?php
		if ( $connected ) {
			echo '</details>';
		}
	}

	/**
	 * Renders the "Connected — N maps" panel below the form.
	 */
	private function render_connection_status(): void {
		echo '<h2>' . esc_html__( 'Connection', 'mapsemble' ) . '</h2>';

		if ( ! $this->api->has_credentials() ) {
			// "Above" only exists when the connect section rendered.
			echo '<p>' . esc_html(
				$this->connect->credentials_are_constants()
					? __( 'Enter your Mapsemble client ID and secret to connect.', 'mapsemble' )
					: __( 'Authenticate on Mapsemble above, or enter your client ID and secret, to connect.', 'mapsemble' )
			) . '</p>';
			return;
		}

		$maps  = $this->api->get_remote_maps();
		$error = $this->api->get_last_error();
		if ( '' !== $error ) {
			printf(
				'<div class="notice notice-error inline"><p>%s</p></div>',
				esc_html( $error )
			);
			return;
		}

		printf(
			'<div class="notice notice-success inline"><p>%s</p></div>',
			esc_html(
				sprintf(
					/* translators: %d: number of maps in the Mapsemble account. */
					_n( 'Connected — %d map found in your Mapsemble account.', 'Connected — %d maps found in your Mapsemble account.', count( $maps ), 'mapsemble' ),
					count( $maps )
				)
			)
		);

		if ( $this->api->looks_like_local_host() ) {
			// Only maps fed from this site are affected. Nothing on the
			// Mapsemble side ever fetches from here for a map whose data lives
			// in Mapsemble, so those work on a local domain with no tunnel at
			// all — worth saying, or this reads as "the plugin does not work
			// locally".
			printf(
				'<div class="notice notice-warning inline"><p>%s</p></div>',
				esc_html__( 'This site runs on a local domain the Mapsemble service cannot reach. Maps that take their data from Mapsemble work as they are; maps built from this site\'s content need the site exposed through a tunnel, with MAPSEMBLE_REMOTE_BASE_URL defined in wp-config.php.', 'mapsemble' )
			);
		}
	}
}