<?php
/**
 * The export screen.
 *
 * Shows what is waiting, what failed and why, and offers the two buttons that
 * matter: export everything, and try the failures again.
 *
 * It also hosts manual signing. In manual mode the server has no key, so the
 * upload cannot happen without a person: this page builds each queued file
 * server-side, hands the bytes to the browser, and the browser signs and PUTs
 * them straight to the gateway. The file never round-trips through anyone
 * else's server, and the key never touches this one.
 *
 * @package SiriusPress
 */

defined( 'ABSPATH' ) || exit;

final class SPE_Admin {

	const PAGE = 'sirius-press-export';

	public static function hooks() {
		add_action( 'admin_menu', array( __CLASS__, 'menu' ), 30 );
		add_action( 'admin_enqueue_scripts', array( __CLASS__, 'enqueue' ) );
		add_action( 'rest_api_init', array( __CLASS__, 'register_routes' ) );
	}

	public static function menu() {
		add_submenu_page(
			'sirius-press',
			__( 'Publishing', 'sirius-press' ),
			__( 'Publishing', 'sirius-press' ),
			'manage_options',
			self::PAGE,
			array( __CLASS__, 'render' )
		);
	}

	public static function enqueue( $hook ) {
		if ( false === strpos( (string) $hook, self::PAGE ) ) {
			return;
		}
		if ( SP_Settings::MODE_SERVER === SP_Settings::mode() ) {
			return; // Nothing to sign here; cron has the key.
		}
		if ( ! class_exists( 'SPA_Login' ) ) {
			return; // Auth plugin inactive — no wallet library to lean on.
		}
		SPA_Login::enqueue_wallet();
		wp_enqueue_script(
			'sirius-press-export',
			SIRIUS_PRESS_EXPORT_URL . 'assets/export.js',
			array( 'sirius-press-wallet', 'wp-api-fetch' ),
			SIRIUS_PRESS_EXPORT_VERSION,
			true
		);
		wp_localize_script(
			'sirius-press-export',
			'SIRIUS_EXPORT',
			array(
				'restUrl' => esc_url_raw( rest_url( 'sirius-press/v1/export' ) ),
				'nonce'   => wp_create_nonce( 'wp_rest' ),
				'gateway' => SP_Settings::gateway(),
				'name'    => SP_Settings::name(),
				'prefix'  => SP_Settings::prefix(),
				'path'    => SP_Settings::derivation_path(),
			)
		);
		add_action( 'admin_footer', array( 'SPA_Login', 'print_config' ) );
	}

	// -------------------------------------------------- manual-signing routes

	public static function register_routes() {
		$can_manage = function () {
			return current_user_can( 'manage_options' );
		};

		register_rest_route(
			'sirius-press/v1',
			'/export/next',
			array(
				'methods'             => WP_REST_Server::READABLE,
				'permission_callback' => $can_manage,
				'callback'            => array( __CLASS__, 'rest_next' ),
			)
		);

		register_rest_route(
			'sirius-press/v1',
			'/export/ack',
			array(
				'methods'             => WP_REST_Server::CREATABLE,
				'permission_callback' => $can_manage,
				'callback'            => array( __CLASS__, 'rest_ack' ),
			)
		);
	}

	/**
	 * Build the next few queued files and hand them to the browser.
	 *
	 * Bodies come back base64-encoded because a queued file may be a PNG, and
	 * JSON has no way to carry arbitrary bytes otherwise.
	 */
	public static function rest_next( WP_REST_Request $request ) {
		$limit = max( 1, min( 5, (int) $request->get_param( 'limit' ) ?: 3 ) );
		$items = array();

		foreach ( SPE_Queue::claim( $limit ) as $row ) {
			$body = SPE_Runner::build( $row );
			if ( is_wp_error( $body ) ) {
				SPE_Queue::mark_failed( $row->id, $body->get_error_message() );
				continue;
			}
			$hash = hash( 'sha256', $body );
			if ( '' !== $row->content_hash && hash_equals( $row->content_hash, $hash ) ) {
				SPE_Queue::mark_done( $row->id, $hash );
				continue;
			}
			$items[] = array(
				'id'       => (int) $row->id,
				'path'     => $row->path,
				'mime'     => SP_Gateway::mime_for( $row->path ),
				'sha256'   => $hash,
				'body_b64' => base64_encode( $body ),
			);
		}

		return rest_ensure_response(
			array(
				'items' => $items,
				'left'  => SPE_Queue::counts()[ SPE_Queue::STATUS_PENDING ],
			)
		);
	}

	/** The browser reports how an upload went. */
	public static function rest_ack( WP_REST_Request $request ) {
		$id    = (int) $request->get_param( 'id' );
		$hash  = (string) $request->get_param( 'sha256' );
		$error = (string) $request->get_param( 'error' );

		if ( '' !== $error ) {
			SPE_Queue::mark_failed( $id, $error );
			return rest_ensure_response( array( 'ok' => false ) );
		}
		if ( ! preg_match( '/^[a-f0-9]{64}$/', $hash ) ) {
			return new WP_Error( 'sirius_bad_hash', __( 'Bad hash.', 'sirius-press' ), array( 'status' => 400 ) );
		}
		SPE_Queue::mark_done( $id, $hash );
		return rest_ensure_response( array( 'ok' => true ) );
	}

	// ------------------------------------------------------------------ page

	public static function render() {
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'You are not allowed to publish this site.', 'sirius-press' ) );
		}

		$notes = array();
		if ( isset( $_POST['sirius_export_action'] ) && check_admin_referer( 'sirius_export' ) ) {
			$action = sanitize_key( wp_unslash( $_POST['sirius_export_action'] ) );
			if ( 'full' === $action ) {
				$n       = SPE_Runner::queue_full_site();
				$notes[] = sprintf(
					/* translators: %d: number of pages queued. */
					_n( '%d page queued for export.', '%d pages queued for export.', $n, 'sirius-press' ),
					$n
				);
			} elseif ( 'retry' === $action ) {
				$n       = SPE_Queue::retry_failed();
				$notes[] = sprintf(
					/* translators: %d: number of failed exports re-queued. */
					_n( '%d failed export queued again.', '%d failed exports queued again.', $n, 'sirius-press' ),
					$n
				);
			} elseif ( 'run' === $action ) {
				$r       = SPE_Runner::run_batch( 20 );
				$notes[] = sprintf(
					/* translators: 1: uploaded, 2: unchanged, 3: failed, 4: remaining. */
					__( 'Uploaded %1$d, %2$d unchanged, %3$d failed, %4$d still queued.', 'sirius-press' ),
					$r['done'],
					$r['skipped'],
					$r['failed'],
					$r['left']
				);
			} elseif ( 'clear' === $action ) {
				SPE_Queue::clear_done();
				$notes[] = __( 'Completed rows cleared.', 'sirius-press' );
			}
		}

		$counts = SPE_Queue::counts();
		$manual = SP_Settings::MODE_SERVER !== SP_Settings::mode();

		echo '<div class="wrap"><h1>' . esc_html__( 'Publishing', 'sirius-press' ) . '</h1>';

		foreach ( $notes as $n ) {
			printf( '<div class="notice notice-success"><p>%s</p></div>', esc_html( $n ) );
		}

		if ( ! SP_Settings::is_configured() ) {
			printf(
				'<div class="notice notice-error"><p>%s <a href="%s">%s</a></p></div>',
				esc_html__( 'No BCNR name is configured, so there is nowhere to publish to.', 'sirius-press' ),
				esc_url( admin_url( 'admin.php?page=sirius-press' ) ),
				esc_html__( 'Settings', 'sirius-press' )
			);
			echo '</div>';
			return;
		}

		/*
		 * Plain permalinks are fatal to a static export and the failure is
		 * silent: every post's URL is `/?p=N`, whose path is `/`, so every
		 * page in the site maps to index.html and each one overwrites the
		 * last. The queue looks healthy the whole time.
		 */
		if ( '' === (string) get_option( 'permalink_structure' ) ) {
			printf(
				'<div class="notice notice-error"><p><strong>%s</strong> %s <a href="%s">%s</a></p></div>',
				esc_html__( 'This site uses plain permalinks.', 'sirius-press' ),
				esc_html__( 'Every page would be exported to the same file and overwrite the one before it, so nothing useful can be published until that is changed.', 'sirius-press' ),
				esc_url( admin_url( 'options-permalink.php' ) ),
				esc_html__( 'Choose a permalink structure', 'sirius-press' )
			);
		}

		printf(
			'<p>%s <code>%s</code>%s</p>',
			esc_html__( 'Publishing to', 'sirius-press' ),
			esc_html( SP_Settings::name() ),
			$manual
				? ' — ' . esc_html__( 'signing happens in your browser, on this page.', 'sirius-press' )
				: ' — ' . esc_html__( 'this server signs uploads by itself.', 'sirius-press' )
		);

		printf(
			'<p><strong>%1$d</strong> %2$s &nbsp; <strong>%3$d</strong> %4$s &nbsp; <strong>%5$d</strong> %6$s</p>',
			(int) $counts[ SPE_Queue::STATUS_PENDING ],
			esc_html__( 'queued', 'sirius-press' ),
			(int) $counts[ SPE_Queue::STATUS_DONE ],
			esc_html__( 'published', 'sirius-press' ),
			(int) $counts[ SPE_Queue::STATUS_FAILED ],
			esc_html__( 'failed', 'sirius-press' )
		);

		echo '<form method="post" style="margin:16px 0">';
		wp_nonce_field( 'sirius_export' );
		echo '<button class="button button-primary" name="sirius_export_action" value="full">'
			. esc_html__( 'Export everything', 'sirius-press' ) . '</button> ';
		if ( ! $manual ) {
			echo '<button class="button" name="sirius_export_action" value="run">'
				. esc_html__( 'Run a batch now', 'sirius-press' ) . '</button> ';
		}
		echo '<button class="button" name="sirius_export_action" value="retry">'
			. esc_html__( 'Try failures again', 'sirius-press' ) . '</button> ';
		echo '<button class="button" name="sirius_export_action" value="clear">'
			. esc_html__( 'Clear finished rows', 'sirius-press' ) . '</button>';
		echo '</form>';

		if ( $manual ) {
			self::render_manual_panel();
		}

		self::render_queue_table();
		echo '</div>';
	}

	private static function render_manual_panel() {
		?>
		<div id="sirius-export-panel" class="sirius-wallet" style="max-width:820px">
			<h2 style="margin-top:0"><?php esc_html_e( 'Sign and upload', 'sirius-press' ); ?></h2>
			<p class="description">
				<?php esc_html_e( 'Your phrase is used in this page to sign each upload and is wiped when the run finishes. Files go straight from this browser to the gateway.', 'sirius-press' ); ?>
			</p>
			<p>
				<label for="sirius_export_phrase"><strong><?php esc_html_e( 'Recovery phrase', 'sirius-press' ); ?></strong></label><br>
				<textarea id="sirius_export_phrase" rows="2" style="width:100%;font-family:monospace"
					autocomplete="off" spellcheck="false"></textarea>
			</p>
			<p>
				<button type="button" class="button button-primary" id="sirius_export_run">
					<?php esc_html_e( 'Publish queued pages', 'sirius-press' ); ?>
				</button>
				<button type="button" class="button" id="sirius_export_stop" hidden>
					<?php esc_html_e( 'Stop', 'sirius-press' ); ?>
				</button>
			</p>
			<p id="sirius_export_status" role="status" aria-live="polite"></p>
			<ul id="sirius_export_log" style="font-family:monospace;font-size:12px;max-height:240px;overflow:auto;margin:0"></ul>
		</div>
		<?php
	}

	private static function render_queue_table() {
		$rows = SPE_Queue::recent( 100 );
		echo '<h2>' . esc_html__( 'Queue', 'sirius-press' ) . '</h2>';
		if ( ! $rows ) {
			echo '<p>' . esc_html__( 'Nothing queued. Publish a post, or use “Export everything”.', 'sirius-press' ) . '</p>';
			return;
		}
		echo '<table class="widefat striped"><thead><tr>';
		echo '<th>' . esc_html__( 'Path', 'sirius-press' ) . '</th>';
		echo '<th style="width:100px">' . esc_html__( 'Status', 'sirius-press' ) . '</th>';
		echo '<th style="width:60px">' . esc_html__( 'Tries', 'sirius-press' ) . '</th>';
		echo '<th>' . esc_html__( 'Last error', 'sirius-press' ) . '</th>';
		echo '</tr></thead><tbody>';
		foreach ( $rows as $row ) {
			$colour = SPE_Queue::STATUS_FAILED === $row->status
				? '#b32d2e'
				: ( SPE_Queue::STATUS_DONE === $row->status ? '#007017' : '#646970' );
			printf(
				'<tr><td><code>%s</code></td><td style="color:%s;font-weight:600">%s</td><td>%d</td><td><small>%s</small></td></tr>',
				esc_html( $row->path ),
				esc_attr( $colour ),
				esc_html( $row->status ),
				(int) $row->attempts,
				esc_html( (string) $row->last_error )
			);
		}
		echo '</tbody></table>';
	}
}