<?php
/**
 * Issues screen: run a scan and review findings with evidence.
 *
 * @package OrbitstemSEO
 */

namespace Orbitstem\SEO\Admin;

use Orbitstem\SEO\Diagnostics\Issues;
use Orbitstem\SEO\Diagnostics\Scanner;
use Orbitstem\SEO\Plugin;

defined( 'ABSPATH' ) || exit;

/**
 * Read-only reporting plus two actions (start scan, process now), both
 * behind the manage capability and a nonce.
 */
class IssuesPage {

	const SLUG   = 'orbitstem-seo-issues';
	const ACTION = 'orbitstem_seo_scan';

	/**
	 * Plugin services.
	 *
	 * @var Plugin
	 */
	private $plugin;

	/**
	 * Constructor.
	 *
	 * @param Plugin $plugin Plugin services.
	 */
	public function __construct( Plugin $plugin ) {
		$this->plugin = $plugin;
	}

	/**
	 * Whether the current user wants simple explanations.
	 *
	 * @return bool
	 */
	public static function simple_mode() {
		return '1' === get_user_meta( get_current_user_id(), 'orbitstem_seo_simple', true );
	}

	/**
	 * One plain sentence per issue: what it is, why it matters, what to do.
	 *
	 * @param string $id Issue id.
	 * @return string
	 */
	public static function plain( $id ) {
		$texts = array(
			'broken_internal_links' => __( 'Some links on your site lead to pages that do not exist. Visitors hit a dead end; point the links at the right page or add a redirect.', 'orbitstem-seo' ),
			'broken_images'         => __( 'Some images on your pages are missing, so visitors see an empty box. Upload the image again or remove it from the post.', 'orbitstem-seo' ),
			'broken_external_links' => __( 'Some links to other websites no longer work. Update or remove them so readers are not sent nowhere.', 'orbitstem-seo' ),
			'redirected_links'      => __( 'Some links go to an old address and get forwarded. They work, but are a little slower; the Repair Center can point them straight at the new address.', 'orbitstem-seo' ),
			'orphaned_content'      => __( 'Nothing on your site links to these pages, so readers and Google rarely find them. Link to them from related posts; the Repair Center can suggest where.', 'orbitstem-seo' ),
			'redirect_chains'       => __( 'Some redirects send visitors to another redirect before they arrive. One step is faster; the Repair Center fixes this in one click.', 'orbitstem-seo' ),
			'redirect_loops'        => __( 'Some redirects send visitors in a circle, so the page never loads. Delete or change one of them.', 'orbitstem-seo' ),
			'sitemap_unavailable'   => __( 'Your sitemap (the list of pages you give to Google) cannot be opened. Check that sitemaps are on in Settings.', 'orbitstem-seo' ),
			'sitemap_errors'        => __( 'Your sitemap lists pages that do not work. Google wastes time on them; fix or remove those pages.', 'orbitstem-seo' ),
			'sitemap_noindex'       => __( 'Your sitemap lists pages that ask not to be shown in Google. That sends mixed signals; usually the page settings need a look.', 'orbitstem-seo' ),
			'sitemap_canonical'     => __( 'Your sitemap lists pages that say another page is the real one. List the real page instead.', 'orbitstem-seo' ),
			'missing_from_sitemap'  => __( 'Some pages that should be found in Google are not in your sitemap, so Google may find them later. Check their sitemap settings.', 'orbitstem-seo' ),
			'missing_title'         => __( 'Some pages have no title for search results. Google then makes one up; give each page a title.', 'orbitstem-seo' ),
			'regressions'           => __( 'Something changed what your pages tell Google, and no edit here explains it. A theme or plugin update is the usual cause; check it soon.', 'orbitstem-seo' ),
			'update_guard'          => __( 'Right after a theme, plugin or WordPress update, some key pages got worse for search. Check the update that just happened.', 'orbitstem-seo' ),
			'cannibals'             => __( 'Several of your pages compete for the same search, so Google has to pick one and both rank lower. Merge them or give each its own topic.', 'orbitstem-seo' ),
			'other_sitemaps'        => __( 'Another sitemap was found (often from an old SEO plugin). Two sitemaps can confuse search engines; remove the old one.', 'orbitstem-seo' ),
		);
		if ( isset( $texts[ $id ] ) ) {
			return $texts[ $id ];
		}
		if ( 0 === strpos( $id, 'head_' ) ) {
			return __( 'Your pages print the same SEO tag more than once, usually because the theme or another plugin adds its own. Search engines may pick the wrong one; turn off the duplicate in that theme or plugin.', 'orbitstem-seo' );
		}
		return '';
	}

	/**
	 * Registers hooks.
	 */
	public function register() {
		add_action( 'admin_menu', array( $this, 'menu' ), 15 );
		add_action( 'admin_post_' . self::ACTION, array( $this, 'handle' ) );
	}

	/**
	 * Adds the submenu page.
	 */
	public function menu() {
		add_submenu_page( Admin::SLUG, __( 'Issues', 'orbitstem-seo' ), __( 'Issues', 'orbitstem-seo' ), Admin::capability(), self::SLUG, array( $this, 'render' ) );
	}

	/**
	 * Starts a scan or processes a time slice now.
	 */
	public function handle() {
		if ( ! current_user_can( Admin::capability() ) ) {
			wp_die( esc_html__( 'You do not have permission to do this.', 'orbitstem-seo' ), 403 );
		}
		check_admin_referer( self::ACTION );
		$task   = isset( $_POST['task'] ) ? sanitize_key( wp_unslash( $_POST['task'] ) ) : '';
		$notice = 'error';

		if ( 'simple' === $task ) {
			update_user_meta( get_current_user_id(), 'orbitstem_seo_simple', self::simple_mode() ? '0' : '1' );
			wp_safe_redirect( admin_url( 'admin.php?page=' . self::SLUG ) );
			exit;
		}
		if ( 'start' === $task && $this->plugin->scanner->start() ) {
			$notice = 'started';
		} elseif ( 'process' === $task ) {
			$this->plugin->jobs->tick( 20 );
			$notice = 'processed';
		}
		wp_safe_redirect( add_query_arg( 'notice', $notice, admin_url( 'admin.php?page=' . self::SLUG ) ) );
		exit;
	}

	/**
	 * Renders the page: scan status, severity filter, one collapsed card per issue.
	 */
	public function render() {
		if ( ! current_user_can( Admin::capability() ) ) {
			wp_die( esc_html__( 'You do not have permission to view this page.', 'orbitstem-seo' ) );
		}
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- display of a notice after redirect.
		$notice   = isset( $_GET['notice'] ) ? sanitize_key( wp_unslash( $_GET['notice'] ) ) : '';
		$messages = array(
			'started'   => __( 'Scan started. It runs in the background in small steps; reload this page to follow it, or use "Process now".', 'orbitstem-seo' ),
			'processed' => __( 'Processed the scan for up to 20 seconds.', 'orbitstem-seo' ),
			'error'     => __( 'The scan could not be started. It may already be running.', 'orbitstem-seo' ),
		);
		$state    = $this->plugin->scanner->status();
		$running  = $state && 'running' === $state['status'];
		$last     = $this->plugin->scanner->last();
		$issues   = $running ? array() : $this->plugin->issues->all();
		$labels   = array(
			'error'   => __( 'Error', 'orbitstem-seo' ),
			'warning' => __( 'Warning', 'orbitstem-seo' ),
			'notice'  => __( 'Notice', 'orbitstem-seo' ),
		);
		$counts   = array_fill_keys( array_keys( $labels ), 0 );
		foreach ( $issues as $issue ) {
			++$counts[ $issue['severity'] ];
		}
		ob_start();
		$this->button( 'start', __( 'Run scan', 'orbitstem-seo' ), $running, true );
		if ( $running ) {
			$this->button( 'process', __( 'Process now', 'orbitstem-seo' ), false, false );
		}
		$actions = ob_get_clean();

		Ui::open( self::SLUG, __( 'SEO Issues', 'orbitstem-seo' ), __( 'Problems found on this site, with evidence and how to fix each one.', 'orbitstem-seo' ), $actions );
		?>
		<?php if ( isset( $messages[ $notice ] ) ) : ?>
			<div class="notice notice-<?php echo 'error' === $notice ? 'error' : 'success'; ?> is-dismissible"><p><?php echo esc_html( $messages[ $notice ] ); ?></p></div>
		<?php endif; ?>

		<div class="os-card os-scanbar">
			<span class="dashicons <?php echo $running ? 'dashicons-update os-spin' : 'dashicons-clock'; ?>" aria-hidden="true"></span>
			<p>
				<?php
				if ( $running ) {
					/* translators: 1: stage name, 2: time */
					echo esc_html( sprintf( __( 'Scan running: stage "%1$s", last step at %2$s.', 'orbitstem-seo' ), is_array( $state['cursor'] ) && isset( $state['cursor']['stage'] ) ? $state['cursor']['stage'] : 'index', wp_date( get_option( 'time_format' ), (int) $state['updated'] ) ) );
				} elseif ( $last ) {
					$s = $last['stats'];
					/* translators: 1: date and time, 2: posts, 3: links, 4: sitemap URLs, 5: URLs checked, 6: pages inspected */
					echo esc_html( sprintf( __( 'Last scan: %1$s. Posts: %2$d, links and images: %3$d, sitemap entries: %4$d, addresses checked: %5$d, pages inspected: %6$d.', 'orbitstem-seo' ), wp_date( get_option( 'date_format' ) . ' ' . get_option( 'time_format' ), (int) $last['time'] ), $s['posts'], $s['links'], $s['sitemap_urls'], $s['checked'], $s['pages'] ) );
				} else {
					esc_html_e( 'No scan has run yet. The scan indexes links in your published content, checks them, compares the sitemap with what should be indexed, and loads a sample of pages to look for duplicate SEO tags. Everything runs on this server.', 'orbitstem-seo' );
				}
				$next = wp_next_scheduled( \Orbitstem\SEO\Repair\Autopilot::SCAN_HOOK );
				if ( ! $running && $next ) {
					echo ' ';
					/* translators: %s: date and time */
					echo esc_html( sprintf( __( 'Next automatic scan: %s.', 'orbitstem-seo' ), wp_date( get_option( 'date_format' ) . ' ' . get_option( 'time_format' ), $next ) ) );
				}
				if ( $state && 'failed' === $state['status'] ) {
					echo ' ';
					/* translators: %s: error message */
					echo esc_html( sprintf( __( 'The last scan stopped with an error: %s', 'orbitstem-seo' ), $state['last_error'] ) );
				}
				?>
			</p>
		</div>

		<?php if ( $last && ! $running && ! $issues ) : ?>
			<div class="os-card"><?php Ui::empty_state( 'dashicons-yes-alt', __( 'No issues found', 'orbitstem-seo' ), __( 'The last scan found nothing to fix. Scans run automatically; you can also run one now.', 'orbitstem-seo' ) ); ?></div>
		<?php endif; ?>

		<?php if ( $issues ) : ?>
			<div class="os-filters" role="group" aria-label="<?php esc_attr_e( 'Show issues by severity', 'orbitstem-seo' ); ?>">
				<button type="button" data-filter="all" aria-pressed="true"><?php esc_html_e( 'All', 'orbitstem-seo' ); ?> <span class="os-count"><?php echo esc_html( number_format_i18n( count( $issues ) ) ); ?></span></button>
				<?php foreach ( $labels as $severity => $label ) : ?>
					<?php if ( $counts[ $severity ] ) : ?>
						<button type="button" id="filter-<?php echo esc_attr( $severity ); ?>" data-filter="<?php echo esc_attr( $severity ); ?>" aria-pressed="false"><?php echo esc_html( $label ); ?> <span class="os-count os-count--<?php echo esc_attr( $severity ); ?>"><?php echo esc_html( number_format_i18n( $counts[ $severity ] ) ); ?></span></button>
					<?php endif; ?>
				<?php endforeach; ?>
				<span class="description os-filters__hint"><?php esc_html_e( 'Click an issue to see the evidence and how to fix it.', 'orbitstem-seo' ); ?></span>
				<form method="post" action="<?php echo esc_url( admin_url( 'admin-post.php' ) ); ?>" class="os-simple-toggle">
					<input type="hidden" name="action" value="<?php echo esc_attr( self::ACTION ); ?>" />
					<input type="hidden" name="task" value="simple" />
					<?php wp_nonce_field( self::ACTION ); ?>
					<button type="submit" class="button-link" aria-pressed="<?php echo self::simple_mode() ? 'true' : 'false'; ?>"><?php echo self::simple_mode() ? esc_html__( 'Simple explanations: on', 'orbitstem-seo' ) : esc_html__( 'Explain like I am new', 'orbitstem-seo' ); ?></button>
				</form>
			</div>
		<?php endif; ?>

		<?php foreach ( $issues as $issue ) : ?>
			<details class="os-collapse os-issue" id="<?php echo esc_attr( $issue['id'] ); ?>" data-severity="<?php echo esc_attr( $issue['severity'] ); ?>">
				<summary>
					<?php echo Ui::badge( $issue['severity'], $labels[ $issue['severity'] ] ); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped in Ui::badge(). ?>
					<span><?php echo esc_html( $issue['title'] ); ?></span>
					<span class="os-chip"><?php echo esc_html( number_format_i18n( $issue['count'] ) ); ?></span>
				</summary>
				<div class="os-collapse__body">
					<?php $plain = self::simple_mode() ? self::plain( $issue['id'] ) : ''; ?>
					<?php if ( '' !== $plain ) : ?>
						<p class="os-plain"><span class="dashicons dashicons-lightbulb" aria-hidden="true"></span> <?php echo esc_html( $plain ); ?></p>
					<?php endif; ?>
					<p><?php echo esc_html( $issue['explanation'] ); ?></p>
					<div class="os-issue__fix">
						<strong><?php esc_html_e( 'How to fix:', 'orbitstem-seo' ); ?></strong> <?php echo esc_html( $issue['fix'] ); ?>
						<?php $fixer = $this->plugin->repair->fixer_for_issue( $issue['id'] ); ?>
						<?php if ( $fixer ) : ?>
							<p><a class="button button-primary" href="
							<?php
							echo esc_url(
								add_query_arg(
									array(
										'page'  => RepairPage::SLUG,
										'fixer' => $fixer->id(),
									),
									admin_url( 'admin.php' )
								)
							);
							?>
																		"><?php echo esc_html( $fixer->label() ); ?> &rarr;</a></p>
						<?php elseif ( in_array( $issue['id'], array( 'redirect_loops', 'broken_internal_links' ), true ) ) : ?>
							<p><a class="button" href="<?php echo esc_url( admin_url( 'admin.php?page=' . RedirectsPage::SLUG ) ); ?>"><?php esc_html_e( 'Manage redirects', 'orbitstem-seo' ); ?></a></p>
						<?php endif; ?>
					</div>
					<?php if ( $issue['rows'] ) : ?>
						<?php $this->table( $issue ); ?>
					<?php endif; ?>
				</div>
			</details>
		<?php endforeach; ?>
		<?php
		Ui::close();
	}

	/**
	 * Evidence table for one issue: the first rows, the rest behind "Show all".
	 *
	 * @param array $issue Issue.
	 */
	private function table( array $issue ) {
		$columns = array();
		foreach ( $issue['columns'] as $key => $label ) {
			foreach ( $issue['rows'] as $row ) {
				if ( isset( $row[ $key ] ) && '' !== (string) $row[ $key ] && '0' !== (string) $row[ $key ] ) {
					$columns[ $key ] = $label;
					break;
				}
			}
		}
		$visible = 5;
		$total   = count( $issue['rows'] );
		?>
		<div class="os-table-wrap">
		<table class="widefat">
			<thead><tr>
				<?php foreach ( $columns as $label ) : ?>
					<th scope="col"><?php echo esc_html( $label ); ?></th>
				<?php endforeach; ?>
			</tr></thead>
			<tbody>
			<?php foreach ( $issue['rows'] as $index => $row ) : ?>
				<tr<?php echo $index >= $visible ? ' data-extra-row' : ''; ?>>
					<?php foreach ( array_keys( $columns ) as $key ) : ?>
						<td><?php $this->cell( $key, isset( $row[ $key ] ) ? $row[ $key ] : '' ); ?></td>
					<?php endforeach; ?>
				</tr>
			<?php endforeach; ?>
			</tbody>
		</table>
		</div>
		<p class="os-table-foot">
			<?php if ( $total > $visible ) : ?>
				<?php /* translators: %d: number of rows */ ?>
				<button type="button" class="button button-small" data-os-more aria-expanded="false" data-more="<?php echo esc_attr( sprintf( __( 'Show all %d', 'orbitstem-seo' ), $total ) ); ?>" data-less="<?php esc_attr_e( 'Show fewer', 'orbitstem-seo' ); ?>"><?php echo esc_html( sprintf( __( 'Show all %d', 'orbitstem-seo' ), $total ) ); ?></button>
			<?php endif; ?>
			<?php if ( $issue['count'] > $total ) : ?>
				<span class="description">
					<?php
					/* translators: 1: rows listed, 2: total */
					echo esc_html( sprintf( __( 'Listing %1$d of %2$d.', 'orbitstem-seo' ), $total, $issue['count'] ) );
					?>
				</span>
			<?php endif; ?>
		</p>
		<?php
	}

	/**
	 * One cell: post IDs become edit links, URLs become links.
	 *
	 * @param string $key   Column.
	 * @param mixed  $value Value.
	 */
	private function cell( $key, $value ) {
		if ( 'post_id' === $key ) {
			$id = (int) $value;
			if ( $id && get_post( $id ) ) {
				$link = get_edit_post_link( $id );
				$name = get_the_title( $id );
				$name = '' !== $name ? $name : '#' . $id;
				if ( $link ) {
					printf( '<a href="%s">%s</a>', esc_url( $link ), esc_html( $name ) );
				} else {
					echo esc_html( $name );
				}
			}
			return;
		}
		if ( in_array( $key, array( 'url', 'redirect_to' ), true ) && is_string( $value ) && preg_match( '#^https?://#', $value ) ) {
			printf( '<a href="%1$s" rel="noopener noreferrer" target="_blank">%2$s</a>', esc_url( $value ), esc_html( $value ) );
			return;
		}
		echo esc_html( (string) $value );
	}

	/**
	 * A POST button.
	 *
	 * @param string $task     Task.
	 * @param string $label    Label.
	 * @param bool   $disabled Disabled.
	 * @param bool   $primary  Primary style.
	 */
	private function button( $task, $label, $disabled, $primary ) {
		?>
		<form method="post" action="<?php echo esc_url( admin_url( 'admin-post.php' ) ); ?>" style="display:inline;margin-right:6px">
			<input type="hidden" name="action" value="<?php echo esc_attr( self::ACTION ); ?>" />
			<input type="hidden" name="task" value="<?php echo esc_attr( $task ); ?>" />
			<input type="hidden" name="_wpnonce" value="<?php echo esc_attr( wp_create_nonce( self::ACTION ) ); ?>" />
			<button type="submit" class="button<?php echo $primary ? ' button-primary' : ''; ?>" <?php disabled( $disabled ); ?>><?php echo esc_html( $label ); ?></button>
		</form>
		<?php
	}
}