<?php
/**
 * THE GOOGLE AND AI CHECK: how the home page looks to Google and to AI
 * assistants such as ChatGPT.
 *
 * Some of this cannot be judged from inside the site: whether robots.txt
 * shuts AI crawlers out, whether the text exists without JavaScript, whether
 * the company can be found in public registers. That is fetched from outside
 * by the Tedrix service (tedrix.se for Swedish admins, tedrix.io otherwise).
 *
 * CONSENT (directory guideline 7): nothing is sent until the user presses
 * "Check my site". Only the site's own home address and the admin language
 * are sent. Documented under "External services" in readme.txt.
 *
 * Also one purely local check: whether WordPress itself asks search engines
 * to stay away (Settings -> Reading).
 *
 * @package Tedrix
 */

defined( 'ABSPATH' ) || exit;

/**
 * Tedrix in the admin's language: tedrix.se is the Swedish site, tedrix.io
 * the English one. Same service behind both.
 *
 * @return string Base URL without trailing slash.
 */
function tedrix_webb() {
	if ( defined( 'TEDRIX_WEBB' ) ) {
		return rtrim( (string) TEDRIX_WEBB, '/' ); // local development only
	}
	return 0 === strpos( get_user_locale(), 'sv' ) ? 'https://tedrix.se' : 'https://tedrix.io';
}

/**
 * Cache key per admin language: the service writes its answer in the language
 * sent, so a cached answer is only shown to someone reading that language.
 *
 * @return string
 */
function tedrix_ai_nyckel() {
	return 'tedrix_ai_kontroll_' . substr( md5( get_user_locale() ), 0, 8 );
}

/**
 * The findings Tedrix can actually fix on a WordPress site through this
 * plugin: title, description, structured data and text on the page. The rest
 * (robots.txt, registers, hosting) only get advice, so they get no button.
 *
 * @return string[]
 */
function tedrix_ai_fixbara() {
	return array( 'titel', 'beskrivning', 'schema', 'org', 'faq', 'svaret' );
}

/**
 * Runs the check against the Tedrix service and caches the answer for a day.
 *
 * @return array{ok: bool, message?: string, antal?: array, punkter?: array, at?: int}
 */
function tedrix_ai_kontroll_kor() {
	/* A site on localhost or a private address cannot be fetched from the
	 * internet. Say so here instead of sending a request that must fail. */
	$vard = (string) wp_parse_url( home_url(), PHP_URL_HOST );
	if ( 'localhost' === $vard || preg_match( '/\.(local|test|localhost)$/', $vard ) || filter_var( $vard, FILTER_VALIDATE_IP ) ) {
		return array(
			'ok'      => false,
			'message' => __( 'This site runs on a local address, so it cannot be checked from the internet. The check works once the site is online.', 'tedrix' ),
		);
	}
	$svar = wp_remote_post(
		tedrix_webb() . '/api/wp/kontroll',
		array(
			'timeout' => 45,
			'headers' => array( 'Content-Type' => 'application/json' ),
			'body'    => wp_json_encode(
				array(
					'url'    => home_url( '/' ),
					'locale' => get_user_locale(),
				)
			),
		)
	);
	if ( is_wp_error( $svar ) ) {
		return array(
			'ok'      => false,
			'message' => __( 'The check could not reach the Tedrix service. Try again in a moment.', 'tedrix' ),
		);
	}
	$data = json_decode( (string) wp_remote_retrieve_body( $svar ), true );
	if ( ! is_array( $data ) || empty( $data['ok'] ) ) {
		return array(
			'ok'      => false,
			'message' => is_array( $data ) && ! empty( $data['message'] ) ? sanitize_text_field( $data['message'] ) : __( 'The check did not return a result. Try again in a moment.', 'tedrix' ),
		);
	}

	$punkter = array();
	foreach ( (array) ( $data['punkter'] ?? array() ) as $p ) {
		if ( ! is_array( $p ) ) {
			continue;
		}
		$niva = in_array( $p['niva'] ?? '', array( 'fel', 'varning', 'ok' ), true ) ? $p['niva'] : 'varning';
		$punkter[] = array(
			'id'     => sanitize_key( (string) ( $p['id'] ?? '' ) ),
			'niva'   => $niva,
			'rubrik' => sanitize_text_field( (string) ( $p['rubrik'] ?? '' ) ),
			'text'   => sanitize_text_field( (string) ( $p['text'] ?? '' ) ),
		);
	}
	$ut = array(
		'ok'      => true,
		'punkter' => $punkter,
		'antal'   => array(
			'fel'     => (int) ( $data['antal']['fel'] ?? 0 ),
			'varning' => (int) ( $data['antal']['varning'] ?? 0 ),
			'ok'      => (int) ( $data['antal']['ok'] ?? 0 ),
		),
		'at'      => time(),
	);
	set_transient( tedrix_ai_nyckel(), $ut, DAY_IN_SECONDS );
	return $ut;
}

/**
 * Renders the Google and AI section. The button posts back to the same page
 * with a nonce; the result is cached so reopening the page costs nothing.
 */
function tedrix_ai_kontroll_sektion() {
	$resultat = get_transient( tedrix_ai_nyckel() );
	if ( isset( $_POST['tedrix_kontrollera'] ) && check_admin_referer( 'tedrix_kontrollera' ) ) {
		$resultat = tedrix_ai_kontroll_kor();
	}
	?>
	<h2><?php esc_html_e( 'Google and AI assistants', 'tedrix' ); ?></h2>
	<p><?php esc_html_e( 'Your home page the way Google and ChatGPT read it.', 'tedrix' ); ?></p>

	<?php if ( '0' === (string) get_option( 'blog_public' ) ) : ?>
		<div class="tdx-larm"><p>
			<strong><?php esc_html_e( 'Your site asks search engines to stay away.', 'tedrix' ); ?></strong>
			<?php esc_html_e( '"Discourage search engines" is ticked under Settings, Reading. Untick it unless that is intended.', 'tedrix' ); ?>
			<a href="<?php echo esc_url( admin_url( 'options-reading.php' ) ); ?>"><?php esc_html_e( 'Open Settings → Reading', 'tedrix' ); ?></a>
		</p></div>
	<?php endif; ?>

	<form method="post" class="tdx-rad">
		<?php wp_nonce_field( 'tedrix_kontrollera' ); ?>
		<button type="submit" name="tedrix_kontrollera" value="1" class="tdx-btn">
			<?php echo is_array( $resultat ) && ! empty( $resultat['ok'] ) ? esc_html__( 'Check again', 'tedrix' ) : esc_html__( 'Check my site', 'tedrix' ); ?>
		</button>
		<span class="tdx-not">
			<?php
			printf(
				/* translators: %s: tedrix.se or tedrix.io */
				esc_html__( 'Sends only your home address to %s. Takes about half a minute.', 'tedrix' ),
				esc_html( (string) wp_parse_url( tedrix_webb(), PHP_URL_HOST ) )
			);
			?>
		</span>
	</form>

	<?php
	if ( ! is_array( $resultat ) ) {
		return;
	}
	if ( empty( $resultat['ok'] ) ) {
		echo '<div class="tdx-larm tdx-gul"><p>' . esc_html( $resultat['message'] ?? '' ) . '</p></div>';
		return;
	}

	$flaggade = array_filter(
		$resultat['punkter'],
		function ( $p ) {
			return 'ok' !== $p['niva'];
		}
	);
	$ok       = array_filter(
		$resultat['punkter'],
		function ( $p ) {
			return 'ok' === $p['niva'];
		}
	);
	?>
	<div class="tdx-siffror">
		<div class="tdx-siffra tdx-fel"><b><?php echo (int) $resultat['antal']['fel']; ?></b><span><i></i><?php esc_html_e( 'Blocking', 'tedrix' ); ?></span></div>
		<div class="tdx-siffra tdx-varn"><b><?php echo (int) $resultat['antal']['varning']; ?></b><span><i></i><?php esc_html_e( 'Could be better', 'tedrix' ); ?></span></div>
		<div class="tdx-siffra tdx-ok"><b><?php echo (int) $resultat['antal']['ok']; ?></b><span><i></i><?php esc_html_e( 'In order', 'tedrix' ); ?></span></div>
	</div>

	<?php
	$fixbara = count(
		array_filter(
			$flaggade,
			function ( $p ) {
				return in_array( $p['id'] ?? '', tedrix_ai_fixbara(), true );
			}
		)
	);
	?>
	<?php if ( $fixbara ) : ?>
		<div class="tdx-fixaalla">
			<p>
				<?php
				printf(
					/* translators: 1: things Tedrix can fix, 2: things found */
					esc_html( _n( 'Tedrix can fix %1$d of the %2$d things below for you.', 'Tedrix can fix %1$d of the %2$d things below for you.', $fixbara, 'tedrix' ) ),
					(int) $fixbara,
					count( $flaggade )
				);
				?>
			</p>
			<a class="tdx-btn" href="<?php echo esc_url( tedrix_fixa_url( 'fix-all-ai' ) ); ?>">&#10022; <?php echo esc_html( tedrix_fixa_alla_text( $fixbara ) ); ?></a>
		</div>
	<?php endif; ?>

	<?php if ( ! $flaggade ) : ?>
		<div class="tdx-larm tdx-gron"><p><?php esc_html_e( 'Your home page is in order.', 'tedrix' ); ?></p></div>
	<?php endif; ?>

	<?php foreach ( $flaggade as $p ) : ?>
		<details class="tdx-punkt<?php echo 'fel' === $p['niva'] ? ' tdx-fel' : ''; ?>">
			<summary><?php echo esc_html( $p['rubrik'] ); ?></summary>
			<p><?php echo esc_html( $p['text'] ); ?></p>
			<?php if ( in_array( $p['id'] ?? '', tedrix_ai_fixbara(), true ) ) : ?>
				<p><a class="tdx-btn-fixa" href="<?php echo esc_url( tedrix_fixa_url( 'fix-ai-' . $p['id'] ) ); ?>"><?php esc_html_e( 'Fix', 'tedrix' ); ?></a></p>
			<?php endif; ?>
		</details>
	<?php endforeach; ?>

	<?php if ( $ok ) : ?>
		<details class="tdx-klara">
			<summary>
				<?php
				printf(
					/* translators: %d: number of checks that passed */
					esc_html( _n( '%d thing is already in order', '%d things are already in order', count( $ok ), 'tedrix' ) ),
					count( $ok )
				);
				?>
			</summary>
			<ul>
				<?php foreach ( $ok as $p ) : ?>
					<li><?php echo esc_html( $p['rubrik'] ); ?></li>
				<?php endforeach; ?>
			</ul>
		</details>
	<?php endif; ?>

	<p class="tdx-not" style="margin:12px 0 0">
		<?php
		printf(
			/* translators: %s: date and time of the check */
			esc_html__( 'Checked %s.', 'tedrix' ),
			esc_html( wp_date( get_option( 'date_format' ) . ' ' . get_option( 'time_format' ), (int) $resultat['at'] ) )
		);
		?>
	</p>
	<?php
}