<?php
/**
 * AI Alt Text Builder: activity log.
 *
 * Records who generated alt text, when, for which image and from which IP address, with the
 * previous alt text whenever the plugin replaces one (so it can be put back); bulk jobs;
 * changes to the plugin settings (never the keys themselves); and, if the site turns it on,
 * WordPress sign-ins, sign-outs and failed sign-ins. Entries stay in this site's own database
 * ({prefix}aatb_log), are kept for 365 days by default and can be viewed and exported as CSV by
 * administrators. Nothing is sent to RankPilotAI.
 */
if ( ! defined( 'ABSPATH' ) ) exit;

final class AATB_Activity_Log {
	const DB_VERSION = '1';
	const OPTION_DB  = 'aatb_log_db_version';
	const PAGE       = 'aatb-activity-log';
	const PER_PAGE   = 50;

	public static function table(): string {
		global $wpdb;
		return $wpdb->prefix . 'aatb_log';
	}

	public static function init(): void {
		add_action( 'admin_init', [ __CLASS__, 'maybe_install' ] );
		add_action( 'aatb_log_prune', [ __CLASS__, 'prune' ] );
		add_action( 'admin_menu', [ __CLASS__, 'menu' ], 20 );
		add_action( 'admin_post_aatb_log_csv', [ __CLASS__, 'export_csv' ] );
		add_action( 'admin_post_aatb_log_settings', [ __CLASS__, 'save_settings' ] );
		add_action( 'update_option_' . AATB_SETTINGS_SLUG, [ __CLASS__, 'settings_changed' ], 10, 2 );
		add_action( 'wp_login', [ __CLASS__, 'on_login' ], 10, 2 );
		add_action( 'wp_logout', [ __CLASS__, 'on_logout' ] );
		add_action( 'wp_login_failed', [ __CLASS__, 'on_login_failed' ] );
	}

	/* ……………………… storage ……………………… */
	public static function install(): void {
		global $wpdb;
		require_once ABSPATH . 'wp-admin/includes/upgrade.php';
		$table   = self::table();
		$charset = $wpdb->get_charset_collate();
		dbDelta( "CREATE TABLE {$table} (
			id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
			created_at datetime NOT NULL,
			user_id bigint(20) unsigned NOT NULL DEFAULT 0,
			user_login varchar(60) NOT NULL DEFAULT '',
			action varchar(32) NOT NULL DEFAULT '',
			attachment_id bigint(20) unsigned NOT NULL DEFAULT 0,
			detail varchar(255) NOT NULL DEFAULT '',
			ip varchar(45) NOT NULL DEFAULT '',
			PRIMARY KEY  (id),
			KEY created_at (created_at),
			KEY action (action)
		) {$charset};" );
		update_option( self::OPTION_DB, self::DB_VERSION, false );
		if ( ! wp_next_scheduled( 'aatb_log_prune' ) ) {
			wp_schedule_event( time() + HOUR_IN_SECONDS, 'daily', 'aatb_log_prune' );
		}
	}

	public static function maybe_install(): void {
		if ( get_option( self::OPTION_DB ) !== self::DB_VERSION ) self::install();
	}

	public static function deactivate(): void {
		wp_clear_scheduled_hook( 'aatb_log_prune' );
	}

	/** Adds one entry. $detail is short free text (mode, tier, result), never a secret. */
	public static function add( string $action, int $attachment_id = 0, string $detail = '', $user = null ): void {
		global $wpdb;
		if ( get_option( self::OPTION_DB ) !== self::DB_VERSION ) return; // table not created yet
		if ( ! $user instanceof WP_User ) $user = wp_get_current_user();
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery -- the plugin's own log table, one insert per event.
		$wpdb->insert(
			self::table(),
			[
				'created_at'    => current_time( 'mysql', true ),
				'user_id'       => (int) $user->ID,
				'user_login'    => substr( (string) $user->user_login, 0, 60 ),
				'action'        => substr( $action, 0, 32 ),
				'attachment_id' => max( 0, $attachment_id ),
				// Characters, not bytes: a byte cut could split a letter and the insert would fail.
				'detail'        => mb_substr( $detail, 0, 255 ),
				'ip'            => self::ip(),
			],
			[ '%s', '%d', '%s', '%s', '%d', '%s', '%s' ]
		);
	}

	/**
	 * Adds the alt text that was replaced to a detail ("… · Previous: …"), cut to fit the
	 * 255-character column. An empty previous text leaves the detail as it is.
	 */
	public static function previous( string $detail, string $prev ): string {
		$prev = trim( $prev );
		if ( '' === $prev ) return $detail;
		$head = ( '' === $detail ? '' : $detail . ' · ' ) . 'Previous: ';
		$room = 255 - mb_strlen( $head );
		if ( mb_strlen( $prev ) > $room ) $prev = mb_substr( $prev, 0, max( 0, $room - 1 ) ) . '…';
		return $head . $prev;
	}

	private static function ip(): string {
		$ip = isset( $_SERVER['REMOTE_ADDR'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REMOTE_ADDR'] ) ) : '';
		/**
		 * Filters the IP address stored in the activity log. A site behind a trusted proxy can
		 * return the visitor's address here.
		 */
		$ip = (string) apply_filters( 'aatb_log_ip', $ip );
		return filter_var( $ip, FILTER_VALIDATE_IP ) ? $ip : '';
	}

	private static function opt( string $key, $default ) {
		$o = get_option( AATB_SETTINGS_SLUG, [] );
		return is_array( $o ) && array_key_exists( $key, $o ) ? $o[ $key ] : $default;
	}

	private static function days(): int {
		return min( 3650, max( 30, (int) self::opt( 'log_days', 365 ) ) );
	}

	public static function prune(): void {
		global $wpdb;
		$cut = gmdate( 'Y-m-d H:i:s', time() - self::days() * DAY_IN_SECONDS );
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- the plugin's own log table.
		$wpdb->query( $wpdb->prepare( "DELETE FROM {$wpdb->prefix}aatb_log WHERE created_at < %s", $cut ) );
	}

	/* ……………………… events ……………………… */
	public static function settings_changed( $old, $new ): void {
		$old = is_array( $old ) ? $old : [];
		$new = is_array( $new ) ? $new : [];
		$changes = [];
		foreach ( [ 'site_token' => 'site key', 'openai_key' => 'OpenAI key' ] as $k => $label ) {
			if ( ( $old[ $k ] ?? '' ) !== ( $new[ $k ] ?? '' ) ) $changes[] = $label . ' ' . ( '' === ( $new[ $k ] ?? '' ) ? 'removed' : 'changed' );
		}
		if ( ( $old['model_choice'] ?? '' ) !== ( $new['model_choice'] ?? '' ) ) {
			$changes[] = 'quality tier: ' . self::tier( (string) ( $old['model_choice'] ?? '' ) ) . ' to ' . self::tier( (string) ( $new['model_choice'] ?? '' ) );
		}
		if ( ( $old['lang_choice'] ?? '' ) !== ( $new['lang_choice'] ?? '' ) ) {
			$changes[] = 'language: ' . ( $old['lang_choice'] ?? '' ) . ' to ' . ( $new['lang_choice'] ?? '' );
		}
		if ( ( $old['custom_prompt'] ?? '' ) !== ( $new['custom_prompt'] ?? '' ) ) $changes[] = 'custom directives changed';
		foreach ( [ 'auto_generate' => 'auto-generate on upload', 'log_signins' => 'sign-in logging' ] as $k => $label ) {
			if ( ! empty( $old[ $k ] ) !== ! empty( $new[ $k ] ) ) $changes[] = $label . ' ' . ( empty( $new[ $k ] ) ? 'off' : 'on' );
		}
		if ( (int) ( $old['log_days'] ?? 365 ) !== (int) ( $new['log_days'] ?? 365 ) ) $changes[] = 'log kept for ' . (int) ( $new['log_days'] ?? 365 ) . ' days';
		if ( $changes ) self::add( 'settings', 0, implode( '; ', $changes ) );
	}

	public static function on_login( $login, $user ): void {
		if ( self::opt( 'log_signins', '' ) ) self::add( 'login', 0, '', $user );
	}

	public static function on_logout( $user_id = 0 ): void {
		if ( ! self::opt( 'log_signins', '' ) ) return;
		$user = get_userdata( (int) $user_id );
		self::add( 'logout', 0, '', $user ?: null );
	}

	public static function on_login_failed( $username ): void {
		if ( ! self::opt( 'log_signins', '' ) ) return;
		self::add( 'login_failed', 0, 'username: ' . sanitize_user( (string) $username ), new WP_User( 0 ) );
	}

	public static function tier( string $model ): string {
		return function_exists( 'aatb_model_tier' ) ? ucfirst( aatb_model_tier( $model ) ) : $model;
	}

	/* ……………………… admin screen ……………………… */
	public static function labels(): array {
		return [
			'generate'        => __( 'Generated alt text', 'ai-alt-text-builder' ),
			'regenerate'      => __( 'Regenerated alt text', 'ai-alt-text-builder' ),
			'generate_failed' => __( 'Generation failed', 'ai-alt-text-builder' ),
			'auto_generate'   => __( 'Generated on upload', 'ai-alt-text-builder' ),
			'bulk_start'      => __( 'Bulk job started', 'ai-alt-text-builder' ),
			'bulk_item'       => __( 'Bulk job: image', 'ai-alt-text-builder' ),
			'bulk_finish'     => __( 'Bulk job ended', 'ai-alt-text-builder' ),
			'settings'        => __( 'Settings changed', 'ai-alt-text-builder' ),
			'login'           => __( 'Signed in', 'ai-alt-text-builder' ),
			'logout'          => __( 'Signed out', 'ai-alt-text-builder' ),
			'login_failed'    => __( 'Failed sign-in', 'ai-alt-text-builder' ),
		];
	}

	public static function menu(): void {
		add_submenu_page( 'ai-alt-text-builder', __( 'Activity log', 'ai-alt-text-builder' ), __( 'Activity log', 'ai-alt-text-builder' ), 'manage_options', self::PAGE, [ __CLASS__, 'render' ] );
	}

	/** Rows for the screen and the CSV, newest first, optionally one action type. */
	private static function rows( string $action, int $limit, int $offset ): array {
		global $wpdb;
		if ( '' !== $action ) {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- the plugin's own log table.
			return (array) $wpdb->get_results( $wpdb->prepare( "SELECT * FROM {$wpdb->prefix}aatb_log WHERE action = %s ORDER BY id DESC LIMIT %d OFFSET %d", $action, $limit, $offset ), ARRAY_A );
		}
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- the plugin's own log table.
		return (array) $wpdb->get_results( $wpdb->prepare( "SELECT * FROM {$wpdb->prefix}aatb_log ORDER BY id DESC LIMIT %d OFFSET %d", $limit, $offset ), ARRAY_A );
	}

	private static function count( string $action ): int {
		global $wpdb;
		if ( '' !== $action ) {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- the plugin's own log table.
			return (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM {$wpdb->prefix}aatb_log WHERE action = %s", $action ) );
		}
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- the plugin's own log table.
		return (int) $wpdb->get_var( "SELECT COUNT(*) FROM {$wpdb->prefix}aatb_log" );
	}

	private static function requested_action(): string {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- read-only filter on an admin screen.
		$a = isset( $_GET['log_action'] ) ? sanitize_key( wp_unslash( $_GET['log_action'] ) ) : '';
		return array_key_exists( $a, self::labels() ) ? $a : '';
	}

	public static function render(): void {
		if ( ! current_user_can( 'manage_options' ) ) return;
		self::maybe_install();
		$labels = self::labels();
		$action = self::requested_action();
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- read-only pagination on an admin screen.
		$paged  = max( 1, isset( $_GET['paged'] ) ? (int) $_GET['paged'] : 1 );
		$total  = self::count( $action );
		$pages  = max( 1, (int) ceil( $total / self::PER_PAGE ) );
		$paged  = min( $paged, $pages );
		$rows   = self::rows( $action, self::PER_PAGE, ( $paged - 1 ) * self::PER_PAGE );
		$base   = admin_url( 'admin.php?page=' . self::PAGE );
		?>
		<div class="wrap">
			<h1><?php esc_html_e( 'Activity log', 'ai-alt-text-builder' ); ?></h1>
			<p><?php esc_html_e( 'Who generated alt text, when, for which image and from which IP address, with the previous alt text whenever the plugin replaced one; bulk jobs; and changes to the plugin settings. Entries are stored in this site’s database only.', 'ai-alt-text-builder' ); ?></p>

			<form method="post" action="<?php echo esc_url( admin_url( 'admin-post.php' ) ); ?>" class="aatb-log-settings">
				<?php wp_nonce_field( 'aatb_log_settings' ); ?>
				<input type="hidden" name="action" value="aatb_log_settings">
				<fieldset>
					<legend class="screen-reader-text"><?php esc_html_e( 'Activity log settings', 'ai-alt-text-builder' ); ?></legend>
					<p>
						<input type="checkbox" id="aatb-log-signins" name="log_signins" value="1" <?php checked( (bool) self::opt( 'log_signins', '' ) ); ?>>
						<label for="aatb-log-signins"><?php esc_html_e( 'Also record WordPress sign-ins, sign-outs and failed sign-ins', 'ai-alt-text-builder' ); ?></label>
					</p>
					<p>
						<label for="aatb-log-days"><?php esc_html_e( 'Keep entries for (days)', 'ai-alt-text-builder' ); ?></label>
						<input type="number" id="aatb-log-days" name="log_days" min="30" max="3650" step="1" value="<?php echo esc_attr( (string) self::days() ); ?>" class="small-text">
						<?php submit_button( __( 'Save', 'ai-alt-text-builder' ), 'secondary', 'submit', false ); ?>
					</p>
				</fieldset>
			</form>

			<form method="get" class="aatb-log-filter">
				<input type="hidden" name="page" value="<?php echo esc_attr( self::PAGE ); ?>">
				<label for="aatb-log-action"><?php esc_html_e( 'Show', 'ai-alt-text-builder' ); ?></label>
				<select id="aatb-log-action" name="log_action">
					<option value=""><?php esc_html_e( 'All activity', 'ai-alt-text-builder' ); ?></option>
					<?php foreach ( $labels as $key => $label ) : ?>
						<option value="<?php echo esc_attr( $key ); ?>" <?php selected( $action, $key ); ?>><?php echo esc_html( $label ); ?></option>
					<?php endforeach; ?>
				</select>
				<?php submit_button( __( 'Filter', 'ai-alt-text-builder' ), 'secondary', '', false ); ?>
				<a class="button" href="<?php echo esc_url( wp_nonce_url( admin_url( 'admin-post.php?action=aatb_log_csv&log_action=' . rawurlencode( $action ) ), 'aatb_log_csv' ) ); ?>"><?php esc_html_e( 'Export CSV', 'ai-alt-text-builder' ); ?></a>
			</form>

			<!-- Scrolls on its own on a narrow screen, so the page does not; focusable for keyboard scrolling. -->
			<div class="aatb-log-scroll" role="region" aria-labelledby="aatb-log-caption" tabindex="0">
			<table class="widefat striped">
				<caption id="aatb-log-caption" class="screen-reader-text"><?php echo esc_html( sprintf( /* translators: 1: page number, 2: number of pages */ __( 'Activity log, page %1$d of %2$d', 'ai-alt-text-builder' ), $paged, $pages ) ); ?></caption>
				<thead><tr>
					<th scope="col"><?php esc_html_e( 'Date', 'ai-alt-text-builder' ); ?></th>
					<th scope="col"><?php esc_html_e( 'User', 'ai-alt-text-builder' ); ?></th>
					<th scope="col"><?php esc_html_e( 'Action', 'ai-alt-text-builder' ); ?></th>
					<th scope="col"><?php esc_html_e( 'Image', 'ai-alt-text-builder' ); ?></th>
					<th scope="col"><?php esc_html_e( 'Details', 'ai-alt-text-builder' ); ?></th>
					<th scope="col"><?php esc_html_e( 'IP address', 'ai-alt-text-builder' ); ?></th>
				</tr></thead>
				<tbody>
				<?php if ( ! $rows ) : ?>
					<tr><td colspan="6"><?php esc_html_e( 'No activity recorded yet.', 'ai-alt-text-builder' ); ?></td></tr>
				<?php endif; ?>
				<?php foreach ( $rows as $r ) : ?>
					<tr>
						<td><?php echo esc_html( get_date_from_gmt( (string) $r['created_at'], get_option( 'date_format' ) . ' ' . get_option( 'time_format' ) ) ); ?></td>
						<td><?php echo esc_html( '' !== $r['user_login'] ? (string) $r['user_login'] : '—' ); ?></td>
						<td><?php echo esc_html( $labels[ $r['action'] ] ?? (string) $r['action'] ); ?></td>
						<td><?php
						$aid = (int) $r['attachment_id'];
						if ( $aid && get_post( $aid ) ) {
							echo '<a href="' . esc_url( (string) get_edit_post_link( $aid ) ) . '">' . esc_html( get_the_title( $aid ) ?: '#' . $aid ) . '</a>';
						} elseif ( $aid ) {
							echo esc_html( '#' . $aid );
						}
						?></td>
						<td><?php echo esc_html( (string) $r['detail'] ); ?></td>
						<td><?php echo esc_html( (string) $r['ip'] ); ?></td>
					</tr>
				<?php endforeach; ?>
				</tbody>
			</table>
			</div>

			<?php if ( $pages > 1 ) : ?>
			<nav class="tablenav" aria-label="<?php esc_attr_e( 'Activity log pages', 'ai-alt-text-builder' ); ?>"><div class="tablenav-pages">
				<?php
				// phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- paginate_links() returns escaped markup.
				echo paginate_links( [ 'base' => add_query_arg( 'paged', '%#%', add_query_arg( 'log_action', $action, $base ) ), 'format' => '', 'current' => $paged, 'total' => $pages ] );
				?>
			</div></nav>
			<?php endif; ?>
		</div>
		<?php
	}

	public static function save_settings(): void {
		if ( ! current_user_can( 'manage_options' ) ) wp_die( esc_html__( 'You are not allowed to do this.', 'ai-alt-text-builder' ), 403 );
		check_admin_referer( 'aatb_log_settings' );
		$o = get_option( AATB_SETTINGS_SLUG, [] );
		$o = is_array( $o ) ? $o : [];
		$o['log_signins'] = empty( $_POST['log_signins'] ) ? '' : '1';
		$o['log_days']    = min( 3650, max( 30, isset( $_POST['log_days'] ) ? (int) $_POST['log_days'] : 365 ) );
		update_option( AATB_SETTINGS_SLUG, $o );
		wp_safe_redirect( admin_url( 'admin.php?page=' . self::PAGE ) );
		exit;
	}

	public static function export_csv(): void {
		if ( ! current_user_can( 'manage_options' ) ) wp_die( esc_html__( 'You are not allowed to do this.', 'ai-alt-text-builder' ), 403 );
		check_admin_referer( 'aatb_log_csv' );
		$labels = self::labels();
		$action = self::requested_action();
		nocache_headers();
		header( 'Content-Type: text/csv; charset=utf-8' );
		header( 'Content-Disposition: attachment; filename="ai-alt-text-builder-activity-' . gmdate( 'Y-m-d' ) . '.csv"' );
		$out = fopen( 'php://output', 'w' );
		fputcsv( $out, [ 'date_utc', 'user', 'action', 'image_id', 'details', 'ip' ] );
		for ( $offset = 0; $rows = self::rows( $action, 1000, $offset ); $offset += 1000 ) {
			foreach ( $rows as $r ) {
				// Cells that start with = + - @ are prefixed so spreadsheets do not run them as formulas.
				$cells = [ $r['created_at'], $r['user_login'], $labels[ $r['action'] ] ?? $r['action'], (int) $r['attachment_id'], $r['detail'], $r['ip'] ];
				fputcsv( $out, array_map( function ( $v ) { $v = (string) $v; return preg_match( '/^[=+\-@]/', $v ) ? "'" . $v : $v; }, $cells ) );
			}
		}
		// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose -- php://output stream.
		fclose( $out );
		exit;
	}
}
AATB_Activity_Log::init();