<?php
/**
 * Email notifications via wp_mail (bounded, opt-in).
 *
 * @package SiteAuditHub
 */

namespace SiteAuditHub;

defined( 'ABSPATH' ) || exit;

/**
 * Notifications.
 */
class Notifications {

	const LOG = 'siteaudithub_mail_log';

	/**
	 * Register hooks.
	 */
	public static function init() {
		add_action( 'siteaudithub_scan_completed', array( __CLASS__, 'on_complete' ) );
	}

	/**
	 * Severities at or above a threshold.
	 *
	 * @param string $threshold critical|high|medium|never.
	 * @return array
	 */
	private static function severities_at_least( $threshold ) {
		$order = array( 'critical', 'high', 'medium' );
		$pos   = array_search( $threshold, $order, true );
		return false === $pos ? array() : array_slice( $order, 0, $pos + 1 );
	}

	/**
	 * Scan completion handler.
	 *
	 * @param int $scan_id Scan.
	 */
	public static function on_complete( $scan_id ) {
		if ( ! (int) Settings::get( 'notify_enabled' ) ) {
			return;
		}
		$scan = Repository::get_scan( $scan_id );
		if ( ! $scan ) {
			return;
		}
		$severities = self::severities_at_least( (string) Settings::get( 'notify_threshold' ) );
		$important  = array();
		if ( $severities ) {
			list( $important ) = Repository::query_findings(
				$scan_id,
				array(
					'severity'      => $severities,
					'change_status' => 'new',
					'per_page'      => 15,
				)
			);
		}
		if ( ! (int) Settings::get( 'notify_on_complete' ) && empty( $important ) ) {
			return;
		}
		$type    = 'integrity' === $scan->scan_type ? __( 'Integrity scan', 'siteaudithub' ) : __( 'Site audit', 'siteaudithub' );
		$subject = $important
			/* translators: 1: site name, 2: scan type */
			? sprintf( __( '[%1$s] %2$s: new important findings', 'siteaudithub' ), wp_specialchars_decode( get_bloginfo( 'name' ), ENT_QUOTES ), $type )
			/* translators: 1: site name, 2: scan type */
			: sprintf( __( '[%1$s] %2$s completed', 'siteaudithub' ), wp_specialchars_decode( get_bloginfo( 'name' ), ENT_QUOTES ), $type );
		self::send( $subject, self::scan_body( $scan, $important ) );
	}

	/**
	 * Plain-text summary of a scan.
	 *
	 * @param object $scan      Scan.
	 * @param array  $important Important new findings.
	 * @return string
	 */
	private static function scan_body( $scan, array $important ) {
		$lines   = array();
		$lines[] = sprintf(
			/* translators: 1: scan id, 2: site URL */
			__( 'SiteAuditHub scan #%1$d finished for %2$s.', 'siteaudithub' ),
			$scan->id,
			home_url( '/' )
		);
		$lines[] = '';
		$matrix  = isset( $scan->summary['matrix'] ) ? (array) $scan->summary['matrix'] : array();
		foreach ( Catalog::modules() as $module => $label ) {
			if ( empty( $matrix[ $module ] ) ) {
				continue;
			}
			$parts = array();
			foreach ( Catalog::severities() as $sev => $sev_label ) {
				if ( ! empty( $matrix[ $module ][ $sev ] ) ) {
					$parts[] = $sev_label . ': ' . (int) $matrix[ $module ][ $sev ];
				}
			}
			$lines[] = $label . ': ' . implode( ', ', $parts );
		}
		if ( isset( $scan->summary['changes'] ) ) {
			$lines[] = '';
			/* translators: 1: new, 2: recurring, 3: resolved */
			$lines[] = sprintf( __( 'New: %1$d · Recurring: %2$d · Resolved since previous scan: %3$d', 'siteaudithub' ), (int) $scan->summary['changes']['new'], (int) $scan->summary['changes']['recurring'], (int) $scan->summary['resolved'] );
		}
		if ( $important ) {
			$lines[] = '';
			$lines[] = __( 'Important new findings:', 'siteaudithub' );
			foreach ( $important as $f ) {
				$lines[] = '- [' . Catalog::label( 'severity', $f->severity ) . '] ' . $f->title . ( $f->item_key ? ': ' . $f->item_key : '' );
			}
		}
		$lines[] = '';
		$lines[] = __( 'Full report:', 'siteaudithub' ) . ' ' . admin_url( 'admin.php?page=siteaudithub-reports&scan=' . (int) $scan->id );
		$lines[] = '';
		$lines[] = __( 'Scores and findings are SiteAuditHub estimates based on automated checks, not certifications.', 'siteaudithub' );
		return implode( "\n", $lines );
	}

	/**
	 * Weekly summary email.
	 */
	public static function weekly_summary() {
		$site      = Repository::latest_completed( 'site' );
		$integrity = Repository::latest_completed( 'integrity' );
		$score     = Scoring::overall();
		$lines     = array();
		/* translators: %s: site URL */
		$lines[] = sprintf( __( 'Weekly SiteAuditHub summary for %s', 'siteaudithub' ), home_url( '/' ) );
		$lines[] = '';
		if ( null !== $score['overall'] ) {
			/* translators: %d: score */
			$lines[] = sprintf( __( 'Overall estimate: %d/100', 'siteaudithub' ), $score['overall'] );
		}
		/* translators: %s: date or "never" */
		$lines[] = sprintf( __( 'Last site audit: %s', 'siteaudithub' ), $site ? $site->finished_at . ' UTC (' . (int) $site->findings_count . ' findings)' : __( 'never', 'siteaudithub' ) );
		/* translators: %s: date or "never" */
		$lines[] = sprintf( __( 'Last integrity scan: %s', 'siteaudithub' ), $integrity ? $integrity->finished_at . ' UTC (' . (int) $integrity->findings_count . ' findings)' : __( 'never', 'siteaudithub' ) );
		$lines[] = '';
		$lines[] = admin_url( 'admin.php?page=siteaudithub' );
		/* translators: %s: site name */
		self::send( sprintf( __( '[%s] Weekly SiteAuditHub summary', 'siteaudithub' ), wp_specialchars_decode( get_bloginfo( 'name' ), ENT_QUOTES ) ), implode( "\n", $lines ) );
	}

	/**
	 * Send a test email.
	 *
	 * @return bool
	 */
	public static function test() {
		return self::send(
			/* translators: %s: site name */
			sprintf( __( '[%s] SiteAuditHub test email', 'siteaudithub' ), wp_specialchars_decode( get_bloginfo( 'name' ), ENT_QUOTES ) ),
			__( 'This is a test message from SiteAuditHub. If you received it, WordPress can deliver notification emails from this site.', 'siteaudithub' )
		);
	}

	/**
	 * Send and log.
	 *
	 * @param string $subject Subject.
	 * @param string $body    Body.
	 * @return bool Whether wp_mail accepted the message (not proof of delivery).
	 */
	public static function send( $subject, $body ) {
		$to = Settings::recipients();
		if ( ! $to ) {
			self::log( $subject, 0, false );
			return false;
		}
		$ok = wp_mail( $to, $subject, $body );
		self::log( $subject, count( $to ), $ok );
		return (bool) $ok;
	}

	/**
	 * Record a mail attempt.
	 *
	 * @param string $subject    Subject.
	 * @param int    $recipients Count.
	 * @param bool   $accepted   wp_mail result.
	 */
	private static function log( $subject, $recipients, $accepted ) {
		$log = get_option( self::LOG, array() );
		$log = is_array( $log ) ? $log : array();
		array_unshift(
			$log,
			array(
				't' => time(),
				's' => mb_substr( $subject, 0, 150 ),
				'r' => (int) $recipients,
				'a' => (bool) $accepted,
			)
		);
		update_option( self::LOG, array_slice( $log, 0, 20 ), false );
	}

	/**
	 * Mail log.
	 *
	 * @return array
	 */
	public static function log_entries() {
		$log = get_option( self::LOG, array() );
		return is_array( $log ) ? $log : array();
	}
}