<?php
/**
 * Maintenance and activity reports, built from the site's activity log.
 *
 * A report covers a period (usually a month, in the site's time zone) and has the work in
 * sections, the totals, and the site's state when the report was made. The same data is
 * shown in WordPress and turned into a PDF (Monthwrap_Pdf).
 *
 * @package Monthwrap
 */

defined( 'ABSPATH' ) || exit;

/**
 * Builds reports.
 */
class Monthwrap_Report {

	const OPTION = 'monthwrap_report';

	/** When the plugin started recording on this site (Unix time). */
	const SINCE = 'monthwrap_recording_since';

	/** Event types by report section. */
	const SECTIONS = array(
		'content'     => array( 'post_published', 'page_updated', 'post_updated' ),
		'maintenance' => array( 'plugin_updated', 'theme_updated', 'core_updated', 'server_updated', 'plugin_installed', 'plugin_removed', 'theme_installed', 'theme_removed' ),
		'backups'     => array( 'backup_completed' ),
		'site'        => array( 'template_updated', 'menu_updated', 'design_updated' ),
		'leads'       => array( 'form_submitted' ),
	);

	/** The maintenance events that count as software updates. */
	const UPDATE_TYPES = array( 'plugin_updated', 'theme_updated', 'core_updated', 'server_updated' );

	/**
	 * The report's branding and options, with defaults.
	 *
	 * @return array{agency_name: string, logo_id: int, color: string, lead_names: bool, credit: bool}
	 */
	public static function settings() {
		$saved = get_option( self::OPTION, array() );
		return wp_parse_args(
			is_array( $saved ) ? $saved : array(),
			array(
				'agency_name' => '',
				'logo_id'     => 0,
				'color'       => '#4f46e5',
				'lead_names'  => false,
				'credit'      => false,
			)
		);
	}

	/**
	 * When the plugin started recording on this site. Set on activation; for sites that had
	 * the plugin before that, the oldest event in the log.
	 *
	 * @return int Unix time.
	 */
	public static function recording_since() {
		$since = (int) get_option( self::SINCE, 0 );
		if ( ! $since ) {
			$first = Monthwrap_Store::first_at();
			$since = $first ? $first : time();
			add_option( self::SINCE, $since, '', false );
		}
		return $since;
	}

	/**
	 * The start and end of a calendar month in the site's time zone.
	 *
	 * @param string $month "YYYY-MM".
	 * @return DateTimeImmutable[] Start (inclusive) and end (exclusive).
	 */
	public static function month_range( $month ) {
		$start = DateTimeImmutable::createFromFormat( '!Y-m', $month, wp_timezone() );
		if ( ! $start ) {
			$start = new DateTimeImmutable( 'first day of this month midnight', wp_timezone() );
		}
		return array( $start, $start->modify( '+1 month' ) );
	}

	/**
	 * The months there's a report for, newest first, as "YYYY-MM" => "October 2026": this
	 * month back to the month recording started, at most twelve.
	 *
	 * @return array<string, string>
	 */
	public static function recent_months() {
		$months = array();
		$first  = wp_date( 'Y-m', self::recording_since() );
		$month  = new DateTimeImmutable( 'first day of this month midnight', wp_timezone() );
		for ( $i = 0; $i < 12 && ( 0 === $i || $month->format( 'Y-m' ) >= $first ); $i++ ) {
			$months[ $month->format( 'Y-m' ) ] = wp_date( 'F Y', $month->getTimestamp() );
			$month                             = $month->modify( '-1 month' );
		}
		return $months;
	}

	/**
	 * How much content, how many updates and how many leads a month had, for the list of
	 * reports.
	 *
	 * @param string $month "YYYY-MM".
	 * @return array{content: int, updates: int, leads: int}
	 */
	public static function month_counts( $month ) {
		list( $start, $end ) = self::month_range( $month );
		$from                = gmdate( 'Y-m-d H:i:s', $start->getTimestamp() );
		$to                  = gmdate( 'Y-m-d H:i:s', $end->getTimestamp() );
		return array(
			'content' => Monthwrap_Store::count_between( $from, $to, self::SECTIONS['content'] ),
			'updates' => Monthwrap_Store::count_between( $from, $to, self::UPDATE_TYPES ),
			'leads'   => Monthwrap_Store::count_between( $from, $to, self::SECTIONS['leads'] ),
		);
	}

	/**
	 * Everything a report shows.
	 *
	 * @param DateTimeImmutable $start Start of the period (inclusive).
	 * @param DateTimeImmutable $end   End of the period (exclusive).
	 * @return array
	 */
	public static function build( DateTimeImmutable $start, DateTimeImmutable $end ) {
		$from     = gmdate( 'Y-m-d H:i:s', $start->getTimestamp() );
		$to       = gmdate( 'Y-m-d H:i:s', $end->getTimestamp() );
		$settings = self::settings();

		$sections = array();
		foreach ( self::SECTIONS as $section => $types ) {
			$sections[ $section ] = array();
			foreach ( array_reverse( Monthwrap_Store::between( $from, $to, $types, 2000 ) ) as $row ) {
				$sections[ $section ][] = $row['event'];
			}
		}

		$leads_by_form = array();
		foreach ( $sections['leads'] as $lead ) {
			$form                   = '' !== (string) ( $lead['form_name'] ?? '' ) ? (string) $lead['form_name'] : __( 'Other forms', 'monthwrap' );
			$leads_by_form[ $form ] = ( $leads_by_form[ $form ] ?? 0 ) + 1;
		}
		arsort( $leads_by_form );

		$updates = array_values(
			array_filter(
				$sections['maintenance'],
				function ( $event ) {
					return in_array( $event['type'], self::UPDATE_TYPES, true );
				}
			)
		);
		$backups   = self::backups( $sections['backups'] );
		$published = count( wp_list_filter( $sections['content'], array( 'type' => 'post_published' ) ) );
		$now       = time();

		$report            = array(
			'site'          => array(
				'name' => html_entity_decode( get_bloginfo( 'name' ), ENT_QUOTES, 'UTF-8' ),
				'url'  => home_url( '/' ),
			),
			'period'        => array(
				'label'   => self::period_label( $start, $end ),
				'month'   => wp_date( 'F', $start->getTimestamp() ),
				'start'   => $start,
				'end'     => $end,
				'current' => $start->getTimestamp() <= $now && $now < $end->getTimestamp(),
				'covers'  => self::covers( $start->getTimestamp(), min( $now, $end->getTimestamp() - 1 ) ),
			),
			'generated'     => wp_date( get_option( 'date_format' ) ),
			'settings'      => $settings,
			'totals'        => array(
				'published' => $published,
				'updated'   => count( $sections['content'] ) - $published,
				'updates'   => count( $updates ),
				'backups'   => $backups['ok'],
				'site'      => count( $sections['site'] ),
				'leads'     => count( $sections['leads'] ),
			),
			'sections'      => $sections,
			'updates'       => $updates,
			'update_parts'  => self::update_parts( $updates ),
			'backups'       => $backups,
			'leads_by_form' => $leads_by_form,
			'status'        => self::site_status(),
		);
		$report['summary'] = self::summary( $report );
		$report['notes']   = self::notes( $report );
		return $report;
	}

	/**
	 * A line under each of the four numbers: "7 published, 4 updated", "6 plugins, 1 theme,
	 * WordPress, PHP", "1 failed, on 13 October", "10 from Contact us, 4 from Free quote".
	 *
	 * @param array $report The report so far.
	 * @return array{content: string, updates: string, backups: string, leads: string}
	 */
	private static function notes( array $report ) {
		$totals  = $report['totals'];
		$backups = $report['backups'];

		if ( $backups['failed'] ) {
			$when   = self::day( strtotime( (string) $backups['last_failed']['occurred_at'] ) );
			$backup = 1 === $backups['failed']
				/* translators: %s: a date, e.g. 13 October. */
				? sprintf( __( '1 failed, on %s', 'monthwrap' ), $when )
				/* translators: 1: number of failed backups, 2: a date, e.g. 13 October. */
				: sprintf( __( '%1$s failed, the latest on %2$s', 'monthwrap' ), number_format_i18n( $backups['failed'] ), $when );
		} elseif ( $backups['last_ok'] ) {
			/* translators: %s: a date, e.g. 25 October. */
			$backup = sprintf( __( 'Latest on %s', 'monthwrap' ), self::day( strtotime( (string) $backups['last_ok']['occurred_at'] ) ) );
		} else {
			$backup = __( 'None recorded', 'monthwrap' );
		}

		$leads = array();
		foreach ( array_slice( $report['leads_by_form'], 0, 2, true ) as $form => $count ) {
			/* translators: 1: number of leads, 2: form name. */
			$leads[] = sprintf( __( '%1$s from %2$s', 'monthwrap' ), number_format_i18n( $count ), $form );
		}
		$others = array_sum( array_slice( $report['leads_by_form'], 2 ) );
		if ( $others ) {
			/* translators: %s: number of leads. */
			$leads[] = sprintf( __( '%s from other forms', 'monthwrap' ), number_format_i18n( $others ) );
		}

		return array(
			/* translators: 1: posts and pages published, 2: posts and pages updated. */
			'content' => sprintf( __( '%1$s published, %2$s updated', 'monthwrap' ), number_format_i18n( $totals['published'] ), number_format_i18n( $totals['updated'] ) ),
			'updates' => $report['update_parts'] ? implode( ', ', $report['update_parts'] ) : __( 'None needed', 'monthwrap' ),
			'backups' => $backup,
			'leads'   => $leads ? implode( ', ', $leads ) : __( 'No form submissions', 'monthwrap' ),
		);
	}

	/**
	 * A day, written the way the site writes dates: "24 October" or "October 24".
	 *
	 * @param int    $timestamp Unix time.
	 * @param string $style     short ("24 Oct"), long ("24 October"), year ("24 October 2026")
	 *                          or weekday ("Saturday 24 October").
	 * @return string
	 */
	public static function day( $timestamp, $style = 'long' ) {
		$formats = self::month_first()
			? array(
				'short'   => 'M j',
				'long'    => 'F j',
				'year'    => 'F j, Y',
				'weekday' => 'l, F j',
			)
			: array(
				'short'   => 'j M',
				'long'    => 'j F',
				'year'    => 'j F Y',
				'weekday' => 'l j F',
			);
		return wp_date( $formats[ $style ] ?? $formats['long'], $timestamp );
	}

	/**
	 * Whether the site's date format puts the month before the day, as in the US.
	 *
	 * @return bool
	 */
	private static function month_first() {
		$format = (string) get_option( 'date_format' );
		return strcspn( $format, 'FMmn' ) < strcspn( $format, 'dj' );
	}

	/**
	 * The days a report covers: "1 to 25 October 2026" or "October 1 to 25, 2026".
	 *
	 * @param int $first Unix time on the first day.
	 * @param int $last  Unix time on the last day.
	 * @return string
	 */
	private static function covers( $first, $last ) {
		if ( wp_date( 'Y-m-d', $first ) === wp_date( 'Y-m-d', $last ) ) {
			return self::day( $first, 'year' );
		}
		if ( wp_date( 'Y-m', $first ) !== wp_date( 'Y-m', $last ) ) {
			/* translators: 1: first day, 2: last day. */
			return sprintf( __( '%1$s to %2$s', 'monthwrap' ), self::day( $first, 'year' ), self::day( $last, 'year' ) );
		}
		return self::month_first()
			/* translators: 1: first day, 2: last day. */
			? sprintf( __( '%1$s to %2$s', 'monthwrap' ), self::day( $first ), wp_date( 'j, Y', $last ) )
			/* translators: 1: first day, 2: last day. */
			: sprintf( __( '%1$s to %2$s', 'monthwrap' ), wp_date( 'j', $first ), self::day( $last, 'year' ) );
	}

	/**
	 * "October 2026" for a whole month, else "1 Oct 2026 – 15 Oct 2026".
	 *
	 * @param DateTimeImmutable $start Start (inclusive).
	 * @param DateTimeImmutable $end   End (exclusive).
	 * @return string
	 */
	private static function period_label( DateTimeImmutable $start, DateTimeImmutable $end ) {
		if ( '01' === $start->format( 'd' ) && $start->modify( '+1 month' )->getTimestamp() === $end->getTimestamp() ) {
			return wp_date( 'F Y', $start->getTimestamp() );
		}
		$format = get_option( 'date_format' );
		return wp_date( $format, $start->getTimestamp() ) . ' – ' . wp_date( $format, $end->modify( '-1 day' )->getTimestamp() );
	}

	/**
	 * Backups in a period: how many worked and failed, the result for each day, and the
	 * tools that made them.
	 *
	 * @param array[] $events Backup events, oldest first.
	 * @return array
	 */
	private static function backups( array $events ) {
		$backups = array(
			'ok'          => 0,
			'failed'      => 0,
			'last_ok'     => null,
			'last_failed' => null,
			'since_ok'    => false,
			'days'        => array(),
			'tools'       => array(),
		);
		foreach ( $events as $event ) {
			$day  = wp_date( 'Y-m-d', strtotime( (string) ( $event['occurred_at'] ?? '' ) ) );
			$tool = (string) ( $event['name'] ?? '' );
			if ( '' !== $tool && ! in_array( $tool, $backups['tools'], true ) ) {
				$backups['tools'][] = $tool;
			}
			if ( 'failed' === ( $event['status'] ?? '' ) ) {
				++$backups['failed'];
				$backups['last_failed'] = $event;
				$backups['since_ok']    = false;
				if ( ! isset( $backups['days'][ $day ] ) ) {
					$backups['days'][ $day ] = 'failed';
				}
			} else {
				++$backups['ok'];
				$backups['last_ok']      = $event;
				$backups['since_ok']     = true;
				$backups['days'][ $day ] = 'ok';
			}
		}
		return $backups;
	}

	/**
	 * What was updated, in words: "6 plugins", "1 theme", "WordPress", "PHP".
	 *
	 * @param array[] $updates Update events.
	 * @return string[]
	 */
	private static function update_parts( array $updates ) {
		$plugins = 0;
		$themes  = 0;
		$core    = false;
		$server  = array();
		foreach ( $updates as $event ) {
			if ( 'plugin_updated' === $event['type'] ) {
				++$plugins;
			} elseif ( 'theme_updated' === $event['type'] ) {
				++$themes;
			} elseif ( 'core_updated' === $event['type'] ) {
				$core = true;
			} elseif ( '' !== (string) ( $event['name'] ?? '' ) ) {
				$server[ (string) $event['name'] ] = true;
			}
		}
		$parts = array();
		if ( $plugins ) {
			/* translators: %s: number of plugins. */
			$parts[] = sprintf( _n( '%s plugin', '%s plugins', $plugins, 'monthwrap' ), number_format_i18n( $plugins ) );
		}
		if ( $themes ) {
			/* translators: %s: number of themes. */
			$parts[] = sprintf( _n( '%s theme', '%s themes', $themes, 'monthwrap' ), number_format_i18n( $themes ) );
		}
		if ( $core ) {
			$parts[] = __( 'WordPress', 'monthwrap' );
		}
		return array_merge( $parts, array_keys( $server ) );
	}

	/**
	 * The report in a sentence or two, from its numbers: "So far this month we published 7
	 * new posts and pages, ... Your forms brought in 14 leads."
	 *
	 * @param array $report The report so far.
	 * @return string
	 */
	private static function summary( array $report ) {
		$totals  = $report['totals'];
		$backups = $report['backups'];
		$did     = array();
		if ( $totals['published'] ) {
			/* translators: %s: number of posts and pages. */
			$did[] = sprintf( _n( 'published %s new post or page', 'published %s new posts and pages', $totals['published'], 'monthwrap' ), number_format_i18n( $totals['published'] ) );
		}
		if ( $totals['updated'] ) {
			/* translators: %s: number of posts and pages. */
			$did[] = sprintf( _n( 'updated %s existing post or page', 'updated %s existing posts and pages', $totals['updated'], 'monthwrap' ), number_format_i18n( $totals['updated'] ) );
		}
		if ( $report['update_parts'] ) {
			/* translators: %s: what was updated, e.g. "6 plugins, 1 theme, WordPress and PHP". */
			$did[] = sprintf( __( 'kept %s up to date', 'monthwrap' ), wp_sprintf( '%l', $report['update_parts'] ) );
		}
		if ( $backups['ok'] && $backups['failed'] ) {
			/* translators: 1: backups that worked, 2: all backups. */
			$did[] = sprintf( _n( 'backed up the site %1$s time out of %2$s', 'backed up the site %1$s times out of %2$s', $backups['ok'], 'monthwrap' ), number_format_i18n( $backups['ok'] ), number_format_i18n( $backups['ok'] + $backups['failed'] ) );
		} elseif ( $backups['ok'] ) {
			/* translators: %s: number of backups. */
			$did[] = sprintf( _n( 'backed up the site %s time', 'backed up the site %s times', $backups['ok'], 'monthwrap' ), number_format_i18n( $backups['ok'] ) );
		}

		$text = '';
		if ( $did && $report['period']['current'] ) {
			/* translators: %s: a list of what was done, e.g. "published 7 new posts and pages and kept 6 plugins up to date". */
			$text = sprintf( __( 'So far this month we %s.', 'monthwrap' ), wp_sprintf( '%l', $did ) );
		} elseif ( $did ) {
			/* translators: 1: month, 2: a list of what was done, e.g. "published 7 new posts and pages and kept 6 plugins up to date". */
			$text = sprintf( __( 'In %1$s we %2$s.', 'monthwrap' ), $report['period']['month'], wp_sprintf( '%l', $did ) );
		}
		if ( $totals['leads'] ) {
			/* translators: %s: number of leads. */
			$text .= ( '' !== $text ? ' ' : '' ) . sprintf( _n( 'Your forms brought in %s lead.', 'Your forms brought in %s leads.', $totals['leads'], 'monthwrap' ), number_format_i18n( $totals['leads'] ) );
		}
		if ( '' === $text ) {
			$text = $report['period']['current'] ? __( 'Nothing has been recorded this month yet.', 'monthwrap' ) : __( 'Nothing was recorded in this period.', 'monthwrap' );
		}
		return $text;
	}

	/**
	 * The site's state now: versions, updates waiting, Site Health and the last backup.
	 *
	 * @return array
	 */
	public static function site_status() {
		global $wpdb;
		if ( ! function_exists( 'get_plugins' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}
		$plugins = get_plugins();

		$waiting = array();
		$updates = get_site_transient( 'update_plugins' );
		foreach ( (array) ( $updates->response ?? array() ) as $file => $update ) {
			if ( isset( $plugins[ $file ] ) ) {
				$waiting[] = trim( $plugins[ $file ]['Name'] . ' ' . ( $update->new_version ?? '' ) );
			}
		}
		$updates = get_site_transient( 'update_themes' );
		foreach ( (array) ( $updates->response ?? array() ) as $slug => $update ) {
			$theme = wp_get_theme( $slug );
			/* translators: 1: theme name, 2: new version. */
			$waiting[] = sprintf( __( '%1$s theme %2$s', 'monthwrap' ), $theme->get( 'Name' ), $update['new_version'] ?? '' );
		}
		$core = get_site_transient( 'update_core' );
		foreach ( (array) ( $core->updates ?? array() ) as $offer ) {
			if ( 'upgrade' === ( $offer->response ?? '' ) ) {
				/* translators: %s: WordPress version. */
				$waiting[] = sprintf( __( 'WordPress %s', 'monthwrap' ), $offer->current ?? '' );
				break;
			}
		}

		$health = json_decode( (string) get_transient( 'health-check-site-status-result' ), true );
		$backup = Monthwrap_Store::between( '1970-01-01 00:00:00', gmdate( 'Y-m-d H:i:s', time() + 60 ), array( 'backup_completed' ), 1 );

		return array(
			'wordpress'   => get_bloginfo( 'version' ),
			'php'         => PHP_VERSION,
			'database'    => ( false !== stripos( (string) $wpdb->db_server_info(), 'mariadb' ) ? 'MariaDB ' : 'MySQL ' ) . $wpdb->db_version(),
			'theme'       => wp_get_theme()->get( 'Name' ),
			'plugins'     => count( (array) get_option( 'active_plugins', array() ) ),
			'waiting'     => $waiting,
			'health'      => is_array( $health ) ? $health : null,
			'last_backup' => $backup ? $backup[0]['event'] : null,
		);
	}
}