<?php
/**
 * Keeps the plugin and the PostaraMail dashboard in step. PostaraMail is the master: settings saved in
 * the dashboard reach this site within 15 minutes (or at once when the PostaraMail screen is opened
 * here), and settings saved here are sent to PostaraMail. If both changed, the dashboard wins.
 * The same call reports stats and receives commands (for example "send the stay-in-touch email").
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class PostaraMail_Sync {

	const HOOK = 'postaramail_sync';

	public static function init() {
		add_action( self::HOOK, array( __CLASS__, 'cron' ) );
	}

	public static function rev() {
		return (int) get_option( 'postaramail_settings_rev', 0 );
	}

	// ---------- Options <-> settings ----------

	/** Everything the dashboard controls, read from this site's options. */
	public static function local_settings() {
		$cmd = get_option( 'postaramail_last_command', 0 );
		return array(
			'reg_mode'           => get_option( 'postaramail_reg_mode', 'off' ),
			'reg_notice'         => get_option( 'postaramail_reg_notice', PostaraMail_Integrations::default_notice( 'reg' ) ),
			'woo_mode'           => get_option( 'postaramail_woo_mode', 'off' ),
			'woo_notice'         => get_option( 'postaramail_woo_notice', PostaraMail_Integrations::default_notice( 'woo' ) ),
			'comment_mode'       => get_option( 'postaramail_comment_mode', 'off' ),
			'optin_label'        => PostaraMail_Integrations::checkbox_label(),
			'owner_confirmed_at' => get_option( 'postaramail_owner_confirmed' ) ? (int) get_option( 'postaramail_owner_confirmed' ) : null,
			'start_automations'  => (bool) get_option( 'postaramail_start_automations', 1 ),
			'default_automation' => (int) get_option( 'postaramail_default_automation', 0 ),
			'exist_banner'       => (bool) get_option( 'postaramail_exist_banner', 0 ),
			'exist_roles'        => is_array( get_option( 'postaramail_exist_roles', null ) ) ? array_values( get_option( 'postaramail_exist_roles' ) ) : null,
			'sync_pending'       => (bool) get_option( 'postaramail_sync_pending', 1 ),
			'form'               => array(
				'button_text'  => get_option( 'postaramail_button_text', __( 'Subscribe', 'postaramail' ) ),
				'consent_text' => get_option( 'postaramail_consent_text', __( 'Yes, I’d like to receive emails. I can unsubscribe at any time.', 'postaramail' ) ),
				'success_text' => get_option( 'postaramail_success_text', __( 'Thanks! You’re subscribed.', 'postaramail' ) ),
			),
			'commands'           => array(),
			'_last_command'      => (int) $cmd,
		);
	}

	/** Applies the dashboard's settings to this site's options. */
	public static function apply( $s ) {
		$text = array(
			'reg_mode'     => 'postaramail_reg_mode',
			'reg_notice'   => 'postaramail_reg_notice',
			'woo_mode'     => 'postaramail_woo_mode',
			'woo_notice'   => 'postaramail_woo_notice',
			'comment_mode' => 'postaramail_comment_mode',
			'optin_label'  => 'postaramail_optin_label',
		);
		foreach ( $text as $key => $opt ) {
			if ( isset( $s[ $key ] ) ) {
				'' === $s[ $key ] ? delete_option( $opt ) : update_option( $opt, sanitize_text_field( $s[ $key ] ) );
			}
		}
		if ( ! empty( $s['owner_confirmed_at'] ) ) {
			update_option( 'postaramail_owner_confirmed', (int) $s['owner_confirmed_at'], false );
		} else {
			delete_option( 'postaramail_owner_confirmed' );
		}
		update_option( 'postaramail_start_automations', ! empty( $s['start_automations'] ) ? 1 : 0 );
		update_option( 'postaramail_default_automation', isset( $s['default_automation'] ) ? absint( $s['default_automation'] ) : 0 );
		update_option( 'postaramail_exist_banner', ! empty( $s['exist_banner'] ) ? 1 : 0 );
		$was = (int) get_option( 'postaramail_sync_pending', 1 );
		update_option( 'postaramail_sync_pending', ( ! isset( $s['sync_pending'] ) || $s['sync_pending'] ) ? 1 : 0 );
		if ( isset( $s['exist_roles'] ) && is_array( $s['exist_roles'] ) ) {
			update_option( 'postaramail_exist_roles', array_values( $s['exist_roles'] ) );
			PostaraMail_Existing::remember_roles();
		} else {
			delete_option( 'postaramail_exist_roles' );
		}
		if ( isset( $s['form'] ) && is_array( $s['form'] ) ) {
			foreach ( array(
				'button_text'  => 'postaramail_button_text',
				'consent_text' => 'postaramail_consent_text',
				'success_text' => 'postaramail_success_text',
			) as $k => $opt ) {
				if ( isset( $s['form'][ $k ] ) ) {
					'' === $s['form'][ $k ] ? delete_option( $opt ) : update_option( $opt, sanitize_text_field( $s['form'][ $k ] ) );
				}
			}
		}
		if ( ! $was && get_option( 'postaramail_sync_pending', 1 ) ) {
			PostaraMail_Pending::schedule_soon();
		}
	}

	// ---------- Talking to PostaraMail ----------

	private static function stats() {
		$stats = get_option( 'postaramail_stats', array( 'added' => 0 ) );
		$c     = PostaraMail_Existing::counts( false ); // the cheap counts only
		$roles = array();
		foreach ( wp_roles()->roles as $slug => $role ) {
			$roles[] = array(
				'slug' => $slug,
				'name' => translate_user_role( $role['name'] ),
			);
		}
		return array(
			'rev'            => self::rev(),
			'plugin_version' => POSTARAMAIL_WP_VERSION,
			'wp_version'     => get_bloginfo( 'version' ),
			'woocommerce'    => class_exists( 'WooCommerce' ),
			'roles'          => $roles,
			'stats'          => array(
				'added'           => (int) $stats['added'],
				'queued'          => PostaraMail_Queue::count(),
				'pending_pushed'  => PostaraMail_Pending::pushed_count(),
				'existing'        => array(
					'yes'     => (int) $c['yes'],
					'no'      => (int) $c['no'],
					'pending' => PostaraMail_Pending::pending_count(),
				),
				'last_command_id' => (int) get_option( 'postaramail_last_command', 0 ),
			),
		);
	}

	/** The background task: also notes that background tasks really run on this site. */
	public static function cron() {
		update_option( 'postaramail_sync_cron_last', time(), false );
		self::run();
	}

	/** At most once a minute. Used when the PostaraMail screen is opened. */
	public static function maybe_run() {
		if ( get_transient( 'postaramail_synced' ) ) {
			return;
		}
		set_transient( 'postaramail_synced', 1, 60 );
		self::run();
		// Anyone still waiting (for example if background tasks do not run on this site) goes now.
		if ( PostaraMail_Pending::enabled() ) {
			PostaraMail_Pending::push_waiting( 100 );
		}
	}

	/** One round trip: report, receive newer settings, run any command. */
	public static function run() {
		if ( ! PostaraMail_API::configured() ) {
			return;
		}
		$r = PostaraMail_API::heartbeat( self::stats() );
		if ( ! $r['ok'] ) {
			update_option(
				'postaramail_sync_error',
				array(
					'message' => substr( (string) $r['message'], 0, 200 ),
					'time'    => time(),
				),
				false
			);
			return;
		}
		delete_option( 'postaramail_sync_error' );
		$d   = $r['data'];
		$rev = isset( $d['rev'] ) ? (int) $d['rev'] : 0;

		if ( isset( $d['settings'] ) && is_array( $d['settings'] ) ) {
			self::apply( $d['settings'] );
			update_option( 'postaramail_settings_rev', $rev, false );
			self::run_commands( $d['settings'] );
		} elseif ( 0 === $rev ) {
			self::push(); // PostaraMail has nothing yet: send this site's settings as the starting point.
		}
		if ( isset( $d['upgrade_url'] ) ) {
			update_option( 'postaramail_upgrade_url', esc_url_raw( $d['upgrade_url'] ), false );
		}
	}

	/** Sends this site's settings to PostaraMail. Returns ok | stale | error. */
	public static function push() {
		if ( ! PostaraMail_API::configured() ) {
			return 'error';
		}
		$settings = self::local_settings();
		unset( $settings['_last_command'], $settings['commands'] );
		$r = PostaraMail_API::put_settings( $settings, self::rev() );
		if ( $r['ok'] ) {
			update_option( 'postaramail_settings_rev', (int) $r['data']['rev'], false );
			return 'ok';
		}
		if ( 'stale' === $r['code'] ) {
			// The dashboard changed first. It wins: take its settings.
			delete_transient( 'postaramail_synced' );
			$h = PostaraMail_API::heartbeat( array_merge( self::stats(), array( 'rev' => -1 ) ) );
			if ( $h['ok'] && isset( $h['data']['settings'] ) ) {
				self::apply( $h['data']['settings'] );
				update_option( 'postaramail_settings_rev', (int) $h['data']['rev'], false );
			}
			return 'stale';
		}
		return 'error';
	}

	private static function run_commands( $s ) {
		$cmd = isset( $s['commands']['send_existing']['id'] ) ? (int) $s['commands']['send_existing']['id'] : 0;
		if ( $cmd > (int) get_option( 'postaramail_last_command', 0 ) ) {
			// The owner confirmed this in PostaraMail ("I am allowed to contact them once to ask").
			PostaraMail_Existing::start_email( true );
			update_option( 'postaramail_last_command', $cmd, false );
		}
	}
}