<?php
/**
 * People who already had an account before the plugin was connected. They are NEVER added silently.
 * Two ways to ask, and only a clear "yes" adds them to PostaraMail:
 *   1. A small prompt after they log in: "Get news by email? Yes / No / Later".
 *   2. One optional email, "Want to stay in touch?", with a Yes link and a No link
 *      (sent by this site, once per person, only after the owner confirms).
 */

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

class PostaraMail_Existing {

	const META   = 'postaramail_optin';  // yes | no
	const ASKED  = 'postaramail_asked';  // timestamp of the email
	const SNOOZE = 'postaramail_snooze';
	const HOOK   = 'postaramail_existing_send';
	const QUEUE  = 'postaramail_existing_queue';

	public static function init() {
		add_action( self::HOOK, array( __CLASS__, 'send_batch' ) );
		add_action( 'template_redirect', array( __CLASS__, 'handle_link' ) );
		if ( PostaraMail_API::configured() && get_option( 'postaramail_exist_banner' ) ) {
			add_action( 'wp_enqueue_scripts', array( __CLASS__, 'banner_assets' ) );
			add_action( 'wp_footer', array( __CLASS__, 'banner' ) );
			add_action( 'rest_api_init', array( __CLASS__, 'route' ) );
		}
	}

	// ---------- Who is eligible ----------

	/** The roles the owner ticked (as shown on screen). */
	public static function roles() {
		$saved = get_option( 'postaramail_exist_roles', null );
		if ( is_array( $saved ) ) {
			return $saved;
		}
		$all = array_keys( wp_roles()->roles );
		return array_values( array_diff( $all, array( 'administrator' ) ) );
	}

	/**
	 * The roles we really include: the ones ticked, PLUS any role created after the owner last saved
	 * (other plugins add their own roles, and those users must not silently vanish). Never administrators.
	 */
	public static function effective_roles() {
		$saved = get_option( 'postaramail_exist_roles', null );
		if ( ! is_array( $saved ) ) {
			return self::roles();
		}
		if ( ! $saved ) {
			return array(); // the owner ticked nothing on purpose: nobody, whatever roles exist
		}
		$all   = array_keys( wp_roles()->roles );
		$known = get_option( 'postaramail_roles_known', null );
		if ( ! is_array( $known ) ) {
			// Saved before this was tracked: the screen then listed only WordPress's own roles (and WooCommerce's).
			$known = array_values( array_intersect( $all, array( 'administrator', 'editor', 'author', 'contributor', 'subscriber', 'customer', 'shop_manager' ) ) );
		}
		$new = array_diff( array_diff( $all, $known ), array( 'administrator' ) );
		return array_values( array_unique( array_merge( $saved, $new ) ) );
	}

	/** Remember which roles existed when the owner last chose, so later roles can be told apart. */
	public static function remember_roles() {
		update_option( 'postaramail_roles_known', array_keys( wp_roles()->roles ), false );
		delete_transient( 'postaramail_breakdown' );
	}

	/** May we list / ask this user? Users with NO role count too (some plugins create them). Administrators only if ticked. */
	public static function role_ok( $user, $roles = null ) {
		$roles = null === $roles ? self::effective_roles() : $roles;
		if ( ! $roles ) {
			return false; // nothing ticked = nobody
		}
		$r = (array) $user->roles;
		if ( in_array( 'administrator', $r, true ) && ! in_array( 'administrator', $roles, true ) ) {
			return false;
		}
		return ! $r || (bool) array_intersect( $r, $roles );
	}

	private static function in_roles( $user ) {
		return self::role_ok( $user );
	}

	/**
	 * Users that have none of the given meta keys and pass the role rule. The role check is done here (not in the
	 * query) so users without a role are not lost; it scans in pages so excluded users never block the rest.
	 */
	public static function scan( $skip_meta, $limit ) {
		$roles = self::effective_roles();
		if ( ! $roles ) {
			return array();
		}
		$out   = array();
		$found = 0;
		$paged = 1;
		while ( $found < $limit && $paged <= 25 ) {
			$mq = array( 'relation' => 'AND' );
			foreach ( $skip_meta as $key ) {
				$mq[] = array(
					'key'     => $key,
					'compare' => 'NOT EXISTS',
				);
			}
			$ids = get_users(
				array(
					'fields'     => 'ID',
					'number'     => 200,
					'paged'      => $paged,
					'orderby'    => 'ID',
					'order'      => 'ASC',
					'meta_query' => $mq,
				)
			);
			if ( ! $ids ) {
				break;
			}
			foreach ( $ids as $id ) {
				$u = get_userdata( $id );
				if ( $u && is_email( $u->user_email ) && self::role_ok( $u, $roles ) ) {
					$out[] = (int) $id;
					++$found;
					if ( count( $out ) >= $limit ) {
						break;
					}
				}
			}
			++$paged;
		}
		return $out;
	}

	/** User ids that have not answered and were not already asked by email (the database does the filtering). */
	public static function pending_ids( $limit = 5000 ) {
		return self::scan( array( self::META, self::ASKED ), $limit );
	}

	public static function counts( $with_pending = true ) {
		global $wpdb;
		$yes = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM {$wpdb->usermeta} WHERE meta_key = %s AND meta_value = 'yes'", self::META ) ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery
		$no  = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM {$wpdb->usermeta} WHERE meta_key = %s AND meta_value = 'no'", self::META ) ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery
		return array(
			'yes'     => $yes,
			'no'      => $no,
			'pending' => $with_pending ? count( self::pending_ids() ) : 0,
			'queued'  => count( (array) get_option( self::QUEUE, array() ) ),
		);
	}

	// ---------- Recording an answer ----------

	public static function record( $user_id, $yes, $how ) {
		update_user_meta( $user_id, self::META, $yes ? 'yes' : 'no' );
		$u = get_userdata( $user_id );
		if ( ! $u || ! is_email( $u->user_email ) ) {
			return;
		}
		if ( ! $yes ) {
			PostaraMail_Subscriber::decline( $u->user_email ); // shows as "Declined" in PostaraMail: never emailed
			return;
		}
		// Their saved country if we have one, otherwise where they are right now (they just clicked).
		$country = PostaraMail_Geo::for_user( $user_id );
		$geo     = PostaraMail_Geo::for_request();
		PostaraMail_Subscriber::subscribe(
			array(
				'email'      => $u->user_email,
				'first'      => $u->first_name ? $u->first_name : '',
				'last'       => $u->last_name ? $u->last_name : '',
				'automation' => (int) get_option( 'postaramail_default_automation', 0 ),
				'source'     => 'existing',
				'consent'    => 'Existing member chose "Yes" to news by email (' . $how . ') on ' . gmdate( 'Y-m-d' ),
				'method'     => 'optin',
				'confirmed'  => true, // they chose yes themselves while logged in or via their own signed link
				'country'    => $country ? $country : $geo['country'],
				'ip'         => $country ? '' : $geo['ip'],
			)
		);
	}

	// ---------- 1. The prompt after login ----------

	/** Whether the logged-in visitor should see the "get news by email?" prompt. */
	private static function should_ask() {
		if ( ! is_user_logged_in() ) {
			return false;
		}
		$user = wp_get_current_user();
		return ! ( get_user_meta( $user->ID, self::META, true ) || ! self::in_roles( $user ) || (int) get_user_meta( $user->ID, self::SNOOZE, true ) > time() );
	}

	/** Loads the prompt's style and script, only for people who will actually see it. */
	public static function banner_assets() {
		if ( ! self::should_ask() ) {
			return;
		}
		wp_enqueue_style( 'postaramail-ask', POSTARAMAIL_WP_URL . 'assets/ask.css', array(), POSTARAMAIL_WP_VERSION );
		wp_enqueue_script( 'postaramail-ask', POSTARAMAIL_WP_URL . 'assets/ask.js', array(), POSTARAMAIL_WP_VERSION, true );
		wp_localize_script(
			'postaramail-ask',
			'PostaraMailAsk',
			array(
				'url'   => esc_url_raw( rest_url( 'postaramail/v1/optin' ) ),
				'nonce' => wp_create_nonce( 'wp_rest' ),
			)
		);
	}

	public static function banner() {
		if ( ! self::should_ask() ) {
			return;
		}
		$site = wp_strip_all_tags( get_bloginfo( 'name' ) );
		?>
		<div id="pm-ask" role="dialog" aria-label="<?php esc_attr_e( 'Email news', 'postaramail' ); ?>">
			<p><strong><?php echo esc_html( $site ); ?></strong> — <?php esc_html_e( 'would you like to get news and offers by email? You can unsubscribe at any time.', 'postaramail' ); ?></p>
			<div class="pm-ask-btns">
				<button type="button" class="pm-yes" data-a="yes"><?php esc_html_e( 'Yes, keep me posted', 'postaramail' ); ?></button>
				<button type="button" data-a="no"><?php esc_html_e( 'No thanks', 'postaramail' ); ?></button>
				<button type="button" data-a="later"><?php esc_html_e( 'Ask me later', 'postaramail' ); ?></button>
			</div>
		</div>
		<?php
	}

	public static function route() {
		register_rest_route(
			'postaramail/v1',
			'/optin',
			array(
				'methods'             => 'POST',
				'permission_callback' => 'is_user_logged_in',
				'callback'            => array( __CLASS__, 'rest_answer' ),
			)
		);
	}

	public static function rest_answer( $request ) {
		$answer = sanitize_key( (string) $request->get_param( 'answer' ) );
		$id     = get_current_user_id();
		if ( 'yes' === $answer ) {
			self::record( $id, true, 'login prompt' );
		} elseif ( 'no' === $answer ) {
			self::record( $id, false, 'login prompt' );
		} else {
			update_user_meta( $id, self::SNOOZE, time() + 7 * DAY_IN_SECONDS );
		}
		return rest_ensure_response( array( 'ok' => true ) );
	}

	// ---------- 2. The "Want to stay in touch?" email ----------

	private static function sign( $user_id, $answer ) {
		return substr( hash_hmac( 'sha256', 'pm-optin:' . (int) $user_id . ':' . $answer, wp_salt( 'auth' ) ), 0, 32 );
	}

	private static function link( $user_id, $answer ) {
		return add_query_arg(
			array(
				'pm_optin' => $answer,
				'u'        => (int) $user_id,
				't'        => self::sign( $user_id, $answer ),
			),
			home_url( '/' )
		);
	}

	/** Called when the owner confirms and presses the button on the Existing users tab. */
	public static function start_email( $confirmed ) {
		if ( ! $confirmed ) {
			return 0;
		}
		update_option( 'postaramail_exist_confirm', time(), false );
		$ids = self::pending_ids();
		update_option( self::QUEUE, $ids, false );
		if ( $ids && ! wp_next_scheduled( self::HOOK ) ) {
			wp_schedule_event( time() + 60, 'postaramail_15min', self::HOOK );
		}
		return count( $ids );
	}

	public static function send_batch() {
		$queue = (array) get_option( self::QUEUE, array() );
		if ( ! $queue ) {
			wp_clear_scheduled_hook( self::HOOK );
			return;
		}
		$batch = array_splice( $queue, 0, 20 );
		$site  = wp_strip_all_tags( get_bloginfo( 'name' ) );
		foreach ( $batch as $id ) {
			$u = get_userdata( $id );
			if ( ! $u || get_user_meta( $id, self::META, true ) || get_user_meta( $id, self::ASKED, true ) || ! is_email( $u->user_email ) ) {
				continue;
			}
			$first   = $u->first_name ? $u->first_name : $u->display_name;
			$yes     = self::link( $id, 'yes' );
			$no      = self::link( $id, 'no' );
			$privacy = function_exists( 'get_privacy_policy_url' ) ? get_privacy_policy_url() : '';
			$body    = '<p>' . sprintf( /* translators: %s: first name */ esc_html__( 'Hi %s,', 'postaramail' ), esc_html( $first ) ) . '</p>'
				. '<p>' . sprintf( /* translators: %s: site name */ esc_html__( 'You have an account on %s. We would like to send you occasional news and offers by email. Would you like that?', 'postaramail' ), '<strong>' . esc_html( $site ) . '</strong>' ) . '</p>'
				. '<p><a href="' . esc_url( $yes ) . '" style="display:inline-block;background:#ff6a0d;color:#14161f;padding:12px 22px;border-radius:10px;font-weight:bold;text-decoration:none;">' . esc_html__( 'Yes, keep me posted', 'postaramail' ) . '</a>'
				. ' &nbsp; <a href="' . esc_url( $no ) . '">' . esc_html__( 'No thanks', 'postaramail' ) . '</a></p>'
				. '<p style="color:#666;font-size:13px;">' . esc_html__( 'If you do nothing, we will not add you to our email list and we will not ask again. You can unsubscribe at any time.', 'postaramail' ) . '</p>'
				. '<p style="color:#666;font-size:13px;">' . esc_html( $site ) . ' · ' . esc_url( home_url( '/' ) ) . ( $privacy ? ' · <a href="' . esc_url( $privacy ) . '">' . esc_html__( 'Privacy policy', 'postaramail' ) . '</a>' : '' ) . '</p>';
			// One question per person, ever: mark it first so a retry can never send it twice.
			update_user_meta( $id, self::ASKED, time() );
			wp_mail( $u->user_email, sprintf( /* translators: %s: site name */ __( 'Do you want news from %s?', 'postaramail' ), $site ), $body, array( 'Content-Type: text/html; charset=UTF-8' ) );
		}
		update_option( self::QUEUE, $queue, false );
		if ( ! $queue ) {
			wp_clear_scheduled_hook( self::HOOK );
		}
	}

	/** The Yes / No links in the email. */
	public static function handle_link() {
		if ( empty( $_GET['pm_optin'] ) || empty( $_GET['u'] ) || empty( $_GET['t'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- signed link instead of a nonce.
			return;
		}
		$answer = 'yes' === $_GET['pm_optin'] ? 'yes' : 'no'; // phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$id     = (int) $_GET['u']; // phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$token  = sanitize_text_field( wp_unslash( $_GET['t'] ) ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended
		if ( ! hash_equals( self::sign( $id, $answer ), $token ) || ! get_userdata( $id ) ) {
			wp_die( esc_html__( 'This link is not valid.', 'postaramail' ), esc_html__( 'Link not valid', 'postaramail' ), array( 'response' => 400 ) );
		}
		self::record( $id, 'yes' === $answer, 'email link' );
		$msg = 'yes' === $answer
			? __( 'Thank you! You are subscribed. You can unsubscribe at any time from any email we send.', 'postaramail' )
			: __( 'No problem. We will not add you to our email list.', 'postaramail' );
		wp_die( esc_html( $msg ) . '<p><a href="' . esc_url( home_url( '/' ) ) . '">' . esc_html__( 'Back to the site', 'postaramail' ) . '</a></p>', esc_html( get_bloginfo( 'name' ) ), array( 'response' => 200 ) ); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
	}
}