<?php
/**
 * Email: LO alerts per milestone, borrower results, receipts, resume links
 * and reminders.
 *
 * Recipients: the application's loan officer (and their extra notify list);
 * else the shortcode's email="" route (2.6); else the site recipients setting.
 * The site recipients can be copied on every LO's alerts (mapp_notify_site_too).
 *
 * The 2.6 subject and message settings are kept as the content of the
 * submitted alert and the English borrower receipt, with {all_fields} now
 * listing every 3.0 answer.
 *
 * @package mortgage_application
 */

namespace Mapp\Notifications;

use Mapp\Application\Repository;
use Mapp\Files\Store;
use Mapp\LoanOfficers\LoanOfficers;
use Mapp\Schema\Schema;

defined( 'ABSPATH' ) || exit;

class Mailer {

	/** Wire hooks. */
	public static function register() {
		add_action( 'mapp_milestone', array( __CLASS__, 'on_milestone' ), 10, 2 );
	}

	/**
	 * Layout placeholders from 2.x. The emails now place the answers, the
	 * buttons, the export downloads and the file lists themselves, so these
	 * are taken out of any text a site saved; only text placeholders
	 * ({first_name}, {last_name}, {email}, {name}) are filled in.
	 */
	const LAYOUT_TOKENS = array( '{all_fields}', '{edit_url}', '{csv_file_url}', '{fnm_file_url}', '{mismo_file_url}', '{documents}', '{docs}', '{admin_url}', '{resume_button}' );

	/**
	 * Saved email text without layout placeholders (and the empty
	 * paragraphs or separators they leave behind).
	 *
	 * @param string $text Text.
	 * @return string
	 */
	public static function clean_template( $text ) {
		$text = str_replace( self::LAYOUT_TOKENS, '', (string) $text );
		$text = preg_replace( '#<(p|div|h[1-6])[^>]*>(\s|&nbsp;|<br\s*/?>|,|:)*</\1>#i', '', $text );
		$text = preg_replace( '/[ \t]*,[ \t]*(?=,|\n|$)/', '', $text );
		$text = preg_replace( "/\n{3,}/", "\n\n", $text );
		return trim( $text );
	}

	/** @var string|null While a test is sent: the only recipient. */
	private static $redirect = null;

	/** @var bool Result of the last send(). */
	private static $last_sent = false;

	/**
	 * Settings "Send Test Email": the real 3.0 email, built from a sample
	 * application (never a borrower's data) and sent only to $to.
	 *
	 * @param string $to   Address typed by the admin.
	 * @param string $type client | admin | reminder.
	 * @return bool Sent.
	 */
	public static function send_test( $to, $type ) {
		$id = self::sample_application();
		if ( ! $id ) {
			return false;
		}
		self::$redirect  = $to;
		self::$last_sent = false;
		// The sample is deleted right after, so its links just open the form.
		$plain = function ( $url, $app_id, $token, $base ) {
			return $base;
		};
		add_filter( 'mapp_resume_url', $plain, 10, 4 );
		try {
			if ( 'client' === $type ) {
				self::borrower_receipt( $id );
			} elseif ( 'reminder' === $type ) {
				self::reminder( $id, \Mapp\Rest\Controller::resume_url( $id, 'sample' ) );
			} else {
				$subject = self::option( 'mortgage_application_mail_subject', 'mortgage_application_use_network_settings' );
				self::lo_alert( $id, 'submitted', $subject ? $subject : __( 'New application: {first_name} {last_name}', '1003-mortgage-application' ), '{all_fields}' );
			}
		} finally {
			remove_filter( 'mapp_resume_url', $plain, 10 );
			self::$redirect = null;
			\Mapp\Integrations\ConnectorGuard::quietly(
				function () use ( $id ) {
					wp_delete_post( $id, true );
				}
			);
		}
		return self::$last_sent;
	}

	/**
	 * A submitted sample application (Jane Sample, purchase in Austin) with
	 * the site's first loan officer. Saved through the normal code so every
	 * derived value is real; deleted right after the test.
	 *
	 * @return int Application ID, or 0.
	 */
	private static function sample_application() {
		$id = Repository::create( array( 'lang' => 'en' ) );
		if ( ! $id ) {
			return 0;
		}
		$los = LoanOfficers::published();
		if ( $los ) {
			update_post_meta( $id, 'mapp_lo_id', (int) key( $los ) );
		}
		Repository::save_answers(
			$id,
			array(
				'purpose'               => 'Home Purchase',
				'zip_code'              => array( 'formatted' => '123 Main St, Austin, TX 78701', 'street' => '123 Main St', 'city' => 'Austin', 'state' => 'TX', 'zip' => '78701' ),
				'home_description'      => 'Single Family',
				'property_use'          => 'Primary Residence',
				'loan_purpose_purchase' => 'Within 30 Days',
				'first_time_buyer'      => 'Yes',
				'purchase_price'        => '350000',
				'down_payment'          => '35000',
				'credit_rating'         => 'Good',
				'military'              => 'No',
				'employment_status'     => 'Employed',
				'monthly_income'        => '8500',
				'first_name'            => 'Jane',
				'last_name'             => 'Sample',
				'email'                 => 'jane.sample@example.com',
				'phone_number'          => '512 555 0199',
				'mailing_address'       => '9 Elm St, Austin, TX 78702',
				'bankruptcy'            => 'No',
				'foreclosure'           => 'No',
			)
		);
		Repository::refresh_derived( $id );
		Repository::advance( $id, Repository::STAGE_CONTACT );
		Repository::advance( $id, Repository::STAGE_SUBMITTED );
		return $id;
	}

	/**
	 * @param int    $id        Application ID.
	 * @param string $milestone Milestone.
	 */
	public static function on_milestone( $id, $milestone ) {
		switch ( $milestone ) {
			case 'contact':
				if ( 'no' !== get_option( 'mapp_alert_partial', 'yes' ) ) {
					self::lo_alert( $id, $milestone, __( 'New lead in progress: {first_name} {last_name}', '1003-mortgage-application' ), __( '{first_name} saved their contact details and is still answering questions. You will get another email when they submit.', '1003-mortgage-application' ) );
				}
				// The contact screen promises the borrower their results.
				if ( 'no' !== get_option( 'mapp_borrower_numbers', 'yes' ) && Repository::STAGE_CONTACT === Repository::stage( $id ) ) {
					self::borrower_numbers( $id );
				}
				break;
			case 'submitted':
				$subject = self::option( 'mortgage_application_mail_subject', 'mortgage_application_use_network_settings' );
				self::lo_alert( $id, $milestone, $subject ? $subject : __( 'New application: {first_name} {last_name}', '1003-mortgage-application' ), '{all_fields}' );
				if ( self::receipt_on() ) {
					self::borrower_receipt( $id );
				}
				break;
			case 'full_submitted':
				self::lo_alert( $id, $milestone, __( 'Full 1003 submitted: {first_name} {last_name}', '1003-mortgage-application' ), __( '{first_name} completed the full application.', '1003-mortgage-application' ) . "\n\n{all_fields}" );
				break;
			case 'documents':
				self::lo_alert( $id, $milestone, __( 'Documents uploaded: {first_name} {last_name}', '1003-mortgage-application' ), __( '{first_name} uploaded documents.', '1003-mortgage-application' ) . "\n\n{documents}" );
				break;
		}
	}

	/**
	 * @param string $option  Option name.
	 * @param string $network Network-settings toggle.
	 * @param string $mode    text | html.
	 * @return string
	 */
	private static function option( $option, $network, $mode = 'text' ) {
		$value = function_exists( 'mapp_get_option_with_shortcode' ) ? (string) mapp_get_option_with_shortcode( $option, $network, $mode ) : (string) get_option( $option, '' );
		// An empty box means the default, not a blank email.
		if ( '' === trim( wp_strip_all_tags( $value ) ) && function_exists( 'mapp_default_option' ) ) {
			$value = mapp_default_option( $option );
		}
		return $value;
	}

	/**
	 * LO-side recipients for an application.
	 *
	 * @param int $id Application ID.
	 * @return string[]
	 */
	public static function recipients( $id ) {
		$out = array();
		$lo  = LoanOfficers::profile( (int) get_post_meta( $id, 'mapp_lo_id', true ) );
		if ( $lo ) {
			$out = $lo['notify'];
		} else {
			$route = (string) get_post_meta( $id, 'dynamic_email', true );
			if ( is_email( $route ) ) {
				$out[] = $route;
			}
		}
		if ( empty( $out ) || 'yes' === get_option( 'mapp_notify_site_too', 'no' ) ) {
			$site = self::option( 'mortgage_application_email_recipients', 'mortgage_application_use_network_settings' );
			$out  = array_merge( $out, array_filter( array_map( 'trim', explode( ',', $site ) ), 'is_email' ) );
		}
		return array_values( array_unique( array_map( 'strtolower', $out ) ) );
	}

	/**
	 * @param int    $id        Application ID.
	 * @param string $milestone Milestone.
	 * @param string $subject   Subject template.
	 * @param string $message   Message template.
	 */
	private static function lo_alert( $id, $milestone, $subject, $message ) {
		$to = self::recipients( $id );
		if ( empty( $to ) && null === self::$redirect ) {
			return;
		}
		$headers = self::reply_to( trim( get_post_meta( $id, 'first_name', true ) . ' ' . get_post_meta( $id, 'last_name', true ) ), (string) get_post_meta( $id, 'email', true ) );
		$body    = self::render( $id, $message, 'lo', $milestone );
		self::send( implode( ', ', $to ), self::fill_text( $id, $subject ), $body, $headers );
	}

	/**
	 * The 2.6 "Client Email Send" switch. 3.0 sends the receipt unless that
	 * switch was saved off (in 2.6 it was off until someone turned it on).
	 *
	 * @return bool
	 */
	public static function receipt_on() {
		$value = function_exists( 'get_front_mortgage_application_option' )
			? get_front_mortgage_application_option( 'mortgage_application_client_email_recipients', 'mortgage_application_use_network_settings' )
			: get_option( 'mortgage_application_client_email_recipients', false );
		return (bool) apply_filters( 'mapp_send_receipt', false === $value || null === $value || 'on' === $value );
	}

	/**
	 * Borrower receipt after the short app: a confirmation, their numbers,
	 * what happens next (with the documents their answers call for), a link
	 * back to upload and finish, then every answer.
	 *
	 * The 2.6 receipt settings still give the subject and the opening (in
	 * English); {all_fields} there is ignored, the answers always go last.
	 *
	 * @param int $id Application ID.
	 */
	private static function borrower_receipt( $id ) {
		$to = sanitize_email( (string) get_post_meta( $id, 'email', true ) );
		if ( ! $to ) {
			return;
		}
		$es = 'es' === get_post_meta( $id, 'mapp_lang', true );
		if ( $es ) {
			$subject = 'Recibimos su solicitud';
			$intro   = "Hola {first_name},\n\nGracias por su solicitud. Esto es lo que sigue.";
		} else {
			$subject = self::option( 'mortgage_application_user_mail_subject', 'mortgage_application_use_network_settings' );
			$intro   = self::option( 'mortgage_application_user_mail_message', 'mortgage_application_use_network_settings', 'html' );
			$subject = $subject ? $subject : __( 'We received your application', '1003-mortgage-application' );
			$intro   = trim( self::clean_template( (string) $intro ) );
			$intro   = '' !== $intro ? $intro : "Hi {first_name},\n\nThank you for your application. Here is what happens next.";
		}
		$lo      = LoanOfficers::profile( (int) get_post_meta( $id, 'mapp_lo_id', true ) );
		$headers = $lo ? self::reply_to( $lo['name'], $lo['email'] ) : array();
		self::send( $to, self::fill_text( $id, $subject ), self::render( $id, $intro . "\n\n{receipt}", 'borrower', 'submitted', array( '{receipt}' => self::receipt_body( $id, $es, $lo ) ) ), $headers );
	}

	/**
	 * @param int        $id Application ID.
	 * @param bool       $es Spanish.
	 * @param array|null $lo LO profile.
	 * @return string HTML.
	 */
	private static function receipt_body( $id, $es, $lo ) {
		$t = function ( $en, $sp ) use ( $es ) {
			return $es ? $sp : $en;
		};
		$h = function ( $text ) {
			return '<p style="margin:28px 0 10px;font-size:15px;line-height:22px;font-weight:600;color:#202124">' . esc_html( $text ) . '</p>';
		};
		$link = Layout::accent();
		$when = (int) get_post_meta( $id, 'mapp_submitted_at', true );
		$when = $when ? $when : time();

		// Confirmation.
		$out  = '<table role="presentation" cellpadding="0" cellspacing="0" width="100%" style="border:1px solid #efefef;border-radius:12px;margin:8px 0 0"><tr><td style="padding:18px 20px">';
		$out .= '<p style="margin:0;font-size:18px;line-height:24px;font-weight:600;color:#202124">&#10003; ' . esc_html( $t( 'Application received', 'Solicitud recibida' ) ) . '</p>';
		$out .= '<p style="margin:4px 0 0;font-size:13px;color:#5f6368">' . esc_html( $t( 'Submitted', 'Enviada el' ) . ' ' . wp_date( 'm-d-Y', $when ) . ' · ' . $t( 'Reference', 'Referencia' ) . ' #' . (int) $id ) . '</p>';
		$out .= '</td></tr></table>';

		// Numbers.
		$rows = \Mapp\Application\Numbers::rows( $id, $es ? 'es' : 'en' );
		if ( $rows ) {
			$out .= $h( $t( 'Your numbers', 'Sus números' ) ) . self::numbers_table( $rows );
			$out .= '<p style="margin:8px 0 0;font-size:12px;color:#5f6368">' . esc_html( $t( 'Estimates from your answers, not a loan offer or a commitment to lend.', 'Estimados según sus respuestas; no son una oferta ni un compromiso de préstamo.' ) ) . '</p>';
		}

		// Next steps.
		$steps   = array();
		$steps[] = $lo
			? sprintf( $t( '%s reviews your application and reaches out.', '%s revisa su solicitud y se comunica con usted.' ), esc_html( $lo['name'] ) ) . ( '' !== $lo['phone'] ? ' <a href="tel:' . esc_attr( preg_replace( '/\D/', '', $lo['phone'] ) ) . '" style="color:' . esc_attr( $link ) . '">' . esc_html( $lo['phone'] ) . '</a>' : '' )
			: esc_html( $t( 'Your loan officer reviews your application and reaches out.', 'Su oficial de préstamos revisa su solicitud y se comunica con usted.' ) );
		$docs = \Mapp\Files\Store::checklist( $id, $es ? 'es' : 'en' );
		$have = wp_list_pluck( Store::files_for( $id ), 'doc_type' );
		$list = '';
		foreach ( $docs as $type => $name ) {
			$done  = in_array( $type, $have, true );
			$list .= '<li style="margin:0 0 4px;color:' . ( $done ? '#5f6368' : '#202124' ) . '">' . esc_html( $name ) . ( $done ? ' <span style="color:#1e7d3a">(' . esc_html( $t( 'received', 'recibido' ) ) . ')</span>' : '' ) . '</li>';
		}
		$steps[] = esc_html( $t( 'Send your documents. These speed things up:', 'Envíe sus documentos. Estos agilizan el proceso:' ) ) . '<ul style="margin:8px 0 0;padding-left:18px">' . $list . '</ul>';
		if ( ! in_array( Repository::stage( $id ), array( Repository::STAGE_FULL_SUBMITTED ), true ) ) {
			$steps[] = esc_html( $t( 'Finish the full application when you are ready. It takes about 15 minutes and saves as you go.', 'Termine la solicitud completa cuando quiera. Toma unos 15 minutos y se guarda sola.' ) );
		}
		$out .= $h( $t( 'What happens next', 'Lo que sigue' ) ) . '<table role="presentation" cellpadding="0" cellspacing="0" width="100%" style="border-collapse:collapse">';
		foreach ( $steps as $n => $step ) {
			$out .= '<tr><td width="36" style="width:36px;padding:0 0 16px;vertical-align:top"><div style="width:26px;height:26px;line-height:26px;border-radius:13px;border:1px solid #dadce0;text-align:center;font-size:13px;font-weight:600;color:#202124">' . ( (int) $n + 1 ) . '</div></td><td style="padding:3px 0 16px;vertical-align:top;font-size:15px;line-height:22px;color:#202124">' . $step . '</td></tr>';
		}
		$out .= '</table>';

		// One token, two places: the document checklist, or where they left off.
		$token   = \Mapp\Application\Tokens::issue( $id, 'link' );
		$buttons = Layout::button( \Mapp\Rest\Controller::resume_url( $id, $token, 'docs' ), $t( 'Upload your documents', 'Suba sus documentos' ) );
		$more    = array();
		if ( Repository::STAGE_FULL_SUBMITTED !== Repository::stage( $id ) ) {
			$more[ $t( 'Continue the full application', 'Continuar la solicitud completa' ) ] = \Mapp\Rest\Controller::resume_url( $id, $token );
		}
		if ( $lo && '' !== $lo['booking_url'] ) {
			/* translators: %s: LO first name */
			$more[ sprintf( $t( 'Book a call with %s', 'Agende una llamada con %s' ), strtok( $lo['name'], ' ' ) ) ] = $lo['booking_url'];
		}
		$out .= $buttons . Layout::buttons( $more );
		$out .= '<p style="margin:8px 0 0;font-size:12px;color:#5f6368">' . esc_html( sprintf( $t( 'The link opens your application and works for %d days. Keep this email.', 'El enlace abre su solicitud y funciona por %d días. Guarde este correo.' ), round( \Mapp\Application\Tokens::lifetime() / DAY_IN_SECONDS ) ) ) . '</p>';

		// Answers.
		$answers = self::answers_table( $id, 'borrower', $es ? 'es' : 'en' );
		if ( '' !== $answers ) {
			$out .= $h( $t( 'Your answers', 'Sus respuestas' ) ) . $answers;
		}
		return $out;
	}

	/**
	 * Numbers as a table, the first (the one that matters) large.
	 *
	 * @param array $rows [ label, value ] rows.
	 * @return string
	 */
	private static function numbers_table( $rows ) {
		$out = '';
		foreach ( array_values( $rows ) as $i => $row ) {
			if ( 0 === $i ) {
				$out .= '<tr><td colspan="2" style="padding:16px 18px 14px;border-bottom:1px solid #efefef"><span style="display:block;font-size:13px;color:#5f6368">' . esc_html( $row[0] ) . '</span><span style="display:block;font-size:28px;line-height:34px;font-weight:600;color:#202124">' . esc_html( $row[1] ) . '</span></td></tr>';
				continue;
			}
			$out .= '<tr><td style="padding:12px 12px 12px 18px;border-bottom:1px solid #efefef;color:#5f6368;font-size:14px">' . esc_html( $row[0] ) . '</td><td style="padding:12px 18px 12px 0;border-bottom:1px solid #efefef;color:#202124;font-weight:600;text-align:right;font-size:14px">' . esc_html( $row[1] ) . '</td></tr>';
		}
		return '<table role="presentation" cellpadding="0" cellspacing="0" width="100%" style="border-collapse:separate;border:1px solid #efefef;border-radius:12px">' . $out . '</table>';
	}

	/**
	 * The borrower's results after the contact step, with a link to continue.
	 *
	 * @param int $id Application ID.
	 */
	public static function borrower_numbers( $id ) {
		$to   = sanitize_email( (string) get_post_meta( $id, 'email', true ) );
		$es   = 'es' === get_post_meta( $id, 'mapp_lang', true );
		$rows = \Mapp\Application\Numbers::rows( $id, $es ? 'es' : 'en' );
		if ( ! $to || ! $rows ) {
			return;
		}
		$table   = self::numbers_table( $rows );
		$url     = \Mapp\Rest\Controller::resume_url( $id, \Mapp\Application\Tokens::issue( $id, 'link' ) );
		$message = $es
			? "Hola {first_name},\n\nEstos son los números de su solicitud:\n\n{numbers}\n\nSolo son estimados, no una oferta ni un compromiso de préstamo.\n\nSu solicitud está guardada. Continúe cuando quiera:\n\n{resume_button}"
			: "Hi {first_name},\n\nHere are the numbers from your application:\n\n{numbers}\n\nThese are estimates, not a loan offer or a commitment to lend.\n\nYour application is saved. Pick up where you left off any time:\n\n{resume_button}";
		$lo      = LoanOfficers::profile( (int) get_post_meta( $id, 'mapp_lo_id', true ) );
		self::send(
			$to,
			$es ? 'Sus números hipotecarios' : 'Your mortgage numbers',
			self::render(
				$id,
				$message,
				'borrower',
				'contact',
				array(
					'{numbers}'       => $table,
					'{resume_button}' => self::button( $url, $es ? 'Continuar mi solicitud' : 'Continue my application' ),
				)
			),
			$lo ? self::reply_to( $lo['name'], $lo['email'] ) : array()
		);
	}

	/**
	 * Email the borrower a resume link.
	 *
	 * @param int    $id  Application ID.
	 * @param string $url Resume URL with token.
	 */
	public static function resume_link( $id, $url ) {
		$to = sanitize_email( (string) get_post_meta( $id, 'email', true ) );
		if ( ! $to ) {
			return;
		}
		$es      = 'es' === get_post_meta( $id, 'mapp_lang', true );
		$subject = $es ? 'Continúe su solicitud' : 'Pick up where you left off';
		$message = $es
			? "Hola {first_name},\n\nUse este enlace para continuar su solicitud donde la dejó:\n\n{resume_button}\n\nEl enlace vence en {resume_days} días. Si usted no lo pidió, puede ignorar este correo."
			: "Hi {first_name},\n\nUse this link to continue your application where you left off:\n\n{resume_button}\n\nThe link expires in {resume_days} days. If you did not ask for it, you can ignore this email.";
		self::send( $to, $subject, self::render( $id, $message, 'borrower', 'resume', array( '{resume_button}' => self::button( $url, $es ? 'Continuar mi solicitud' : 'Continue my application' ) ) ) );
	}

	/**
	 * Reminder for an application left at the contact stage.
	 *
	 * @param int    $id  Application ID.
	 * @param string $url Resume URL with token.
	 */
	public static function reminder( $id, $url ) {
		$to = sanitize_email( (string) get_post_meta( $id, 'email', true ) );
		if ( ! $to ) {
			return;
		}
		$es      = 'es' === get_post_meta( $id, 'mapp_lang', true );
		$subject = self::option( 'mortgage_application_reminder_mail_subject', 'mortgage_application_use_network_settings' );
		$message = self::option( 'mortgage_application_reminder_mail_message', 'mortgage_application_use_network_settings', 'html' );
		$message = self::clean_template( $message );
		if ( $es || '' === trim( wp_strip_all_tags( $message ) ) ) {
			$subject = $es ? 'Su solicitud está casi lista' : ( $subject ? $subject : 'Your application is almost done' );
			$message = $es
				? "Hola {first_name},\n\nSu solicitud está guardada. Termínela en un par de minutos."
				: "Hi {first_name},\n\nYour application is saved. You can finish it in a couple of minutes.";
		}
		// The button always follows the text.
		$message .= "\n\n{edit_url}";
		self::send( $to, self::fill_text( $id, $subject ), self::render( $id, $message, 'borrower', 'reminder', array( '{edit_url}' => self::button( $url, $es ? 'Terminar mi solicitud' : 'Finish my application' ) ) ), self::lo_reply_to( $id ) );
	}

	/**
	 * Reminder for a full 1003 that was started and left (built-in text).
	 *
	 * @param int    $id  Application ID.
	 * @param string $url Resume URL with token.
	 */
	public static function full_reminder( $id, $url ) {
		$to = sanitize_email( (string) get_post_meta( $id, 'email', true ) );
		if ( ! $to ) {
			return;
		}
		$es      = 'es' === get_post_meta( $id, 'mapp_lang', true );
		$subject = $es ? 'Termine su solicitud completa' : 'Finish your full application';
		$message = $es
			? "Hola {first_name},\n\nSu solicitud completa está guardada, con todas sus respuestas. Continúe donde la dejó:\n\n{edit_url}\n\nSi tiene preguntas, responda a este correo."
			: "Hi {first_name},\n\nYour full application is saved with everything you have answered so far. Pick up where you left off:\n\n{edit_url}\n\nQuestions? Just reply to this email.";
		self::send( $to, $subject, self::render( $id, $message, 'borrower', 'reminder', array( '{edit_url}' => self::button( $url, $es ? 'Continuar mi solicitud' : 'Finish my full application' ) ) ), self::lo_reply_to( $id ) );
	}

	/**
	 * Reply-To the application's loan officer, if it has one.
	 *
	 * @param int $id Application ID.
	 * @return string[]
	 */
	private static function lo_reply_to( $id ) {
		$lo = LoanOfficers::profile( (int) get_post_meta( $id, 'mapp_lo_id', true ) );
		return $lo ? self::reply_to( $lo['name'], $lo['email'] ) : array();
	}

	/**
	 * Fill placeholders and wrap in the email layout.
	 *
	 * Order matters: the template (admin-written or built in) gets paragraphs
	 * and kses first; then placeholders are filled, borrower values escaped;
	 * generated tables and buttons go in last, untouched.
	 *
	 * @param int    $id        Application ID.
	 * @param string $message   Template (HTML or text).
	 * @param string $audience  lo | borrower.
	 * @param string $milestone Milestone.
	 * @param array  $extra     More placeholder => HTML.
	 * @return string HTML.
	 */
	private static function render( $id, $message, $audience, $milestone, $extra = array() ) {
		$lang = 'borrower' === $audience && 'es' === get_post_meta( $id, 'mapp_lang', true ) ? 'es' : 'en';
		$lo   = LoanOfficers::profile( (int) get_post_meta( $id, 'mapp_lo_id', true ) );

		$message = trim( (string) $message );
		if ( ! preg_match( '/<(p|div|table|br|ul|ol|h[1-6])\b/i', $message ) ) {
			$message = wpautop( $message );
		}
		$message = wp_kses_post( $message );

		$replace = array_merge(
			array(
				'{first_name}'     => esc_html( (string) get_post_meta( $id, 'first_name', true ) ),
				'{last_name}'      => esc_html( (string) get_post_meta( $id, 'last_name', true ) ),
				'{email}'          => esc_html( (string) get_post_meta( $id, 'email', true ) ),
				'{all_fields}'     => self::answers_table( $id, $audience, $lang ),
				'{documents}'      => self::documents_list( $id, 'documents' === $milestone ),
				'{lo_name}'        => $lo ? esc_html( $lo['name'] ) : '',
				'{lo_phone}'       => $lo ? esc_html( $lo['phone'] ) : '',
				'{lo_email}'       => $lo ? esc_html( $lo['email'] ) : '',
				'{lo_nmls}'        => $lo ? esc_html( $lo['nmls'] ) : '',
				'{resume_days}'    => (string) round( \Mapp\Application\Tokens::lifetime() / DAY_IN_SECONDS ),
				'{admin_url}'      => esc_url( admin_url( 'post.php?post=' . (int) $id . '&action=edit' ) ),
				'{application_id}' => (string) (int) $id,
			),
			$extra
		);
		$message = strtr( $message, $replace );
		// Export buttons (Pro license). Templates may place them; LO alerts get
		// the row anyway. Unlicensed: the placeholders are dropped.
		$exports = 'lo' === $audience ? self::export_links( $id ) : array();
		$intro   = '<p style="margin:24px 0 0;font-size:13px;color:#5f6368">Download for your LOS (built from the latest answers when you click; sign in as an administrator):</p>';
		$tags    = array( '{mismo_file_url}' => 'MISMO 3.4', '{fnm_file_url}' => 'FNM 3.2', '{csv_file_url}' => 'CSV' );
		$first   = null;
		$named   = array();
		foreach ( $tags as $tag => $label ) {
			$at = strpos( $message, $tag );
			if ( false !== $at ) {
				$named[ $label ] = isset( $exports[ $label ] ) ? $exports[ $label ] : null;
				$first           = null === $first ? $at : min( $first, $at );
			}
		}
		$placed = (bool) $named;
		if ( $placed ) {
			// The template's export tags become one row, where the first one was.
			$row     = array_filter( $named );
			$message = substr_replace( $message, '{mapp_exports}', $first, 0 );
			$message = str_replace( array_keys( $tags ), '', $message );
			$message = str_replace( '{mapp_exports}', $row ? $intro . Layout::buttons( $row ) : '', $message );
			$message = preg_replace( '#<p>(\s|&nbsp;|<br\s*/?>)*</p>#i', '', $message );
		}
		$message = str_replace( '{edit_url}', '', $message );

		if ( 'lo' === $audience ) {
			$message = self::summary( $id, $milestone ) . $message;
			if ( $exports && ! $placed && in_array( $milestone, array( 'submitted', 'full_submitted', 'documents' ), true ) ) {
				$message .= $intro . Layout::buttons( $exports );
			}
			$message .= '<div style="margin:24px 0 0">' . self::button( admin_url( 'post.php?post=' . (int) $id . '&action=edit' ), 'Open application' ) . '</div>';
		}
		return Layout::wrap( $message, $lo, $lang );
	}

	/**
	 * The LO's at-a-glance block: who, how to reach them, what they want.
	 *
	 * @param int    $id        Application ID.
	 * @param string $milestone Milestone.
	 * @return string
	 */
	private static function summary( $id, $milestone ) {
		$get    = function ( $key ) use ( $id ) {
			return (string) get_post_meta( $id, $key, true );
		};
		$stages = array(
			'contact'        => 'In progress (contact saved)',
			'submitted'      => 'Short app submitted',
			'full_submitted' => 'Full 1003 submitted',
			'documents'      => 'Documents uploaded',
		);
		$link   = Layout::accent();
		$name   = trim( $get( 'first_name' ) . ' ' . $get( 'last_name' ) );
		$phone  = $get( 'phone_number' );
		$email  = $get( 'email' );
		$facts  = array_filter(
			array(
				'Home Purchase' === $get( 'purpose' ) ? 'Purchase' : ( 'Home Refinance' === $get( 'purpose' ) ? 'Refinance' : '' ),
				'' !== $get( 'loan_amount' ) ? '$' . number_format( (float) $get( 'loan_amount' ) ) . ' estimated loan' : '',
				Schema::display_value( 'credit_rating', $get( 'credit_rating' ) ),
				$get( 'property_city' ) ? $get( 'property_city' ) . ( $get( 'property_state' ) ? ', ' . $get( 'property_state' ) : '' ) : '',
			)
		);
		$source = $get( 'mapp_utm_source' );
		$out    = '<p style="margin:0 0 4px;font-size:12px;color:#5f6368">' . esc_html( isset( $stages[ $milestone ] ) ? $stages[ $milestone ] : '' ) . '</p>';
		$out   .= '<p style="margin:0 0 12px;font-size:20px;line-height:26px;font-weight:600;color:#202124">' . esc_html( '' !== $name ? $name : 'New applicant' ) . '</p>';
		$lines  = array();
		if ( '' !== $phone ) {
			$lines[] = '<a href="tel:' . esc_attr( preg_replace( '/\D/', '', $phone ) ) . '" style="color:' . esc_attr( $link ) . '">' . esc_html( $phone ) . '</a>';
		}
		if ( '' !== $email ) {
			$lines[] = '<a href="mailto:' . esc_attr( $email ) . '" style="color:' . esc_attr( $link ) . '">' . esc_html( $email ) . '</a>';
		}
		if ( $lines ) {
			$out .= '<p style="margin:0 0 8px">' . implode( ' &middot; ', $lines ) . '</p>';
		}
		if ( $facts ) {
			$out .= '<p style="margin:0 0 8px;color:#202124">' . esc_html( implode( ' · ', $facts ) ) . '</p>';
		}
		if ( 'yes' !== $get( 'consent_tcpa' ) ) {
			$out .= '<p style="margin:0 0 8px;color:#b3261e;font-size:13px">No call/text consent given: email only, or call manually.</p>';
		}
		if ( '' !== $source ) {
			$out .= '<p style="margin:0 0 8px;color:#5f6368;font-size:13px">Source: ' . esc_html( $source ) . '</p>';
		}
		return $out . '<hr style="border:0;border-top:1px solid #efefef;margin:16px 0">';
	}

	/**
	 * Subject placeholders (plain text).
	 *
	 * @param int    $id      Application ID.
	 * @param string $subject Subject.
	 * @return string
	 */
	private static function fill_text( $id, $subject ) {
		return trim(
			strtr(
				$subject,
				array(
					'{first_name}' => (string) get_post_meta( $id, 'first_name', true ),
					'{last_name}'  => (string) get_post_meta( $id, 'last_name', true ),
					'{email}'      => (string) get_post_meta( $id, 'email', true ),
				)
			)
		);
	}

	/**
	 * Every answer as a two-column table. SSNs are masked; borrowers see the
	 * questions as they were asked, LOs see short labels.
	 *
	 * @param int    $id       Application ID.
	 * @param string $audience lo | borrower.
	 * @param string $lang     Language.
	 * @return string
	 */
	public static function answers_table( $id, $audience, $lang ) {
		$answers = Repository::answers( $id, 'lo' === $audience );
		$rows    = '';
		foreach ( array( 'short', 'contact', 'final', 'full' ) as $stage ) {
			foreach ( Schema::questions_in( $stage ) as $key => $def ) {
				if ( ! isset( $answers[ $key ] ) || 'consent' === $def['type'] || ! Schema::is_visible( $key, $answers ) ) {
					continue;
				}
				$value = Schema::display_value( $key, $answers[ $key ], $lang );
				if ( '' === $value ) {
					continue;
				}
				$label = 'lo' === $audience ? Schema::admin_label( $key ) : Schema::text( $def['label'], $lang );
				$rows .= '<tr><td style="padding:8px 12px 8px 0;border-bottom:1px solid #efefef;color:#5f6368;vertical-align:top;width:45%">' . esc_html( $label ) . '</td>'
					. '<td style="padding:8px 0;border-bottom:1px solid #efefef;color:#202124;vertical-align:top">' . nl2br( esc_html( $value ) ) . '</td></tr>';
			}
		}
		$loan_amount = get_post_meta( $id, 'loan_amount', true );
		if ( '' !== $loan_amount && 'lo' === $audience ) {
			$rows .= '<tr><td style="padding:8px 12px 8px 0;color:#5f6368">Estimated loan amount</td><td style="padding:8px 0;color:#202124">$' . esc_html( number_format( (float) $loan_amount ) ) . '</td></tr>';
		}
		return $rows ? '<table role="presentation" cellpadding="0" cellspacing="0" width="100%" style="border-collapse:collapse;font-size:14px;line-height:20px">' . $rows . '</table>' : '';
	}

	/**
	 * Signed download links for the application's documents.
	 *
	 * @param int  $id         Application ID.
	 * @param bool $this_batch Only the batch just sent (the documents alert).
	 * @return string
	 */
	private static function documents_list( $id, $this_batch = false ) {
		$batch   = (int) get_post_meta( $id, 'mapp_documents_batch', true );
		$items   = '';
		$earlier = 0;
		foreach ( Store::files_for( $id ) as $file_id => $file ) {
			if ( $this_batch && $batch && (int) ( isset( $file['batch'] ) ? $file['batch'] : 0 ) !== $batch ) {
				++$earlier;
				continue;
			}
			$type   = isset( $file['doc_type'] ) && '' !== $file['doc_type'] ? Store::doc_label( $file['doc_type'] ) : '';
			$items .= '<tr><td style="padding:10px 12px 10px 0;border-bottom:1px solid #efefef;vertical-align:top"><a href="' . esc_url( Store::signed_url( $id, $file_id, 'email' ) ) . '" style="color:' . esc_attr( Layout::accent() ) . ';font-weight:600">' . esc_html( $file['name'] ) . '</a>' . ( '' !== $type ? '<br><span style="color:#5f6368;font-size:13px">' . esc_html( $type ) . '</span>' : '' ) . '</td><td style="padding:10px 0;border-bottom:1px solid #efefef;color:#5f6368;font-size:13px;text-align:right;vertical-align:top;white-space:nowrap">' . esc_html( size_format( $file['size'] ) ) . '</td></tr>';
		}
		if ( '' === $items ) {
			return '';
		}
		$out = '<table role="presentation" cellpadding="0" cellspacing="0" width="100%" style="border-collapse:collapse;font-size:14px">' . $items . '</table>';
		if ( $earlier ) {
			/* translators: %d: count */
			$out .= '<p style="color:#5f6368;font-size:13px;margin:10px 0 0">' . esc_html( sprintf( _n( '%d earlier file is on the application.', '%d earlier files are on the application.', $earlier, '1003-mortgage-application' ), $earlier ) ) . '</p>';
		}
		/* translators: %d: days */
		return $out . '<p style="color:#5f6368;font-size:12px;margin:10px 0 0">' . esc_html( sprintf( __( 'Links expire in %d days.', '1003-mortgage-application' ), Store::link_days() ) ) . '</p>';
	}

	/**
	 * @param string $url   URL.
	 * @param string $label Label.
	 * @return string
	 */
	public static function button( $url, $label ) {
		return Layout::button( $url, $label );
	}

	/**
	 * Export downloads for the LO alert (added by the Pro module). The links
	 * run the export when clicked, so the file always has the latest answers;
	 * the handler requires a signed-in administrator.
	 *
	 * @param int $id Application ID.
	 * @return array Label => URL.
	 */
	public static function export_links( $id ) {
		if ( ! function_exists( 'mapp_generate_export_token' ) ) {
			return array();
		}
		$base = add_query_arg(
			array(
				'action'       => 'mortgage_application_export_applications',
				'post'         => (int) $id,
				'export_token' => mapp_generate_export_token( $id ),
			),
			admin_url( 'admin-post.php' )
		);
		return (array) apply_filters( 'mapp_email_export_links', array(), $id, $base );
	}

	/**
	 * A Reply-To header with a quoted display name.
	 *
	 * @param string $name  Name.
	 * @param string $email Email.
	 * @return string[]
	 */
	private static function reply_to( $name, $email ) {
		$email = sanitize_email( $email );
		if ( ! is_email( $email ) ) {
			return array();
		}
		$name = trim( str_replace( array( '"', "\r", "\n", '\\' ), '', (string) $name ) );
		return array( 'Reply-To: ' . ( '' !== $name ? '"' . $name . '" ' : '' ) . '<' . $email . '>' );
	}

	/**
	 * Send with the 2.6 From / Reply-To settings. Not through 2.6's
	 * mortgage_mail(): its wp_kses_post pass strips the <head> (charset,
	 * color-scheme) and Outlook markup. Template text is kses'd in render().
	 *
	 * @param string $to      Recipients.
	 * @param string $subject Subject.
	 * @param string $html    Body.
	 * @param array  $headers Headers.
	 * @return bool
	 */
	public static function send( $to, $subject, $html, $headers = array() ) {
		if ( null !== self::$redirect ) {
			$to      = self::$redirect;
			$subject = '[TEST] ' . $subject;
		}
		$from      = sanitize_email( self::option( 'mortgage_application_mail_from', 'mortgage_application_use_network_settings' ) );
		$from      = is_email( $from ) ? $from : (string) get_option( 'admin_email' );
		$from_name = trim( str_replace( array( '"', "\r", "\n" ), '', sanitize_text_field( self::option( 'mortgage_application_mail_from_name', 'mortgage_application_use_network_settings' ) ) ) );
		$from_name = '' !== $from_name ? $from_name : get_bloginfo( 'name' );
		if ( ! preg_grep( '/^Reply-To:/i', $headers ) ) {
			$reply = sanitize_email( self::option( 'mortgage_application_mail_reply_to', 'mortgage_application_use_network_settings' ) );
			if ( is_email( $reply ) ) {
				$headers[] = 'Reply-To: <' . $reply . '>';
			}
		}
		$headers[] = 'From: "' . $from_name . '" <' . $from . '>';
		$headers[] = 'Content-Type: text/html; charset=UTF-8';
		$subject   = str_replace( array( "\r", "\n" ), ' ', wp_strip_all_tags( $subject ) );
		$sent      = wp_mail( $to, $subject, $html, $headers );
		self::$last_sent = (bool) $sent;
		if ( ! $sent && defined( 'WP_DEBUG' ) && WP_DEBUG ) {
			error_log( '1003 Mortgage Application: wp_mail returned false for "' . $subject . '"' ); // phpcs:ignore WordPress.PHP.DevelopmentFunctions
		}
		return (bool) $sent;
	}
}