<?php
/**
 * The e-mail the site owner gets when money arrives: once per payment and outcome.
 *
 * @package CryptowayButton
 */

namespace CryptowayButton;

defined( 'ABSPATH' ) || exit;

final class Email {

    /** Outcomes worth an e-mail: paid, and every status a person has to look at. */
    private const NOTIFY = [ Payment::STATUS_PAID, Payment::STATUS_UNDERPAID, Payment::STATUS_LATE, Payment::STATUS_AML, Payment::STATUS_HOLD ];

    private function __construct() {}

    public static function notify( Payment $payment, string $status ): void {
        if ( ! Settings::email_enabled() || ! in_array( $status, self::NOTIFY, true ) ) {
            return;
        }

        $sent = $payment->meta_array( Payment::META_EMAILED );

        if ( in_array( $status, $sent, true ) ) {
            return;
        }

        $sent[] = $status;
        $payment->set_meta( Payment::META_EMAILED, $sent );

        $to = Settings::email_to();

        if ( '' === $to ) {
            return;
        }

        $site    = wp_specialchars_decode( (string) get_option( 'blogname' ), ENT_QUOTES );
        $amount  = Amounts::fiat( $payment->amount(), $payment->currency() );
        $label   = Payment::status_label( $status );
        $manager = new PaymentManager( $payment );

        /* translators: 1: site name, 2: amount with currency, 3: status label */
        $subject = sprintf( __( '[%1$s] Crypto payment %2$s — %3$s', 'cryptoway-button' ), $site, $amount, $label );

        $lines   = [];
        $lines[] = sprintf(
            /* translators: 1: status label, 2: amount with currency, 3: what the payment is for */
            __( '%1$s: %2$s — %3$s', 'cryptoway-button' ),
            $label,
            $amount,
            $payment->title()
        );
        $lines[] = '';

        foreach ( $manager->amount_rows() as $row_label => $value ) {
            $lines[] = $row_label . ': ' . $value;
        }

        foreach ( $payment->payer() as $field => $value ) {
            $name = match ( $field ) {
                'name'    => __( 'Name', 'cryptoway-button' ),
                'email'   => __( 'E-mail', 'cryptoway-button' ),
                default   => __( 'Message', 'cryptoway-button' ),
            };
            $lines[] = $name . ': ' . $value;
        }

        $history = $payment->history();
        if ( $history ) {
            $lines[] = '';
            $lines[] = (string) end( $history )['m'];
        }

        $lines[] = '';
        $lines[] = __( 'Invoice', 'cryptoway-button' ) . ': ' . $payment->invoice_id();
        $lines[] = __( 'Payment', 'cryptoway-button' ) . ': ' . $payment->admin_url();

        self::send( $to, $subject, $lines, sprintf( 'the e-mail about payment #%d (%s)', $payment->id(), $status ) );
    }

    /**
     * wp_mail() with a log line when it fails: a site without working mail otherwise loses every
     * notice without a trace. The address is not logged.
     *
     * @param string[] $lines
     */
    private static function send( string $to, string $subject, array $lines, string $what ): void {
        if ( ! wp_mail( $to, $subject, implode( "\n", $lines ) ) ) {
            Log::write( sprintf( 'Could not send %s: wp_mail() failed. Check that this site can send e-mail.', $what ) );
        }
    }

    /**
     * To the payer, once, when a payment for paid content is confirmed and the payer left an
     * e-mail: the link that opens the content again on any device.
     */
    public static function payer( Payment $payment, string $status ): void {
        if ( Payment::STATUS_PAID !== $status || Button::AFTER_CONTENT !== $payment->after() ) {
            return;
        }

        $to = (string) ( $payment->payer()['email'] ?? '' );

        if ( '' === $to || ! is_email( $to ) ) {
            return;
        }

        $sent = $payment->meta_array( Payment::META_EMAILED );

        if ( in_array( 'payer', $sent, true ) ) {
            return;
        }

        $sent[] = 'payer';
        $payment->set_meta( Payment::META_EMAILED, $sent );

        self::access_link( $payment );
    }

    /**
     * The access-link mail itself: on confirmation, and again whenever the payer asks for it
     * under the button ("Already paid?"). The payer's e-mail was checked when the payment started.
     *
     * @param bool $again True when the payer asked for the link again: a subject that says so.
     */
    public static function access_link( Payment $payment, bool $again = false ): void {
        $to    = (string) ( $payment->payer()['email'] ?? '' );
        $until = Button::access_until( $payment );

        if ( '' === $to || ! is_email( $to ) || $until <= time() ) {
            return;
        }

        $site = wp_specialchars_decode( (string) get_option( 'blogname' ), ENT_QUOTES );

        $subject = $again
            /* translators: %s: site name */
            ? sprintf( __( '[%s] Your access link', 'cryptoway-button' ), $site )
            /* translators: %s: site name */
            : sprintf( __( '[%s] Your payment is confirmed', 'cryptoway-button' ), $site );

        $lines   = [];
        $lines[] = sprintf(
            /* translators: 1: what the payment is for, 2: amount with currency */
            __( 'Thank you! Your payment for "%1$s" (%2$s) is confirmed.', 'cryptoway-button' ),
            $payment->title(),
            Amounts::fiat( $payment->amount(), $payment->currency() )
        );
        $lines[] = '';
        $lines[] = __( 'Open what you paid for with this link (it works on any device):', 'cryptoway-button' );
        $lines[] = Checkout::done_url( $payment );
        $lines[] = '';
        /* translators: %s: date */
        $lines[] = sprintf( __( 'The link stays open until %s.', 'cryptoway-button' ), wp_date( (string) get_option( 'date_format' ), $until ) );

        self::send( $to, $subject, $lines, sprintf( 'the access link of payment #%d', $payment->id() ) );
    }
}