<?php

namespace com\fwdekker\deathnotifier\mailer;

use com\fwdekker\deathnotifier\Action;
use com\fwdekker\deathnotifier\Config;
use com\fwdekker\deathnotifier\validator\EqualsCliSecretRule;
use com\fwdekker\deathnotifier\UnexpectedException;
use com\fwdekker\deathnotifier\validator\InvalidInputException;
use com\fwdekker\deathnotifier\validator\RuleSet;
use PHPMailer\PHPMailer\Exception as PHPMailerException;
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\SMTP;


/**
 * Sends all emails in an {@see EmailQueue}.
 */
class ProcessEmailQueueAction extends Action
{
    /**
     * @var EmailQueue the `EmailQueue` of which all emails should be sent
     */
    private readonly EmailQueue $email_queue;


    /**
     * Constructs a new `ProcessEmailQueueAction`.
     *
     * @param EmailQueue $email_queue the `EmailQueue` of which all emails should be sent
     */
    public function __construct(EmailQueue $email_queue)
    {
        $this->email_queue = $email_queue;
    }


    /**
     * Sends all emails in the {@see $email_queue}.
     *
     * @param array<int|string, mixed> $inputs `"password": string`: the CLI password
     * @return null
     * @throws InvalidInputException if the CLI password is wrong
     * @throws UnexpectedException if the mailer fails to send an email
     */
    public function handle(array $inputs): mixed
    {
        (new RuleSet(["password" => [new EqualsCliSecretRule()]]))->check($inputs);

        $mailer = $this->create_mailer();
        $emails = $this->email_queue->get_queue();
        foreach ($emails as $email) {
            $mailer->Subject = $email["subject"];
            $mailer->Body = $email["body"];

            try {
                $mailer->addAddress($email["recipient"]);
                $mailer->send();
            } catch (PHPMailerException $exception) {
                $mailer->getSMTPInstance()->reset();
                throw new UnexpectedException("Failed to send email.", previous: $exception);
            }

            $mailer->clearAddresses();
        }
        $this->email_queue->unqueue_emails($emails);

        return null;
    }


    /**
     * Creates a {@see PHPMailer} to send emails with.
     *
     * @throws UnexpectedException if the {@see PHPMailer} could not be created
     */
    private function create_mailer(): PHPMailer
    {
        $config = Config::get();

        $mailer = new PHPMailer();
        $mailer->IsSMTP();
        $mailer->CharSet = "UTF-8";

        $mailer->SMTPAuth = true;
        $mailer->SMTPDebug = SMTP::DEBUG_OFF;
        $mailer->SMTPKeepAlive = true;
        $mailer->SMTPSecure = PHPMailer::ENCRYPTION_SMTPS;
        $mailer->Host = $config["mail"]["host"];
        $mailer->Port = $config["mail"]["port"];
        $mailer->Username = $config["mail"]["username"];
        $mailer->Password = $config["mail"]["password"];
        try {
            $mailer->setFrom($config["mail"]["username"], $config["mail"]["from_name"]);
        } catch (PHPMailerException $exception) {
            $mailer->smtpClose();
            throw new UnexpectedException(
                "Failed to set 'from' address while processing email queue.",
                previous: $exception
            );
        }

        return $mailer;
    }
}