<?php

namespace com\fwdekker\deathnotifier\mailer;

use Exception;


/**
 * A serializable email that can be queued in a database and can be sent.
 *
 * When serialized, an email is represented by the type of email and two arguments. When deserialized, an email can be
 * constructed from those arguments, and the implementation returns a specific subject and message.
 */
abstract class Email
{
    /**
     * @var string A string identifying the type of email.
     */
    public string $type;
    /**
     * @var string The intended recipient of the email.
     */
    public string $recipient;
    /**
     * @var string The first argument to construct the email.
     */
    public string $arg1 = "";
    /**
     * @var string The second argument to construct the email.
     */
    public string $arg2 = "";


    /**
     * Returns the subject header of the email.
     *
     * @return string the subject header of the email
     */
    public abstract function getSubject(): string;

    /**
     * Returns the body of the email.
     *
     * @param array<string, array<string, mixed>> $config the software configuration
     * @return string the body of the email
     */
    public abstract function getBody(array $config): string;


    /**
     * Deserializes an email back into an instance.
     *
     * Only types of emails that are known can be deserialized.
     *
     * @param string $type the type of email to deserialize
     * @param string $recipient the intended recipient of the email
     * @param string $arg1 the first argument to construct the email
     * @param string $arg2 the second argument to construct the email
     * @return Email a deserialized email
     * @throws Exception if the `type` is not recognized
     */
    public static function deserialize(string $type, string $recipient, string $arg1, string $arg2): Email
    {
        return match ($type) {
            RegisterEmail::TYPE => new RegisterEmail($recipient, $arg1),
            VerifyEmailEmail::TYPE => new VerifyEmailEmail($recipient, $arg1),
            ChangedEmailEmail::TYPE => new ChangedEmailEmail($recipient, $arg1),
            ChangedPasswordEmail::TYPE => new ChangedPasswordEmail($recipient),
            ResetPasswordEmail::TYPE => new ResetPasswordEmail($recipient, $arg1),
            NotifyArticleDeletedEmail::TYPE => new NotifyArticleDeletedEmail($recipient, $arg1),
            NotifyArticleUndeletedEmail::TYPE => new NotifyArticleUndeletedEmail($recipient, $arg1),
            NotifyStatusChangedEmail::TYPE => new NotifyStatusChangedEmail($recipient, $arg1, $arg2),
            default => throw new Exception("Unknown email type $type."),
        };
    }
}