<?php

namespace com\fwdekker\deathnotifier\user;

use com\fwdekker\deathnotifier\Action;
use com\fwdekker\deathnotifier\Config;
use com\fwdekker\deathnotifier\mailer\Email;
use com\fwdekker\deathnotifier\mailer\EmailQueue;
use com\fwdekker\deathnotifier\tracking\TrackingList;
use com\fwdekker\deathnotifier\UnexpectedException;
use com\fwdekker\deathnotifier\validation\InvalidTypeException;
use com\fwdekker\deathnotifier\validation\InvalidValueException;
use com\fwdekker\deathnotifier\validation\IsEmailRule;
use com\fwdekker\deathnotifier\validation\IsValidCsrfTokenRule;
use com\fwdekker\deathnotifier\validation\RuleSet;
use com\fwdekker\deathnotifier\validation\LoginValidator;


/**
 * Changes the user's email address and sends the user a verification link.
 *
 * @see ChangeEmailFromEmail
 * @see ChangeEmailToEmail
 */
class ChangeEmailAction extends Action
{
    /**
     * @var UserList the list to change the user's email address in
     */
    private readonly UserList $user_list;
    /**
     * @var EmailQueue the queue to add notifications to
     */
    private readonly EmailQueue $email_queue;


    /**
     * Constructs a new `ChangeEmailAction`.
     *
     * @param UserList $user_list the list to change the user's email address in
     * @param EmailQueue $email_queue the queue to add notifications to
     */
    public function __construct(UserList $user_list, EmailQueue $email_queue)
    {
        $this->user_list = $user_list;
        $this->email_queue = $email_queue;
    }


    /**
     * Changes the user's email address and sends the user a verification link.
     *
     * Requires that the user is logged in and that a valid CSRF token is present.
     *
     * @param array<int|string, mixed> $inputs `"token": string`: a valid CSRF token, `"email": string`: the new email
     * address
     * @return null
     * @throws InvalidTypeException if any of the inputs has the incorrect type
     * @throws InvalidValueException if the user is not logged in, if no valid CSRF token is present, if the email
     * address is invalid, if the email address is not different, or if the email address is already used
     * @throws UnexpectedException if the current user has been deleted
     * @noinspection PhpDocRedundantThrowsInspection can be thrown through {@see TrackingList::transaction()}
     */
    public function handle(array $inputs): mixed
    {
        (new LoginValidator(validate_logged_in: true))->check($_SESSION);
        (new RuleSet([
            "token" => [new IsValidCsrfTokenRule()],
            "email" => [new IsEmailRule()],
        ]))->check($inputs);

        $this->user_list->transaction(function () use ($inputs) {
            $user_data = $this->user_list->get_user_by_uuid($_SESSION["uuid"]);
            if ($user_data === null)
                throw new UnexpectedException("Failed to retrieve user data. Please refresh the page and try again.");
            if ($inputs["email"] === $user_data["email"])
                throw new InvalidValueException("That is already your email address.", "email");
            if ($this->user_list->has_user_with_email($inputs["email"]))
                throw new InvalidValueException("That email address is already in use by someone else.", "email");

            $token = $this->user_list->set_email($_SESSION["uuid"], $inputs["email"]);
            $this->email_queue->queue_emails([
                new ChangeEmailFromEmail($user_data["email"], $inputs["email"]),
                new ChangeEmailToEmail($inputs["email"], $user_data["email"], $token)
            ]);
        });

        return null;
    }
}


/**
 * An email informing a user that their email has been changed and needs to be verified, sent to the user's old email
 * address.
 *
 * @see ChangeEmailAction
 */
class ChangeEmailFromEmail extends Email
{
    /**
     * A string identifying the type of email.
     */
    public const TYPE = "changed-email-from";

    /**
     * @var string the new email address
     */
    public readonly string $new_email;


    /**
     * Constructs a new `ChangeEmailFromEmail`.
     *
     * @param string $recipient the intended recipient of the email
     * @param string $new_email the new email address
     */
    public function __construct(string $recipient, string $new_email)
    {
        parent::__construct($this::TYPE, $recipient);

        $this->new_email = $new_email;
    }


    public function get_subject(): string
    {
        return "Your email address has been changed";
    }

    public function get_body(): string
    {
        $base_path = Config::get("server.base_path");

        return
            "You changed the email address of your Death Notifier account from $this->recipient to $this->new_email. " .
            "Until you verify your email address, you will not receive any notifications on either email address. " .
            "Check the inbox of $this->new_email for a verification link." .
            "\n\n" .
            "If you did not request a change of email address, log in at the Death Notifier website, change your " .
            "password, and change your email address back." .
            "\n\n" .
            $base_path;
    }
}

/**
 * An email informing a user that their email has been changed and needs to be verified, sent to the user's new email
 * address that needs to be verified.
 *
 * @see ChangeEmailAction
 */
class ChangeEmailToEmail extends Email
{
    /**
     * A string identifying the type of email.
     */
    public const TYPE = "changed-email-to";

    /**
     * @var string the old email address
     */
    public readonly string $old_email;
    /**
     * @var string the token to verify the email address with
     */
    public readonly string $token;


    /**
     * Constructs a new `ChangeEmailEmail`.
     *
     * @param string $recipient the intended recipient of the email
     * @param string $old_email the old email address
     * @param string $token the token to verify the email address with
     */
    public function __construct(string $recipient, string $old_email, string $token)
    {
        parent::__construct($this::TYPE, $recipient);

        $this->old_email = $old_email;
        $this->token = $token;
    }


    public function get_subject(): string
    {
        return "Verify your new email address";
    }

    public function get_body(): string
    {
        $base_path = Config::get("server.base_path");
        $verify_path = "$base_path?action=verify-email&email=" . rawurlencode($this->recipient) . "&token=$this->token";

        return
            "You changed the email address of your Death Notifier account from $this->old_email to $this->recipient. " .
            "Until you verify your email address, you will not receive any notifications. " .
            "You can verify your new email address by clicking the link below. " .
            "This link will expire after " . UserList::MINUTES_VALID_VERIFICATION . " minutes." .
            "\n" .
            "Verify: $verify_path" .
            "\n\n" .
            $base_path;
    }
}