<?php


use Gregwar\Captcha\CaptchaBuilder;
use Lewp\Resolve;

return new class extends Lewp\Module
{

    const KEY_CSRF_TOKEN = 'csrf_token';
    const KEY_CAPTCHA_PHRASE = 'captcha_phrase';

    private function createForm()
    {
        $form = $this->createAndSetupElement(
            'form',
            '',
            [
                'method' => 'post',
                'action' => '',
            ]
        );
        // LABEL NAME
        $label_name = $this->createAndSetupElement(
            'label',
            $this->loadTextFile(Resolve::arrayToId([
                $this->getLanguage(),
                'name'
            ])),
            [
                'for' => 'name',
            ]
        );
        $form->appendChild($label_name);
        // NAME INPUT
        $name = $this->createAndSetupElement(
            'input',
            '',
            [
                'id' => 'name',
                'name' => 'name',
                'type' => 'text',
                'value' => $_POST['name'] ?? '',
            ]
        );
        $form->appendChild($name);
        // LABEL Email
        $label_email = $this->createAndSetupElement(
            'label',
            $this->loadTextFile(Resolve::arrayToId([
                $this->getLanguage(),
                'email'
            ])),
            [
                'for' => 'email'
            ]
        );
        $form->appendChild($label_email);
        // EMAIL INPUT
        $email = $this->createAndSetupElement(
            'input',
            '',
            [
                'id' => 'email',
                'name' => 'email',
                'type' => 'email',
                'value' => $_POST['email'] ?? '',
            ]
        );
        $form->appendChild($email);
        // LABEL Message
        $label_message = $this->createAndSetupElement(
            'label',
            $this->loadTextFile(Resolve::arrayToId([
                $this->getLanguage(),
                'message'
            ])),
            [
                'for' => 'message'
            ]
        );
        $form->appendChild($label_message);
        // MESSAGE INPUT
        $message = $this->createAndSetupElement(
            'textarea',
            $_POST['message'] ?? '',
            [
                'id' => 'message',
                'name' => 'message',
            ]
        );
        $form->appendChild($message);
        // LABEL Captcha
        $label_captcha = $this->createAndSetupElement(
            'label',
            '',
            [
                'for' => self::KEY_CAPTCHA_PHRASE
            ]
        );
        $label_captcha->appendChild($this->generateCaptcha());
        $form->appendChild($label_captcha);
        // CAPTCHA INPUT
        $captcha = $this->createAndSetupElement(
            'input',
            '',
            [
                'id' => 'captchainput',
                'name' => self::KEY_CAPTCHA_PHRASE,
                'type' => 'text',
            ]
        );
        $form->appendChild($captcha);
        // SUBMIT BUTTON
        $submit = $this->createAndSetupElement(
            'button',
            $this->loadTextFile(Resolve::arrayToId([
                $this->getLanguage(),
                'submit'
            ])),
            [
                'id' => 'submit',
                'type' => 'submit',
            ]
        );
        $form->appendChild($submit);
        // ADD CSRF CHECK
        $form->appendChild($this->generateCsrfInput());
        return $form;
    }

    private function generateCsrfInput()
    {
        // create token and save to session
        $token = bin2hex(random_bytes(6));
        $this->getSession()->set(self::KEY_CSRF_TOKEN, $token);
        return $this->createAndSetupElement(
            'input',
            '',
            [
                'type' => 'hidden',
                'name' => self::KEY_CSRF_TOKEN,
                'value' => $token,
            ]
        );
    }

    private function validateCsrfInput() : bool
    {
        if (!$this->formSubmitted()) {
            return true;
        }

        $token = $this->getSession()->get(self::KEY_CSRF_TOKEN);
        if (
            is_null($_POST[self::KEY_CSRF_TOKEN])
            || $_POST[self::KEY_CSRF_TOKEN] !== $token
        ) {
            return false;
        }
        return true;
    }

    private function generateCaptcha()
    {
        $builder = new CaptchaBuilder();
        $builder->build();
        $this->getSession()->set(self::KEY_CAPTCHA_PHRASE, $builder->getPhrase());
        $img_captcha = $this->createAndSetupElement(
            'img',
            '',
            [
                'id' => 'captcha',
                'src' => $builder->inline(),
            ]
        );
        return $img_captcha;
    }

    private function validateCaptcha() : bool
    {
        if (!$this->formSubmitted()) {
            return true;
        }

        $valid_phrase = $this->getSession()->get(self::KEY_CAPTCHA_PHRASE);
        if (
            is_null($_POST[self::KEY_CAPTCHA_PHRASE])
            || $_POST[self::KEY_CAPTCHA_PHRASE] !== $valid_phrase
        ) {
            return false;
        }
        return true;
    }

    private function formSubmitted()
    {
        return (
            !is_null($_POST['name'])
            || !is_null($_POST['email'])
            || !is_null($_POST['message'])
        ) ? true : false;
    }

    public function run(array $options = []) : bool
    {
        if (!$this->validateCsrfInput()) {
            $this->getSession()->getFlashBag()->add(
                'error',
                $this->loadTextFile(Resolve::arrayToId([
                    $this->getLanguage(),
                    'flashmessages',
                    'error',
                    'csrf-failed'
                ]))
            );
        }
        if (!$this->validateCaptcha()) {
            $this->getSession()->getFlashBag()->add(
                'error',
                $this->loadTextFile(Resolve::arrayToId([
                    $this->getLanguage(),
                    'flashmessages',
                    'error',
                    'captcha-failed'
                ]))
            );
        }
        $form = $this->createForm();
        $this->appendChild($form);

        return true;
    }

    public function onWebsocketRequest(
        \Lewp\Websocket\Message $message
    ) : \Lewp\Websocket\Message {
    }
};