<?php

class WizardStep
{
    public $page = "";
    public array $redirects = array();
    public string $warning = "";
    public $code = null;
    public function __construct($step)
    {
        if (isset($step['page'])) {
            $this->page = $step['page'];
        }
        if (isset($step['redirects'])) {
            $this->redirects = $step['redirects'];
        }
    }
    public function setCurrentStep()
    {
        if (!empty($this->redirects)) {
            foreach ($this->redirects as $redirect) {
                if (isset($redirect['==']) && isset($redirect['id'])) {
                    foreach ($redirect['=='] as $key => $value) {
                        if (isset($_POST[$key]) && $_POST[$key] == $value) {
                            $_POST['step'] = $redirect['id'];
                            if (isset($redirect['warning'])) {
                                $this->warning = $redirect['warning'];
                            }
                            return;
                        }
                    }
                }
                if (isset($redirect['!=']) && isset($redirect['id'])) {
                    foreach ($redirect['!='] as $key => $value) {
                        if (isset($_POST[$key]) && $_POST[$key] != $value) {
                            $_POST['step'] = $redirect['id'];
                            if (isset($redirect['warning'])) {
                                $this->warning = $redirect['warning'];
                            }
                            return;
                        }
                    }
                }
                if (isset($redirect['>']) && isset($redirect['id'])) {
                    foreach ($redirect['>'] as $key => $value) {
                        if (isset($_POST[$key]) && $_POST[$key] > $value) {
                            $_POST['step'] = $redirect['id'];
                            if (isset($redirect['warning'])) {
                                $this->warning = $redirect['warning'];
                            }
                            return;
                        }
                    }
                }
                if (isset($redirect['<']) && isset($redirect['id'])) {
                    foreach ($redirect['<'] as $key => $value) {
                        if (isset($_POST[$key]) && $_POST[$key] < $value) {
                            $_POST['step'] = $redirect['id'];
                            if (isset($redirect['warning'])) {
                                $this->warning = $redirect['warning'];
                            }
                            return;
                        }
                    }
                }
                if (isset($redirect['>=']) && isset($redirect['id'])) {
                    foreach ($redirect['>='] as $key => $value) {
                        if (isset($_POST[$key]) && $_POST[$key] >= $value) {
                            $_POST['step'] = $redirect['id'];
                            if (isset($redirect['warning'])) {
                                $this->warning = $redirect['warning'];
                            }
                            return;
                        }
                    }
                }
                if (isset($redirect['<=']) && isset($redirect['id'])) {
                    foreach ($redirect['<='] as $key => $value) {
                        if (isset($_POST[$key]) && $_POST[$key] <= $value) {
                            $_POST['step'] = $redirect['id'];
                            if (isset($redirect['warning'])) {
                                $this->warning = $redirect['warning'];
                            }
                            return;
                        }
                    }
                }
            }
        }
    }
    public function setCode(callable $function)
    {
        $this->code = $function;
    }
}

class Wizard
{
    private string $header = "";
    private string $firststep = "";
    private array $steps = array();
    private string $footer = "";
    private array $storedvariables = array();
    public function __construct($json_file = '../wizard.json')
    {
        $stepsArray = json_decode(file_get_contents($json_file), true);
        $this->header = $stepsArray['header'];
        $this->firststep = $stepsArray['firststep'];
        foreach ($stepsArray['steps'] as $step) {
            $this->steps[$step['id']] = new WizardStep($step);
        }
        $this->footer = $stepsArray['footer'];
        if (isset($_POST['storedvariables'])) {
            $this->storedvariables = json_decode($_POST['storedvariables'], JSON_FORCE_OBJECT);
        }
    }
    public function renderPHP()
    {
        echo $this->header;
        if (isset($_POST['stepfrom'])) {
            $this->steps[$_POST['stepfrom']]->setCurrentStep();
            if (isset($_POST['step']) && ($_POST['step'] != $_POST['stepfrom'])) {
                if (!is_null($this->steps[$_POST['stepfrom']]->code)) {
                    $this->storedvariables[$_POST['stepfrom']] = call_user_func($this->steps[$_POST['stepfrom']]->code, $this->storedvariables);
                }
            }
        }
        if (!isset($_POST['step'])) {
            $_POST['step'] = $this->firststep;
        }
        // If warning not set this does not add anything to the page:
        echo $this->steps[$_POST['step']]->warning;
        $pagedom = new DOMDocument();
        $pageval = $this->steps[$_POST['step']]->page;
        if (is_array($pageval)) {
            $page = "\xEF\xBB\xBF";
            foreach ($pageval as $pagepart) {
                foreach ($pagepart as $element => $content) {
                    if ($element == 'text') {
                        $page .= $content;
                    } elseif ($element == 'variable') {
                        $tmpcontent = $this->storedvariables;
                        foreach (explode('/', $content) as $pathpart) {
                            $tmpcontent = $tmpcontent[$pathpart];
                        }
                        $page .= $tmpcontent;
                    }
                }
            }
        } else {
            $page = "\xEF\xBB\xBF" . $pageval;
        }
        libxml_use_internal_errors(true);
        $pagedom->loadHTML($page);
        foreach (libxml_get_errors() as $error) {
            echo "<p>Error when parsing html for step \"" . $_POST['step'] . "\":" . $error->line . " " . $error->column . " " . $error->message . "</p>";
        }
        $forms = $pagedom->getElementsByTagName('form');
        foreach ($forms as $form) {
            $input = $pagedom->createElement('input');
            $input->setAttribute('type', 'hidden');
            $input->setAttribute('name', 'storedvariables');
            $input->setAttribute('value', json_encode($this->storedvariables, JSON_FORCE_OBJECT));
            $form->appendChild($input);
        }
        echo $pagedom->saveHTML();
        echo $this->footer;
    }
    public function addCode($stepid, $function)
    {
        $this->steps[$stepid]->setCode($function);
    }
}