<?php
require_once("Util.php");
require_once("TopicData.php");

class SubjectData
{
    public string $id;
    public string $displayName;
    public string $description;
    public string $color;
    public string $buttonText;
    public string $icon;
    public array $topics;

    public static function getAll() : array
    {
        $result = array();

        $subjectDirectory = "config/subjects";
        $subjectNames = scandir($subjectDirectory);
        foreach ($subjectNames as $subjectName) {
            if ($subjectName == "." || $subjectName == "..") {
                continue;
            }

            $subjectData = SubjectData::fromName($subjectName);
            if(!isset($subjectData)) {
                continue;
            }

            $result[] = $subjectData;
        }

        return $result;
    }

    public static function fromName($subjectName) : SubjectData|null
    {
        $result = new SubjectData();

        $subjectName = Util::removeIllegalCharacters($subjectName);

        $subjectDirectory = "config/subjects/$subjectName";
        $filename = "$subjectDirectory/properties.json";
        $data = Util::parseJsonFromFile($filename);

        $result->id = $subjectName;

        if(isset($data->displayName)) {
            $result->displayName = $data->displayName;
        } else {
            return null;
        }

        if(isset($data->description)) {
            $result->description = $data->description;
        } else {
            return null;
        }

        if(isset($data->color)) {
            $result->color = $data->color;
        } else {
            return null;
        }

        if(isset($data->buttonText)) {
            $result->buttonText = $data->buttonText;
        } else {
            return null;
        }

        if(isset($data->icon)) {
            $result->icon = $data->icon;
        } else {
            return null;
        }

        $result->topics = TopicData::getAll($subjectName);

        return $result;
    }
}