<?php

declare(strict_types=1);

namespace ModulesCore;

final class ModuleRegistry
{
    /** @var array<int, array<string, mixed>>|null */
    private ?array $desktopApps = null;

    public function __construct(
        private readonly string $modulesPath,
    ) {
    }

    /**
     * @return array<int, array<string, mixed>>
     */
    public function desktopApps(): array
    {
        if ($this->desktopApps !== null) {
            return $this->desktopApps;
        }

        $apps = [];

        foreach ($this->moduleDirectories() as $moduleName => $modulePath) {
            $desktopConfigPath = $modulePath . '/desktop.php';
            if (!is_file($desktopConfigPath)) {
                continue;
            }

            $desktopConfig = require $desktopConfigPath;
            if (!is_array($desktopConfig)) {
                continue;
            }

            $manifest = $this->readJson($modulePath . '/module.json');
            $desktopConfig['module_id'] = $moduleName;
            $desktopConfig['title'] ??= (string) ($manifest['title'] ?? ucfirst($moduleName));
            $desktopConfig['summary'] ??= (string) ($manifest['description'] ?? '');
            $desktopConfig['required_groups'] ??= array_values(array_map(
                'strval',
                (array) ($manifest['auth']['groups'] ?? [])
            ));
            $desktopConfig['enabled_by_default'] ??= (bool) ($manifest['enabled_by_default'] ?? false);
            $apps[] = $desktopConfig;
        }

        return $this->desktopApps = $apps;
    }

    public function modulePath(string $moduleName): ?string
    {
        $directories = $this->moduleDirectories();

        return $directories[$moduleName] ?? null;
    }

    /**
     * @return array<string, string>
     */
    private function moduleDirectories(): array
    {
        $paths = glob(rtrim($this->modulesPath, '/') . '/*', GLOB_ONLYDIR);
        if (!is_array($paths)) {
            return [];
        }

        $directories = [];

        foreach ($paths as $path) {
            $moduleName = basename($path);
            if ($moduleName === '' || $moduleName[0] === '.') {
                continue;
            }

            $directories[$moduleName] = $path;
        }

        ksort($directories);

        return $directories;
    }

    /**
     * @return array<string, mixed>
     */
    private function readJson(string $path): array
    {
        if (!is_file($path)) {
            return [];
        }

        $raw = file_get_contents($path);
        if ($raw === false || trim($raw) === '') {
            return [];
        }

        $decoded = json_decode($raw, true);

        return is_array($decoded) ? $decoded : [];
    }
}