<?php

namespace Modules\Stylist\Services;

use Illuminate\Filesystem\Filesystem;
use Illuminate\Http\UploadedFile;
use Modules\Settings\Services\SettingsRepository;
use Modules\Stylist\Theme\Loader;
use Modules\Stylist\Theme\Theme;
use RuntimeException;
use ZipArchive;

final class ThemePackageManager
{
    public function __construct(private readonly Filesystem $files, private readonly Loader $loader, private readonly ThemeValidator $validator, private readonly SettingsRepository $settings) {}

    public function install(UploadedFile $upload): Theme
    {
        if (strtolower($upload->getClientOriginalExtension()) !== 'zip') {
            throw new RuntimeException('Only ZIP theme packages may be installed.');
        }
        $temporary = storage_path('app/stylist/install-'.bin2hex(random_bytes(8)));
        $this->files->ensureDirectoryExists($temporary);
        $zip = new ZipArchive;
        if ($zip->open($upload->getRealPath()) !== true) {
            throw new RuntimeException('The uploaded ZIP could not be opened.');
        }
        for ($i = 0; $i < $zip->numFiles; $i++) {
            $name = $zip->getNameIndex($i);
            if (str_contains($name, '..') || str_starts_with($name, '/') || str_contains($name, "\0")) {
                $zip->close();
                throw new RuntimeException('The ZIP contains an unsafe path.');
            }
        }
        $zip->extractTo($temporary);
        $zip->close();
        $manifest = collect($this->files->allFiles($temporary))->first(fn ($file) => $file->getFilename() === 'theme.json');
        if (! $manifest) {
            $this->files->deleteDirectory($temporary);
            throw new RuntimeException('The package does not contain theme.json.');
        }
        $source = $manifest->getPath();
        $theme = $this->loader->fromPath($source);
        if ($theme->parent() && ! $this->loader->all()->has($theme->parent())) {
            throw new RuntimeException('Parent theme '.$theme->parent().' is not installed.');
        }
        $issues = $this->validator->validate($theme);
        if (collect($issues)->contains('severity', 'error')) {
            throw new RuntimeException('Accessibility validation failed: '.collect($issues)->where('severity', 'error')->pluck('message')->implode(' '));
        }
        $target = rtrim((string) config('stylist.themes_path'), '/').'/'.$theme->key();
        if ($this->files->isDirectory($target)) {
            $this->files->deleteDirectory($target);
        }
        $this->files->copyDirectory($source, $target);
        $this->files->deleteDirectory($temporary);
        $this->loader->flush();

        return $this->loader->find($theme->key());
    }

    public function uninstall(Theme $theme): void
    {
        $active = $theme->type() === 'frontend'
            ? $this->settings->get('frontend_theme', config('stylist.default_frontend_theme'), 'site')
            : $this->settings->get('backend_theme', config('stylist.default_backend_theme'), 'site');
        if ($active === $theme->key()) {
            throw new RuntimeException('The active theme cannot be uninstalled. Activate another theme first.');
        }
        $projectRoot = realpath((string) config('stylist.themes_path'));
        $themePath = realpath($theme->path());
        if (! $projectRoot || ! $themePath || ! str_starts_with($themePath, $projectRoot.DIRECTORY_SEPARATOR)) {
            throw new RuntimeException('Bundled themes cannot be uninstalled.');
        }
        if (collect($this->loader->all())->contains(fn (Theme $candidate) => $candidate->parent() === $theme->key())) {
            throw new RuntimeException('This theme has installed child themes.');
        }
        $this->files->deleteDirectory($themePath);
        $this->loader->flush();
    }

    public function export(Theme $theme): string
    {
        $directory = storage_path('app/stylist/exports');
        $this->files->ensureDirectoryExists($directory);
        $path = $directory.'/'.$theme->key().'-'.$theme->version().'.zip';
        $zip = new ZipArchive;
        if ($zip->open($path, ZipArchive::CREATE | ZipArchive::OVERWRITE) !== true) {
            throw new RuntimeException('Unable to create theme archive.');
        }
        foreach ($this->files->allFiles($theme->path()) as $file) {
            $zip->addFile($file->getPathname(), $theme->key().'/'.$file->getRelativePathname());
        }
        $zip->close();

        return $path;
    }
}