<?php

namespace Modules\Stylist\Theme;

use Illuminate\Filesystem\Filesystem;
use Illuminate\Support\Collection;
use Modules\Stylist\Theme\Exceptions\ThemeNotFoundException;

final class Loader
{
    private ?Collection $themes = null;

    public function __construct(
        private readonly Filesystem $files,
        private readonly Json $json,
        private readonly ManifestValidator $validator,
    ) {}

    public function all(): Collection
    {
        if ($this->themes !== null) {
            return $this->themes;
        }

        $themes = collect();

        foreach ($this->roots() as $root) {
            if (! $this->files->isDirectory($root)) {
                continue;
            }

            foreach ($this->files->directories($root) as $themePath) {
                try {
                    $theme = $this->fromPath($themePath);
                    $themes->put($theme->key(), $theme);
                } catch (\Throwable $exception) {
                    report($exception);
                }
            }
        }

        return $this->themes = $themes->sortKeys();
    }

    public function find(string $key): Theme
    {
        $theme = $this->all()->get($key);

        if (! $theme) {
            throw ThemeNotFoundException::forKey($key);
        }

        return $theme;
    }

    public function fromPath(string $path): Theme
    {
        $data = $this->validator->validate($this->json->read($path), $path);

        return new Theme(
            key: $data['key'],
            name: $data['name'],
            path: rtrim($path, DIRECTORY_SEPARATOR),
            stylesheet: $data['stylesheet'],
            script: $data['script'],
            variables: $data['variables'],
            meta: $data,
        );
    }

    public function flush(): void
    {
        $this->themes = null;
    }

    /** @return array<int, string> */
    public function roots(): array
    {
        return array_values(array_unique(array_filter([
            (string) config('stylist.themes_path'),
        ])));
    }
}