<?php

namespace App\Http\Controllers;

use App\Models\NewsPost;
use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
use Illuminate\Foundation\Validation\ValidatesRequests;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Routing\Controller as BaseController;
use Illuminate\Support\Str;
use Illuminate\Validation\Rule;

class NewsPostController extends BaseController
{
    use AuthorizesRequests, ValidatesRequests;

    public function __construct()
    {
        // zápis jen pro přihlášené (admin policy vyřešíš přes Policy)
        $this->middleware('auth:sanctum')->only(['store', 'update', 'destroy']);
    }

    /**
     * Display a listing of the resource.
     *
     * Podporuje volitelný dotazový parametr ?lang=cs / ?lang=en
     * Pokud je lang zadán, title/content/excerpt budou vráceny jen v daném jazyce.
     */
    public function index(Request $request): JsonResponse
    {
        $perPage = (int) $request->get('per_page', 10);
        $limit = (int) $request->get('limit', 0);
        $includeUnpublished = $request->boolean('include_unpublished', false);

        // volitelný jazyk – pokud není, použije se app locale
        $lang = $request->query('lang');
        if (! is_string($lang) || $lang === '') {
            $lang = app()->getLocale();
        }

        $query = NewsPost::query()
            ->orderByDesc('published_at');

        if (! $includeUnpublished) {
            $query->where('is_published', true)
                ->whereNotNull('published_at')
                ->where('published_at', '<=', now());
        }

        if ($limit > 0) {
            $items = $query->limit($limit)->get();
        } else {
            $items = $query->paginate($perPage);
        }

        $mapTranslation = function (NewsPost $post) use ($lang) {
            $data = $post->toArray();

            // getTranslation(attr, lang, useFallback=true)
            $data['title']   = $post->getTranslation('title', $lang, true);
            $data['content'] = $post->getTranslation('content', $lang, true);
            $data['excerpt'] = $post->getTranslation('excerpt', $lang, true);

            return $data;
        };

        if ($limit > 0) {
            $items = $items->map($mapTranslation);
            return response()->json($items);
        }

        $items->getCollection()->transform($mapTranslation);

        return response()->json($items);
    }

    /**
     * Detail novinky (přes slug).
     * Public – ale jen pokud je publikovaná, jinak 404.
     */
    public function show(NewsPost $news): JsonResponse
    {
        if (
            ! $news->is_published ||
            ! $news->published_at ||
            $news->published_at->isFuture()
        ) {
            abort(404);
        }

        return response()->json($news);
    }

    /**
     * Vytvoření novinky (admin).
     */
    public function store(Request $request): JsonResponse
    {
        $this->authorize('create', NewsPost::class);

        $data = $this->validateData($request);

        if (empty($data['slug'])) {
            $data['slug'] = $this->makeSlugFromTitle($data['title'] ?? null);
        }

        if (! empty($data['is_published']) && empty($data['published_at'])) {
            $data['published_at'] = now();
        }

        $data['author_id'] = $request->user()?->id;

        $news = NewsPost::create($data);

        return response()->json($news, 201);
    }

    /**
     * Aktualizace novinky (admin).
     */
    public function update(Request $request, NewsPost $news): JsonResponse
    {
        $this->authorize('update', $news);

        $data = $this->validateData($request, partial: true);

        // pokud přišla změna title a není explicitně zadaný slug, dopočítej ho
        if (
            array_key_exists('title', $data) &&
            (! array_key_exists('slug', $data) || empty($data['slug']))
        ) {
            $generated = $this->makeSlugFromTitle($data['title']);
            if ($generated !== null) {
                $data['slug'] = $generated;
            }
        }

        if (
            array_key_exists('is_published', $data) &&
            $data['is_published'] &&
            empty($data['published_at'])
        ) {
            $data['published_at'] = $news->published_at ?? now();
        }

        $news->fill($data);
        $news->save();

        return response()->json($news);
    }

    /**
     * Smazání novinky (admin).
     */
    public function destroy(NewsPost $news): JsonResponse
    {
        $this->authorize('delete', $news);

        $news->delete();

        return response()->json(null, 204);
    }

    /**
     * Validace dat.
     *
     * Podporuje:
     *  - string hodnoty (jednotlivý překlad pro aktuální locale)
     *  - pole překladů: { "cs": "...", "en": "..." }
     */
    protected function validateData(Request $request, bool $partial = false): array
    {
        $required = $partial ? 'sometimes' : 'required';

        /** @var NewsPost|null $routeNews */
        $routeNews = $request->route('news'); // může být null, nebo model díky route model bindingu

        $rules = [
            'title' => [
                $required,
                function (string $attribute, $value, \Closure $fail) {
                    if (is_string($value)) {
                        if (mb_strlen($value) > 255) {
                            $fail('The '.$attribute.' may not be greater than 255 characters.');
                        }
                        return;
                    }

                    if (is_array($value)) {
                        foreach ($value as $locale => $text) {
                            if (! is_string($text)) {
                                $fail("The {$attribute}.{$locale} must be a string.");
                                return;
                            }
                            if (mb_strlen($text) > 255) {
                                $fail("The {$attribute}.{$locale} may not be greater than 255 characters.");
                                return;
                            }
                        }
                        return;
                    }

                    $fail('The '.$attribute.' must be a string or an array of translated strings.');
                },
            ],

            'slug' => [
                'sometimes',
                'nullable',
                'string',
                'max:255',
                Rule::unique('news_posts', 'slug')->ignore($routeNews?->getKey()),
            ],

            'content' => [
                $required,
                function (string $attribute, $value, \Closure $fail) {
                    if (is_string($value)) {
                        return;
                    }

                    if (is_array($value)) {
                        foreach ($value as $locale => $text) {
                            if (! is_string($text)) {
                                $fail("The {$attribute}.{$locale} must be a string.");
                                return;
                            }
                        }
                        return;
                    }

                    $fail('The '.$attribute.' must be a string or an array of translated strings.');
                },
            ],

            'excerpt' => [
                'sometimes',
                function (string $attribute, $value, \Closure $fail) {
                    if ($value === null) {
                        return;
                    }

                    if (is_string($value)) {
                        if (mb_strlen($value) > 500) {
                            $fail('The '.$attribute.' may not be greater than 500 characters.');
                        }
                        return;
                    }

                    if (is_array($value)) {
                        foreach ($value as $locale => $text) {
                            if (! is_string($text)) {
                                $fail("The {$attribute}.{$locale} must be a string.");
                                return;
                            }
                            if (mb_strlen($text) > 500) {
                                $fail("The {$attribute}.{$locale} may not be greater than 500 characters.");
                                return;
                            }
                        }
                        return;
                    }

                    $fail('The '.$attribute.' must be null, a string, or an array of translated strings.');
                },
            ],

            'is_published' => ['sometimes', 'boolean'],
            'published_at' => ['sometimes', 'nullable', 'date'],
        ];

        return $request->validate($rules);
    }

    /**
     * Vytvoří slug z titulku – umí pracovat jak se stringem, tak s polem překladů.
     *
     * - pokud je $title string → slug z něj
     * - pokud je $title array → použije se:
     *     title[aktuální_locale] || title['en'] || první dostupná hodnota
     */
    protected function makeSlugFromTitle(string|array|null $title): ?string
    {
        if ($title === null) {
            return null;
        }

        if (is_array($title)) {
            $locale = app()->getLocale();

            $base = $title[$locale]
                ?? $title['en']
                ?? reset($title);

            if (! is_string($base) || $base === '') {
                return null;
            }

            return Str::slug($base);
        }

        if ($title === '') {
            return null;
        }

        return Str::slug($title);
    }
}