<?php

namespace App\Http\Controllers;

use App\Models\Category;
use Illuminate\Http\Request;
use Illuminate\Http\JsonResponse;
use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
use Illuminate\Foundation\Validation\ValidatesRequests;
use Illuminate\Routing\Controller as BaseController;

class CategoryController extends BaseController
{
    use AuthorizesRequests, ValidatesRequests;

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

    /**
     * Seznam kategorií (API, JSON).
     */
    public function index(Request $request): JsonResponse
    {
        $perPage = (int) $request->get('per_page', 100);

        $categories = Category::query()
            ->with(['ediCategories', 'contests'])
            ->orderBy('order')
            ->paginate($perPage);

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

    /**
     * Vytvoření nové kategorie.
     * Autorizace přes CategoryPolicy@create.
     */
    public function store(Request $request): JsonResponse
    {
        $this->authorize('create', Category::class);

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

        $category = Category::create($data);

        if (array_key_exists('edi_category_ids', $relations)) {
            $category->ediCategories()->sync($relations['edi_category_ids']);
        }

        if (array_key_exists('contest_ids', $relations)) {
            $category->contests()->sync($relations['contest_ids']);
        }

        $category->load(['ediCategories', 'contests']);

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

    /**
     * Detail jedné kategorie.
     */
    public function show(Category $category): JsonResponse
    {
        $category->load(['ediCategories', 'contests']);

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

    /**
     * Aktualizace existující kategorie (partial update).
     * Autorizace přes CategoryPolicy@update.
     */
    public function update(Request $request, Category $category): JsonResponse
    {
        $this->authorize('update', $category);

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

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

        if (array_key_exists('edi_category_ids', $relations)) {
            $category->ediCategories()->sync($relations['edi_category_ids']);
        }

        if (array_key_exists('contest_ids', $relations)) {
            $category->contests()->sync($relations['contest_ids']);
        }

        $category->load(['ediCategories', 'contests']);

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

    /**
     * Smazání kategorie.
     * Autorizace přes CategoryPolicy@delete.
     */
    public function destroy(Category $category): JsonResponse
    {
        $this->authorize('delete', $category);

        $category->delete();

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

    /**
     * Společná validace dat pro store/update.
     */
    protected function validateData(Request $request, bool $partial = false): array
    {
        $required = $partial ? 'sometimes' : 'required';

        return $request->validate([
            'name'  => [$required, 'string', 'max:255'],
            'order' => [$required, 'integer'],
        ]);
    }

    /**
     * Validace ID relací (EDI kategorie a soutěže).
     */
    protected function validateRelations(Request $request): array
    {
        return $request->validate([
            'edi_category_ids'   => ['sometimes', 'array'],
            'edi_category_ids.*' => ['integer', 'exists:edi_categories,id'],
            'contest_ids'        => ['sometimes', 'array'],
            'contest_ids.*'      => ['integer', 'exists:contests,id'],
        ]);
    }
}