<?php

namespace App\Http\Controllers\Admin;

use App\Enums\PriceType;
use App\Http\Controllers\Concerns\ParsesDataTableQuery;
use App\Http\Controllers\Controller;
use App\Http\Requests\Admin\ProductRequest;
use App\Models\Category;
use App\Models\Product;
use App\Models\ProductPrice;
use App\Models\ProductVariant;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Inertia\Inertia;
use Inertia\Response;

class ProductController extends Controller
{
    use ParsesDataTableQuery;

    public function index(Request $request): Response
    {
        $tableQuery = $this->parseDataTableQuery($request);
        $search = $tableQuery['search'];
        $sort = $tableQuery['sort'];
        $direction = $tableQuery['direction'];
        $isActive = $request->string('is_active')->toString();

        $query = Product::query()
            ->with([
                'categories',
                'variants' => fn ($query) => $query
                    ->with(['prices' => fn ($query) => $query->orderBy('type')])
                    ->orderBy('created_at'),
            ])
            ->when($search !== '', function (Builder $query) use ($search): void {
                $query->where(function (Builder $query) use ($search): void {
                    $query->where('name', 'like', "%{$search}%")
                        ->orWhere('slug', 'like', "%{$search}%")
                        ->orWhere('description', 'like', "%{$search}%")
                        ->orWhereHas('categories', fn (Builder $query) => $query->where('name', 'like', "%{$search}%"))
                        ->orWhereHas('variants', fn (Builder $query) => $query->where('name', 'like', "%{$search}%"));
                });
            })
            ->when(
                $isActive !== '',
                fn (Builder $query) => $query->where('is_active', $isActive === '1')
            );

        $this->applySorting($query, $sort, $direction);

        $products = $query
            ->paginate(10)
            ->withQueryString();

        $rows = $products->getCollection()
            ->flatMap(fn (Product $product, int $index) => $this->flattenProductForTable($product, $index, $products->firstItem() ?? 1))
            ->values()
            ->all();

        return Inertia::render('admin/products/Index', [
            'rows' => $rows,
            'pagination' => [
                'current_page' => $products->currentPage(),
                'last_page' => $products->lastPage(),
                'per_page' => $products->perPage(),
                'total' => $products->total(),
                'links' => $products->linkCollection()->toArray(),
            ],
            'filters' => $this->dataTableFilters($tableQuery, [
                'is_active' => $isActive,
            ]),
        ]);
    }

    public function create(): Response
    {
        return Inertia::render('admin/products/Create', [
            'categories' => $this->categoryOptions(),
            'priceTypes' => PriceType::selectOptions(),
        ]);
    }

    public function store(ProductRequest $request): RedirectResponse
    {
        $validated = $request->validated();

        DB::transaction(function () use ($validated): void {
            $product = Product::create([
                'name' => $validated['name'],
                'description' => $validated['description'] ?? null,
                'is_active' => true,
            ]);

            $product->categories()->sync($validated['category_ids']);

            foreach ($validated['variants'] as $variantData) {
                $this->createVariant($product, $variantData);
            }
        });

        Inertia::flash('success', 'Produk berhasil ditambahkan.');

        return redirect()->route('admin.master.products.index');
    }

    public function edit(Product $product): Response
    {
        $product->load([
            'categories',
            'variants' => fn ($query) => $query
                ->with(['prices' => fn ($query) => $query->orderBy('type')])
                ->orderBy('created_at'),
        ]);

        return Inertia::render('admin/products/Edit', [
            'categories' => $this->categoryOptions(),
            'priceTypes' => PriceType::selectOptions(),
            'product' => $this->transformProductForForm($product),
        ]);
    }

    public function update(ProductRequest $request, Product $product): RedirectResponse
    {
        $validated = $request->validated();

        DB::transaction(function () use ($validated, $product): void {
            $product->name = $validated['name'];
            $product->description = $validated['description'] ?? null;
            $product->save();

            $product->categories()->sync($validated['category_ids']);

            $submittedVariantIds = collect($validated['variants'])
                ->pluck('id')
                ->filter()
                ->map(fn ($id) => (int) $id)
                ->all();

            $product->variants()
                ->whereNotIn('id', $submittedVariantIds)
                ->get()
                ->each(fn (ProductVariant $variant) => $variant->delete());

            foreach ($validated['variants'] as $variantData) {
                if (! empty($variantData['id'])) {
                    $variant = $product->variants()->findOrFail($variantData['id']);
                    $variant->name = $variantData['name'];
                    $variant->stock = $variantData['stock'];
                    $variant->save();
                    $this->syncVariantPrices($variant, $variantData['prices']);

                    continue;
                }

                $this->createVariant($product, $variantData);
            }
        });

        Inertia::flash('success', 'Produk berhasil diperbarui.');

        return redirect()->route('admin.master.products.index');
    }

    public function toggleStatus(Request $request, Product $product): RedirectResponse
    {
        $validated = $request->validate([
            'is_active' => ['required', 'boolean'],
        ]);

        $product->is_active = $validated['is_active'];
        $product->save();

        Inertia::flash('success', 'Status produk berhasil diperbarui.');

        return back();
    }

    public function destroy(Product $product): RedirectResponse
    {
        DB::transaction(function () use ($product): void {
            $product->variants()->delete();
            $product->categories()->detach();
            $product->delete();
        });

        Inertia::flash('success', 'Produk berhasil dihapus.');

        return redirect()->route('admin.master.products.index');
    }

    private function applySorting(Builder $query, string $sort, string $direction): void
    {
        if (in_array($sort, ['name', 'slug', 'is_active'], true)) {
            $query->orderBy($sort, $direction);

            return;
        }

        $query->latest();
    }

    /**
     * @return list<array{value: int, label: string}>
     */
    private function categoryOptions(): array
    {
        return Category::query()
            ->orderBy('name')
            ->get(['id', 'name'])
            ->map(fn (Category $category) => [
                'value' => $category->id,
                'label' => $category->name,
            ])
            ->all();
    }

    /**
     * @param  array<string, mixed>  $variantData
     */
    private function createVariant(Product $product, array $variantData): ProductVariant
    {
        $variant = $product->variants()->create([
            'name' => $variantData['name'],
            'stock' => $variantData['stock'],
        ]);

        $this->syncVariantPrices($variant, $variantData['prices']);

        return $variant;
    }

    /**
     * @param  list<array{type: string, price: float|int|string}>  $prices
     */
    private function syncVariantPrices(ProductVariant $variant, array $prices): void
    {
        foreach ($prices as $priceData) {
            ProductPrice::updateOrCreate(
                [
                    'variant_id' => $variant->id,
                    'type' => $priceData['type'],
                ],
                [
                    'price' => $priceData['price'],
                ],
            );
        }
    }

    /**
     * @return list<array<string, mixed>>
     */
    private function flattenProductForTable(Product $product, int $productIndex, int $firstItem): array
    {
        $variants = $product->variants->isNotEmpty()
            ? $product->variants
            : collect([null]);

        $variantCount = $variants->count();

        return $variants
            ->values()
            ->map(function ($variant, int $variantIndex) use ($product, $productIndex, $firstItem, $variantCount) {
                return [
                    'row_id' => $variant
                        ? "{$product->id}-{$variant->id}"
                        : "{$product->id}-empty",
                    'product_id' => $product->id,
                    'product_name' => $product->name,
                    'categories' => $product->categories
                        ->map(fn (Category $category) => [
                            'id' => $category->id,
                            'name' => $category->name,
                        ])
                        ->values()
                        ->all(),
                    'is_active' => $product->is_active,
                    'is_first_variant' => $variantIndex === 0,
                    'variant_count' => $variantCount,
                    'product_row_number' => $firstItem + $productIndex,
                    'variant_id' => $variant?->id,
                    'variant_name' => $variant?->name,
                    'stock' => $variant?->stock,
                    'prices' => $variant
                        ? $variant->prices
                            ->map(fn (ProductPrice $price) => [
                                'type' => $price->type->value,
                                'type_label' => $price->type->label(),
                                'price' => $price->price,
                                'price_formatted' => $this->formatPrice($price->price),
                            ])
                            ->values()
                            ->all()
                        : [],
                ];
            })
            ->all();
    }

    /**
     * @return array<string, mixed>
     */
    private function transformProductForForm(Product $product): array
    {
        return [
            'id' => $product->id,
            'name' => $product->name,
            'description' => $product->description,
            'category_ids' => $product->categories->pluck('id')->all(),
            'variants' => $product->variants
                ->map(fn (ProductVariant $variant) => [
                    'id' => $variant->id,
                    'name' => $variant->name,
                    'stock' => $variant->stock,
                    'prices' => collect(PriceType::cases())
                        ->mapWithKeys(function (PriceType $type) use ($variant) {
                            $price = $variant->prices->firstWhere('type', $type);

                            return [
                                $type->value => $price ? (string) (int) $price->price : '',
                            ];
                        })
                        ->all(),
                ])
                ->values()
                ->all(),
        ];
    }

    private function formatPrice(float|string $price): string
    {
        return 'Rp '.number_format((float) $price, 0, ',', '.');
    }
}