<?php

namespace App\Http\Controllers\Pos;

use App\Http\Controllers\Controller;
use App\Http\Controllers\Pos\Concerns\ScopesToAccount;
use App\Models\PosCategory;
use App\Models\PosModifierGroup;
use App\Models\PosProduct;
use App\Models\PosSaleLine;
use App\Models\PosStation;
use App\Services\Crm\CrmClient;
use App\Services\Import\PosProductCsvImportService;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\View\View;
use RuntimeException;
use Symfony\Component\HttpFoundation\StreamedResponse;

/**
 * Products are mode-aware:
 *  - Retail    → the catalog lives in Ladill CRM; CRUD is proxied to the CRM
 *                products API (no local copy), keeping one source of truth.
 *  - Restaurant → a local pos_products catalog with POS-only depth (category,
 *                 kitchen station, course, modifier groups), kept unique to POS.
 */
class ProductController extends Controller
{
    use ScopesToAccount;

    public function __construct(private readonly \App\Services\Pos\SubscriptionService $subscriptions) {}

    public function index(Request $request): View
    {
        if ($this->isRestaurant($request)) {
            $products = PosProduct::owned($this->ownerRef($request))
                ->with('category')->orderBy('name')->paginate(30)->withQueryString();

            return view('pos.products.index', compact('products'));
        }

        $search = trim((string) $request->query('search', ''));
        // Live CRM products only (not services) — same filter as the register.
        $response = CrmClient::for($this->ownerRef($request))->products([
            'type' => 'product',
            'per_page' => 100,
            'search' => $search !== '' ? $search : null,
        ]);

        return view('pos.products.retail.index', [
            'products' => (array) ($response['data'] ?? []),
            'search' => $search,
        ]);
    }

    public function create(Request $request): View
    {
        if ($this->isRestaurant($request)) {
            return view('pos.products.create', [
                'product' => new PosProduct(['currency' => config('pos.default_currency', 'GHS'), 'is_active' => true]),
                'selectedGroups' => [],
                ...$this->formOptions($request),
            ]);
        }

        return view('pos.products.retail.create');
    }

    public function store(Request $request): RedirectResponse
    {
        $user = ladill_account() ?? $request->user();
        $restaurant = $this->isRestaurant($request);

        if (! $this->subscriptions->canAddProduct($user, $this->ownerRef($request), $restaurant)) {
            return redirect()->route('pos.pro.index')
                ->with('upsell', 'You have reached the free plan limit of '.(int) config('pos.free.max_products', 50).' products. Upgrade to Pro for an unlimited catalog.');
        }

        if ($restaurant) {
            $product = PosProduct::create([...$this->localValidated($request), 'owner_ref' => $this->ownerRef($request)]);
            $product->modifierGroups()->sync($this->groupIds($request));

            return redirect()->route('pos.products.index')->with('success', 'Product added.');
        }

        CrmClient::for($this->ownerRef($request))->createProduct($this->crmPayload($request));

        return redirect()->route('pos.products.index')->with('success', 'Product added.');
    }

    public function edit(Request $request, string $product): View
    {
        if ($this->isRestaurant($request)) {
            $model = PosProduct::owned($this->ownerRef($request))->findOrFail((int) $product);

            return view('pos.products.edit', [
                'product' => $model,
                'selectedGroups' => $model->modifierGroups()->pluck('pos_modifier_groups.id')->all(),
                ...$this->formOptions($request),
            ]);
        }

        return view('pos.products.retail.edit', ['product' => CrmClient::for($this->ownerRef($request))->product($product)]);
    }

    public function update(Request $request, string $product): RedirectResponse
    {
        if ($this->isRestaurant($request)) {
            $model = PosProduct::owned($this->ownerRef($request))->findOrFail((int) $product);
            $model->update($this->localValidated($request));
            $model->modifierGroups()->sync($this->groupIds($request));

            return redirect()->route('pos.products.index')->with('success', 'Product updated.');
        }

        CrmClient::for($this->ownerRef($request))->updateProduct($product, $this->crmPayload($request));

        return redirect()->route('pos.products.index')->with('success', 'Product updated.');
    }

    public function destroy(Request $request, string $product): RedirectResponse
    {
        if ($this->isRestaurant($request)) {
            $model = PosProduct::owned($this->ownerRef($request))->findOrFail((int) $product);
            $model->delete();

            return redirect()->route('pos.products.index')->with('success', 'Product removed.');
        }

        CrmClient::for($this->ownerRef($request))->deleteProduct($product);

        return redirect()->route('pos.products.index')->with('success', 'Product removed.');
    }

    /** Bulk CSV import — upload form (mode-aware target catalog). */
    public function importForm(Request $request): View
    {
        return view('pos.products.import', [
            'restaurant' => $this->isRestaurant($request),
        ]);
    }

    /** Bulk CSV import — handle the upload. */
    public function import(Request $request, PosProductCsvImportService $import): RedirectResponse
    {
        $request->validate([
            'file' => ['required', 'file', 'mimes:csv,txt', 'max:10240'],
        ]);

        try {
            $result = $import->import(
                $this->ownerRef($request),
                $request->file('file'),
                $this->isRestaurant($request),
            );
        } catch (RuntimeException $e) {
            return back()->with('error', $e->getMessage());
        }

        $message = "Imported {$result['imported']} product(s).";
        if ($result['skipped'] > 0) {
            $message .= " Skipped {$result['skipped']}.";
        }

        return redirect()->route('pos.products.index')
            ->with('success', $message)
            ->with('import_errors', array_slice($result['errors'], 0, 50));
    }

    /** Bulk CSV import — downloadable template with example rows. */
    public function importTemplate(Request $request): StreamedResponse
    {
        $restaurant = $this->isRestaurant($request);
        $filename = 'pos-products-template.csv';

        return response()->streamDownload(function () use ($restaurant) {
            $out = fopen('php://output', 'wb');
            if ($restaurant) {
                fputcsv($out, ['name', 'sku', 'price', 'currency', 'category', 'active']);
                fputcsv($out, ['Coffee', 'CFE-01', '15.00', 'GHS', 'Drinks', 'yes']);
                fputcsv($out, ['Croissant', 'CRS-02', '8.50', 'GHS', 'Pastry', 'yes']);
            } else {
                fputcsv($out, ['name', 'sku', 'price', 'currency', 'description', 'tax_rate', 'active']);
                fputcsv($out, ['Mug', 'MUG-01', '25.00', 'GHS', 'Ceramic mug', '0', 'yes']);
                fputcsv($out, ['T-Shirt', 'TSH-02', '60.00', 'GHS', 'Cotton tee', '0', 'yes']);
            }
            fclose($out);
        }, $filename, ['Content-Type' => 'text/csv']);
    }

    private function isRestaurant(Request $request): bool
    {
        // Use the acting branch — not "any restaurant location exists" — so a
        // retail register still sees the live CRM product catalog.
        return $this->location($request)->isRestaurant();
    }

    /** Retail: payload for the CRM products API (always type=product for POS). */
    private function crmPayload(Request $request): array
    {
        $data = $request->validate([
            'name' => ['required', 'string', 'max:255'],
            'sku' => ['nullable', 'string', 'max:80'],
            'description' => ['nullable', 'string', 'max:5000'],
            'unit_price' => ['nullable', 'numeric', 'min:0'],
            'currency' => ['nullable', 'string', 'size:3'],
            'tax_rate' => ['nullable', 'numeric', 'min:0', 'max:100'],
            'is_active' => ['sometimes', 'boolean'],
        ]);

        return [
            'name' => $data['name'],
            'sku' => $data['sku'] ?? null,
            'type' => 'product',
            'description' => $data['description'] ?? null,
            'unit_price_minor' => (int) round(((float) ($data['unit_price'] ?? 0)) * 100),
            'currency' => strtoupper($data['currency'] ?? config('pos.default_currency', 'GHS')),
            'tax_rate' => (float) ($data['tax_rate'] ?? 0),
            'active' => $request->boolean('is_active', true),
        ];
    }

    /** @return array<string, mixed> */
    private function formOptions(Request $request): array
    {
        $owner = $this->ownerRef($request);

        return [
            'restaurant' => true,
            'categories' => PosCategory::owned($owner)->orderBy('name')->get(),
            'stations' => PosStation::owned($owner)->orderBy('name')->get(),
            'modifierGroups' => PosModifierGroup::owned($owner)->orderBy('name')->get(),
        ];
    }

    /** @return list<int> */
    private function groupIds(Request $request): array
    {
        $owner = $this->ownerRef($request);
        $ids = array_map('intval', (array) $request->input('modifier_group_ids', []));

        return PosModifierGroup::owned($owner)->whereIn('id', $ids)->pluck('id')->all();
    }

    /** Restaurant: local pos_products attributes. */
    private function localValidated(Request $request): array
    {
        $owner = $this->ownerRef($request);

        $data = $request->validate([
            'name' => ['required', 'string', 'max:200'],
            'sku' => ['nullable', 'string', 'max:80'],
            'price' => ['required', 'numeric', 'min:0.01'],
            'currency' => ['nullable', 'string', 'size:3'],
            'is_active' => ['sometimes', 'boolean'],
            'category_id' => ['nullable', 'integer'],
            'station_id' => ['nullable', 'integer'],
            'course' => ['nullable', 'in:'.implode(',', array_keys(PosSaleLine::COURSES))],
        ]);

        $categoryId = ($data['category_id'] ?? null) && PosCategory::owned($owner)->whereKey($data['category_id'])->exists()
            ? (int) $data['category_id'] : null;
        $stationId = ($data['station_id'] ?? null) && PosStation::owned($owner)->whereKey($data['station_id'])->exists()
            ? (int) $data['station_id'] : null;

        return [
            'name' => $data['name'],
            'sku' => $data['sku'] ?? null,
            'price_minor' => (int) round(((float) $data['price']) * 100),
            'currency' => strtoupper($data['currency'] ?? config('pos.default_currency', 'GHS')),
            'is_active' => $request->boolean('is_active', true),
            'category_id' => $categoryId,
            'station_id' => $stationId,
            'course' => $data['course'] ?? null,
        ];
    }
}