<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use App\Http\Requests\Admin\StoreManualAdjustmentRequest;
use App\Models\Product;
use App\Models\StockAdjustment;
use App\Models\StockMovement;
use App\Models\VariantStockMovement;
use Illuminate\Http\RedirectResponse;
use Illuminate\Support\Facades\DB;
use Illuminate\View\View;

class StockAdjustmentController extends Controller
{
    public function manual(): View
    {
        $this->authorize('stock-adjustments.manage');
        $reasonOptions = StoreManualAdjustmentRequest::reasonOptions();
        return view('admin.stock-adjustments.manual', compact('reasonOptions'));
    }

    public function storeManual(StoreManualAdjustmentRequest $request): RedirectResponse
    {
        $this->authorize('stock-adjustments.manage');
        $data = $request->validated();
        $productId = $data['variant_id'] ?? $data['product_id'];
        $product = Product::findOrFail($productId);
        $beforeQty = (float) $product->current_stock;
        $quantity = (float) $data['quantity'];
        $afterQty = $data['adjustment_type'] === StockAdjustment::TYPE_ADDITION
            ? $beforeQty + $quantity
            : $beforeQty - $quantity;

        try {
            DB::transaction(function () use ($data, $product, $productId, $beforeQty, $afterQty) {
                $delta = (int) round($afterQty - $beforeQty);
                StockAdjustment::create([
                    'product_id' => $data['product_id'],
                    'variant_id' => $data['variant_id'] ?? null,
                    'adjustment_type' => $data['adjustment_type'],
                    'before_qty' => $beforeQty,
                    'adjusted_qty' => abs($afterQty - $beforeQty),
                    'after_qty' => $afterQty,
                    'reason' => $data['reason'],
                    'remarks' => $data['remarks'],
                    'reference_type' => StockAdjustment::REFERENCE_MANUAL,
                    'reference_id' => null,
                    'created_by' => auth()->id(),
                ]);

                if ($delta !== 0) {
                    if ($data['variant_id'] ?? null) {
                        VariantStockMovement::create([
                            'product_id' => $data['variant_id'],
                            'type' => VariantStockMovement::TYPE_ADJUSTMENT,
                            'quantity' => $delta,
                            'notes' => $data['remarks'],
                            'created_by' => auth()->id(),
                        ]);
                    } else {
                        StockMovement::create([
                            'product_id' => $data['product_id'],
                            'type' => StockMovement::TYPE_ADJUSTMENT,
                            'quantity' => $delta,
                            'notes' => $data['remarks'],
                            'created_by' => auth()->id(),
                        ]);
                    }
                    $product->recalculateStock();
                }
            });
            return redirect()->route('admin.stock-adjustments.index')
                ->with('success', 'Manual adjustment applied.');
        } catch (\Exception $e) {
            return redirect()->back()->withInput()->with('error', $e->getMessage());
        }
    }

    public function index(): View
    {
        $this->authorize('stock-adjustments.view');
        $adjustments = StockAdjustment::with(['product', 'variant', 'creator'])
            ->latest()
            ->paginate(25);
        return view('admin.stock-adjustments.index', compact('adjustments'));
    }
}