<?php

namespace App\Http\Controllers;

use App\Models\Collection;
use App\Models\CollectionItem;
use App\Models\CollectionType;
use App\Models\Product;
use App\Models\StockAdjustment;
use App\Models\Account;
use Illuminate\Http\Request;
use Carbon\Carbon;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Auth;

class CollectionController extends Controller
{
    public function index(Request $request)
    {
        $user = Auth::guard('web')->user() ?? Auth::guard('receptionist')->user();
        if (!$user) return response()->json(['message' => 'Unauthenticated'], 401);

        $branchId = $user->isReceptionist() ? $user->branch_id : $request->query('branch_id');
        $startDate = $request->query('start_date');
        $endDate = $request->query('end_date');
        $paymentMethod = $request->query('payment_method');

        $query = Collection::with(['branch', 'type', 'items.product']);

        if ($branchId) {
            $query->where('branch_id', $branchId);
        }
        if ($startDate) {
            $query->where('date', '>=', $startDate);
        }
        if ($endDate) {
            $query->where('date', '<=', $endDate);
        }
        if ($paymentMethod) {
            $query->where('payment_method', $paymentMethod);
        }

        return response()->json($query->orderBy('date', 'desc')->get()->map(function($c) {
            $originalAmount = $c->items->sum('subtotal');
            $c->is_adjusted = $originalAmount > 0 && abs($c->amount - $originalAmount) > 0.01;
            $c->original_amount = $originalAmount;
            return $c;
        }));
    }

    public function store(Request $request)
    {
        $user = Auth::guard('web')->user() ?? Auth::guard('receptionist')->user();
        if (!$user) return response()->json(['message' => 'Unauthenticated'], 401);

        $data = $request->all();
        if ($user->isReceptionist()) {
            $data['branch_id'] = $user->branch_id;
        }

        $validated = \Illuminate\Support\Facades\Validator::make($data, [
            'date' => 'required|date',
            'branch_id' => 'required|exists:branches,id',
            'collection_type_id' => 'required|exists:collection_types,id',
            'payment_method' => 'required|string',
            'amount' => 'required|numeric|min:0',
            'remarks' => 'nullable|string',
            'items' => 'nullable|array',
            'items.*.product_id' => 'required_with:items|exists:products,id',
            'items.*.quantity' => 'required_with:items|integer|min:1',
            'items.*.unit_price' => 'required_with:items|numeric|min:0',
        ])->validate();

        return DB::transaction(function () use ($validated) {
            $count = Collection::count() + 1;
            $transactionId = "COL-" . (1000 + $count);

            $collection = Collection::create([
                'date' => $validated['date'],
                'branch_id' => $validated['branch_id'],
                'collection_type_id' => $validated['collection_type_id'],
                'payment_method' => $validated['payment_method'],
                'amount' => $validated['amount'],
                'remarks' => $validated['remarks'],
                'transaction_id' => $transactionId
            ]);

            $type = CollectionType::find($validated['collection_type_id']);

            if (isset($validated['items']) && !empty($validated['items'])) {
                foreach ($validated['items'] as $item) {
                    CollectionItem::create([
                        'collection_id' => $collection->id,
                        'product_id' => $item['product_id'],
                        'quantity' => $item['quantity'],
                        'unit_price' => $item['unit_price'],
                        'subtotal' => $item['quantity'] * $item['unit_price']
                    ]);

                    // If it's a "Product sale" type, we should also track inventory
                    // Checking if the type name is "Product sale"
                    if (strtolower($type->name) === 'product sale' || strtolower($type->name) === 'product saled') {
                        $product = Product::find($item['product_id']);
                        $newStock = $product->current_stock - $item['quantity'];
                        
                        $status = 'In Stock';
                        if ($newStock <= 0) $status = 'Out of Stock';
                        else if ($newStock <= $product->reorder_level) $status = 'Low Stock';

                        $product->update([
                            'current_stock' => $newStock,
                            'status' => $status
                        ]);

                        StockAdjustment::create([
                            'product_id' => $product->id,
                            'adjustment_qty' => -$item['quantity'],
                            'new_stock' => $newStock,
                            'adjustment_date' => $validated['date'],
                            'reason' => 'Sale',
                            'remarks' => "Collection #{$transactionId}"
                        ]);
                    }
                }
            }

            // Record to Ledger
            Account::create([
                'date' => $validated['date'],
                'time' => Carbon::parse($validated['date'])->isToday() ? Carbon::now()->toTimeString() : '00:00:00',
                'credit' => $validated['amount'],
                'debit' => 0,
                'type' => 'income',
                'branch_id' => $validated['branch_id'],
                'accountable_id' => $collection->id,
                'accountable_type' => Collection::class,
                'description' => "Collection [{$type->name}] #{$transactionId}"
            ]);

            return response()->json($collection->load(['branch', 'type', 'items.product']), 201);
        });
    }

    public function show($id)
    {
        $collection = Collection::with(['branch', 'type', 'items.product'])->findOrFail($id);
        $user = Auth::guard('web')->user() ?? Auth::guard('receptionist')->user();
        if ($user && $user->isReceptionist() && $collection->branch_id != $user->branch_id) {
            return response()->json(['message' => 'Unauthorized'], 403);
        }
        return response()->json($collection);
    }
}