<?php

namespace App\Http\Controllers\Frontend;

use App\Http\Controllers\Controller;
use App\Models\Cart;
use App\Models\Order;
use App\Models\OrderItem;
use App\Models\Product;
use App\Models\Setting;
use App\Services\MetaConversionsService;
use Illuminate\Http\Request;

class CheckoutController extends Controller
{
    private function getSessionId(): string
    {
        return session()->getId();
    }

    private function calculateShipping(iterable $cartItems, string $area): float
    {
        $globalInside  = (float) Setting::get('shipping_inside_dhaka', 60);
        $globalOutside = (float) Setting::get('shipping_outside_dhaka', 120);
        $globalRate    = $area === 'inside_dhaka' ? $globalInside : $globalOutside;

        $maxCharge = 0;
        foreach ($cartItems as $item) {
            $product  = $item->product;
            $custom   = $area === 'inside_dhaka'
                ? $product->shipping_inside_dhaka
                : $product->shipping_outside_dhaka;

            // null = use global; 0 = free; number = custom rate
            $charge = $custom !== null ? (float) $custom : $globalRate;
            if ($charge > $maxCharge) {
                $maxCharge = $charge;
            }
        }

        return $maxCharge;
    }

    public function index()
    {
        $cartItems = Cart::with(['product', 'variation'])
            ->where('session_id', $this->getSessionId())
            ->get();

        if ($cartItems->isEmpty()) {
            return redirect()->route('home')->with('error', 'Your cart is empty.');
        }

        $subtotal = $cartItems->sum(function ($item) {
            $price = $item->product->current_price + ($item->variation?->price_adjustment ?? 0);
            return $price * $item->quantity;
        });

        $insideCharge  = $this->calculateShipping($cartItems, 'inside_dhaka');
        $outsideCharge = $this->calculateShipping($cartItems, 'outside_dhaka');

        // Server-side InitiateCheckout event
        $capi = app(MetaConversionsService::class);
        $pixelEventId = $capi->sendInitiateCheckout(
            $subtotal,
            $cartItems->sum('quantity')
        );

        return view('frontend.checkout', compact('cartItems', 'subtotal', 'insideCharge', 'outsideCharge', 'pixelEventId'));
    }

    public function buyNow(Request $request)
    {
        $request->validate([
            'product_id'   => 'required|exists:products,id',
            'variation_id' => 'nullable|exists:product_variations,id',
            'quantity'     => 'required|integer|min:1',
        ]);

        $sessionId = $this->getSessionId();

        Cart::where('session_id', $sessionId)->delete();
        Cart::create([
            'session_id'   => $sessionId,
            'product_id'   => $request->product_id,
            'variation_id' => $request->variation_id,
            'quantity'     => $request->quantity,
        ]);

        return redirect()->route('checkout');
    }

    public function store(Request $request)
    {
        $isMfs = in_array($request->payment_method, ['bkash', 'rocket', 'nagad']);

        $request->validate([
            'name'            => 'required|string|max:255',
            'address'         => 'required|string|max:1000',
            'mobile'          => 'required|string|max:20',
            'note'            => 'nullable|string|max:1000',
            'shipping_area'   => 'required|in:inside_dhaka,outside_dhaka',
            'payment_method'  => 'required|in:cod,bkash,rocket,nagad',
            'payment_phone'   => $isMfs ? 'required|string|max:20' : 'nullable',
            'payment_trx_id'  => $isMfs ? 'required|string|max:100' : 'nullable',
        ], [
            'payment_phone.required'  => 'পেমেন্ট নম্বর দিন।',
            'payment_trx_id.required' => 'Transaction ID দিন।',
        ]);

        $sessionId = $this->getSessionId();
        $cartItems = Cart::with(['product', 'variation'])
            ->where('session_id', $sessionId)
            ->get();

        if ($cartItems->isEmpty()) {
            return redirect()->route('home')->with('error', 'Your cart is empty.');
        }

        $subtotal       = $cartItems->sum(function ($item) {
            $price = $item->product->current_price + ($item->variation?->price_adjustment ?? 0);
            return $price * $item->quantity;
        });

        $shippingArea   = $request->shipping_area;
        $shippingCharge = $this->calculateShipping($cartItems, $shippingArea);
        $total          = $subtotal + $shippingCharge;

        $order = Order::create([
            'name'            => $request->name,
            'address'         => $request->address,
            'mobile'          => $request->mobile,
            'note'            => $request->note,
            'payment_method'  => $request->payment_method,
            'payment_phone'   => $request->payment_phone,
            'payment_trx_id'  => $request->payment_trx_id,
            'shipping_area'   => $shippingArea,
            'shipping_charge' => $shippingCharge,
            'subtotal'        => $subtotal,
            'total'           => $total,
        ]);

        foreach ($cartItems as $item) {
            $price = $item->product->current_price + ($item->variation?->price_adjustment ?? 0);
            OrderItem::create([
                'order_id'          => $order->id,
                'product_id'        => $item->product_id,
                'variation_id'      => $item->variation_id,
                'product_name'      => $item->product->name,
                'variation_details' => $item->variation?->label,
                'price'             => $price,
                'quantity'          => $item->quantity,
                'subtotal'          => $price * $item->quantity,
            ]);
        }

        Cart::where('session_id', $sessionId)->delete();

        // Server-side Purchase event (most important — fires after order confirmed)
        $contentIds = $cartItems->pluck('product_id')->filter()->map(fn($id) => (string)$id)->values()->toArray();
        $capi = app(MetaConversionsService::class);
        $purchaseEventId = $capi->sendPurchase(
            $total,
            $request->mobile,
            $contentIds,
            $cartItems->sum('quantity'),
            $order->order_number
        );

        // Flash pixel Purchase data — read by layout on thank-you page
        session()->flash('pixel_purchase', json_encode([
            'value'        => round($total, 2),
            'currency'     => 'BDT',
            'content_type' => 'product',
            'content_ids'  => $contentIds,
            'num_items'    => (int) $cartItems->sum('quantity'),
            'order_id'     => $order->order_number,
        ]));
        session()->flash('pixel_event_id', $purchaseEventId);
        session()->flash('purchase_event_id', $purchaseEventId);

        return redirect()->route('order.success', $order->order_number);
    }

    public function success(string $orderNumber)
    {
        $order = Order::with('items')->where('order_number', $orderNumber)->firstOrFail();
        $purchaseEventId = session('purchase_event_id', '');
        return view('frontend.order-success', compact('order', 'purchaseEventId'));
    }

    public function track(Request $request)
    {
        $order = null;

        if ($request->filled('order_number')) {
            $order = Order::with(['items', 'trackingUpdates'])
                ->where('order_number', $request->order_number)
                ->where('mobile', $request->mobile)
                ->first();
        }

        return view('frontend.tracking', compact('order'));
    }
}