<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Models\Transaksi;
use App\Models\DetailTransaksi;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Auth;

class TransaksiController extends Controller
{
    /**
     * PROSES CHECKOUT / MENYIMPAN TRANSAKSI.
     * Menggunakan DB Transaction agar data header dan detail tersimpan atomik (bersamaan).
     */
    public function store(Request $request)
    {
        $cart = session()->get('cart');
        
        // Validasi Keranjang (Backend validation)
        if (!$cart) {
            return redirect()->route('shop')->with('error', 'Keranjang kosong!');
        }

        // Validasi Input User
        $request->validate([
            'alamat_pengiriman' => 'required|string|max:500',
            'no_hp' => 'required|numeric',
            'nama_lengkap' => 'required|string|max:255',
        ]);

        try {
            DB::beginTransaction();

            $subtotal = $this->hitungSubtotal($cart);
            $ongkir = 10000;
            $total_bayar = $subtotal + $ongkir;

            $transaksi = Transaksi::create([
                'pembeli_id' => Auth::guard('pembeli')->id(), 
                'tanggal_transaksi' => now(),
                'alamat_pengiriman' => $request->alamat_pengiriman,
                'total_harga' => $total_bayar,
                'status' => 'pending', 
                'kode_invoice' => 'INV/' . date('Ymd') . '/' . mt_rand(1000, 9999),
                'catatan' => $request->catatan, 
            ]);

            foreach ($cart as $id_produk => $details) {
                DetailTransaksi::create([
                    'transaksi_id' => $transaksi->id,
                    'produk_id' => $id_produk,
                    'jumlah' => $details['quantity'],
                    'harga_satuan' => $details['price'],
                    'subtotal' => $details['price'] * $details['quantity'],
                ]);
            }

            DB::commit();

            session()->forget('cart');

            return redirect()->route('home')->with('success', 'Pesanan berhasil dibuat! Kode Invoice: ' . $transaksi->kode_invoice);

        } catch (\Exception $e) {
            DB::rollBack();
            return redirect()->back()->with('error', 'Terjadi kesalahan saat memproses transaksi: ' . $e->getMessage());
        }
    }

    /**
     * Helper untuk menghitung subtotal belanjaan dari session.
     */
    private function hitungSubtotal($cart)
    {
        $total = 0;
        foreach($cart as $id => $details) {
            $total += $details['price'] * $details['quantity'];
        }
        return $total;
    }
}