Bagian 2: Manajemen Produk

<?php

namespace App\Exceptions;

use RuntimeException;

class EmptyCartException extends RuntimeException
{
    public function __construct()
    {
        parent::__construct('Keranjang belanja kosong.');
    }
}

<?php

namespace App\Exceptions;

use App\Models\Product;
use RuntimeException;

class InsufficientStockException extends RuntimeException
{
    public function __construct(public readonly Product $product, public readonly int $requested)
    {
        parent::__construct(sprintf(
            'Stok %s tidak cukup: tersedia %d, diminta %d.',
            $product->name,
            $product->stock,
            $requested,
        ));
    }
}

<?php

namespace App\Exceptions;

use RuntimeException;

class InvalidStatusTransitionException extends RuntimeException
{
    public function __construct(public readonly string $from, public readonly string $to)
    {
        parent::__construct(sprintf(
            'Perubahan status dari "%s" ke "%s" tidak diizinkan.',
            $from,
            $to,
        ));
    }
}

<?php

namespace App\Exceptions;

use RuntimeException;

class ProductUnavailableException extends RuntimeException
{
    public function __construct()
    {
        parent::__construct(
            'Ada produk di keranjang yang sudah tidak tersedia lagi. Hapus produk tersebut lalu coba kembali.',
        );
    }
}

<?php

namespace App\Http\Controllers;

use Illuminate\Contracts\View\View;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;

class AuthController extends Controller
{
    public function showLogin(): View
    {
        return view('auth.login');
    }

    public function login(Request $request): RedirectResponse
    {
        $credentials = $request->validate([
            'email' => ['required', 'email'],
            'password' => ['required'],
        ]);

        if (Auth::attempt($credentials)) {
            $request->session()->regenerate();

            return redirect()->intended(route('catalog.index'));
        }

        return back()
            ->withErrors(['email' => 'Email atau password salah.'])
            ->onlyInput('email');
    }

    public function logout(Request $request): RedirectResponse
    {
        Auth::logout();

        $request->session()->invalidate();
        $request->session()->regenerateToken();

        return redirect()->route('catalog.index');
    }
}

<?php

namespace App\Http\Controllers;

use App\Http\Requests\CartItemRequest;
use App\Http\Requests\CartQuantityRequest;
use App\Models\Product;
use App\Services\CartService;
use Illuminate\Contracts\View\View;
use Illuminate\Http\RedirectResponse;

class CartController extends Controller
{
    public function __construct(private readonly CartService $cart)
    {
    }

    public function index(): View
    {
        return view('cart.index', [
            'items' => $this->cart->items(),
            'total' => $this->cart->total(),
            'count' => $this->cart->count(),
        ]);
    }

    /**
     * Tambah produk ke keranjang. Berlaku juga untuk tamu:
     * keranjang hidup di session, bukan di tabel database.
     */
    public function store(CartItemRequest $request): RedirectResponse
    {
        $this->cart->add((int) $request->integer('product_id'), (int) $request->integer('qty'));

        $product = Product::findOrFail($request->integer('product_id'));

        return back()
            ->with('status', "{$product->name} ({$request->integer('qty')} pcs) masuk keranjang.");
    }

    public function update(CartQuantityRequest $request, Product $product): RedirectResponse
    {
        $this->cart->setQuantity($product->id, (int) $request->integer('qty'));

        return redirect()
            ->route('cart.index')
            ->with('status', "Jumlah {$product->name} diperbarui.");
    }

    public function destroy(Product $product): RedirectResponse
    {
        $this->cart->remove($product->id);

        return redirect()
            ->route('cart.index')
            ->with('status', "{$product->name} dihapus dari keranjang.");
    }
}

<?php

namespace App\Http\Controllers;

use App\Models\Product;
use Illuminate\Contracts\View\View;

class CatalogController extends Controller
{
    /**
     * Katalog publik: hanya produk aktif, tamu boleh melihat.
     */
    public function index(): View
    {
        $products = Product::query()
            ->active()
            ->orderBy('name')
            ->paginate(8)
            ->withQueryString();

        return view('catalog.index', ['products' => $products]);
    }
}

<?php

namespace App\Http\Controllers;

use App\Exceptions\EmptyCartException;
use App\Exceptions\InsufficientStockException;
use App\Exceptions\ProductUnavailableException;
use App\Services\CartService;
use App\Services\CheckoutService;
use Illuminate\Contracts\View\View;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;

class CheckoutController extends Controller
{
    public function __construct(
        private readonly CartService $cart,
        private readonly CheckoutService $checkout,
    ) {
    }

    /**
     * Halaman tinjauan sebelum pesanan dibuat.
     */
    public function review(): View
    {
        return view('checkout.review', [
            'items' => $this->cart->items(),
            'total' => $this->cart->total(),
        ]);
    }

    /**
     * Jalankan checkout: keranjang berubah menjadi pesanan.
     */
    public function store(Request $request): RedirectResponse
    {
        try {
            $order = $this->checkout->checkout($request->user());
        } catch (InsufficientStockException $exception) {
            return back()->withErrors(['cart' => $exception->getMessage()]);
        } catch (EmptyCartException|ProductUnavailableException $exception) {
            return back()->withErrors(['cart' => $exception->getMessage()]);
        }

        return redirect()
            ->route('orders.show', $order)
            ->with('status', "Pesanan #{$order->id} berhasil dibuat.");
    }
}

<?php

namespace App\Http\Controllers;

abstract class Controller
{
    //
}

<?php

namespace App\Http\Controllers;

use App\Exceptions\InvalidStatusTransitionException;
use App\Http\Requests\OrderStatusRequest;
use App\Models\Order;
use Illuminate\Contracts\View\View;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;

class OrderController extends Controller
{
    /**
     * Daftar pesanan milik pengguna yang sedang login.
     */
    public function index(Request $request): View
    {
        $orders = $request->user()
            ->orders()
            ->latest('id')
            ->paginate(10);

        return view('orders.index', ['orders' => $orders]);
    }

    /**
     * Detail pesanan: item dengan harga snapshot + riwayat status.
     */
    public function show(Request $request, Order $order): View
    {
        abort_unless($order->user_id === $request->user()->id, 403);

        $order->load('items.product');

        return view('orders.show', [
            'order' => $order,
            'histories' => $order->histories()->with('user')->oldest('id')->get(),
        ]);
    }

    /**
     * Pindahkan status pesanan dan catat riwayatnya.
     */
    public function updateStatus(OrderStatusRequest $request, Order $order): RedirectResponse
    {
        abort_unless($order->user_id === $request->user()->id, 403);

        try {
            $order->transitionTo(
                $request->string('status')->toString(),
                $request->user(),
                $request->string('note')->toString() ?: null,
            );
        } catch (InvalidStatusTransitionException $exception) {
            return back()->withErrors(['status' => $exception->getMessage()]);
        }

        return redirect()
            ->route('orders.show', $order)
            ->with('status', 'Status pesanan menjadi ' . $order->status . '.');
    }
}

<?php

namespace App\Http\Controllers;

use App\Http\Requests\ProductRequest;
use App\Models\Product;
use Illuminate\Contracts\View\View;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;

class ProductController extends Controller
{
    /**
     * Daftar produk untuk admin: termasuk yang nonaktif.
     */
    public function index(Request $request): View
    {
        $products = Product::query()
            ->orderBy('name')
            ->paginate(10);

        return view('products.index', ['products' => $products]);
    }

    public function create(): View
    {
        return view('products.create', ['product' => new Product()]);
    }

    public function store(ProductRequest $request): RedirectResponse
    {
        $product = Product::create($request->validated());

        return redirect()
            ->route('products.show', $product)
            ->with('status', "Produk {$product->name} berhasil disimpan.");
    }

    public function show(Product $product): View
    {
        return view('products.show', ['product' => $product]);
    }

    public function edit(Product $product): View
    {
        return view('products.edit', ['product' => $product]);
    }

    public function update(ProductRequest $request, Product $product): RedirectResponse
    {
        $product->update($request->validated());

        return redirect()
            ->route('products.show', $product)
            ->with('status', "Produk {$product->name} berhasil diperbarui.");
    }

    public function destroy(Product $product): RedirectResponse
    {
        $name = $product->name;
        $product->delete();

        return redirect()
            ->route('products.index')
            ->with('status', "Produk {$name} berhasil dihapus.");
    }
}

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Validation\Rule;

class CartItemRequest extends FormRequest
{
    public function rules(): array
    {
        return [
            'product_id' => [
                'required',
                'integer',
                // Hanya produk aktif yang boleh masuk keranjang.
                Rule::exists('products', 'id')->where('is_active', true),
            ],
            'qty' => ['required', 'integer', 'min:1', 'max:99'],
        ];
    }

    public function attributes(): array
    {
        return [
            'product_id' => 'produk',
            'qty' => 'jumlah',
        ];
    }
}

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class CartQuantityRequest extends FormRequest
{
    public function rules(): array
    {
        return [
            // Nol diizinkan: artinya hapus produk dari keranjang.
            'qty' => ['required', 'integer', 'min:0', 'max:99'],
        ];
    }

    public function attributes(): array
    {
        return [
            'qty' => 'jumlah',
        ];
    }
}

<?php

namespace App\Http\Requests;

use App\Models\Order;
use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Validation\Rule;

class OrderStatusRequest extends FormRequest
{
    public function rules(): array
    {
        return [
            'status' => ['required', 'string', Rule::in(Order::STATUSES)],
            'note' => ['nullable', 'string', 'max:255'],
        ];
    }

    public function attributes(): array
    {
        return [
            'status' => 'status',
            'note' => 'catatan',
        ];
    }
}

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class ProductRequest extends FormRequest
{
    /**
     * Checkbox yang tidak dicentang tidak mengirim nilai apa pun,
     * jadi lengkapi dulu dengan boolean() sebelum divalidasi.
     */
    protected function prepareForValidation(): void
    {
        $this->merge(['is_active' => $this->boolean('is_active')]);
    }

    /**
     * Aturan yang sama dipakai untuk menyimpan dan mengubah produk.
     */
    public function rules(): array
    {
        return [
            'name' => ['required', 'string', 'max:100'],
            'description' => ['nullable', 'string', 'max:1000'],
            'price' => ['required', 'integer', 'min:0'],
            'stock' => ['required', 'integer', 'min:0'],
            'is_active' => ['required', 'boolean'],
        ];
    }

    public function attributes(): array
    {
        return [
            'name' => 'nama produk',
            'description' => 'deskripsi',
            'price' => 'harga',
            'stock' => 'stok',
            'is_active' => 'status aktif',
        ];
    }
}

<?php

namespace App\Models;

use App\Exceptions\InvalidStatusTransitionException;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Support\Facades\DB;

class Order extends Model
{
    public const STATUS_PENDING = 'pending';
    public const STATUS_PAID = 'paid';
    public const STATUS_SHIPPED = 'shipped';
    public const STATUS_COMPLETED = 'completed';
    public const STATUS_CANCELLED = 'cancelled';

    public const STATUSES = [
        self::STATUS_PENDING,
        self::STATUS_PAID,
        self::STATUS_SHIPPED,
        self::STATUS_COMPLETED,
        self::STATUS_CANCELLED,
    ];

    /**
     * Peta transisi status yang sah. Kuncinya adalah status saat ini,
     * nilainya daftar status yang boleh dituju.
     */
    public const TRANSITIONS = [
        self::STATUS_PENDING => [self::STATUS_PAID, self::STATUS_CANCELLED],
        self::STATUS_PAID => [self::STATUS_SHIPPED, self::STATUS_CANCELLED],
        self::STATUS_SHIPPED => [self::STATUS_COMPLETED],
        self::STATUS_COMPLETED => [],
        self::STATUS_CANCELLED => [],
    ];

    protected $fillable = [
        'user_id',
        'total',
        'status',
    ];

    protected function casts(): array
    {
        return [
            'total' => 'integer',
            'status' => 'string',
        ];
    }

    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }

    public function items(): HasMany
    {
        return $this->hasMany(OrderItem::class);
    }

    public function histories(): HasMany
    {
        return $this->hasMany(OrderStatusHistory::class);
    }

    /**
     * Daftar status yang boleh dituju dari status saat ini.
     *
     * @return list<string>
     */
    public function allowedTransitions(): array
    {
        return self::TRANSITIONS[$this->status] ?? [];
    }

    public function canTransitionTo(string $status): bool
    {
        return in_array($status, $this->allowedTransitions(), true);
    }

    /**
     * Pindahkan status pesanan dan catat riwayatnya secara atomik.
     */
    public function transitionTo(string $status, ?User $user = null, ?string $note = null): void
    {
        DB::transaction(function () use ($status, $user, $note): void {
            // Baca ulang dan kunci baris pesanan agar dua request tidak
            // memindahkan status yang sama secara bersamaan.
            $locked = Order::query()
                ->whereKey($this->id)
                ->lockForUpdate()
                ->firstOrFail();

            if (! $locked->canTransitionTo($status)) {
                throw new InvalidStatusTransitionException($locked->status, $status);
            }

            $from = $locked->status;
            $locked->status = $status;
            $locked->save();

            $locked->histories()->create([
                'from' => $from,
                'to' => $status,
                'user_id' => $user?->id,
                'note' => $note,
            ]);
        });

        $this->refresh();
    }
}

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

class OrderItem extends Model
{
    protected $fillable = [
        'order_id',
        'product_id',
        'qty',
        'price',
    ];

    protected function casts(): array
    {
        return [
            'qty' => 'integer',
            'price' => 'integer',
        ];
    }

    public function order(): BelongsTo
    {
        return $this->belongsTo(Order::class);
    }

    public function product(): BelongsTo
    {
        return $this->belongsTo(Product::class);
    }

    /**
     * Subtotal satu baris: harga snapshot dikali jumlah.
     */
    public function getSubtotalAttribute(): int
    {
        return $this->price * $this->qty;
    }
}

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

class OrderStatusHistory extends Model
{
    protected $fillable = [
        'order_id',
        'from',
        'to',
        'user_id',
        'note',
    ];

    protected function casts(): array
    {
        return [
            'from' => 'string',
            'to' => 'string',
        ];
    }

    public function order(): BelongsTo
    {
        return $this->belongsTo(Order::class);
    }

    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }
}

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\HasMany;

class Product extends Model
{
    protected $fillable = [
        'name',
        'description',
        'price',
        'stock',
        'is_active',
    ];

    protected function casts(): array
    {
        return [
            'price' => 'integer',
            'stock' => 'integer',
            'is_active' => 'boolean',
        ];
    }

    public function orderItems(): HasMany
    {
        return $this->hasMany(OrderItem::class);
    }

    /**
     * Produk aktif yang boleh tampil di katalog dan dimasukkan
     * ke keranjang.
     */
    public function scopeActive(Builder $query): Builder
    {
        return $query->where('is_active', true);
    }
}

<?php

namespace App\Models;

// use Illuminate\Contracts\Auth\MustVerifyEmail;
use Database\Factories\UserFactory;
use Illuminate\Database\Eloquent\Attributes\Fillable;
use Illuminate\Database\Eloquent\Attributes\Hidden;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;

#[Fillable(['name', 'email', 'password'])]
#[Hidden(['password', 'remember_token'])]
class User extends Authenticatable
{
    /** @use HasFactory<UserFactory> */
    use HasFactory, Notifiable;

    /**
     * Get the attributes that should be cast.
     *
     * @return array<string, string>
     */
    protected function casts(): array
    {
        return [
            'email_verified_at' => 'datetime',
            'password' => 'hashed',
        ];
    }

    public function orders(): HasMany
    {
        return $this->hasMany(Order::class);
    }
}

<?php

namespace App\Services;

use App\Models\Product;
use Illuminate\Contracts\Session\Session;
use Illuminate\Support\Collection;

/**
 * Keranjang belanja berbasis session.
 *
 * Session menyimpan pasangan product_id => qty, tanpa tabel khusus:
 * keranjang bersifat sementara, per pengguna, dan boleh hilang saat
 * session berakhir. Hanya pesanan hasil checkout yang permanen.
 */
class CartService
{
    private const KEY = 'cart';

    public function __construct(private readonly Session $session)
    {
    }

    /**
     * Isi keranjang: [product_id => qty].
     *
     * @return array<int, int>
     */
    public function get(): array
    {
        return $this->session->get(self::KEY, []);
    }

    public function isEmpty(): bool
    {
        return $this->get() === [];
    }

    /**
     * Tambah jumlah produk; produk yang sama digabung.
     */
    public function add(int $productId, int $qty): void
    {
        $cart = $this->get();
        $cart[$productId] = ($cart[$productId] ?? 0) + $qty;

        $this->session->put(self::KEY, $cart);
    }

    /**
     * Set jumlah produk; jumlah nol berarti hapus dari keranjang.
     */
    public function setQuantity(int $productId, int $qty): void
    {
        $cart = $this->get();

        if ($qty <= 0) {
            unset($cart[$productId]);
        } else {
            $cart[$productId] = $qty;
        }

        $this->session->put(self::KEY, $cart);
    }

    public function remove(int $productId): void
    {
        $cart = $this->get();
        unset($cart[$productId]);

        $this->session->put(self::KEY, $cart);
    }

    public function clear(): void
    {
        $this->session->forget(self::KEY);
    }

    /**
     * Baris keranjang yang siap ditampilkan, selalu urut product_id.
     *
     * @return Collection<int, array{product: Product, qty: int, subtotal: int}>
     */
    public function items(): Collection
    {
        $cart = $this->get();

        if ($cart === []) {
            return collect();
        }

        $products = Product::query()
            ->whereIn('id', array_keys($cart))
            ->orderBy('id')
            ->get()
            ->keyBy('id');

        return $products
            ->map(fn (Product $product): array => [
                'product' => $product,
                'qty' => $cart[$product->id],
                'subtotal' => $product->price * $cart[$product->id],
            ])
            ->values();
    }

    /**
     * Total harga seluruh keranjang berdasarkan harga saat ini.
     */
    public function total(): int
    {
        return $this->items()->sum('subtotal');
    }

    /**
     * Total jumlah barang (bukan jumlah jenis produk).
     */
    public function count(): int
    {
        return array_sum($this->get());
    }
}

<?php

namespace App\Services;

use App\Exceptions\EmptyCartException;
use App\Exceptions\InsufficientStockException;
use App\Exceptions\ProductUnavailableException;
use App\Models\Order;
use App\Models\OrderItem;
use App\Models\Product;
use App\Models\User;
use Illuminate\Support\Facades\DB;

/**
 * Mengubah keranjang session menjadi pesanan permanen.
 *
 * Seluruh pekerjaan berat berjalan di dalam DB::transaction():
 * kunci baris produk, periksa ulang stok, kurangi stok, buat
 * pesanan beserta itemnya (harga snapshot), lalu tulis riwayat
 * status pertama. Keranjang hanya dibersihkan setelah commit.
 */
class CheckoutService
{
    public function __construct(private readonly CartService $cart)
    {
    }

    public function checkout(User $user): Order
    {
        if ($this->cart->isEmpty()) {
            throw new EmptyCartException();
        }

        $cart = $this->cart->get();

        $order = DB::transaction(function () use ($user, $cart): Order {
            // Kunci semua baris produk sekaligus dengan urutan id yang
            // tetap, agar dua checkout bersamaan tidak saling mengunci
            // dalam urutan berbeda (mencegah deadlock).
            $products = Product::query()
                ->whereIn('id', array_keys($cart))
                ->orderBy('id')
                ->lockForUpdate()
                ->get()
                ->keyBy('id');

            // Periksa ulang ketersediaan dan stok dari baris yang dikunci.
            foreach ($cart as $productId => $qty) {
                $product = $products->get($productId);

                if ($product === null || $product->is_active === false) {
                    throw new ProductUnavailableException();
                }

                if ($product->stock < $qty) {
                    throw new InsufficientStockException($product, $qty);
                }
            }

            // Hitung total dan siapkan item dengan harga snapshot:
            // harga yang dibaca saat checkout, bukan saat masuk keranjang.
            $total = 0;
            $items = [];

            foreach ($cart as $productId => $qty) {
                $product = $products->get($productId);

                $total += $product->price * $qty;
                $items[] = [
                    'product_id' => $product->id,
                    'qty' => $qty,
                    'price' => $product->price,
                ];
            }

            $order = $user->orders()->create([
                'total' => $total,
                'status' => Order::STATUS_PENDING,
            ]);

            foreach ($items as $item) {
                $order->items()->create($item);
            }

            foreach ($products as $product) {
                $product->stock -= $cart[$product->id];
                $product->save();
            }

            $order->histories()->create([
                'from' => null,
                'to' => Order::STATUS_PENDING,
                'user_id' => $user->id,
                'note' => 'Pesanan dibuat dari keranjang.',
            ]);

            return $order;
        });

        // Keranjang hanya dibersihkan setelah transaksi berhasil di-commit.
        $this->cart->clear();

        return $order;
    }
}

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    public function up(): void
    {
        Schema::create('products', function (Blueprint $table) {
            $table->id();
            $table->string('name', 100);
            $table->text('description')->nullable();
            $table->unsignedInteger('price');
            $table->unsignedInteger('stock')->default(0);
            $table->boolean('is_active')->default(true);
            $table->timestamps();
        });
    }

    public function down(): void
    {
        Schema::dropIfExists('products');
    }
};

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    public function up(): void
    {
        Schema::create('orders', function (Blueprint $table) {
            $table->id();
            $table->foreignId('user_id')
                ->constrained()
                ->cascadeOnDelete();
            $table->unsignedBigInteger('total')->default(0);
            $table->enum('status', ['pending', 'paid', 'shipped', 'completed', 'cancelled'])
                ->default('pending');
            $table->timestamps();
            $table->index(['user_id', 'id']);
        });
    }

    public function down(): void
    {
        Schema::dropIfExists('orders');
    }
};

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    public function up(): void
    {
        Schema::create('order_items', function (Blueprint $table) {
            $table->id();
            $table->foreignId('order_id')
                ->constrained()
                ->cascadeOnDelete();
            $table->foreignId('product_id')
                ->constrained()
                ->restrictOnDelete();
            $table->unsignedInteger('qty');
            $table->unsignedInteger('price');
            $table->timestamps();

            // Satu pesanan paling banyak satu baris per produk,
            // karena keranjang disimpan sebagai pasangan produk => jumlah.
            $table->unique(['order_id', 'product_id']);
        });
    }

    public function down(): void
    {
        Schema::dropIfExists('order_items');
    }
};

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    public function up(): void
    {
        Schema::create('order_status_histories', function (Blueprint $table) {
            $table->id();
            $table->foreignId('order_id')
                ->constrained()
                ->cascadeOnDelete();
            // NULL berarti pesanan baru dibuat (transisi pertama menuju pending).
            $table->enum('from', ['pending', 'paid', 'shipped', 'completed', 'cancelled'])
                ->nullable();
            $table->enum('to', ['pending', 'paid', 'shipped', 'completed', 'cancelled']);
            $table->foreignId('user_id')
                ->nullable()
                ->constrained()
                ->nullOnDelete();
            $table->string('note')->nullable();
            $table->timestamps();
            $table->index(['order_id', 'id']);
        });
    }

    public function down(): void
    {
        Schema::dropIfExists('order_status_histories');
    }
};

<?php

namespace Database\Seeders;

use App\Models\Product;
use App\Models\User;
use Illuminate\Database\Seeder;
use Illuminate\Support\Facades\Hash;

class DatabaseSeeder extends Seeder
{
    public function run(): void
    {
        User::create([
            'name' => 'Budi Santoso',
            'email' => '[email protected]',
            'password' => Hash::make('password'),
        ]);

        User::create([
            'name' => 'Siti Rahayu',
            'email' => '[email protected]',
            'password' => Hash::make('password'),
        ]);

        $products = [
            [
                'name' => 'Kopi Arabika Gayo 250g',
                'description' => 'Biji kopi single origin dari Gayo, roasting medium.',
                'price' => 75000,
                'stock' => 25,
                'is_active' => true,
            ],
            [
                'name' => 'Teh Hijau Melati 100g',
                'description' => 'Teh hijau wangi melati dalam kemasan tin.',
                'price' => 35000,
                'stock' => 40,
                'is_active' => true,
            ],
            [
                'name' => 'Gula Aren Cair 500ml',
                'description' => 'Pemanis alami dari aren, cocok untuk kopi dan teh.',
                'price' => 28000,
                'stock' => 15,
                'is_active' => true,
            ],
            [
                'name' => 'Madu Hutan 250ml',
                'description' => 'Madu multiflora tanpa campuran gula.',
                'price' => 95000,
                'stock' => 10,
                'is_active' => true,
            ],
            [
                'name' => 'Beras Merah 1kg',
                'description' => null,
                'price' => 22000,
                'stock' => 30,
                'is_active' => true,
            ],
            [
                'name' => 'Keripik Singkong Balado',
                'description' => 'Sedang tidak dijual: menunggu kemasan baru.',
                'price' => 18000,
                'stock' => 50,
                'is_active' => false,
            ],
        ];

        foreach ($products as $product) {
            Product::create($product);
        }
    }
}

<?php

use App\Http\Controllers\AuthController;
use App\Http\Controllers\CartController;
use App\Http\Controllers\CatalogController;
use App\Http\Controllers\CheckoutController;
use App\Http\Controllers\OrderController;
use App\Http\Controllers\ProductController;
use Illuminate\Support\Facades\Route;

Route::get('/', [CatalogController::class, 'index'])->name('catalog.index');

Route::middleware('guest')->group(function () {
    Route::get('login', [AuthController::class, 'showLogin'])->name('login');
    Route::post('login', [AuthController::class, 'login'])->name('login.attempt');
});

Route::post('logout', [AuthController::class, 'logout'])
    ->middleware('auth')
    ->name('logout');

// Keranjang hidup di session, jadi tamu pun boleh menggunakannya.
Route::get('cart', [CartController::class, 'index'])->name('cart.index');
Route::post('cart', [CartController::class, 'store'])->name('cart.store');
Route::put('cart/{product}', [CartController::class, 'update'])->name('cart.update');
Route::delete('cart/{product}', [CartController::class, 'destroy'])->name('cart.destroy');

Route::middleware('auth')->group(function () {
    Route::get('checkout', [CheckoutController::class, 'review'])->name('checkout.review');
    Route::post('checkout', [CheckoutController::class, 'store'])->name('checkout.store');

    Route::get('orders', [OrderController::class, 'index'])->name('orders.index');
    Route::get('orders/{order}', [OrderController::class, 'show'])->name('orders.show');
    Route::post('orders/{order}/status', [OrderController::class, 'updateStatus'])->name('orders.status');

    Route::resource('products', ProductController::class);
});

<?php

namespace Tests\Feature;

use App\Models\User;
use Illuminate\Foundation\Testing\RefreshDatabase;
use Tests\TestCase;

class AuthTest extends TestCase
{
    use RefreshDatabase;

    public function test_tamu_diarahkan_ke_halaman_login(): void
    {
        $this->get(route('products.index'))
            ->assertRedirect(route('login'));
    }

    public function test_login_berhasil_dan_gagal(): void
    {
        User::factory()->create([
            'name' => 'Budi Santoso',
            'email' => '[email protected]',
            'password' => 'password',
        ]);

        $this->from(route('login'))
            ->post(route('login.attempt'), [
                'email' => '[email protected]',
                'password' => 'salah',
            ])
            ->assertSessionHasErrors('email');

        $this->from(route('login'))
            ->post(route('login.attempt'), [
                'email' => '[email protected]',
                'password' => 'password',
            ])
            ->assertRedirect(route('catalog.index'));

        $this->assertAuthenticated();
    }

    public function test_logout_mengakhiri_sesi(): void
    {
        $user = User::factory()->create([
            'name' => 'Budi Santoso',
            'email' => '[email protected]',
        ]);

        $this->actingAs($user)
            ->post(route('logout'))
            ->assertRedirect(route('catalog.index'));

        $this->assertGuest();
    }
}

<?php

namespace Tests\Feature;

use App\Models\Product;
use App\Models\User;
use App\Services\CartService;
use Illuminate\Foundation\Testing\RefreshDatabase;
use Tests\TestCase;

class CartTest extends TestCase
{
    use RefreshDatabase;

    private function user(): User
    {
        return User::factory()->create([
            'name' => 'Budi Santoso',
            'email' => '[email protected]',
        ]);
    }

    private function product(array $overrides = []): Product
    {
        return Product::create([
            'name' => 'Kopi Arabika Gayo 250g',
            'description' => 'Biji kopi single origin dari Gayo, roasting medium.',
            'price' => 75000,
            'stock' => 25,
            'is_active' => true,
            ...$overrides,
        ]);
    }

    public function test_tamu_bisa_menambah_produk_ke_keranjang(): void
    {
        $product = $this->product();

        $this->from(route('catalog.index'))
            ->post(route('cart.store'), [
                'product_id' => $product->id,
                'qty' => 2,
            ])
            ->assertRedirect(route('catalog.index'));

        $this->assertSame([$product->id => 2], app(CartService::class)->get());
    }

    public function test_menambah_produk_sama_menggabungkan_jumlah(): void
    {
        $product = $this->product();

        $cart = app(CartService::class);
        $cart->add($product->id, 2);
        $cart->add($product->id, 3);

        $this->assertSame([$product->id => 5], $cart->get());
        $this->assertSame(5, $cart->count());
    }

    public function test_jumlah_produk_bisa_diperbarui(): void
    {
        $user = $this->user();
        $product = $this->product();

        app(CartService::class)->add($product->id, 2);

        $this->actingAs($user)
            ->from(route('cart.index'))
            ->put(route('cart.update', $product), ['qty' => 4])
            ->assertRedirect(route('cart.index'));

        $this->assertSame([$product->id => 4], app(CartService::class)->get());
    }

    public function test_update_jumlah_nol_menghapus_produk(): void
    {
        $user = $this->user();
        $product = $this->product();

        app(CartService::class)->add($product->id, 2);

        $this->actingAs($user)
            ->put(route('cart.update', $product), ['qty' => 0]);

        $this->assertSame([], app(CartService::class)->get());
    }

    public function test_produk_bisa_dihapus_dari_keranjang(): void
    {
        $user = $this->user();
        $product = $this->product();

        app(CartService::class)->add($product->id, 2);

        $this->actingAs($user)
            ->delete(route('cart.destroy', $product))
            ->assertRedirect(route('cart.index'));

        $this->assertSame([], app(CartService::class)->get());
    }

    public function test_produk_nonaktif_ditolak_masuk_keranjang(): void
    {
        $product = $this->product(['is_active' => false]);

        $this->from(route('catalog.index'))
            ->post(route('cart.store'), [
                'product_id' => $product->id,
                'qty' => 1,
            ])
            ->assertSessionHasErrors('product_id');

        $this->assertSame([], app(CartService::class)->get());
    }

    public function test_validasi_form_keranjang_ditolak(): void
    {
        $product = $this->product();

        $this->from(route('catalog.index'))
            ->post(route('cart.store'), [
                'product_id' => $product->id,
                'qty' => 0,
            ])
            ->assertSessionHasErrors('qty');

        $this->from(route('catalog.index'))
            ->post(route('cart.store'), [
                'product_id' => 99999,
                'qty' => 1,
            ])
            ->assertSessionHasErrors('product_id');

        $this->assertSame([], app(CartService::class)->get());
    }

    public function test_halaman_keranjang_menampilkan_isi_dan_total(): void
    {
        $user = $this->user();
        $kopi = $this->product();
        $teh = $this->product([
            'name' => 'Teh Hijau Melati 100g',
            'price' => 35000,
        ]);

        app(CartService::class)->add($kopi->id, 2); // 150000
        app(CartService::class)->add($teh->id, 1);  //  35000

        $this->actingAs($user)
            ->get(route('cart.index'))
            ->assertOk()
            ->assertSee('Kopi Arabika Gayo 250g')
            ->assertSee('Teh Hijau Melati 100g')
            ->assertSee('Rp185.000')
            ->assertSee('3 barang');
    }
}