ANTOOZA-BACKEND/Tests/Application.Tests/PaymentCancelHandlerTests.cs

using Domain.Entities.Common.ValueObject;
using Domain.Entities.Payments.ValueObject;
using Domain.Entities.Wallets;
using Domain.Entities.Wallets.ValueObject;
using Microsoft.EntityFrameworkCore;
using CancelCommand = Application.Features.Api.Payment.Cancel.Command;
using CancelHandler = Application.Features.Api.Payment.Cancel.Handler;

namespace Application.Tests;

[TestClass]
public sealed class PaymentCancelHandlerTests
{
    [TestMethod]
    public async Task Cancel_RefundsPgCharged_WithChargeCancelledTx()
    {
        // P0 #3 재현: 취소 환불이 Balances 미로딩 + Adjusted 버킷 차감으로
        // Danal 취소 성공 후 예외가 발생했다 (PG-지갑 desync).
        // 기대 행위: PgCharged 에서 회수하고 ChargeCancelled 트랜잭션을 기록한다.
        using var db = TestDb.Create();
        var memberID = await TestDb.CreateMemberAsync(db);
        var wallet = Wallet.Create(memberID);
        wallet.CreditPgCharge(Money.KRW(10000), "충전", "SEED");
        await db.Wallet.AddAsync(wallet);
        var order = await TestDb.CreateOrderAsync(db, memberID, 10000, paid: true);
        var fake = new FakeDanalPayService();
        var handler = new CancelHandler(db, fake);

        var result = await handler.Handle(new CancelCommand(order.OrderID, memberID), default);

        Assert.IsTrue(result.IsSuccess, $"취소가 성공해야 한다: {(result.IsSuccess ? "" : result.Error.Description)}");

        using var verify = TestDb.Create();
        var savedOrder = await verify.PaymentOrder.SingleAsync(o => o.OrderID == order.OrderID);
        Assert.AreEqual(PaymentStatus.Cancelled, savedOrder.Status);

        var savedWallet = await verify.Wallet.Include(w => w.Balances).Include(w => w.Transactions).AsSplitQuery().SingleAsync(w => w.MemberID == memberID);
        Assert.AreEqual(0m, savedWallet.Balances.Single(b => b.Type == WalletBalanceType.PgCharged).Amount.Value, "환불은 PgCharged 에서 회수한다");
        Assert.IsTrue(savedWallet.Transactions.Any(t => t.TxType == WalletTransactionType.ChargeCancelled && t.Amount.Value == 10000m && t.RefID == order.OrderID), "ChargeCancelled 원장 기록이 있어야 한다");
    }

    [TestMethod]
    public async Task PointsAlreadySpent_Fails_BeforePgCall()
    {
        // 기대 행위: 충전 포인트를 이미 사용했다면 PG 호출 전에 거절한다.
        using var db = TestDb.Create();
        var memberID = await TestDb.CreateMemberAsync(db);
        var wallet = Wallet.Create(memberID);
        wallet.CreditPgCharge(Money.KRW(10000), "충전", "SEED");
        wallet.Spend(Money.KRW(8000), "사용");
        await db.Wallet.AddAsync(wallet);
        var order = await TestDb.CreateOrderAsync(db, memberID, 10000, paid: true);
        var fake = new FakeDanalPayService();
        var handler = new CancelHandler(db, fake);

        var result = await handler.Handle(new CancelCommand(order.OrderID, memberID), default);

        Assert.IsFalse(result.IsSuccess, "사용분이 있으면 취소를 거절해야 한다");
        Assert.AreEqual(0, fake.CancelCallCount, "거절은 PG 호출 전에 이뤄져야 한다");

        using var verify = TestDb.Create();
        var savedOrder = await verify.PaymentOrder.SingleAsync(o => o.OrderID == order.OrderID);
        Assert.AreEqual(PaymentStatus.Paid, savedOrder.Status, "주문 상태는 그대로 Paid 여야 한다");
    }

    [TestMethod]
    public async Task WalletMissing_Fails_BeforePgCall()
    {
        // P0 #3 파생 재현: 기존 코드는 지갑이 없으면 PG 취소 후 포인트 회수를 조용히 건너뛰었다
        // (사용자가 돈을 돌려받고 포인트도 유지). 기대 행위: PG 호출 전에 거절한다.
        using var db = TestDb.Create();
        var memberID = await TestDb.CreateMemberAsync(db);
        var order = await TestDb.CreateOrderAsync(db, memberID, 10000, paid: true);
        var fake = new FakeDanalPayService();
        var handler = new CancelHandler(db, fake);

        var result = await handler.Handle(new CancelCommand(order.OrderID, memberID), default);

        Assert.IsFalse(result.IsSuccess, "지갑이 없으면 취소를 거절해야 한다");
        Assert.AreEqual(0, fake.CancelCallCount, "거절은 PG 호출 전에 이뤄져야 한다");
    }

    [TestMethod]
    public async Task PgCommException_LeavesOrderPaid_And_WalletUntouched()
    {
        // 리뷰 #8 재현: PG 취소 통신 예외 경로가 무테스트라, DebitChargeCancel 을 PG 앞으로 옮기는
        // 회귀(선차감 후 PG 실패 → 실제 미취소인데 포인트 차감)를 잡지 못했다.
        // 기대 행위: 예외 시 지갑 무변경 + 주문 Paid 유지.
        using var db = TestDb.Create();
        var memberID = await TestDb.CreateMemberAsync(db);
        var wallet = Wallet.Create(memberID);
        wallet.CreditPgCharge(Money.KRW(10000), "충전", "SEED");
        await db.Wallet.AddAsync(wallet);
        var order = await TestDb.CreateOrderAsync(db, memberID, 10000, paid: true);
        var fake = new FakeDanalPayService { CancelException = new HttpRequestException("timeout") };
        var handler = new CancelHandler(db, fake);

        var result = await handler.Handle(new CancelCommand(order.OrderID, memberID), default);

        Assert.IsFalse(result.IsSuccess);

        using var verify = TestDb.Create();
        var savedOrder = await verify.PaymentOrder.SingleAsync(o => o.OrderID == order.OrderID);
        Assert.AreEqual(PaymentStatus.Paid, savedOrder.Status, "PG 취소 실패 시 주문은 Paid 로 유지");

        var savedWallet = await verify.Wallet.Include(w => w.Balances).AsSplitQuery().SingleAsync(w => w.MemberID == memberID);
        Assert.AreEqual(10000m, savedWallet.Balances.Single(b => b.Type == WalletBalanceType.PgCharged).Amount.Value, "PG 미취소 시 포인트는 차감되지 않아야 한다");
    }

    [TestMethod]
    public async Task NotPaidOrder_Fails()
    {
        using var db = TestDb.Create();
        var memberID = await TestDb.CreateMemberAsync(db);
        var wallet = Wallet.Create(memberID);
        await db.Wallet.AddAsync(wallet);
        var order = await TestDb.CreateOrderAsync(db, memberID);
        var fake = new FakeDanalPayService();
        var handler = new CancelHandler(db, fake);

        var result = await handler.Handle(new CancelCommand(order.OrderID, memberID), default);

        Assert.IsFalse(result.IsSuccess);
        Assert.AreEqual(0, fake.CancelCallCount);
    }
}