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.Toss.Cancel.Command;
using CancelHandler = Application.Features.Api.Payment.Toss.Cancel.Handler;

namespace Application.Tests;

[TestClass]
public sealed class TossCancelHandlerTests
{
    [TestMethod]
    public async Task Cancel_RefundsPgCharged_WithChargeCancelledTx()
    {
        // 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 FakeTossPaymentService();
        var handler = new CancelHandler(db, fake, FakeAppDbContextFactory.Instance);

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

        Assert.IsTrue(result.IsSuccess, $"취소가 성공해야 한다: {(result.IsSuccess ? "" : result.Error.Description)}");
        Assert.AreEqual(1, fake.CancelCallCount);

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

        var savedCancel = await verify.TossCancel.SingleAsync(c => c.OrderID == order.OrderID);
        Assert.IsTrue(savedCancel.IsSuccess, "취소 성공 응답이 기록되어야 한다");
        Assert.AreEqual("CANCELED", savedCancel.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 캐시를 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 FakeTossPaymentService();
        var handler = new CancelHandler(db, fake, FakeAppDbContextFactory.Instance);

        var result = await handler.Handle(new CancelCommand(order.OrderID, null, 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()
    {
        // 지갑이 없으면 PG 호출 전에 거절한다 (PG 환불 + 캐시 유지 desync 방지).
        using var db = TestDb.Create();
        var memberID = await TestDb.CreateMemberAsync(db);
        var order = await TestDb.CreateOrderAsync(db, memberID, 10000, paid: true);
        var fake = new FakeTossPaymentService();
        var handler = new CancelHandler(db, fake, FakeAppDbContextFactory.Instance);

        var result = await handler.Handle(new CancelCommand(order.OrderID, null, 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()
    {
        // PG 취소 통신 예외 시 지갑 무변경 + 주문 Paid 유지 (선차감 회귀 방지).
        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 FakeTossPaymentService { CancelException = new HttpRequestException("timeout") };
        var handler = new CancelHandler(db, fake, FakeAppDbContextFactory.Instance);

        var result = await handler.Handle(new CancelCommand(order.OrderID, null, 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 캐시는 차감되지 않아야 한다");
    }

    [TestMethod]
    public async Task ConflictThenPointsSpent_WritesReconcileLog_AndThrows()
    {
        // Phase 1.5: PG 취소 성공 후 저장이 동시성 충돌로 실패했고, 그 사이 캐시가 사용돼
        // 재시도(리로드 재적용)도 불가능한 경우 — PG 는 이미 환불됐으므로 자동 복구 불가.
        // 기대 행위: PaymentReconcileLog 를 독립 커밋으로 남기고 예외를 전파한다(기존 실패 흐름 유지).
        int memberID;
        string orderID;
        int orderPk;
        using (var setup = TestDb.Create())
        {
            memberID = await TestDb.CreateMemberAsync(setup);
            var wallet = Wallet.Create(memberID);
            wallet.CreditPgCharge(Money.KRW(10000), "충전", "SEED");
            await setup.Wallet.AddAsync(wallet);
            var order = await TestDb.CreateOrderAsync(setup, memberID, 10000, paid: true);
            orderID = order.OrderID;
            orderPk = order.ID;
        }

        using var db = TestDb.Create();
        // 핸들러 컨텍스트에 지갑/잔액을 미리 추적시켜 stale rowversion 상태를 만든다
        // (선검증은 stale 잔액 10000 을 보고 통과 → PG 취소 성공 → 저장에서 충돌)
        _ = await db.Wallet.Include(w => w.Balances).AsSplitQuery().SingleAsync(w => w.MemberID == memberID);

        using (var other = TestDb.Create())
        {
            var concurrent = await other.Wallet.Include(w => w.Balances).AsSplitQuery().SingleAsync(w => w.MemberID == memberID);
            concurrent.Spend(Money.KRW(8000), "동시 사용");
            await other.SaveChangesAsync(default);
        }

        var fake = new FakeTossPaymentService();
        var handler = new CancelHandler(db, fake, FakeAppDbContextFactory.Instance);

        await Assert.ThrowsExceptionAsync<InvalidOperationException>(() => handler.Handle(new CancelCommand(orderID, null, memberID), default));
        Assert.AreEqual(1, fake.CancelCallCount, "PG 취소는 1회만 호출되어야 한다");

        using var verify = TestDb.Create();
        var log = await verify.PaymentReconcileLog.SingleOrDefaultAsync(l => l.PaymentOrderID == orderPk);
        Assert.IsNotNull(log, "대사 로그가 독립 커밋으로 남아야 한다");
        Assert.AreEqual(ReconcileKind.Cancel, log.Kind);
        Assert.AreEqual(10000, log.Amount);

        var savedOrder = await verify.PaymentOrder.SingleAsync(o => o.OrderID == orderID);
        Assert.AreEqual(PaymentStatus.Paid, savedOrder.Status, "재시도 실패 시 로컬 상태는 미변경(수동 대사 대상)이어야 한다");

        var savedWallet = await verify.Wallet.Include(w => w.Balances).AsSplitQuery().SingleAsync(w => w.MemberID == memberID);
        Assert.AreEqual(2000m, savedWallet.Balances.Single(b => b.Type == WalletBalanceType.PgCharged).Amount.Value, "동시 사용 반영 외 지갑 변경이 없어야 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 FakeTossPaymentService();
        var handler = new CancelHandler(db, fake, FakeAppDbContextFactory.Instance);

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

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