using FluentAssertions;
using IBKRTrader.Core.Logging;
using IBKRTrader.Core.Orders;
using IBKRTrader.Core.Persistence.Ef;
using IBKRTrader.Core.Persistence.Entities;
using IBKRTrader.Core.Settings;
using IBKRTrader.Core.Trading;
using Microsoft.EntityFrameworkCore;
using NSubstitute;

namespace IBKRTrader.Tests.Orders;

[Trait("cat", "unit")]
public class OrderManagerTests
{
    private sealed class InMemoryFactory : IDbContextFactory<CoreDbContext>
    {
        private readonly DbContextOptions<CoreDbContext> _options;
        public InMemoryFactory(DbContextOptions<CoreDbContext> options) => _options = options;
        public CoreDbContext CreateDbContext() => new(_options);
    }

    private static (OrderManager Sut, IBrokerOrderBook OrderBook, IDbContextFactory<CoreDbContext> Dbf, SettingsService Settings) CreateSut()
    {
        var options = new DbContextOptionsBuilder<CoreDbContext>()
            .UseInMemoryDatabase(Guid.NewGuid().ToString())
            .Options;
        var factory = new InMemoryFactory(options);
        var orderBook = Substitute.For<IBrokerOrderBook>();
        var settings = new SettingsService();
        var logger = new LoggingService();

        var sut = new OrderManager(orderBook, factory, settings, logger);
        return (sut, orderBook, factory, settings);
    }

    [Fact]
    public async Task GetOrderOverviewAsync_IdentifiesBackedAndUnbackedOrders()
    {
        var (sut, orderBook, dbf, _) = CreateSut();

        // 1. Broker-Orders vorbereiten
        var bo1 = new BrokerOrder(
            OrderId: 101, PermId: 1001, Instrument: InstrumentRef.ForStock("AAPL"),
            Side: TradeSide.Buy, Quantity: 10, Filled: 0, Remaining: 10,
            OrderType: "LMT", LimitPrice: 150m, Status: "Submitted", Account: "U123");

        var bo2 = new BrokerOrder(
            OrderId: 102, PermId: 1002, Instrument: InstrumentRef.ForStock("MSFT"),
            Side: TradeSide.Buy, Quantity: 5, Filled: 0, Remaining: 5,
            OrderType: "LMT", LimitPrice: 400m, Status: "Submitted", Account: "U123");

        orderBook.GetOpenOrdersAsync(Arg.Any<CancellationToken>())
                 .Returns([bo1, bo2]);

        // 2. Eigene Kapitalbindung nur für bo1 anlegen
        await using (var db = dbf.CreateDbContext())
        {
            db.Reservations.Add(new CoreReservation
            {
                Id            = 1,
                SignalId      = "sig-1",
                Book          = "CT",
                Side          = "BUY",
                Quantity      = 10,
                ContractKey   = "AAPL",
                Amount        = 1500m,
                Currency      = "USD",
                State         = ReservationState.Submitted,
                BrokerOrderId = "101",
                CreatedAt     = DateTime.UtcNow,
                UpdatedAt     = DateTime.UtcNow
            });
            await db.SaveChangesAsync();
        }

        // Act
        var overview = await sut.GetOrderOverviewAsync();

        // Assert
        overview.BrokerReachable.Should().BeTrue();
        overview.Orders.Should().HaveCount(2);

        var managed1 = overview.Orders.First(o => o.BrokerOrder.OrderId == 101);
        managed1.IsBackedByReservation.Should().BeTrue();
        managed1.ReservationId.Should().Be(1);
        managed1.Book.Should().Be("CT");

        var managed2 = overview.Orders.First(o => o.BrokerOrder.OrderId == 102);
        managed2.IsBackedByReservation.Should().BeFalse();
        managed2.ReservationId.Should().BeNull();

        overview.UnbackedOrders.Should().HaveCount(1);
        overview.UnbackedOrders.Single().BrokerOrder.OrderId.Should().Be(102);
    }

    [Fact]
    public async Task CancelOrderAsync_DelegatesToBrokerOrderBook()
    {
        var (sut, orderBook, _, _) = CreateSut();
        orderBook.CancelOrderAsync(101, Arg.Any<CancellationToken>()).Returns(true);

        var result = await sut.CancelOrderAsync(101);

        result.Success.Should().BeTrue();
        result.Message.Should().Contain("101");
        await orderBook.Received(1).CancelOrderAsync(101, Arg.Any<CancellationToken>());
    }

    [Fact]
    public async Task CancelAllOrdersAsync_RejectsWhenNotPaperMode()
    {
        var (sut, orderBook, _, settings) = CreateSut();
        settings.Settings.Trading.Mode = "Live";

        var result = await sut.CancelAllOrdersAsync();

        result.Success.Should().BeFalse();
        result.Message.Should().Contain("Handelsmodus");
        await orderBook.DidNotReceive().GetOpenOrdersAsync(Arg.Any<CancellationToken>());
    }

    [Fact]
    public async Task CancelAllOrdersAsync_CancelsAllOrdersInPaperMode()
    {
        var (sut, orderBook, _, settings) = CreateSut();
        settings.Settings.Trading.Mode = "Paper";

        var bo1 = new BrokerOrder(
            OrderId: 201, PermId: 2001, Instrument: InstrumentRef.ForStock("AAPL"),
            Side: TradeSide.Buy, Quantity: 10, Filled: 0, Remaining: 10,
            OrderType: "LMT", LimitPrice: 150m, Status: "Submitted", Account: "U123");

        var bo2 = new BrokerOrder(
            OrderId: 202, PermId: 2002, Instrument: InstrumentRef.ForStock("MSFT"),
            Side: TradeSide.Buy, Quantity: 5, Filled: 0, Remaining: 5,
            OrderType: "LMT", LimitPrice: 400m, Status: "Submitted", Account: "U123");

        orderBook.GetOpenOrdersAsync(Arg.Any<CancellationToken>()).Returns([bo1, bo2]);
        orderBook.CancelOrderAsync(Arg.Any<int>(), Arg.Any<CancellationToken>()).Returns(true);

        var result = await sut.CancelAllOrdersAsync();

        result.Success.Should().BeTrue();
        result.Cancelled.Should().Be(2);
        result.Total.Should().Be(2);
        await orderBook.Received(1).CancelOrderAsync(201, Arg.Any<CancellationToken>());
        await orderBook.Received(1).CancelOrderAsync(202, Arg.Any<CancellationToken>());
    }

    [Fact]
    public async Task GetOrderOverviewAsync_WhenReservationHasNoBrokerOrderId_TreatedAsUnbacked()
    {
        var (sut, orderBook, dbf, _) = CreateSut();

        var bo = new BrokerOrder(
            OrderId: 301, PermId: 3001, Instrument: InstrumentRef.ForStock("NVDA"),
            Side: TradeSide.Buy, Quantity: 20, Filled: 0, Remaining: 20,
            OrderType: "LMT", LimitPrice: 120m, Status: "Submitted", Account: "U123");

        orderBook.GetOpenOrdersAsync(Arg.Any<CancellationToken>()).Returns([bo]);

        await using (var db = dbf.CreateDbContext())
        {
            db.Reservations.Add(new CoreReservation
            {
                Id            = 10,
                SignalId      = "sig-nvda",
                Book          = "CT",
                Side          = "BUY",
                Quantity      = 20,
                ContractKey   = "NVDA",
                Amount        = 2400m,
                Currency      = "USD",
                State         = ReservationState.Reserved,
                BrokerOrderId = null, // noch keine Order-ID zugewiesen
                CreatedAt     = DateTime.UtcNow,
                UpdatedAt     = DateTime.UtcNow
            });
            await db.SaveChangesAsync();
        }

        var overview = await sut.GetOrderOverviewAsync();

        overview.BrokerReachable.Should().BeTrue();
        overview.Orders.Should().HaveCount(1);
        var mo = overview.Orders.Single();
        mo.IsBackedByReservation.Should().BeFalse();
        overview.UnbackedOrders.Should().HaveCount(1);
    }

    [Fact]
    public async Task GetOrderOverviewAsync_HandlesBrokerException_Gracefully()
    {
        var (sut, orderBook, _, _) = CreateSut();
        orderBook.GetOpenOrdersAsync(Arg.Any<CancellationToken>())
                 .Returns<IReadOnlyList<BrokerOrder>>(_ => throw new InvalidOperationException("Broker offline"));

        var overview = await sut.GetOrderOverviewAsync();

        overview.BrokerReachable.Should().BeFalse();
        overview.Orders.Should().BeEmpty();
    }

    [Fact]
    public async Task CancelOrderAsync_WhenBrokerReturnsFalse_ReportsFailure()
    {
        var (sut, orderBook, _, _) = CreateSut();
        orderBook.CancelOrderAsync(999, Arg.Any<CancellationToken>()).Returns(false);

        var result = await sut.CancelOrderAsync(999);

        result.Success.Should().BeFalse();
        result.Message.Should().Contain("NICHT bestätigt");
    }
}