using FluentAssertions;
using IBKRTrader.Core.Analytics;
using IBKRTrader.Core.Persistence.Entities;

namespace IBKRTrader.Tests.Analytics;

[Trait("cat", "unit")]
public class RealizedPnlEngineTests
{
    private static CoreTrade Fill(string action, decimal qty, decimal price, int minute, string symbol = "AAPL") =>
        new()
        {
            Module = "CT", Symbol = symbol, Action = action,
            Quantity = qty, Price = price, TotalValue = qty * price,
            TradedAt = new DateTime(2026, 1, 1, 0, minute, 0, DateTimeKind.Utc)
        };

    [Fact]
    public void BuyThenSellAll_RealizesFullPnl()
    {
        var fills = new[] { Fill("BUY", 10, 100m, 0), Fill("SELL", 10, 130m, 1) };

        var realized = RealizedPnlEngine.Match(fills);

        realized.Should().HaveCount(1);
        realized[0].RealizedPnl.Should().Be(300m);  // (130-100)*10
    }

    [Fact]
    public void Sell_MatchesOldestLotsFirst_Fifo()
    {
        var fills = new[]
        {
            Fill("BUY", 10, 100m, 0),
            Fill("BUY", 10, 120m, 1),
            Fill("SELL", 15, 130m, 2)   // 10 gegen 100er-Lot, 5 gegen 120er-Lot
        };

        var realized = RealizedPnlEngine.Match(fills);

        realized.Should().HaveCount(2);
        realized[0].RealizedPnl.Should().Be((130m - 100m) * 10m);  // 300
        realized[1].RealizedPnl.Should().Be((130m - 120m) * 5m);   // 50
        RealizedPnlEngine.TotalRealized(fills).Should().Be(350m);
    }

    [Fact]
    public void PartialSell_LeavesRemainderOpen()
    {
        var fills = new[] { Fill("BUY", 10, 100m, 0), Fill("SELL", 4, 130m, 1) };

        var realized = RealizedPnlEngine.Match(fills);

        realized.Should().HaveCount(1);
        realized[0].Quantity.Should().Be(4m);
        realized[0].RealizedPnl.Should().Be(120m);
    }

    [Fact]
    public void SellExceedingHoldings_IgnoresSurplus_NoShort()
    {
        var fills = new[] { Fill("BUY", 5, 100m, 0), Fill("SELL", 8, 130m, 1) };

        var realized = RealizedPnlEngine.Match(fills);

        realized.Should().HaveCount(1);
        realized[0].Quantity.Should().Be(5m);   // nur die gehaltenen 5 realisiert
    }

    [Fact]
    public void SeparatesBySymbol()
    {
        var fills = new[]
        {
            Fill("BUY", 10, 100m, 0, "AAPL"),
            Fill("BUY", 10, 50m, 1, "MSFT"),
            Fill("SELL", 10, 130m, 2, "AAPL")
        };

        var realized = RealizedPnlEngine.Match(fills);

        realized.Should().HaveCount(1);
        realized[0].Symbol.Should().Be("AAPL");
    }
}