using System;
using System.Collections.Generic;
using System.Numerics;
using Skeleton.Algebra.Extensions;
using Skeleton.Algebra.ScalarFieldStructure;
using Skeleton.DataStructure.Packs.MatrixDecompositions;
using Skeleton.Samples;
using Skeleton.Utils;

namespace Skeleton.Test;

public static class DecompositionTest
{
    [DatapointSource]
    public static readonly IEnumerable<C44> TestMatrices = 
        100.ScaleSamples(-1, 1).C44InvertibleSamples();

    private static readonly Action<C44> OnFail = x =>
    {
        
        PLUPack<Complex, C44> res = x.PLUDecomposition();
        Console.WriteLine("======================================");
        Console.WriteLine(x.Representation);
        Console.WriteLine("-------");
        Console.WriteLine();
        Console.WriteLine(x.Det());
        Console.WriteLine();
        Console.WriteLine(res.Det);
        
        Console.WriteLine("P");
        Console.WriteLine(res.P.Representation);
        Console.WriteLine("L");
        Console.WriteLine(res.L.Representation);
        Console.WriteLine("U");
        Console.WriteLine(res.U.Representation);
        Console.WriteLine("+++++++++");
        Console.WriteLine((res.P * res.L * res.U).Representation);
        Console.WriteLine("======================================");
    };

    [Theory]
    public static void C44PLUTest(C44 data)
    {
        Action<C44> rawTest = x =>
        {
            PLUPack<Complex, C44> res = x.PLUDecomposition();
            Assert.IsTrue((res.P * res.L * res.U).IsEqualApprox(x));
            Assert.IsTrue(res.Det.IsEqualApprox(x.Det()));  
        };
        rawTest.OnFail(OnFail)(data);
    }

    [Test]
    public static void R44PLUTest()
    {
        R44 t = new R44(
            1, 2, 4, 8,
            2, 8, 16, 64,
            2, 8, 32, 128,
            2, 8, 32, 256
        );
        PLUPack<double, R44> x = t.PLUDecomposition();
        Assert.IsTrue(RealFieldStructure.Structure.IsEqualApprox(x.Det, t.Det()));
        Assert.IsTrue((x.P * x.L * x.U).IsEqualApprox(t));

        R44 tt = new R44(
            0, 1, 2, 1,
            1, 0, 0, 0,
            2, 1, 2, 1,
            1, 2, 4, 3
        );
        PLUPack<double, R44> xy = tt.PLUDecomposition();
        Console.WriteLine($"{tt.Det()}   x   {xy.Det}");
        Assert.IsTrue(RealFieldStructure.Structure.IsEqualApprox(tt.Det(), xy.Det));
        
        Console.WriteLine(xy.L.Representation);
        Console.WriteLine();
        Console.WriteLine((xy.P * xy.L * xy.U).Representation);
        Assert.IsTrue((xy.P * xy.L * xy.U).IsEqualApprox(tt));
    }

    [Test]
    public static void R22PLUTest()
    {
        R22 a = new R22(3, 6, 2, 1);
        var s = a.PLUDecomposition();
        Assert.IsTrue(s.Det.IsEqualApprox(-9));
        Assert.IsTrue((s.P * s.L * s.U).IsEqualApprox(a));
    }

    [Test]
    public static void R33PLUTest()
    {
        R33 a = new R33(
            1, 2, 3,
            3, 5, 7,
            2, 4, 1
        );
        var s = a.PLUDecomposition();
        Console.WriteLine("P");
        Console.WriteLine(s.P.Representation);
        Console.WriteLine("L");
        Console.WriteLine(s.L.Representation);
        Console.WriteLine("U");
        Console.WriteLine(s.U.Representation);
        Console.WriteLine($"{s.Det}   x   {a.Det()}");
        Assert.IsTrue(s.Det.IsEqualApprox(a.Det()));
        Assert.IsTrue((s.P * s.L * s.U).IsEqualApprox(a));

    }
    [Test]
    public static void C33QRDcompositionTest()
    {
        C33 a = new (
            0, 3, 1,
            0, 4, -2,
            2, 1, 1
        );
        var w = a.QRDecomposition();
        Assert.IsTrue(w.Q.Property.IsOrthogonal);
        Assert.IsTrue(w.R.Property.IsUpperTriangle);
        Assert.IsTrue((w.Q * w.R).IsEqualApprox(a));
    }

    [Theory]
    public static void C44QRDecompositionTest(C44 data)
    {
        Action<C44> rawTest = x =>
        {
            QRPair<C44> qr = x.QRDecomposition();
            Assert.IsTrue((qr.Q * qr.R).IsEqualApprox(x));
            Assert.IsTrue(qr.Q.Property.IsUnitary);
            Assert.IsTrue(qr.R.Property.IsUpperTriangle);
        };
        rawTest.OnFail(OnFail)(data);
    }

}