using Xunit;
using TALib;
using System.Diagnostics.CodeAnalysis;
using System.Security.Cryptography;

namespace QuanTAlib;

public class TAlibTests
{
    private readonly GbmFeed feed;
    private readonly RandomNumberGenerator rng;
    private readonly double range;
    private readonly int iterations;
    private readonly double[] data;
    private readonly double[] TALIB;

    public TAlibTests()
    {
        rng = RandomNumberGenerator.Create();
        feed = new(sigma: 0.5, mu: 0.0);
        range = 1e-9;
        feed.Add(10000);
        iterations = 3;
        data = feed.Close.v.ToArray();
        TALIB = new double[data.Count()];
    }

    private int GetRandomNumber(int minValue, int maxValue)
    {
        byte[] randomBytes = new byte[4];
        rng.GetBytes(randomBytes);
        int randomInt = BitConverter.ToInt32(randomBytes, 0);
        return Math.Abs(randomInt % (maxValue - minValue)) + minValue;
    }

    [Fact]
    public void SMA()
    {
        for (int run = 0; run < iterations; run++)
        {
            int period = GetRandomNumber(5, 55);
            Sma ma = new(period);
            TSeries QL = new();
            foreach (TBar item in feed)
            { QL.Add(ma.Calc(new TValue(item.Time, item.Close))); }
            Core.Sma(data, 0, QL.Length - 1, TALIB, out int outBegIdx, out _, period);
            Assert.Equal(QL.Length, TALIB.Count());
            for (int i = QL.Length - 1; i > period; i--)
            {
                Assert.InRange(TALIB[i - outBegIdx] - QL[i].Value, -range, range);
            }
        }
    }

    [Fact]
    public void EMA()
    {
        for (int run = 0; run < iterations; run++)
        {
            int period = GetRandomNumber(5, 55);
            Ema ma = new(period, useSma: true);
            TSeries QL = new();
            foreach (TBar item in feed)
            { QL.Add(ma.Calc(new TValue(item.Time, item.Close))); }
            Core.Ema(data, 0, QL.Length - 1, TALIB, out int outBegIdx, out _, period);
            Assert.Equal(QL.Length, TALIB.Count());
            for (int i = QL.Length - 1; i > period; i--)
            {
                Assert.InRange(TALIB[i - outBegIdx] - QL[i].Value, -range, range);
            }
        }
    }

    [Fact]
    public void DEMA()
    {
        for (int run = 0; run < iterations; run++)
        {
            int period = GetRandomNumber(5, 55);
            Dema ma = new(period);
            TSeries QL = new();
            foreach (TBar item in feed)
            { QL.Add(ma.Calc(new TValue(item.Time, item.Close))); }
            Core.Dema(data, 0, QL.Length - 1, TALIB, out int outBegIdx, out _, period);
            Assert.Equal(QL.Length, TALIB.Length);
            for (int i = QL.Length - 1; i > period * 20; i--)
            {
                Assert.InRange(TALIB[i - outBegIdx] - QL[i].Value, -range, range);
            }
        }
    }

    [Fact]
    public void TEMA()
    {
        for (int run = 0; run < iterations; run++)
        {
            int period = GetRandomNumber(5, 55);
            Tema ma = new(period);
            TSeries QL = new();
            foreach (TBar item in feed)
            { QL.Add(ma.Calc(new TValue(item.Time, item.Close))); }
            Core.Tema(data, 0, QL.Length - 1, TALIB, out int outBegIdx, out _, period);
            Assert.Equal(QL.Length, TALIB.Length);
            for (int i = QL.Length - 1; i > period * 20; i--)
            {
                Assert.InRange(TALIB[i - outBegIdx] - QL[i].Value, -range, range);
            }
        }
    }

    [Fact]
    public void T3()
    {
        for (int run = 0; run < iterations; run++)
        {
            int period = GetRandomNumber(5, 55);
            T3 ma = new(period, vfactor: 0.7, useSma: false);
            TSeries QL = new();
            foreach (TBar item in feed)
            { QL.Add(ma.Calc(new TValue(item.Time, item.Close))); }
            Core.T3(data, 0, QL.Length - 1, TALIB, out int outBegIdx, out _, optInTimePeriod: period, optInVFactor: 0.7);
            Assert.Equal(QL.Length, TALIB.Length);
            for (int i = QL.Length - 1; i > period * 20; i--)
            {
                Assert.InRange(TALIB[i - outBegIdx] - QL[i].Value, -range, range);
            }
        }
    }
}