using Pcie8586Probe.Models;

namespace Pcie8586Probe.Acquisition;

public static class CodeConverter
{
    public static double CodeToVolts(ushort code, InputRange range)
    {
        return range switch
        {
            InputRange.PlusMinus5V => ((10_000.0 / 65_536.0) * code - 5_000.0) / 1_000.0,
            InputRange.PlusMinus1V => ((2_000.0 / 65_536.0) * code - 1_000.0) / 1_000.0,
            _ => throw new ArgumentOutOfRangeException(nameof(range), range, null)
        };
    }

    public static double[][] Deinterleave(ReadOnlySpan<ushort> raw, int channelCount, InputRange range)
    {
        if (channelCount is not (1 or 2 or 4 or 8))
        {
            throw new ArgumentOutOfRangeException(nameof(channelCount), "Channel count must be 1, 2, 4, or 8.");
        }

        if (raw.Length % channelCount != 0)
        {
            throw new ArgumentException("Raw sample length must be divisible by channel count.", nameof(raw));
        }

        var samplesPerChannel = raw.Length / channelCount;
        var result = new double[channelCount][];
        for (var channel = 0; channel < channelCount; channel++)
        {
            result[channel] = new double[samplesPerChannel];
        }

        for (var sample = 0; sample < samplesPerChannel; sample++)
        {
            var baseIndex = sample * channelCount;
            for (var channel = 0; channel < channelCount; channel++)
            {
                result[channel][sample] = CodeToVolts(raw[baseIndex + channel], range);
            }
        }

        return result;
    }
}