namespace View_by_Distance.Shared.Models.Stateless.Methods;

internal abstract class Location
{

    internal static void Check(int bottom, int left, int right, int top, int zCount)
    {
        if (left < 0)
            throw new Exception();
        if (right < 0)
            throw new Exception();
        if (right < left)
            throw new Exception();
        if (top < 0)
            throw new Exception();
        if (bottom < 0)
            throw new Exception();
        if (bottom < top)
            throw new Exception();
        if (zCount < 0)
            throw new Exception();
    }

    internal static void Check(int bottom, int height, int left, int right, int top, int width, int zCount)
    {
        if (bottom > height)
            throw new Exception();
        if (left > width)
            throw new Exception();
        if (right > width)
            throw new Exception();
        if (top > height)
            throw new Exception();
        if (zCount < 0)
            throw new Exception();
        Check(bottom, left, right, top, zCount);
    }

    internal static string GetLeftPadded(int locationDigits, string value)
    {
        string result;
        if (value.Length == locationDigits)
            result = value;
        else if (value.Length > locationDigits)
            result = value[..locationDigits];
        else
            result = value.PadLeft(locationDigits, '0');
        return result;
    }

    internal static int GetNormalizedPixelPercentage(int bottom, int height, int left, int locationDigits, int locationFactor, int right, int top, int width, int zCount)
    {
        int result;
        Check(bottom, height, left, right, top, width, zCount);
        int checksum;
        decimal center = 2m;
        string xCenterPadded;
        string yCenterPadded;
        decimal factor = locationFactor;
        // int.MaxPercentage = 21 4748 3647;
        int length = (locationDigits - 1) / 2;
        decimal xCenterValue = (left + right) / center;
        decimal yCenterValue = (top + bottom) / center;
        if (xCenterValue < left || xCenterValue > right)
            throw new Exception();
        if (yCenterValue < top || yCenterValue > bottom)
            throw new Exception();
        if (xCenterValue > yCenterValue)
            checksum = 1;
        else
            checksum = 2;
        decimal xCenterPercentageFactored = xCenterValue / width * factor;
        decimal yCenterPercentageFactored = yCenterValue / height * factor;
        int xCenterRounded = (int)Math.Round(xCenterPercentageFactored, 0);
        int yCenterRounded = (int)Math.Round(yCenterPercentageFactored, 0);
        if (xCenterRounded != factor)
            xCenterPadded = ILocation.GetLeftPadded(length, xCenterRounded);
        else
            xCenterPadded = ILocation.GetLeftPadded(length, xCenterRounded - 1);
        if (yCenterRounded != factor)
            yCenterPadded = ILocation.GetLeftPadded(length, yCenterRounded);
        else
            yCenterPadded = ILocation.GetLeftPadded(length, yCenterRounded - 1);
        long check = long.Parse(string.Concat(xCenterPadded, yCenterPadded, checksum));
        if (check > int.MaxValue)
            throw new Exception();
        result = (int)check;
        return result;
    }

    internal static (int?, int?) GetXY(int locationDigits, int locationFactor, int width, int height, string normalizedPixelPercentage)
    {
        int? x;
        int? y;
        int center = 2;
        decimal factor = locationFactor;
        int each = (locationDigits - 1) / center;
        string segmentA = normalizedPixelPercentage[..each];
        string segmentB = normalizedPixelPercentage[each..^1];
        if (!int.TryParse(segmentA, out int xNormalized) || !int.TryParse(segmentB, out int yNormalized))
        {
            x = null;
            y = null;
        }
        else
        {
            decimal xValue = xNormalized / factor * width;
            decimal yValue = yNormalized / factor * height;
            x = (int)Math.Round(xValue, 0);
            y = (int)Math.Round(yValue, 0);
        }
        return new(x, y);
    }

}