using System.Drawing;

namespace View_by_Distance.Shared.Models.Stateless.Methods;

internal abstract class Location
{

    internal static bool Check(int bottom, int left, int right, int top, int zCount, bool throwException)
    {
        bool result = true;
        if (left < 0)
            result = false;
        if (right < 0)
            result = false;
        if (right < left)
            result = false;
        if (top < 0)
            result = false;
        if (bottom < 0)
            result = false;
        if (bottom < top)
            result = false;
        if (zCount < 0)
            result = false;
        if (throwException && !result)
            throw new Exception();
        return result;
    }

    internal static bool Check(int bottom, int height, int left, int right, int top, int width, int zCount, bool throwException)
    {
        bool result = true;
        if (bottom > height)
            result = false;
        if (left > width)
            result = false;
        if (right > width)
            result = false;
        if (top > height)
            result = false;
        if (zCount < 0)
            result = false;
        if (result)
            result = Check(bottom, left, right, top, zCount, throwException);
        if (throwException && !result)
            throw new Exception();
        return result;
    }

    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 (decimal?, decimal?, decimal?, decimal?) GetHeightLeftTopWidth(int bottom, int height, int left, int right, int top, int width, int zCount)
    {
        (decimal?, decimal?, decimal?, decimal?) result;
        bool verified = Check(bottom, height, left, right, top, width, zCount, throwException: false);
        decimal t = top;
        decimal l = left;
        decimal w = right - l;
        decimal h = bottom - t;
        decimal xHeightPercentageFactored = h / height;
        decimal xLeftPercentageFactored = l / width;
        decimal xTopPercentageFactored = t / height;
        decimal xWidthPercentageFactored = w / width;
        if (!verified)
            result = new(null, null, null, null);
        else
            result = new(xHeightPercentageFactored, xLeftPercentageFactored, xTopPercentageFactored, xWidthPercentageFactored);
        return result;
    }

    internal static int GetNormalizedRectangle(int bottom, int height, int left, int locationDigits, int right, int top, int width, int zCount)
    {
        int result;
        string check;
        bool verified = Check(bottom, height, left, right, top, width, zCount, throwException: false);
        int checksum = left > top ? 4 : 8;
        if (!verified)
            check = string.Concat(checksum, new string('0', locationDigits - 1));
        else
        {
            decimal factor = 100;
            int factorMinusOne = (int)factor - 1;
            int length = (locationDigits - 1) / 4;
            decimal x = left / (decimal)width * factor;
            decimal y = top / (decimal)height * factor;
            decimal w = (right - left) / (decimal)width * factor;
            decimal h = (bottom - top) / (decimal)height * factor;
            string xPadded = x < factor ? ILocation.GetLeftPadded(length, (int)x) : ILocation.GetLeftPadded(length, factorMinusOne);
            string yPadded = y < factor ? ILocation.GetLeftPadded(length, (int)y) : ILocation.GetLeftPadded(length, factorMinusOne);
            string widthPadded = w < factor ? ILocation.GetLeftPadded(length, (int)w) : ILocation.GetLeftPadded(length, factorMinusOne);
            string heightPadded = h < factor ? ILocation.GetLeftPadded(length, (int)h) : ILocation.GetLeftPadded(length, factorMinusOne);
            check = string.Concat(checksum, xPadded, yPadded, widthPadded, heightPadded);
        }
        long value = long.Parse(check);
        if (value > int.MaxValue)
            throw new Exception();
        result = (int)value;
        return result;
    }

    internal static (int?, int?) GetXY(int locationDigits, int locationFactor, int width, int height, string normalizedRectangle)
    {
        int? x;
        int? y;
        int center = 2;
        decimal factor = locationFactor;
        int each = (locationDigits - 1) / center;
        string segmentA = normalizedRectangle[..each];
        string segmentB = normalizedRectangle[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);
    }

    internal static int GetConfidencePercent(int faceConfidencePercent, float[] rangeFaceConfidence, double confidence)
    {
        int result = (int)(confidence / rangeFaceConfidence[1] * faceConfidencePercent);
        return result;
    }

    internal static Rectangle? GetNormalizedRectangle(int locationDigits, string normalizedRectangle)
    {
        Rectangle? result;
        int length = (locationDigits - 1) / 4;
        string[] segments = new string[]
        {
            normalizedRectangle[..1],
            normalizedRectangle.Substring(1, length),
            normalizedRectangle.Substring(3, length),
            normalizedRectangle.Substring(5, length),
            normalizedRectangle.Substring(7, length)
        };
        if (string.Join(string.Empty, segments) != normalizedRectangle)
            result = null;
        else
        {
            if (!int.TryParse(segments[1], out int xNormalized) || !int.TryParse(segments[2], out int yNormalized) || !int.TryParse(segments[3], out int wNormalized) || !int.TryParse(segments[4], out int hNormalized))
                result = null;
            else
                result = new(xNormalized, yNormalized, wNormalized, hNormalized);
        }
        return result;
    }

    private static Rectangle? GetRectangle(int locationDigits, int height, string normalizedRectangle, int width)
    {
        Rectangle? result;
        Rectangle? rectangle = GetNormalizedRectangle(locationDigits, normalizedRectangle);
        if (rectangle is null)
            result = null;
        else
        {
            decimal factor = 100;
            result = new((int)(rectangle.Value.X / factor * width), (int)(rectangle.Value.Y / factor * height), (int)(rectangle.Value.Width / factor * width), (int)(rectangle.Value.Height / factor * height));
        }
        return result;
    }

    internal static Rectangle? GetRectangle(Rectangle checkRectangle, int height, int locationDigits, int locationFactor, string normalizedRectangle, int width, bool useOldWay)
    {
        Rectangle? result;
        if (useOldWay)
        {
            (int? x, int? y) = GetXY(locationDigits, locationFactor, width, height, normalizedRectangle);
            if (x is null || y is null)
                throw new Exception();
            result = new(x.Value - (checkRectangle.Width / 2), y.Value - (checkRectangle.Height / 2), checkRectangle.Width, checkRectangle.Height);
        }
        else
        {
            if (normalizedRectangle.Length != locationDigits)
                result = null;
            else
            {
                result = GetRectangle(locationDigits, height, normalizedRectangle, width);
                if (result is null)
                    throw new NullReferenceException(nameof(result));
            }
        }
        return result;
    }

    internal static Rectangle? GetRectangle(int height, int locationDigits, int locationFactor, string normalizedRectangle, int outputResolutionHeight, int outputResolutionWidth, int width)
    {
        Rectangle? result;
        if (normalizedRectangle.Length == locationDigits && normalizedRectangle[0] is '4' or '8')
            result = GetRectangle(locationDigits, outputResolutionHeight, normalizedRectangle, outputResolutionWidth);
        else
        {
            (int? x, int? y) = GetXY(locationDigits, locationFactor, outputResolutionWidth, outputResolutionHeight, normalizedRectangle);
            if (x is null || y is null)
                throw new Exception();
            result = new(x.Value - (width / 2), y.Value - (height / 2), width, height);
        }
        return result;
    }

    private static bool Matches(Models.OutputResolution outputResolution, DatabaseFile databaseFile)
    {
        bool result = outputResolution.Height == databaseFile.FileHeight && outputResolution.Width == databaseFile.FileWidth;
        return result;
    }

    internal static Rectangle? GetRectangle(Models.OutputResolution outputResolution, DatabaseFile databaseFile, Marker marker)
    {
        Rectangle? result;
        bool matches = Matches(outputResolution, databaseFile);
        if (!matches)
            result = null;
        else
            result = new((int)Math.Ceiling(marker.X * databaseFile.FileWidth), (int)Math.Ceiling(marker.Y * databaseFile.FileHeight), (int)Math.Ceiling(marker.W * databaseFile.FileWidth), (int)Math.Ceiling(marker.H * databaseFile.FileHeight));
        return result;
    }

    private static Models.Location? GetLocation(DatabaseFile databaseFile, Marker marker, Rectangle rectangle)
    {
        Models.Location? result;
        bool verified = Check(rectangle.Bottom, databaseFile.FileHeight, rectangle.Left, rectangle.Right, rectangle.Top, databaseFile.FileWidth, zCount: 1, throwException: false);
        if (!verified)
            result = null;
        else
            result = new(rectangle.Bottom, marker.Score / 100, rectangle.Left, rectangle.Right, rectangle.Top);
        return result;
    }

    internal static Models.Location? GetLocation(int height, Rectangle rectangle, int width)
    {
        Models.Location? result;
        double confidence = 0;
        bool verified = Check(rectangle.Bottom, height, rectangle.Left, rectangle.Right, rectangle.Top, width, zCount: 1, throwException: false);
        if (!verified)
            result = null;
        else
            result = new(rectangle.Bottom, confidence, rectangle.Left, rectangle.Right, rectangle.Top);
        return result;
    }

    internal static Models.Location? GetLocation(Models.OutputResolution outputResolution, DatabaseFile databaseFile, Marker marker)
    {
        Models.Location? result;
        Rectangle? rectangle = GetRectangle(outputResolution, databaseFile, marker);
        if (rectangle is null)
            result = null;
        else
            result = GetLocation(databaseFile, marker, rectangle.Value);
        return result;
    }

    internal static List<Models.Location> GetLocations<T>(List<MappingFromPhotoPrism> mappingFromPhotoPrismCollection, List<Models.Face> faces, List<LocationContainer<T>> containers)
    {
        List<Models.Location> results = new();
        bool any;
        bool matches;
        Rectangle dlibRectangle;
        Rectangle? prismRectangle;
        Models.Location? location;
        Rectangle intersectRectangle;
        Models.OutputResolution? outputResolution = null;
        foreach (Models.Face face in faces)
        {
            if (face.Location is null || face.OutputResolution is null)
                continue;
            results.Add(face.Location);
            outputResolution ??= face.OutputResolution;
        }
        int before = results.Count;
        foreach (LocationContainer<T> locationContainer in containers)
        {
            if (locationContainer.Location is null)
                continue;
            results.Add(locationContainer.Location);
        }
        foreach (MappingFromPhotoPrism mappingFromPhotoPrism in mappingFromPhotoPrismCollection)
        {
            if (outputResolution is null)
                break;
            matches = Matches(outputResolution, mappingFromPhotoPrism.DatabaseFile);
            if (!matches)
                break;
            foreach (Marker marker in mappingFromPhotoPrism.Markers)
            {
                any = false;
                prismRectangle = GetRectangle(outputResolution, mappingFromPhotoPrism.DatabaseFile, marker);
                if (prismRectangle is null)
                    break;
                location = GetLocation(mappingFromPhotoPrism.DatabaseFile, marker, prismRectangle.Value);
                if (location is null)
                    break;
                foreach (LocationContainer<T> locationContainer in containers)
                {
                    if (any)
                        continue;
                    if (locationContainer.Location is null)
                        continue;
                    dlibRectangle = new(locationContainer.Location.Left, locationContainer.Location.Top, locationContainer.Location.Right - locationContainer.Location.Left, locationContainer.Location.Bottom - locationContainer.Location.Top);
                    intersectRectangle = Rectangle.Intersect(prismRectangle.Value, dlibRectangle);
                    if (intersectRectangle.Width == 0 && intersectRectangle.Height == 0)
                        continue;
                    any = true;
                    break;
                }
                foreach (Models.Face face in faces)
                {
                    if (any)
                        continue;
                    if (face.Location is null || face.OutputResolution is null)
                        continue;
                    dlibRectangle = new(face.Location.Left, face.Location.Top, face.Location.Right - face.Location.Left, face.Location.Bottom - face.Location.Top);
                    intersectRectangle = Rectangle.Intersect(prismRectangle.Value, dlibRectangle);
                    if (intersectRectangle.Width == 0 && intersectRectangle.Height == 0)
                        continue;
                    any = true;
                    break;
                }
                if (!any)
                    results.Add(location);
            }
        }
        if (before == results.Count)
            results.Clear();
        return results;
    }

    internal static List<Models.Face> FilterByIntersect(Models.Face[] faces, int normalizedRectangle)
    {
        List<Models.Face> results = new();
        bool useOldWay;
        double? percent;
        Rectangle checkRectangle;
        Rectangle? sourceRectangle;
        Rectangle intersectRectangle;
        foreach (Models.Face face in faces)
        {
            if (face.Location is null || face.OutputResolution is null)
                continue;
            checkRectangle = new(face.Location.Left, face.Location.Top, face.Location.Right - face.Location.Left, face.Location.Bottom - face.Location.Top);
            for (int i = 1; i < 3; i++)
            {
                useOldWay = i == 1;
                sourceRectangle = ILocation.GetRectangle(checkRectangle, Stateless.ILocation.Digits, Stateless.ILocation.Factor, normalizedRectangle, face.OutputResolution, useOldWay);
                if (sourceRectangle is null)
                    continue;
                intersectRectangle = Rectangle.Intersect(checkRectangle, sourceRectangle.Value);
                if (intersectRectangle.Width == 0 || intersectRectangle.Height == 0)
                    continue;
                percent = (double)intersectRectangle.Width * intersectRectangle.Height / (checkRectangle.Width * checkRectangle.Height);
                if (percent < 0.000001)
                    continue;
                results.Add(face);
            }
        }
        return results;
    }

}