using Avalonia.Media;
using System.Security.Cryptography;
using System.Text;

namespace Toolkit.UI.Controls.Avalonia;

public class PersonPictureColourGenerator
{
    private readonly string[] colours =
    [
        "#FFB900",
        "#FF8C00",
        "#F7630C",
        "#CA5010",
        "#DA3B01",
        "#EF6950",
        "#D13438",
        "#FF4343",
        "#E74856",
        "#E81123",
        "#EA005E",
        "#C30052",
        "#E3008C",
        "#BF0077",
        "#C239B3",
        "#9A0089",
        "#0078D7",
        "#0063B1",
        "#8E8CD8",
        "#6B69D6",
        "#8764B8",
        "#744DA9",
        "#B146C2",
        "#881798",
        "#0099BC",
        "#2D7D9A",
        "#00B7C3",
        "#038387",
        "#00B294",
        "#018574",
        "#00CC6A",
        "#10893E",
        "#7A7574",
        "#5D5A58",
        "#68768A",
        "#515C6B",
        "#567C73",
        "#486860",
        "#498205",
        "#107C10",
        "#767676",
        "#4C4A48",
        "#69797E",
        "#4A5459",
        "#647C64",
        "#525E54",
        "#847545",
        "#7E735F"
    ];

    public Color GenerateColour(string input)
    {
        byte[] hashBytes = GetHash(input);
        int colourIndex = BitConverter.ToInt32(hashBytes, 0) % colours.Length;
        colourIndex = Math.Abs(colourIndex);

        return HexToColour(colours[colourIndex]);
    }

    private byte[] GetHash(string input)
    {
        return SHA256.HashData(Encoding.UTF8.GetBytes(input));
    }

    private Color HexToColour(string hex)
    {
        hex = hex.Replace("#", string.Empty);

        byte a = 255;
        byte r = byte.Parse(hex.Substring(0, 2), System.Globalization.NumberStyles.HexNumber);
        byte g = byte.Parse(hex.Substring(2, 2), System.Globalization.NumberStyles.HexNumber);
        byte b = byte.Parse(hex.Substring(4, 2), System.Globalization.NumberStyles.HexNumber);

        return Color.FromArgb(a, r, g, b);
    }
}