using Microsoft.Xna.Framework;
using System;
using System.Text;

namespace Barotrauma
{
    public static partial class ToolBox
    {
        // Convert an RGB value into an HLS value.
        public static Vector3 RgbToHLS(this Color color)
        {
            double h, l, s;

            // Convert RGB to a 0.0 to 1.0 range.
            double double_r = color.R / 255.0;
            double double_g = color.G / 255.0;
            double double_b = color.B / 255.0;

            // Get the maximum and minimum RGB components.
            double max = double_r;
            if (max < double_g) max = double_g;
            if (max < double_b) max = double_b;

            double min = double_r;
            if (min > double_g) min = double_g;
            if (min > double_b) min = double_b;

            double diff = max - min;
            l = (max + min) / 2;
            if (Math.Abs(diff) < 0.00001)
            {
                s = 0;
                h = 0;  // H is really undefined.
            }
            else
            {
                if (l <= 0.5) s = diff / (max + min);
                else s = diff / (2 - max - min);

                double r_dist = (max - double_r) / diff;
                double g_dist = (max - double_g) / diff;
                double b_dist = (max - double_b) / diff;

                if (double_r == max) h = b_dist - g_dist;
                else if (double_g == max) h = 2 + r_dist - b_dist;
                else h = 4 + g_dist - r_dist;

                h = h * 60;
                if (h < 0) h += 360;
            }

            return new Vector3((float)h, (float)l, (float)s);
        }

        // Convert an HLS value into an RGB value.
        public static Color HLSToRGB(Vector3 hls)
        {
            double h = hls.X, l = hls.Y, s = hls.Z;

            double p2;
            if (l <= 0.5) p2 = l * (1 + s);
            else p2 = l + s - l * s;

            double p1 = 2 * l - p2;
            double double_r, double_g, double_b;
            if (s == 0)
            {
                double_r = l;
                double_g = l;
                double_b = l;
            }
            else
            {
                double_r = QqhToRgb(p1, p2, h + 120);
                double_g = QqhToRgb(p1, p2, h);
                double_b = QqhToRgb(p1, p2, h - 120);
            }

            // Convert RGB to the 0 to 255 range.
            return new Color((byte)(double_r * 255.0), (byte)(double_g * 255.0), (byte)(double_b * 255.0));
        }

        private static double QqhToRgb(double q1, double q2, double hue)
        {
            if (hue > 360) hue -= 360;
            else if (hue < 0) hue += 360;

            if (hue < 60) return q1 + (q2 - q1) * hue / 60;
            if (hue < 180) return q2;
            if (hue < 240) return q1 + (q2 - q1) * (240 - hue) / 60;
            return q1;
        }

        public static string LimitString(string str, ScalableFont font, int maxWidth)
        {
            if (maxWidth <= 0 || string.IsNullOrWhiteSpace(str)) return "";

            float currWidth = font.MeasureString("...").X;
            for (int i = 0; i < str.Length; i++)
            {
                currWidth += font.MeasureString(str[i].ToString()).X;

                if (currWidth > maxWidth)
                {
                    return str.Substring(0, Math.Max(i - 2, 1)) + "...";
                }
            }

            return str;
        }

        public static string WrapText(string text, float lineLength, ScalableFont font, float textScale = 1.0f) //TODO: could integrate this into the ScalableFont class directly
        {
            if (font.MeasureString(text).X < lineLength) return text;

            text = text.Replace("\n", " \n ");

            string[] words = text.Split(' ');

            StringBuilder wrappedText = new StringBuilder();
            float linePos = 0f;
            float spaceWidth = font.MeasureString(" ").X * textScale;
            for (int i = 0; i < words.Length; ++i)
            {
                if (string.IsNullOrWhiteSpace(words[i]) && words[i] != "\n") continue;

                Vector2 size = font.MeasureString(words[i]) * textScale;
                if (size.X > lineLength)
                {
                    if (linePos == 0.0f)
                    {
                        wrappedText.AppendLine(words[i]);
                    }
                    else
                    {
                        do
                        {
                            if (words[i].Length == 0) break;

                            wrappedText.Append(words[i][0]);
                            words[i] = words[i].Remove(0, 1);

                            linePos += size.X;
                        } while (words[i].Length > 0 && (size = font.MeasureString((words[i][0]).ToString()) * textScale).X + linePos < lineLength);

                        wrappedText.Append("\n");
                        linePos = 0.0f;
                        i--;
                    }

                    continue;
                }

                if (linePos + size.X < lineLength)
                {
                    wrappedText.Append(words[i]);
                    if (words[i] == "\n")
                    {
                        linePos = 0.0f;
                    }
                    else
                    {

                        linePos += size.X + spaceWidth;
                    }
                }
                else
                {
                    wrappedText.Append("\n");
                    wrappedText.Append(words[i]);

                    linePos = size.X + spaceWidth;
                }

                if (i < words.Length - 1) wrappedText.Append(" ");
            }

            return wrappedText.ToString();
        }
    }
}