using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace Nikse.SubtitleEdit.Core.SubtitleFormats
{
    /// <summary>
    /// The ULTECH caption file format (ULT/ULD file) is a compact binary file that stores captions with embedded EIA-608 control codes
    /// http://en.wikipedia.org/wiki/EIA-608
    /// </summary>
    public class Ultech130 : SubtitleFormat
    {
        private const string UltechId = "ULTECH\01.30";

        public override string Extension
        {
            get { return ".ult"; }
        }

        public const string NameOfFormat = "Ultech 1.30 Caption";

        public override string Name
        {
            get { return NameOfFormat; }
        }

        public override bool IsTimeBased
        {
            get { return true; }
        }

        public static void Save(string fileName, Subtitle subtitle)
        {
            using (var fs = new FileStream(fileName, FileMode.Create, FileAccess.Write))
            {
                byte[] buffer = Encoding.ASCII.GetBytes(UltechId);
                fs.Write(buffer, 0, buffer.Length);

                buffer = new byte[] { 0, 0, 2, 0x1D, 0 }; // ?
                fs.Write(buffer, 0, buffer.Length);

                int numberOfLines = subtitle.Paragraphs.Count;
                fs.WriteByte((byte)(numberOfLines % 256)); // paragraphs - low byte
                fs.WriteByte((byte)(numberOfLines / 256)); // paragraphs - high byte

                buffer = new byte[] { 0, 0, 0, 0, 0x1, 0, 0xF, 0x15, 0, 0, 0, 0, 0, 0, 0, 0x1, 0, 0xE, 0x15, 0, 0, 0, 0, 0, 0, 0, 0x1, 0, 0xD, 0x15, 0, 0, 0, 0, 0, 0, 0, 0x1, 0, 0xC, 0x15, 0, 0, 0, 0, 0, 0, 0, 0x1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; // ?
                fs.Write(buffer, 0, buffer.Length);

                buffer = Encoding.ASCII.GetBytes("Subtitle Edit");
                fs.Write(buffer, 0, buffer.Length);

                while (fs.Length < 512)
                    fs.WriteByte(0);

                var footer = new byte[] { 0xF1, 0x0B, 0x00, 0x00, 0x00, 0x1B, 0x18, 0x14, 0x20, 0x14, 0x2E, 0x14, 0x2F, 0x00 }; // footer

                // paragraphs
                foreach (Paragraph p in subtitle.Paragraphs)
                {
                    // convert line breaks
                    var sb = new StringBuilder();
                    var line = new StringBuilder();
                    int skipCount = 0;
                    int numberOfNewLines = Utilities.GetNumberOfLines(p.Text);
                    bool italic = p.Text.StartsWith("<i>") && p.Text.EndsWith("</i>");
                    string text = HtmlUtil.RemoveHtmlTags(p.Text, true);
                    if (italic)
                    {
                        sb.Append('\u0011');
                        sb.Append('\u002E');
                    }
                    int y = 0x74 - (numberOfNewLines * 0x20);
                    for (int j = 0; j < text.Length; j++)
                    {
                        if (text.Substring(j).StartsWith(Environment.NewLine, StringComparison.Ordinal))
                        {
                            y += 0x20;
                            if (line.Length > 0)
                                sb.Append(line);
                            line.Clear();
                            skipCount = Environment.NewLine.Length - 1;
                            sb.Append('\u0014');
                            sb.Append(Convert.ToChar((byte)(y)));

                            //center
                            sb.Append('\u0017');
                            sb.Append('\u0021');

                            if (italic)
                            {
                                sb.Append('\u0011');
                                sb.Append('\u002E');
                            }
                        }
                        else if (skipCount == 0)
                        {
                            line.Append(text[j]);
                        }
                        else
                        {
                            skipCount--;
                        }
                    }
                    if (line.Length > 0)
                        sb.Append(line);
                    text = sb.ToString();

                    // codes?
                    buffer = new byte[] {
                        0x14,
                        0x20,
                        0x14,
                        0x2E,
                        0x14,
                        (byte)(0x74 - (numberOfNewLines * 0x20)),

                        0x17, 0x21, // 0x1721=center, 0x1722=right ?
                    };

                    //if (text.StartsWith("{\\a6}"))
                    //{
                    //    text = p.Text.Remove(0, 5);
                    //    buffer[7] = 1; // align top
                    //}
                    //else if (text.StartsWith("{\\a1}"))
                    //{
                    //    text = p.Text.Remove(0, 5);
                    //    buffer[8] = 0x0A; // align left
                    //}
                    //else if (text.StartsWith("{\\a3}"))
                    //{
                    //    text = p.Text.Remove(0, 5);
                    //    buffer[8] = 0x1E; // align right
                    //}
                    //else if (text.StartsWith("{\\a5}"))
                    //{
                    //    text = p.Text.Remove(0, 5);
                    //    buffer[7] = 1; // align top
                    //    buffer[8] = 05; // align left
                    //}
                    //else if (text.StartsWith("{\\a7}"))
                    //{
                    //    text = p.Text.Remove(0, 5);
                    //    buffer[7] = 1; // align top
                    //    buffer[8] = 0xc; // align right
                    //}

                    fs.WriteByte(0xF1); //ID of start record

                    // length
                    int length = text.Length + 15;
                    fs.WriteByte((byte)(length));
                    fs.WriteByte(0);

                    // start time
                    WriteTime(fs, p.StartTime);
                    fs.Write(buffer, 0, buffer.Length);

                    // text
                    buffer = Encoding.ASCII.GetBytes(text);
                    fs.Write(buffer, 0, buffer.Length); // Text starter på index 19 (0 baseret)
                    fs.WriteByte(0x14);
                    fs.WriteByte(0x2F);
                    fs.WriteByte(0);

                    // end time
                    fs.WriteByte(0xF1); // id of start record
                    fs.WriteByte(7); // length of end time
                    fs.WriteByte(0);
                    WriteTime(fs, p.EndTime);
                    fs.WriteByte(0x14);
                    fs.WriteByte(0x2c);
                    fs.WriteByte(0);
                }

                buffer = footer;
                fs.Write(buffer, 0, buffer.Length);
            }
        }

        private static void WriteTime(FileStream fs, TimeCode timeCode)
        {
            fs.WriteByte((byte)timeCode.Hours);
            fs.WriteByte((byte)timeCode.Minutes);
            fs.WriteByte((byte)timeCode.Seconds);
            fs.WriteByte((byte)MillisecondsToFramesMaxFrameRate(timeCode.Milliseconds));
        }

        public override bool IsMine(List<string> lines, string fileName)
        {
            if (!string.IsNullOrEmpty(fileName) && File.Exists(fileName))
            {
                var fi = new FileInfo(fileName);
                if (fi.Length >= 200 && fi.Length < 1024000) // not too small or too big
                {
                    if (fileName.EndsWith(".ult", StringComparison.OrdinalIgnoreCase) || fileName.EndsWith(".uld", StringComparison.OrdinalIgnoreCase)) //  drop frame is often named uld, and ult for non-drop
                    {
                        byte[] buffer = FileUtil.ReadAllBytesShared(fileName);
                        string id = Encoding.ASCII.GetString(buffer, 0, UltechId.Length);
                        return id == UltechId;
                    }
                }
            }
            return false;
        }

        public override string ToText(Subtitle subtitle, string title)
        {
            return "Not supported!";
        }

        private static TimeCode DecodeTimestamp(byte[] buffer, int index)
        {
            return new TimeCode(buffer[index], buffer[index + 1], buffer[index + 2], FramesToMillisecondsMax999(buffer[index + 3]));
        }

        public override void LoadSubtitle(Subtitle subtitle, List<string> lines, string fileName)
        {
            subtitle.Paragraphs.Clear();
            subtitle.Header = null;
            byte[] buffer = FileUtil.ReadAllBytesShared(fileName);

            int i = 512;
            Paragraph last = null;
            var sb = new StringBuilder();
            while (i < buffer.Length - 25)
            {
                var p = new Paragraph();
                int length = buffer[i + 1];

                p.StartTime = DecodeTimestamp(buffer, i + 3);
                if (last != null && Math.Abs(last.EndTime.TotalMilliseconds) < 0.001)
                    last.EndTime.TotalMilliseconds = p.StartTime.TotalMilliseconds - 1;

                if (length > 22)
                {
                    int start = i + 7;
                    sb.Clear();
                    int skipCount = 0;
                    bool italics = false;
                    //bool font = false;
                    for (int k = start; k < length + i; k++)
                    {
                        byte b = buffer[k];
                        if (skipCount > 0)
                        {
                            skipCount--;
                        }
                        else if (b < 0x1F)
                        {
                            byte b2 = buffer[k + 1];
                            skipCount = 1;
                            if (sb.Length > 0 && !sb.ToString().EndsWith(Environment.NewLine) && !sb.EndsWith('>'))
                            {
                                //if (font)
                                //    sb.Append("</font>");
                                if (italics)
                                    sb.Append("</i>");
                                sb.AppendLine();
                                //font = false;
                                italics = false;
                            }
                            //string code = VobSub.Helper.IntToBin(buffer[k] * 256 + buffer[k+1], 16);
                            //var codeBytes = new List<char>();
                            //if (b == 0x11 && b2 == 0x28)
                            //{
                            //    sb.Append("<font color=\"red\">");
                            //    font = true;
                            //}
                            //else

                            if (b == 0x11 && b2 == 0x2e)
                            {
                                sb.Append("<i>");
                                italics = true;
                            }

                            //foreach (char ch in code)
                            //    codeBytes.Insert(0, ch);
                            //if (codeBytes[13] == '0' && codeBytes[14] == '0' && codeBytes[12] == '1' && codeBytes[6] == '1')
                            //{ // preamble address code
                            //    if (code.Substring(11, 4) == "1000")
                            //    {
                            //        sb.Append("<font color=\"green\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0010")
                            //    {
                            //        sb.Append("<font color=\"blue\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0011")
                            //    {
                            //        sb.Append("<font color=\"cyan\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0100")
                            //    {
                            //        sb.Append("<font color=\"red\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0101")
                            //    {
                            //        sb.Append("<font color=\"yellow\">");
                            //        font = true;
                            //    }
                            //    //else if (code.Substring(11, 4) == "0110")
                            //    //{
                            //    //    sb.Append("<font color=\"magenta\">");
                            //    //    font = true;
                            //    //}
                            //}
                            //else if (codeBytes[14] == '0' && codeBytes[13] == '0' && codeBytes[10] == '0' && codeBytes[9] == '0' && codeBytes[6] == '0' &&
                            //         codeBytes[12] == '1' && codeBytes[8] == '1' && codeBytes[6] == '1')
                            //{ // midrow code

                            //    if (code.Substring(11, 4) == "1000")
                            //    {
                            //        sb.Append("<font color=\"green\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0010")
                            //    {
                            //        sb.Append("<font color=\"blue\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0011")
                            //    {
                            //        sb.Append("<font color=\"cyan\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0100")
                            //    {
                            //        sb.Append("<font color=\"red\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0101")
                            //    {
                            //        sb.Append("<font color=\"yellow\">");
                            //        font = true;
                            //    }
                            //    //else if (code.Substring(11, 4) == "0110")
                            //    //{
                            //    //    sb.Append("<font color=\"magenta\">");
                            //    //    font = true;
                            //    //}
                            //}
                            //else if ((codeBytes[14] == '0' && codeBytes[13] == '0' && codeBytes[9] == '0' && codeBytes[6] == '0' && codeBytes[4] == '0' &&
                            //         codeBytes[12] == '1' && codeBytes[10] == '1' && codeBytes[5] == '1') || b == 0x11)
                            //{ // codeBytes[10] == 0 ???
                            //    //control codes
                            //    if (code.Substring(11, 4) == "0111" && buffer[k] == 0x11)
                            //    {
                            //        sb.Append("<i>");
                            //        italics = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "1000")
                            //    {
                            //        sb.Append("<font color=\"green\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0010")
                            //    {
                            //        sb.Append("<font color=\"blue\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0011")
                            //    {
                            //        sb.Append("<font color=\"cyan\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0100")
                            //    {
                            //        sb.Append("<font color=\"red\">");
                            //        font = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0101")
                            //    {
                            //        sb.Append("<font color=\"yellow\">");
                            //        font = true;
                            //    }
                            //    //else if (code.Substring(11, 4) == "0110")
                            //    //{
                            //    //    sb.Append("<font color=\"magenta\">");
                            //    //    font = true;
                            //    //}
                            //}
                            //else
                            //{
                            //    if (code.Substring(11, 4) == "0111" && buffer[k] == 0x11)
                            //    {
                            //        sb.Append("<i>");
                            //        italics = true;
                            //    }
                            //    else if (code.Substring(11, 4) == "0101" && b == 0x11)
                            //    {
                            //        sb.Append("<font color=\"yellow\">");
                            //        font = true;
                            //    }
                            ////    if (code.Substring(11, 4) == "0111")
                            ////    {
                            ////        //System.Windows.Forms.MessageBox.Show(code);
                            ////        sb.Append("<i>");
                            ////    }
                            ////    else if (code.Substring(11, 4) == "0101")
                            ////        sb.Append("<font color=\"yellow\">");
                            //}
                        }
                        else if (b == 0x80)
                        {
                            //if (sb.Length == 0)
                            //    break;

                            //if (sb.Length > 0 && !sb.ToString().EndsWith(Environment.NewLine))
                            //{
                            //    if (font)
                            //        sb.Append("</font>");
                            //    if (italics)
                            //        sb.Append("</i>");
                            //    sb.AppendLine();
                            //    font = false;
                            //    italics = false;
                            //}
                        }
                        else
                        {
                            sb.Append(Encoding.GetEncoding(1252).GetString(buffer, k, 1));
                        }
                    }
                    p.Text = sb.ToString().Trim();
                    //if (font)
                    //    p.Text += "</font>";
                    if (italics)
                        p.Text += "</i>";
                    p.Text = p.Text.Replace(Environment.NewLine + Environment.NewLine, Environment.NewLine);
                    p.Text = p.Text.Replace(Environment.NewLine + Environment.NewLine, Environment.NewLine);
                    p.Text = p.Text.Replace(Environment.NewLine + Environment.NewLine, Environment.NewLine);
                    subtitle.Paragraphs.Add(p);
                }
                else if (last != null)
                {
                    last.EndTime.TotalMilliseconds = p.StartTime.TotalMilliseconds;
                }
                last = p;

                i += length + 3;
            }
            if (last != null)
            {
                if (Math.Abs(last.EndTime.TotalMilliseconds) < 0.001)
                    last.EndTime.TotalMilliseconds = last.StartTime.TotalMilliseconds + 2500;
                if (last.Duration.TotalMilliseconds > Configuration.Settings.General.SubtitleMaximumDisplayMilliseconds)
                    last.EndTime.TotalMilliseconds = last.StartTime.TotalMilliseconds + Utilities.GetOptimalDisplayMilliseconds(last.Text);
            }

            subtitle.Renumber();
        }

        public override List<string> AlternateExtensions
        {
            get
            {
                return new List<string>() { ".uld" }; // Ultech drop frame
            }
        }

    }
}