using System;
using System.Text;
using System.IO;
using System.Windows.Forms;

namespace ConvertM3U
{
    class Program
    {
        static void Main( string[] args )
        {
            if( args.Length < 1 ) { return; }

            string path = args[0];

            if( File.Exists( path ) )
            {
                string title = "ConvertM3U.exe";

                string ext = Path.GetExtension( path );
                {
                    if( ext.ToLower() != ".m3u" )
                    {
                        if( MessageBox.Show( "拡張子が .m3u でないファイルが渡されました。\r\n続行しますか？", title, MessageBoxButtons.OKCancel )
                             != DialogResult.OK )
                        {
                            return;
                        }
                    }
                }
                string newFilePath;
                {
                    string dir = Path.GetDirectoryName( path );
                    string fileName = Path.GetFileNameWithoutExtension( path );
                    newFilePath = dir + "\\" + fileName + "_" + ext;
                }

                string name = Path.GetFileName( path );
                string newName = Path.GetFileName( newFilePath );

                if( File.Exists( newFilePath ) )
                {
                    StringBuilder sb = new StringBuilder();
                    sb.AppendLine( "ファイルの変換 :" );
                    sb.Append( name );
                    sb.Append( " -> " );
                    sb.AppendLine( newName );
                    sb.Append( "すでに \"" );
                    sb.Append( newName );
                    sb.Append( "\" というファイルが存在しますが、上書きしてよろしいですか？" );
                    if( MessageBox.Show( sb.ToString(), title, MessageBoxButtons.OKCancel ) != DialogResult.OK )
                    {
                        return;
                    }
                }

                try
                {
                    Convert( path, newFilePath );

                    MessageBox.Show( "ファイルの変換完了 : \r\n" + name + " -> " + newName, title );
                }
                catch( Exception ex )
                {
                    MessageBox.Show( ex.Message );
                }

            }
        }


        internal static void Convert( string path, string newFilePath )
        {
            System.Text.Encoding enc = System.Text.Encoding.Default;

            string source;
            using( StreamReader sr = new StreamReader( path, enc ) )
            {
                source = sr.ReadToEnd();
                sr.Close();
            }

            using( StreamWriter sw = new StreamWriter( newFilePath, false, enc ) )
            {
                StringReader sr = new StringReader( source );
                {
                    M3UConverter.ConvertM3uToS9Format( sr, sw );
                }

                sw.Close();
            }
        }

   
    }

    public static class M3UConverter
    {
        public static void ConvertM3uToS9Format( TextReader source, TextWriter output )
        {
            output.WriteLine( "#EXTM3U" );
            string line;

            while( (line = source.ReadLine()) != null )
            {
                if( string.IsNullOrEmpty( line ) ) { continue; }

                output.WriteLine( "#EXTINF:" );
                output.WriteLine( line );
            }
        }

    }

}