private bool ParseLine(ParsedLyrics lyrics, TextReader reader)
{
var leftBracket = reader.Read();
if (leftBracket == -1)
{
return(false);
}
else if (leftBracket == '\n')
{
return(true);
}
else if (leftBracket != '[')
{
goto ParseError;
}
var firstChar = (char)reader.Read();
if (firstChar == -1)
{
return(false);
}
else if (leftBracket == '\n')
{
return(true);
}
else if (char.IsDigit(firstChar))
{
if (!InnerSettings.MetaDataOnly)
{
ParseSentence(lyrics, reader, firstChar);
}
else
{
return(false);
}
}
else
{
ParseMetaData(lyrics, reader, firstChar);
}
return(true);
ParseError:
reader.ReadLine();
return(true);
}
private static void ParseSentence(ParsedLyrics lyrics, TextReader reader, char firstChar)
{
var startTimes = new List <TimeSpan>(4);
TimeBuilder.Clear();
TimeBuilder.Append(firstChar);
var parsedTime = ParseTime(reader);
if (!parsedTime.HasValue)
{
goto IgnoreLine;
}
startTimes.Add(parsedTime.Value);
int nextChar;
while ((nextChar = reader.Read()) == '[')
{
TimeBuilder.Clear();
parsedTime = ParseTime(reader);
if (!parsedTime.HasValue)
{
goto IgnoreLine;
}
startTimes.Add(parsedTime.Value);
}
var value = nextChar == -1 || nextChar == '\n' ?
string.Empty : (char)nextChar + reader.ReadLine().Trim();
foreach (var startTime in startTimes)
{
lyrics.Sentences.Add(new ParsedSentence {
StartTime = startTime, Value = value
});
}
return;
IgnoreLine:
reader.ReadLine();
}
/// <summary>
/// Parse lyrics from TextReader.
/// </summary>
/// <param name="reader">TextReader</param>
/// <returns>Parsed Lyrics</returns>
public async Task <ParsedLyrics> ParseAsync(TextReader reader)
{
return(await Task.Run(() =>
{
try
{
var result = new ParsedLyrics();
while (ParseLine(result, reader))
{
}
if (InnerSettings.PostProcess)
{
PostProcess(result);
}
return result;
}
catch (Exception exception)
{
throw new ParseException(Resources.ExceptionMessages.GenericFailure, exception);
}
}));
}
private static void PostProcess(ParsedLyrics lyrics)
{
lyrics.Sentences.Sort(Comparer);
var hasOffset = lyrics.OffsetMs != 0;
var offset = TimeSpan.FromMilliseconds(lyrics.OffsetMs);
if (lyrics.Sentences.Count == 0)
{
return;
}
var previous = lyrics.Sentences[0];
previous.Sequence = 0;
if (hasOffset)
{
previous.StartTime = previous.StartTime.Add(offset);
if (previous.StartTime < TimeSpan.Zero)
{
throw new ParseException(Resources.ExceptionMessages.InvalidOffset);
}
}
for (var i = 1; i < lyrics.Sentences.Count; i++)
{
var current = lyrics.Sentences[i];
current.Sequence = i;
if (hasOffset)
{
current.StartTime = current.StartTime.Add(offset);
}
previous.EndTime = current.StartTime;
previous.Duration = previous.EndTime - previous.StartTime;
previous = current;
}
}
private static void ParseMetaData(ParsedLyrics lyrics, TextReader reader, char firstChar)
{
MetaType metaType;
if (firstChar == 'a')
{
var secondChar = reader.Read();
if (secondChar == -1 || secondChar == '\n')
{
return;
}
else if (secondChar == 'l')
{
metaType = MetaType.Album;
}
else if (secondChar == 'r')
{
metaType = MetaType.Artist;
}
else if (secondChar == 'u')
{
metaType = MetaType.Author;
}
else
{
goto IgnoreLine;
}
}
else if (firstChar == 'b')
{
var secondChar = reader.Read();
if (secondChar == -1 || secondChar == '\n')
{
return;
}
else if (secondChar == 'y')
{
metaType = MetaType.LrcCreator;
}
else
{
goto IgnoreLine;
}
}
else if (firstChar == 'o')
{
var nextFiveChars = new char[5];
reader.Read(nextFiveChars, 0, 5);
if (nextFiveChars.SequenceEqual(OffsetNexts))
{
metaType = MetaType.Offset;
}
else
{
goto IgnoreLine;
}
}
else if (firstChar == 't')
{
var secondChar = reader.Read();
if (secondChar == 'i')
{
metaType = MetaType.Title;
}
else
{
goto IgnoreLine;
}
}
else if (firstChar == -1 || firstChar == '\n')
{
return;
}
else
{
goto IgnoreLine;
}
var nextChar = reader.Read();
if (nextChar == -1 || nextChar == '\n')
{
return;
}
else if (nextChar != ':')
{
goto IgnoreLine;
}
var line = reader.ReadLine();
if (line == null)
{
return;
}
var value = line.Trim();
if (value[value.Length - 1] == ']')
{
value = value.Substring(0, value.Length - 1);
}
if (metaType == MetaType.Album)
{
lyrics.Album = value;
}
else if (metaType == MetaType.Artist)
{
lyrics.Artist = value;
}
else if (metaType == MetaType.Author)
{
lyrics.Author = value;
}
else if (metaType == MetaType.LrcCreator)
{
lyrics.LrcCreator = value;
}
else if (metaType == MetaType.Offset)
{
lyrics.OffsetMs = int.Parse(value);
}
else if (metaType == MetaType.Title)
{
lyrics.Title = value;
}
return;
IgnoreLine:
reader.ReadLine();
}
