/// <summary>
/// Initializes a new instance of the <see cref="LrcFile"/> class.
/// </summary>
/// <param name="metadata">The metadata.</param>
/// <param name="lyrics">The lyrics.</param>
/// <param name="applyOffset">if set to <c>true</c> apply the offset in metadata, otherwise ignore the offset.</param>
public LrcFile(ILrcMetadata metadata, IEnumerable <IOneLineLyric> lyrics, bool applyOffset)
{
if (metadata == null)
{
throw new ArgumentNullException("metadata");
}
if (lyrics == null)
{
throw new ArgumentNullException("lyrics");
}
Metadata = metadata;
var array = lyrics.OrderBy(l => l.Timestamp).ToArray();
for (var i = 0; i < array.Length; ++i)
{
if (applyOffset && metadata.Offset.HasValue)
{
var oneLineLyric = array[i] as OneLineLyric;
if (oneLineLyric != null)
{
oneLineLyric.Timestamp -= metadata.Offset.Value;
}
else
{
array[i] = new OneLineLyric(array[i].Timestamp - metadata.Offset.Value, array[i].Content);
}
}
if (i > 0 && array[i].Timestamp == array[i - 1].Timestamp)
{
throw new FormatException(string.Format("Found duplicate timestamp '{0}' with lyric '{1}' and '{2}'.", array[i].Timestamp, array[i - 1].Content, array[i].Content));
}
}
_lyrics = array;
}
/// <summary>
/// Create a new new instance of the <see cref="ILrcFile"/> interface with the specified LRC text.
/// </summary>
/// <param name="lrcText">The LRC text.</param>
/// <param name="allowBracketInContent">If true, brackets are allowed in content and parsed as content (reserved tags are still parsed properly)</param>
/// <returns></returns>
public static ILrcFile FromText(string lrcText, bool allowBracketInContent = false)
{
if (lrcText == null)
{
throw new ArgumentNullException("lrcText");
}
var pairs = new List <KeyValuePair <string, string> >();
var titles = new List <string>();
var sb = new StringBuilder();
// 0: Line start. Expect line ending or [.
// 1: Reading title. Expect ] or all characters except line ending.
// 2: Reading content. Expect line ending or [ or other charactors.
var state = 0;
for (var i = 0; i <= lrcText.Length; ++i)
{
var ended = i >= lrcText.Length;
var ch = ended ? (char)0 : lrcText[i];
// ReSharper disable once IdentifierTypo
var unescaped = false;
if (ch == '\\')
{
++i;
ended = i >= lrcText.Length;
if (ended)
{
throw new FormatException("Expect one charactor after '\\' but reaches the end.");
}
ch = lrcText[i];
unescaped = true;
}
switch (state)
{
case 0:
if (!unescaped && ch == '[')
{
state = 1;
}
else if (!unescaped && (ch == '\r' || ch == '\n') || ended)
{
state = 0;
}
else
{
throw new FormatException(string.Format("Expect '[' at position {0}", i));
}
break;
case 1:
if (!unescaped && ch == ']')
{
state = 2;
titles.Add(sb.ToString());
sb.Clear();
}
else if (!unescaped && (ch == '\r' || ch == '\n') || ended)
{
throw new FormatException(string.Format("Expect ']' at position {0}", i));
}
else
{
sb.Append(ch); // append to title
}
break;
case 2:
if (!unescaped && (ch == '\r' || ch == '\n') || ended)
{
state = 0;
var content = sb.ToString();
pairs.AddRange(titles.Select(t => new KeyValuePair <string, string>(t, content)));
sb.Clear();
titles.Clear();
}
else if (!unescaped && ch == '[')
{
if (sb.Length > 0)
{
state = 1;
var content = sb.ToString();
pairs.AddRange(titles.Select(t => new KeyValuePair <string, string>(t, content)));
sb.Clear();
titles.Clear();
}
else
{
state = 1;
}
}
else
{
sb.Append(ch);
}
break;
}
}
var lyrics = new List <IOneLineLyric>();
var metadata = new LrcMetadata();
string offsetString = null;
foreach (var pair in pairs)
{
// Parse timestamp
var match = TimestampRegex.Match(pair.Key);
if (match.Success)
{
var minutes = int.Parse(match.Groups["minutes"].Value);
var seconds = double.Parse(match.Groups["seconds"].Value);
var timestamp = TimeSpan.FromSeconds(minutes * 60 + seconds);
lyrics.Add(new OneLineLyric(timestamp, pair.Value));
continue;
}
// Parse metadata
match = MetadataRegex.Match(pair.Key);
if (match.Success)
{
var title = match.Groups["title"].Value.ToLower();
var content = match.Groups["content"].Value;
if (title == "ti")
{
if (metadata.Title != null && content != metadata.Title)
{
throw new FormatException(string.Format("Duplicate LRC metadata found. Metadata name: '{0}', Values: '{1}', '{2}'", "ti", metadata.Title, content));
}
metadata.Title = content;
}
else if (title == "ar")
{
if (metadata.Artist != null && content != metadata.Artist)
{
throw new FormatException(string.Format("Duplicate LRC metadata found. Metadata name: '{0}', Values: '{1}', '{2}'", "ar", metadata.Artist, content));
}
metadata.Artist = content;
}
else if (title == "al")
{
if (metadata.Album != null && content != metadata.Album)
{
throw new FormatException(string.Format("Duplicate LRC metadata found. Metadata name: '{0}', Values: '{1}', '{2}'", "al", metadata.Album, content));
}
metadata.Album = content;
}
else if (title == "by")
{
if (metadata.Maker != null && content != metadata.Maker)
{
throw new FormatException(string.Format("Duplicate LRC metadata found. Metadata name: '{0}', Values: '{1}', '{2}'", "by", metadata.Maker, content));
}
metadata.Maker = content;
}
else if (title == "offset")
{
if (offsetString != null && content != offsetString)
{
throw new FormatException(string.Format("Duplicate LRC metadata found. Metadata name: '{0}', Values: '{1}', '{2}'", "offset", offsetString, content));
}
offsetString = content;
metadata.Offset = TimeSpan.FromMilliseconds(double.Parse(content));
}
// ReSharper disable once RedundantIfElseBlock
else
{
// Ingore unsupported tag
}
}
else
{
if (allowBracketInContent)
{
var lastLyric = lyrics.LastOrDefault();
if (lastLyric != null)
{
lyrics.Remove(lastLyric);
var newLyric = new OneLineLyric(lastLyric.Timestamp,
string.Format("{0}[{1}]{2}", lastLyric.Content, pair.Key, pair.Value));
lyrics.Add(newLyric);
}
}
else
{
throw new FormatException(string.Format("Unknown tag [{0}]", pair.Key));
}
}
}
if (lyrics.Count == 0)
{
throw new FormatException("Invalid or empty LRC text. Can't find any lyrics.");
}
return(new LrcFile(metadata, lyrics, true));
}