WindowsMusicPlayer-TheUntamedMusicPlayer/The Untamed Music Player/Models/LyricSlice.cs

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Text.RegularExpressions;

namespace The_Untamed_Music_Player.Models;
public partial class LyricSlice : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler? PropertyChanged;
    protected void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    private string _content = "";
    public string Content
    {
        get => _content;
        set
        {
            _content = value;
            OnPropertyChanged(nameof(Content));
        }
    }

    private double _time;
    public double Time
    {
        get => _time;
        set
        {
            _time = value;
            OnPropertyChanged(nameof(Time));
        }
    }

    public LyricSlice(double time, string content)
    {
        Time = time;
        Content = content;
    }

    [GeneratedRegex(@".*\](.*)")]
    private static partial Regex RegexWord();

    [GeneratedRegex(@"\[([0-9.:]*)\]", RegexOptions.Compiled)]
    private static partial Regex RegexTime();

    public static ObservableCollection<LyricSlice> GetLyricSlices(string lyric)
    {
        var lyricSlices = new List<LyricSlice>();

        if (string.IsNullOrEmpty(lyric))
        {
            return [];
        }
        var lines = lyric.Split('\n');
        double? lastTime = null;//上一行有歌词的行的时间
        double emptyStartTime = 0;//空白行开始时间
        var inEmptyBlock = false;
        var emptyLines = new List<LyricSlice>();
        foreach (var line in lines)
        {
            if (line != null)
            {
                if (line.StartsWith("[ti:") || line.StartsWith("[ar:") || line.StartsWith("[al:") || line.StartsWith("[by:") || line.StartsWith("[offset:"))//歌曲名、艺人名、专辑名、歌词制作人、歌词时间补偿值
                {
                    continue;
                }

                try
                {
                    var regexword = RegexWord();//获取歌词文本的正则表达式
                    var regextime = RegexTime();//获取时间戳的正则表达式
                    var WORD = regexword.Match(line).Groups[1].Value;//获取歌词文本
                    var TIME = regextime.Matches(line);//获取时间戳

                    if (string.IsNullOrWhiteSpace(WORD))//歌词文本为空
                    {
                        if (!inEmptyBlock)
                        {
                            emptyStartTime = TIME.Count > 0 ? TimeSpan.Parse("00:" + TIME[0].Groups[1].Value).TotalMilliseconds : lastTime ?? 0;//将时间戳转换为毫秒(只保留第一组, 防止一行歌词里面有多个时间)
                            if (emptyStartTime == lastTime)
                            {
                                emptyStartTime += 1; // 如果空白行和上一行有歌词的行时间相同，空白行的时间加1毫秒
                            }
                            inEmptyBlock = true;
                        }
                    }
                    else
                    {
                        if (inEmptyBlock)
                        {
                            var emptyEndTime = TIME.Count > 0 ? TimeSpan.Parse("00:" + TIME[0].Groups[1].Value).TotalMilliseconds : lastTime ?? 0;
                            if (emptyEndTime - emptyStartTime > 5000)
                            {
                                lyricSlices.Add(new LyricSlice(emptyStartTime, "•••"));
                            }
                            inEmptyBlock = false;
                        }

                        foreach (Match item in TIME)
                        {
                            var time = TimeSpan.Parse("00:" + item.Groups[1].Value).TotalMilliseconds;
                            lyricSlices.Add(new LyricSlice(time, WORD));
                            lastTime = time;
                        }
                    }
                }
                catch
                {
                    continue;
                }
            }
        }
        if (inEmptyBlock && emptyLines.Count > 0)
        {
            var emptyEndTime = emptyLines.Last().Time;
            if (emptyEndTime - emptyStartTime > 5000)
            {
                lyricSlices.Add(new LyricSlice(emptyStartTime, "•••"));
            }
        }

        return new ObservableCollection<LyricSlice>(lyricSlices.OrderBy(t => t.Time));//将 lyricSlices 列表按时间戳排序。
    }
}