sinmai-mods/MoreChartFormats/Simai/SimaiReader.cs

using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using Manager;
using MoreChartFormats.Simai.Errors;
using MoreChartFormats.Simai.LexicalAnalysis;
using MoreChartFormats.Simai.Structures;
using MoreChartFormats.Simai.SyntacticAnalysis;

namespace MoreChartFormats.Simai;

public class SimaiReader
{
    public static List<Token> Tokenize(string value)
    {
        return new Tokenizer(value).GetTokens().ToList();
    }
    
    public static void Deserialize(IEnumerable<Token> tokens, NotesReferences refs)
    {
        new Deserializer(tokens).GetChart(refs);
    }

    public static void ReadBpmChanges(IEnumerable<Token> tokens, NotesReferences refs)
    {
        var currentTime = new NotesTime();
        var subdivision = 4f;
        var deltaGrids = 0f;

        var nr = refs.Reader;
        var header = refs.Header;
        var composition = refs.Composition;

        foreach (var token in tokens)
        {
            switch (token.type)
            {
                case TokenType.Tempo:
                {
                    var deltaBars = deltaGrids / header._resolutionTime;
                    var bar = (int)deltaBars;
                    var grid = (int)((deltaBars - bar) * header._resolutionTime);
                    
                    currentTime += new NotesTime(bar, grid, nr);
                    deltaGrids -= bar * header._resolutionTime + grid;
                    
                    var bpmChangeData = new BPMChangeData();
                    bpmChangeData.time.copy(currentTime);

                    if (!float.TryParse(token.lexeme, NumberStyles.Any, CultureInfo.InvariantCulture,
                            out bpmChangeData.bpm))
                    {
                        throw new UnexpectedCharacterException(token.line, token.character, "0-9 or \".\"");
                    }
                    
                    composition._bpmList.Add(bpmChangeData);
                    break;
                }
                case TokenType.Subdivision:
                {
                    if (token.lexeme[0] == '#')
                    {
                        throw new UnsupportedSyntaxException(token.line, token.character);
                    }
                    
                    if (!float.TryParse(token.lexeme, NumberStyles.Any, CultureInfo.InvariantCulture, out subdivision))
                    {
                        throw new UnexpectedCharacterException(token.line, token.character, "0-9 or \".\"");
                    }
                    break;
                }
                case TokenType.TimeStep:
                {
                    deltaGrids += header._resolutionTime / subdivision;
                    break;
                }
                default:
                    continue;
            }
        }

        if (composition._bpmList.Count == 0)
        {
            var dummyBpmChange = new BPMChangeData { bpm = ReaderConst.DEFAULT_BPM };
            dummyBpmChange.time.init(0, 0, nr);
            
            composition._bpmList.Add(dummyBpmChange);
        }
    }
}