namespace Qrakhen.Qamp.Core.Tokenization;

public readonly record struct Token(
    TokenType Type,
    string? Value = "",
    TokenPosition Position = default,
    StreamSpan Span = default
)
{
   public static Token Void = new(TokenType.Void);
   public static Token Error(string? message = null) => new Token(TokenType.Error, message);
   public static Token Eof(string? message = null) => new Token(TokenType.Eof, message);

   public override string ToString()
   {
      return $"[@{Position}] <{Type}> ({Value ?? "?"})";
   }

   public bool IsCompilationIrrelevant => Type == TokenType.NewLine || Type == TokenType.Comment || Type == TokenType.Whitespace;
}

public readonly record struct StreamSpan(long Start = -1, long Length = 0);

public readonly record struct TokenPosition(int Line = -1, int Column = -1)
{
   public static readonly TokenPosition None = new(-1, -1);

   public bool IsNone => this == None;

   public override string ToString()
   {
      return $"{Line}:{Column}";
   }

   public TokenPosition Previous => new(Line, Column - 1);

   public static TokenPosition operator +(TokenPosition a, TokenPosition b) =>
       new(a.Line + b.Line, a.Column + b.Column);

   public static TokenPosition operator -(TokenPosition a, TokenPosition b) =>
       new(a.Line - b.Line, a.Column - b.Column);
}