use common::*;

#[derive(Debug, PartialEq, Clone)]
pub struct Token<'a> {
  pub index:  usize,
  pub line:   usize,
  pub column: usize,
  pub text:   &'a str,
  pub prefix: &'a str,
  pub lexeme: &'a str,
  pub kind:   TokenKind,
}

impl<'a> Token<'a> {
  pub fn error(&self, kind: CompilationErrorKind<'a>) -> CompilationError<'a> {
    CompilationError {
      text:   self.text,
      index:  self.index + self.prefix.len(),
      line:   self.line,
      column: self.column + self.prefix.len(),
      width:  Some(self.lexeme.len()),
      kind:   kind,
    }
  }
}

#[derive(Debug, PartialEq, Clone, Copy)]
pub enum TokenKind {
  At,
  Backtick,
  Colon,
  Comment,
  Dedent,
  Eof,
  Eol,
  Equals,
  Indent,
  InterpolationEnd,
  InterpolationStart,
  Line,
  Name,
  ParenL,
  ParenR,
  Plus,
  RawString,
  StringToken,
  Text,
}

impl Display for TokenKind {
  fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
    use TokenKind::*;
    write!(f, "{}", match *self {
      Backtick           => "backtick",
      Colon              => "':'",
      Comment            => "comment",
      Dedent             => "dedent",
      Eof                => "end of file",
      Eol                => "end of line",
      Equals             => "'='",
      Indent             => "indent",
      InterpolationEnd   => "'}}'",
      InterpolationStart => "'{{'",
      Line               => "command",
      Name               => "name",
      Plus               => "'+'",
      At                 => "'@'",
      ParenL             => "'('",
      ParenR             => "')'",
      StringToken        => "string",
      RawString          => "raw string",
      Text               => "command text",
    })
  }
}