class Codec

# Codec provides the image/Codec standard library API.
class Codec
  # Codec.value stores instance state.
  # @type Nil
  value: nil

  # Codec.initialize stores image data or a path.
  # @param value String value value.
  # @return Self the initialized object.
  initialize: value = nil ->
    self.value = value

  # Codec.identify is a compatibility alias for Codec.metadata.
  # @param data Array data value.
  # @return Any the resulting value.
  identify: data = nil ->
    self.metadata(data)

  # Codec.identify_file is a compatibility alias for Codec.metadata_file.
  # @param path String path value.
  # @return Any the resulting value.
  identify_file: path = nil ->
    self.metadata_file(path)

  # Codec.metadata reads image metadata from encoded bytes.
  # @param data Array data value.
  # @return Any the resulting value.
  metadata: data = nil ->
    if data == nil
      data = self.value
    text = bytes_text(data)
    parts = text.split("\n")
    if parts.len() == 0
      raise error("image.identify: unsupported or malformed image")
    header = parts[0].split(":")
    if header.len() != 6 or header[0] != "TYAIMG"
      raise error("image.identify: unsupported or malformed image")
    format = header[1]
    if not Codec(nil).supported_format?(format)
      raise error("image.identify: unsupported format " + format)
    { format: format, width: header[2].to_i(), height: header[3].to_i(), frames: header[5].to_i(), animated: header[5].to_i() > 1, has_alpha: header[4] == "1", color_space: "srgb" }

  # Codec.metadata_file reads image metadata from a file.
  # @param path String path value.
  # @return Any the resulting value.
  metadata_file: path = nil ->
    if path == nil
      path = self.value
    Codec(nil).metadata(file.File(path).read_bytes())

  # Codec.supported_format? provides the image/Codec standard library operation.
  # @param format String format value.
  # @return Boolean whether the condition is true.
  supported_format?: format ->
    format == "png" or format == "jpeg" or format == "gif" or format == "bmp" or format == "ppm"