# File actionpack/lib/action_dispatch/http/mime_type.rb, line 235
def lookup(string)
  lookup = Mime.lookup_by_string
  return lookup[string] if lookup.key?(string)
  return WILDCARD if string == "*/*"

  # fallback to the media-type without parameters if it was not found
  string = string.split(";", 2)[0]&.rstrip
  lookup[string] || Type.new(string)
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 245
def lookup_by_extension(extension)
  Mime.lookup_by_extension[extension.is_a?(Symbol) ? extension.name : extension.to_s]
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 341
def initialize(string, symbol = nil, synonyms = nil)
  unless MIME_REGEXP.match?(string)
    raise InvalidMimeType, "#{string.inspect} is not a valid MIME type"
  end
  @symbol = symbol
  @synonyms = if synonyms&.any?
    synonyms.map { |synonym| synonym.dup.freeze }.freeze
  else
    [].freeze
  end
  @string = string.dup.freeze
  @hash = [@string, @synonyms, @symbol].hash
  freeze
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 271
def parse(accept_header)
  if !accept_header.include?(",")
    if (index = accept_header.index(PARAMETER_SEPARATOR_REGEXP))
      accept_header = accept_header[0, index].strip
    end
    return [] if accept_header.blank?
    parse_trailing_star(accept_header) || Array(Mime::Type.lookup(accept_header))
  else
    list, index = [], 0
    accept_header.scan(ACCEPT_HEADER_REGEXP).each do |header|
      params, q = header.split(PARAMETER_SEPARATOR_REGEXP)

      next unless params
      params.strip!
      next if params.empty?

      params = parse_trailing_star(params) || [params]

      params.each do |m|
        list << AcceptItem.new(index, m.to_s, q)
        index += 1
      end
    end
    AcceptList.sort! list
  end
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 307
def parse_data_with_trailing_star(type)
  Mime.registry.select { |m| m.match?(type) }
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 298
def parse_trailing_star(accept_header)
  parse_data_with_trailing_star($1) if accept_header =~ TRAILING_STAR_REGEXP
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 256
def register(string, symbol, mime_type_synonyms = [], extension_synonyms = [], skip_lookup = false)
  new_mime = Type.new(string, symbol, mime_type_synonyms)

  Mime.update do |registry, string_lookup, extension_lookup|
    registry << new_mime
    ([string] + mime_type_synonyms).each { |str| string_lookup[-str] = new_mime } unless skip_lookup
    ([symbol] + extension_synonyms).each { |ext| extension_lookup[-ext.to_s] = new_mime }
  end

  @on_change_callbacks.each do |callback|
    callback.call(new_mime, true)
  end
  new_mime
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 252
def register_alias(string, symbol, extension_synonyms = [])
  register(string, symbol, [], extension_synonyms, true)
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 230
def register_callback(&block)
  on_change { |mime, registered| block.call(mime) if registered }
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 316
def unregister(symbol)
  symbol = symbol.downcase
  if mime = Mime[symbol]
    Mime.update do |registry, string_lookup, extension_lookup|
      registry.delete_if { |v| v.eql?(mime) }
      string_lookup.delete_if { |_, v| v.eql?(mime) }
      extension_lookup.delete_if { |_, v| v.eql?(mime) }
    end

    @on_change_callbacks.each do |callback|
      callback.call(mime, false)
    end
  end
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 386
def ==(mime_type)
  return false unless mime_type
  if mime_type.is_a?(Symbol)
    # `format == :json` is the common call. Compare the symbol directly, and
    # use `Symbol#name` so that the string comparison doesn't allocate.
    return true if @symbol == mime_type
    mime_string = mime_type.name
  else
    mime_string = mime_type.to_s
  end
  return true if @string == mime_string || @synonyms.include?(mime_string)

  mime_symbol = mime_type.to_sym
  @symbol == mime_symbol || @synonyms.any? { |synonym| synonym.to_sym == mime_symbol }
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 378
def ===(list)
  if list.is_a?(Array)
    (@synonyms + [ self ]).any? { |synonym| list.include?(synonym) }
  else
    super
  end
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 409
def =~(mime_type)
  return false unless mime_type
  regexp = Regexp.new(Regexp.quote(mime_type.to_s))
  @synonyms.any? { |synonym| synonym.to_s =~ regexp } || @string =~ regexp
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 425
def all?; false; end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 402
def eql?(other)
  super || (self.class == other.class &&
            @string    == other.string &&
            @synonyms  == other.synonyms &&
            @symbol    == other.symbol)
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 421
def html?
  (symbol == :html) || @string.include?("html")
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 415
def match?(mime_type)
  return false unless mime_type
  regexp = Regexp.new(Regexp.quote(mime_type.to_s))
  @synonyms.any? { |synonym| synonym.to_s.match?(regexp) } || @string.match?(regexp)
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 374
def ref
  symbol || to_s
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 362
def to_s
  @string
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 366
def to_str
  to_s
end

# File actionpack/lib/action_dispatch/http/mime_type.rb, line 370
def to_sym
  @symbol
end