class UserAgent

def self.parse(string)
  if string.nil? || string.strip == ""
    string = DEFAULT_USER_AGENT
  end
  agents = Browsers::Base.new
  while m = string.to_s.match(MATCHER)
    agents << new(m[1], m[2], m[4])
    string = string[m[0].length..-1].strip
  end
  Browsers.extend(agents)
end

def <=>(other)
  if @product == other.product
    @version <=> other.version
  else
    false
  end
end

def detect_comment(&block)
  comment && comment.detect(&block)
end

def eql?(other)
  @product == other.product &&
    @version == other.version &&
    @comment == other.comment
end

def initialize(product, version = nil, comment = nil)
  if product
    @product = product
  else
    raise ArgumentError, "expected a value for product"
  end
  if version && !version.empty?
    @version = Version.new(version)
  else
    @version = Version.new
  end
  if comment.respond_to?(:split)
    @comment = comment.split("; ")
  else
    @comment = comment
  end
end

def to_s
  to_str
end

def to_str
  if @product && !@version.nil? && @comment
    "#{@product}/#{@version} (#{@comment.join("; ")})"
  elsif @product && !@version.nil?
    "#{@product}/#{@version}"
  elsif @product && @comment
    "#{@product} (#{@comment.join("; ")})"
  else
    @product
  end
end