class HTTP::Options

def [](option)
  send(option) rescue nil
end

def argument_error!(message)
  fail(Error, message, caller[1..-1])
end

def dup
  dupped = super
  yield(dupped) if block_given?
  dupped
end

def initialize(options = {})
  @response  = options[:response]  || :auto
  @proxy     = options[:proxy]     || {}
  @body      = options[:body]
  @params    = options[:params]
  @form      = options[:form]
  @json      = options[:json]
  @follow    = options[:follow]
  @headers   = HTTP::Headers.coerce(options[:headers] || {})
  @socket_class     = options[:socket_class]     || self.class.default_socket_class
  @ssl_socket_class = options[:ssl_socket_class] || self.class.default_ssl_socket_class
  @ssl_context      = options[:ssl_context]
end

def merge(other)
  h1, h2 = to_hash, other.to_hash
  merged = h1.merge(h2) do |k, v1, v2|
    case k
    when :headers
      v1.merge(v2)
    else
      v2
    end
  end
  self.class.new(merged)
end

def new(options = {})
  return options if options.is_a?(self)
  super
end

def to_hash
  # FIXME: hardcoding these fields blows! We should have a declarative
  # way of specifying all the options fields, and ensure they *all*
  # get serialized here, rather than manually having to add them each time
  {
    :response         => response,
    :headers          => headers.to_h,
    :proxy            => proxy,
    :params           => params,
    :form             => form,
    :json             => json,
    :body             => body,
    :follow           => follow,
    :socket_class     => socket_class,
    :ssl_socket_class => ssl_socket_class,
    :ssl_context      => ssl_context
 }
end

def with_body(body)
  dup do |opts|
    opts.body = body
  end
end

def with_follow(follow)
  dup do |opts|
    opts.follow = follow
  end
end

def with_form(form)
  dup do |opts|
    opts.form = form
  end
end

def with_headers(headers)
  dup do |opts|
    opts.headers = self.headers.merge(headers)
  end
end

def with_json(data)
  dup do |opts|
    opts.json = data
  end
end

def with_params(params)
  dup do |opts|
    opts.params = params
  end
end

def with_proxy(proxy_hash)
  dup do |opts|
    opts.proxy = proxy_hash
  end
end