class HTTP::Client

def build_request(verb, uri, opts = {})
  opts    = @default_options.merge(opts)
  uri     = make_request_uri(uri, opts)
  headers = make_request_headers(opts)
  body    = make_request_body(opts, headers)
  req = HTTP::Request.new(
    :verb           => verb,
    :uri            => uri,
    :uri_normalizer => opts.feature(:normalize_uri)&.normalizer,
    :proxy          => opts.proxy,
    :headers        => headers,
    :body           => body
  )
  wrap_request(req, opts)
end

def build_response(req, options)
  Response.new(
    :status        => @connection.status_code,
    :version       => @connection.http_version,
    :headers       => @connection.headers,
    :proxy_headers => @connection.proxy_response_headers,
    :connection    => @connection,
    :encoding      => options.encoding,
    :request       => req
  )
end

def close
  @connection&.close
  @connection = nil
  @state = :clean
end

def initialize(default_options = {})
  @default_options = HTTP::Options.new(default_options)
  @connection = nil
  @state = :clean
end

def make_form_data(form)
  return form if form.is_a? HTTP::FormData::Multipart
  return form if form.is_a? HTTP::FormData::Urlencoded
  HTTP::FormData.create(form)
end

def make_request_body(opts, headers)
  case
  when opts.body
    opts.body
  when opts.form
    form = make_form_data(opts.form)
    headers[Headers::CONTENT_TYPE] ||= form.content_type
    form
  when opts.json
    body = MimeType[:json].encode opts.json
    headers[Headers::CONTENT_TYPE] ||= "application/json; charset=#{body.encoding.name.downcase}"
    body
  end
end

def make_request_headers(opts)
  headers = opts.headers
  # Tell the server to keep the conn open
  headers[Headers::CONNECTION] = default_options.persistent? ? Connection::KEEP_ALIVE : Connection::CLOSE
  cookies = opts.cookies.values
  unless cookies.empty?
    cookies = opts.headers.get(Headers::COOKIE).concat(cookies).join("; ")
    headers[Headers::COOKIE] = cookies
  end
  headers
end

def make_request_uri(uri, opts)
  uri = uri.to_s
  uri = "#{default_options.persistent}#{uri}" if default_options.persistent? && uri !~ HTTP_OR_HTTPS_RE
  uri = HTTP::URI.parse uri
  uri.query_values = uri.query_values(Array).to_a.concat(opts.params.to_a) if opts.params && !opts.params.empty?
  # Some proxies (seen on WEBRick) fail if URL has
  # empty path (e.g. `http://example.com`) while it's RFC-complaint:
  # http://tools.ietf.org/html/rfc1738#section-3.1
  uri.path = "/" if uri.path.empty?
  uri
end

def perform(req, options)
  verify_connection!(req.uri)
  @state = :dirty
  begin
    @connection ||= HTTP::Connection.new(req, options)
    unless @connection.failed_proxy_connect?
      @connection.send_request(req)
      @connection.read_headers!
    end
  rescue Error => e
    options.features.each_value do |feature|
      feature.on_error(req, e)
    end
    raise
  end
  res = build_response(req, options)
  res = options.features.inject(res) do |response, (_name, feature)|
    feature.wrap_response(response)
  end
  @connection.finish_response if req.verb == :head
  @state = :clean
  res
rescue
  close
  raise
end

def request(verb, uri, opts = {})
  opts = @default_options.merge(opts)
  req = build_request(verb, uri, opts)
  res = perform(req, opts)
  return res unless opts.follow
  Redirector.new(opts.follow).perform(req, res) do |request|
    perform(wrap_request(request, opts), opts)
  end
end

def verify_connection!(uri)
  if default_options.persistent? && uri.origin != default_options.persistent
    raise StateError, "Persistence is enabled for #{default_options.persistent}, but we got #{uri.origin}"
  end
  # We re-create the connection object because we want to let prior requests
  # lazily load the body as long as possible, and this mimics prior functionality.
  return close if @connection && (!@connection.keep_alive? || @connection.expired?)
  # If we get into a bad state (eg, Timeout.timeout ensure being killed)
  # close the connection to prevent potential for mixed responses.
  return close if @state == :dirty
end

def wrap_request(req, opts)
  opts.features.inject(req) do |request, (_name, feature)|
    feature.wrap_request(request)
  end
end