request.rb

# frozen_string_literal: true

require "forwardable"
require "base64"
require "time"

require "http/errors"
require "http/headers"
require "http/request/body"
require "http/request/writer"
require "http/version"
require "http/uri"

module HTTP
  class Request
    extend Forwardable

    include HTTP::Headers::Mixin

    # The method given was not understood
    class UnsupportedMethodError < RequestError; end

    # The scheme of given URI was not understood
    class UnsupportedSchemeError < RequestError; end

    # Default User-Agent header value
    USER_AGENT = "http.rb/#{HTTP::VERSION}".freeze

    METHODS = [
      # RFC 2616: Hypertext Transfer Protocol -- HTTP/1.1
      :options, :get, :head, :post, :put, :delete, :trace, :connect,

      # RFC 2518: HTTP Extensions for Distributed Authoring -- WEBDAV
      :propfind, :proppatch, :mkcol, :copy, :move, :lock, :unlock,

      # RFC 3648: WebDAV Ordered Collections Protocol
      :orderpatch,

      # RFC 3744: WebDAV Access Control Protocol
      :acl,

      # RFC 6352: vCard Extensions to WebDAV -- CardDAV
      :report,

      # RFC 5789: PATCH Method for HTTP
      :patch,

      # draft-reschke-webdav-search: WebDAV Search
      :search,

      # RFC 4791: Calendaring Extensions to WebDAV -- CalDAV
      :mkcalendar,

      # Implemented by several caching servers, like Squid, Varnish or Fastly
      :purge
    ].freeze

    # Allowed schemes
    SCHEMES = %i[http https ws wss].freeze

    # Default ports of supported schemes
    PORTS = {
      http:  80,
      https: 443,
      ws:    80,
      wss:   443
    }.freeze

    # Method is given as a lowercase symbol e.g. :get, :post
    attr_reader :verb

    # Scheme is normalized to be a lowercase symbol e.g. :http, :https
    attr_reader :scheme

    attr_reader :uri_normalizer

    # "Request URI" as per RFC 2616
    # http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html
    attr_reader :uri
    attr_reader :proxy, :body, :version

    # @option opts [String] :version
    # @option opts [#to_s] :verb HTTP request method
    # @option opts [#call] :uri_normalizer (HTTP::URI::NORMALIZER)
    # @option opts [HTTP::URI, #to_s] :uri
    # @option opts [Hash] :headers
    # @option opts [Hash] :proxy
    # @option opts [String, Enumerable, IO, nil] :body
    def initialize(opts)
      @verb           = opts.fetch(:verb).to_s.downcase.to_sym
      @uri_normalizer = opts[:uri_normalizer] || HTTP::URI::NORMALIZER

      @uri    = @uri_normalizer.call(opts.fetch(:uri))
      @scheme = @uri.scheme.to_s.downcase.to_sym if @uri.scheme

      raise(UnsupportedMethodError, "unknown method: #{verb}") unless METHODS.include?(@verb)
      raise(UnsupportedSchemeError, "unknown scheme: #{scheme}") unless SCHEMES.include?(@scheme)

      @proxy   = opts[:proxy] || {}
      @version = opts[:version] || "1.1"
      @headers = prepare_headers(opts[:headers])
      @body    = prepare_body(opts[:body])
    end

    # Returns new Request with updated uri
    def redirect(uri, verb = @verb)
      headers = self.headers.dup
      headers.delete(Headers::HOST)

      new_body = body.source
      if verb == :get
        # request bodies should not always be resubmitted when following a redirect
        # some servers will close the connection after receiving the request headers
        # which may cause Errno::ECONNRESET: Connection reset by peer
        # see https://github.com/httprb/http/issues/649
        # new_body = Request::Body.new(nil)
        new_body = nil
        # the CONTENT_TYPE header causes problems if set on a get request w/ an empty body
        # the server might assume that there should be content if it is set to multipart
        # rack raises EmptyContentError if this happens
        headers.delete(Headers::CONTENT_TYPE)
      end

      self.class.new(
        verb:           verb,
        uri:            @uri.join(uri),
        headers:        headers,
        proxy:          proxy,
        body:           new_body,
        version:        version,
        uri_normalizer: uri_normalizer
      )
    end

    # Stream the request to a socket
    def stream(socket)
      include_proxy_headers if using_proxy? && !@uri.https?
      Request::Writer.new(socket, body, headers, headline).stream
    end

    # Is this request using a proxy?
    def using_proxy?
      proxy && proxy.keys.size >= 2
    end

    # Is this request using an authenticated proxy?
    def using_authenticated_proxy?
      proxy && proxy.keys.size >= 4
    end

    def include_proxy_headers
      headers.merge!(proxy[:proxy_headers]) if proxy.key?(:proxy_headers)
      include_proxy_authorization_header if using_authenticated_proxy?
    end

    # Compute and add the Proxy-Authorization header
    def include_proxy_authorization_header
      headers[Headers::PROXY_AUTHORIZATION] = proxy_authorization_header
    end

    def proxy_authorization_header
      digest = Base64.strict_encode64("#{proxy[:proxy_username]}:#{proxy[:proxy_password]}")
      "Basic #{digest}"
    end

    # Setup tunnel through proxy for SSL request
    def connect_using_proxy(socket)
      Request::Writer.new(socket, nil, proxy_connect_headers, proxy_connect_header).connect_through_proxy
    end

    # Compute HTTP request header for direct or proxy request
    def headline
      request_uri =
        if using_proxy? && !uri.https?
          uri.omit(:fragment)
        else
          uri.request_uri
        end.to_s

      raise RequestError, "Invalid request URI: #{request_uri.inspect}" if request_uri.match?(/\s/)

      "#{verb.to_s.upcase} #{request_uri} HTTP/#{version}"
    end

    # Compute HTTP request header SSL proxy connection
    def proxy_connect_header
      "CONNECT #{host}:#{port} HTTP/#{version}"
    end

    # Headers to send with proxy connect request
    def proxy_connect_headers
      connect_headers = HTTP::Headers.coerce(
        Headers::HOST       => headers[Headers::HOST],
        Headers::USER_AGENT => headers[Headers::USER_AGENT]
      )

      connect_headers[Headers::PROXY_AUTHORIZATION] = proxy_authorization_header if using_authenticated_proxy?
      connect_headers.merge!(proxy[:proxy_headers]) if proxy.key?(:proxy_headers)
      connect_headers
    end

    # Host for tcp socket
    def socket_host
      using_proxy? ? proxy[:proxy_address] : host
    end

    # Port for tcp socket
    def socket_port
      using_proxy? ? proxy[:proxy_port] : port
    end

    # Human-readable representation of base request info.
    #
    # @example
    #
    #     req.inspect
    #     # => #<HTTP::Request/1.1 GET https://example.com>
    #
    # @return [String]
    def inspect
      "#<#{self.class}/#{@version} #{verb.to_s.upcase} #{uri}>"
    end

    private

    # @!attribute [r] host
    #   @return [String]
    def_delegator :@uri, :host

    # @!attribute [r] port
    #   @return [Fixnum]
    def port
      @uri.port || @uri.default_port
    end

    # @return [String] Default host (with port if needed) header value.
    def default_host_header_value
      value = PORTS[@scheme] == port ? host : "#{host}:#{port}"

      raise RequestError, "Invalid host: #{value.inspect}" if value.match?(/\s/)

      value
    end

    def prepare_body(body)
      body.is_a?(Request::Body) ? body : Request::Body.new(body)
    end

    def prepare_headers(headers)
      headers = HTTP::Headers.coerce(headers || {})

      headers[Headers::HOST]       ||= default_host_header_value
      headers[Headers::USER_AGENT] ||= USER_AGENT

      headers
    end
  end
end