# frozen_string_literal: true

module Faraday
  class Adapter
    # This class provides the main implementation for your adapter.
    # There are some key responsibilities that your adapter should satisfy:
    # * Initialize and store internally the client you chose (e.g. Net::HTTP)
    # * Process requests and save the response (see `#call`)
    class HTTPClient < Faraday::Adapter
      dependency 'httpclient'

      def build_connection(env)
        @client ||= ::HTTPClient.new.tap do |cli|
          # enable compression
          cli.transparent_gzip_decompression = true
        end

        if (req = env[:request])
          if (proxy = req[:proxy])
            configure_proxy @client, proxy
          end

          if (bind = req[:bind])
            configure_socket @client, bind
          end

          configure_timeouts @client, req
        end

        if env[:url].scheme == 'https' && (ssl = env[:ssl])
          configure_ssl @client, ssl
        end

        configure_client @client

        @client
      end

      def call(env)
        super

        # TODO: Don't stream yet.
        # https://github.com/nahi/httpclient/pull/90
        env[:body] = env[:body].read if env[:body].respond_to? :read

        connection(env) do |http|
          resp = http.request env[:method], env[:url],
                              body: env[:body],
                              header: env[:request_headers]

          if (req = env[:request]).stream_response?
            warn "Streaming downloads for #{self.class.name} " \
              'are not yet implemented.'
            req.on_data.call(resp.body, resp.body.bytesize)
          end
          save_response env, resp.status, resp.body, resp.headers, resp.reason

          @app.call env
        end
      rescue ::HTTPClient::TimeoutError, Errno::ETIMEDOUT
        raise Faraday::TimeoutError, $ERROR_INFO
      rescue ::HTTPClient::BadResponseError => e
        if e.message.include?('status 407')
          raise Faraday::ConnectionFailed,
                %(407 "Proxy Authentication Required ")
        end

        raise Faraday::ClientError, $ERROR_INFO
      rescue Errno::EADDRNOTAVAIL, Errno::ECONNREFUSED, IOError, SocketError
        raise Faraday::ConnectionFailed, $ERROR_INFO
      rescue StandardError => e
        if defined?(::OpenSSL::SSL::SSLError) && \
           e.is_a?(::OpenSSL::SSL::SSLError)
          raise Faraday::SSLError, e
        end

        raise
      end

      # @param bind [Hash]
      def configure_socket(client, bind)
        client.socket_local.host = bind[:host]
        client.socket_local.port = bind[:port]
      end

      # Configure proxy URI and any user credentials.
      #
      # @param proxy [Hash]
      def configure_proxy(client, proxy)
        client.proxy = proxy[:uri]
        return unless proxy[:user] && proxy[:password]

        client.set_proxy_auth(proxy[:user], proxy[:password])
      end

      # @param ssl [Hash]
      def configure_ssl(client, ssl)
        ssl_config = client.ssl_config
        ssl_config.verify_mode = ssl_verify_mode(ssl)
        ssl_config.cert_store = ssl_cert_store(ssl)

        ssl_config.add_trust_ca ssl[:ca_file] if ssl[:ca_file]
        ssl_config.add_trust_ca ssl[:ca_path] if ssl[:ca_path]
        ssl_config.client_cert = ssl[:client_cert] if ssl[:client_cert]
        ssl_config.client_key = ssl[:client_key] if ssl[:client_key]
        ssl_config.verify_depth = ssl[:verify_depth] if ssl[:verify_depth]
      end

      # @param req [Hash]
      def configure_timeouts(client, req)
        if (sec = request_timeout(:open, req))
          client.connect_timeout = sec
        end

        if (sec = request_timeout(:write, req))
          client.send_timeout = sec
        end

        return unless (sec = request_timeout(:read, req))

        client.receive_timeout = sec
      end

      def configure_client(client)
        @config_block&.call(client)
      end

      # @param ssl [Hash]
      # @return [OpenSSL::X509::Store]
      def ssl_cert_store(ssl)
        return ssl[:cert_store] if ssl[:cert_store]

        # Memoize the cert store so that the same one is passed to
        # HTTPClient each time, to avoid resyncing SSL sessions when
        # it's changed

        # Use the default cert store by default, i.e. system ca certs
        @ssl_cert_store ||= OpenSSL::X509::Store.new.tap(&:set_default_paths)
      end

      # @param ssl [Hash]
      def ssl_verify_mode(ssl)
        ssl[:verify_mode] || begin
          if ssl.fetch(:verify, true)
            OpenSSL::SSL::VERIFY_PEER |
              OpenSSL::SSL::VERIFY_FAIL_IF_NO_PEER_CERT
          else
            OpenSSL::SSL::VERIFY_NONE
          end
        end
      end
    end
  end
end
