class Protocol::Rack::Adapter::Generic

def self.extract_protocol(env, response, headers) 

def self.extract_protocol(env, response, headers)
	if protocol = response.protocol
		# This is the newer mechanism for protocol upgrade:
		if env["rack.protocol"]
			headers["rack.protocol"] = protocol
		
		# Older mechanism for protocol upgrade:
		elsif env[CGI::HTTP_UPGRADE]
			headers["upgrade"] = protocol
			headers["connection"] = "upgrade"
		end
	end
end

def self.parse_file(...) 

def self.parse_file(...)
	# This is the old interface, which was changed in Rack 3.
	::Rack::Builder.parse_file(...).first
end

def self.wrap(app) 

def self.wrap(app)
	self.new(app)
end

def call(request)

@parameter request [Protocol::HTTP::Request] The incoming request.

Build a rack `env` from the incoming request and apply it to the rack middleware. 
def call(request)
	env = self.make_environment(request)
	
	status, headers, body = @app.call(env)
	
	# The status must always be an integer.
	unless status.is_a?(Integer)
		raise ArgumentError, "Status must be an integer!"
	end
	
	# Headers must always be a hash or equivalent.
	unless headers
		raise ArgumentError, "Headers must not be nil!"
	end
	
	headers, meta = self.wrap_headers(headers)
	
	return Response.wrap(env, status, headers, meta, body, request)
rescue => exception
	Console.error(self, exception)
	
	body&.close if body.respond_to?(:close)
	
	env&.[](RACK_RESPONSE_FINISHED)&.each do |callback|
		callback.call(env, status, headers, exception)
	end
	
	return failure_response(exception)
end

def failure_response(exception)

@returns [Protocol::HTTP::Response]
@parameter exception [Exception]
Generate a suitable response for the given exception. 
def failure_response(exception)
	Protocol::HTTP::Response.for_exception(exception)
end

def initialize(app)

@parameter app [Object] The rack middleware.
Initialize the rack adaptor middleware. 
def initialize(app)
	@app = app
	
	raise ArgumentError, "App must be callable!" unless @app.respond_to?(:call)
end

def logger 

def logger
	Console
end

def make_environment(request) 

def make_environment(request)
	{
		request: request
	}
end

def unwrap_headers(headers, env)

@parameter env [Hash] The rack request `env`.
@parameter headers [Protocol::HTTP::Headers] The raw HTTP request headers.

Rack separates multiple headers with the same key, into a single field with multiple lines.

Unwrap raw HTTP headers into the CGI-style expected by Rack middleware. 
def unwrap_headers(headers, env)
	headers.each do |key, value|
		http_key = "HTTP_#{key.upcase.tr('-', '_')}"
		
		if current_value = env[http_key]
			if http_key == CGI::HTTP_COOKIE
				env[http_key] = "#{current_value};#{value}"
			else
				env[http_key] = "#{current_value},#{value}"
			end
		else
			env[http_key] = value
		end
	end
end

def unwrap_request(request, env)

@parameter env [Hash] The rack `env`.
@parameter request [Protocol::HTTP::Request] The incoming request.

- Set `env['REMOTE_ADDR']` to the request remote adress.
- Set the `env['HTTP_X_FORWARDED_PROTO']` header to the request scheme.
- Set the `env['HTTP_HOST']` header to the request authority.
- Set the `env['CONTENT_TYPE']` and `env['CONTENT_LENGTH']` based on the incoming request body.

Process the incoming request into a valid rack `env`. 
def unwrap_request(request, env)
	if content_type = request.headers.delete("content-type")
		env[CGI::CONTENT_TYPE] = content_type
	end
	
	# In some situations we don't know the content length, e.g. when using chunked encoding, or when decompressing the body.
	if body = request.body and length = body.length
		env[CGI::CONTENT_LENGTH] = length.to_s
	end
	
	self.unwrap_headers(request.headers, env)
	
	# For the sake of compatibility, we set the `HTTP_UPGRADE` header to the requested protocol.
	if protocol = request.protocol and request.version.start_with?("HTTP/1")
		env[CGI::HTTP_UPGRADE] = Array(protocol).join(",")
	end
	
	if request.respond_to?(:hijack?) and request.hijack?
		env[RACK_IS_HIJACK] = true
		env[RACK_HIJACK] = proc{request.hijack!.io.dup}
	end
	
	# HTTP/2 prefers `:authority` over `host`, so we do this for backwards compatibility.
	env[CGI::HTTP_HOST] ||= request.authority
				
	if peer = request.peer
		env[CGI::REMOTE_ADDR] = peer.ip_address
	end
end