from pprint import pformat

from twisted.internet import reactor
from twisted.internet.defer import Deferred
from twisted.internet.protocol import Protocol
from twisted.web.client import Agent
from twisted.web.http_headers import Headers


class BeginningPrinter(Protocol):
    def __init__(self, finished):
        self.finished = finished
        self.remaining = 1024 * 10

    def dataReceived(self, bytes):
        if self.remaining:
            display = bytes[: self.remaining]
            print("Some data received:")
            print(display)
            self.remaining -= len(display)

    def connectionLost(self, reason):
        print("Finished receiving body:", reason.getErrorMessage())
        self.finished.callback(None)


agent = Agent(reactor)
d = agent.request(
    b"GET",
    b"http://httpbin.com/anything/",
    Headers({"User-Agent": ["Twisted Web Client Example"]}),
    None,
)


def cbRequest(response):
    print("Response version:", response.version)
    print("Response code:", response.code)
    print("Response phrase:", response.phrase)
    print("Response headers:")
    print(pformat(list(response.headers.getAllRawHeaders())))
    finished = Deferred()
    response.deliverBody(BeginningPrinter(finished))
    return finished


d.addCallback(cbRequest)


def cbShutdown(ignored):
    reactor.stop()


d.addBoth(cbShutdown)

reactor.run()