# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.

"""
Tests for L{twisted.web.twcgi}.
"""

import sys
import os
import json
from io import BytesIO

from twisted.trial import unittest
from twisted.internet import reactor, interfaces, error
from twisted.python import util, failure, log
from twisted.web.http import NOT_FOUND, INTERNAL_SERVER_ERROR
from twisted.web import client, twcgi, server, resource, http_headers
from twisted.web.test._util import _render
from twisted.web.test.test_web import DummyRequest

DUMMY_CGI = '''\
print("Header: OK")
print("")
print("cgi output")
'''

DUAL_HEADER_CGI = '''\
print("Header: spam")
print("Header: eggs")
print("")
print("cgi output")
'''

BROKEN_HEADER_CGI = '''\
print("XYZ")
print("")
print("cgi output")
'''

SPECIAL_HEADER_CGI = '''\
print("Server: monkeys")
print("Date: last year")
print("")
print("cgi output")
'''

READINPUT_CGI = '''\
# This is an example of a correctly-written CGI script which reads a body
# from stdin, which only reads env['CONTENT_LENGTH'] bytes.

import os, sys

body_length = int(os.environ.get('CONTENT_LENGTH',0))
indata = sys.stdin.read(body_length)
print("Header: OK")
print("")
print("readinput ok")
'''

READALLINPUT_CGI = '''\
# This is an example of the typical (incorrect) CGI script which expects
# the server to close stdin when the body of the request is complete.
# A correct CGI should only read env['CONTENT_LENGTH'] bytes.

import sys

indata = sys.stdin.read()
print("Header: OK")
print("")
print("readallinput ok")
'''

NO_DUPLICATE_CONTENT_TYPE_HEADER_CGI = '''\
print("content-type: text/cgi-duplicate-test")
print("")
print("cgi output")
'''

HEADER_OUTPUT_CGI = '''\
import json
import os
print("")
print("")
vals = {x:y for x,y in os.environ.items() if x.startswith("HTTP_")}
print(json.dumps(vals))
'''

class PythonScript(twcgi.FilteredScript):
    filter = sys.executable



class CGITests(unittest.TestCase):
    """
    Tests for L{twcgi.FilteredScript}.
    """

    if not interfaces.IReactorProcess.providedBy(reactor):
        skip = "CGI tests require a functional reactor.spawnProcess()"


    def startServer(self, cgi):
        root = resource.Resource()
        cgipath = util.sibpath(__file__, cgi)
        root.putChild(b"cgi", PythonScript(cgipath))
        site = server.Site(root)
        self.p = reactor.listenTCP(0, site)
        return self.p.getHost().port


    def tearDown(self):
        if getattr(self, 'p', None):
            return self.p.stopListening()


    def writeCGI(self, source):
        cgiFilename = os.path.abspath(self.mktemp())
        with open(cgiFilename, 'wt') as cgiFile:
            cgiFile.write(source)
        return cgiFilename


    def test_CGI(self):
        cgiFilename = self.writeCGI(DUMMY_CGI)

        portnum = self.startServer(cgiFilename)
        url = 'http://localhost:%d/cgi' % (portnum,)
        url = url.encode("ascii")
        d = client.Agent(reactor).request(b"GET", url)
        d.addCallback(client.readBody)
        d.addCallback(self._testCGI_1)
        return d


    def _testCGI_1(self, res):
        self.assertEqual(res, b"cgi output" + os.linesep.encode("ascii"))


    def test_protectedServerAndDate(self):
        """
        If the CGI script emits a I{Server} or I{Date} header, these are
        ignored.
        """
        cgiFilename = self.writeCGI(SPECIAL_HEADER_CGI)

        portnum = self.startServer(cgiFilename)
        url = "http://localhost:%d/cgi" % (portnum,)
        url = url.encode("ascii")
        agent = client.Agent(reactor)
        d = agent.request(b"GET", url)
        d.addCallback(discardBody)
        def checkResponse(response):
            self.assertNotIn('monkeys',
                             response.headers.getRawHeaders('server'))
            self.assertNotIn('last year',
                             response.headers.getRawHeaders('date'))
        d.addCallback(checkResponse)
        return d


    def test_noDuplicateContentTypeHeaders(self):
        """
        If the CGI script emits a I{content-type} header, make sure that the
        server doesn't add an additional (duplicate) one, as per ticket 4786.
        """
        cgiFilename = self.writeCGI(NO_DUPLICATE_CONTENT_TYPE_HEADER_CGI)

        portnum = self.startServer(cgiFilename)
        url = "http://localhost:%d/cgi" % (portnum,)
        url = url.encode("ascii")
        agent = client.Agent(reactor)
        d = agent.request(b"GET", url)
        d.addCallback(discardBody)
        def checkResponse(response):
            self.assertEqual(
                response.headers.getRawHeaders('content-type'),
                ['text/cgi-duplicate-test'])
            return response
        d.addCallback(checkResponse)
        return d


    def test_noProxyPassthrough(self):
        """
        The CGI script is never called with the Proxy header passed through.
        """
        cgiFilename = self.writeCGI(HEADER_OUTPUT_CGI)

        portnum = self.startServer(cgiFilename)
        url = "http://localhost:%d/cgi" % (portnum,)
        url = url.encode("ascii")

        agent = client.Agent(reactor)

        headers = http_headers.Headers({b"Proxy": [b"foo"],
                                        b"X-Innocent-Header": [b"bar"]})
        d = agent.request(b"GET", url, headers=headers)

        def checkResponse(response):
            headers = json.loads(response.decode("ascii"))
            self.assertEqual(
                set(headers.keys()),
                {"HTTP_HOST", "HTTP_CONNECTION", "HTTP_X_INNOCENT_HEADER"})

        d.addCallback(client.readBody)
        d.addCallback(checkResponse)
        return d


    def test_duplicateHeaderCGI(self):
        """
        If a CGI script emits two instances of the same header, both are sent
        in the response.
        """
        cgiFilename = self.writeCGI(DUAL_HEADER_CGI)

        portnum = self.startServer(cgiFilename)
        url = "http://localhost:%d/cgi" % (portnum,)
        url = url.encode("ascii")
        agent = client.Agent(reactor)
        d = agent.request(b"GET", url)
        d.addCallback(discardBody)
        def checkResponse(response):
            self.assertEqual(
                response.headers.getRawHeaders('header'), ['spam', 'eggs'])
        d.addCallback(checkResponse)
        return d


    def test_malformedHeaderCGI(self):
        """
        Check for the error message in the duplicated header
        """
        cgiFilename = self.writeCGI(BROKEN_HEADER_CGI)

        portnum = self.startServer(cgiFilename)
        url = "http://localhost:%d/cgi" % (portnum,)
        url = url.encode("ascii")
        agent = client.Agent(reactor)
        d = agent.request(b"GET", url)
        d.addCallback(discardBody)
        loggedMessages = []

        def addMessage(eventDict):
            loggedMessages.append(log.textFromEventDict(eventDict))

        log.addObserver(addMessage)
        self.addCleanup(log.removeObserver, addMessage)

        def checkResponse(ignored):
            self.assertIn("ignoring malformed CGI header: " + repr(b'XYZ'),
                          loggedMessages)

        d.addCallback(checkResponse)
        return d


    def test_ReadEmptyInput(self):
        cgiFilename = os.path.abspath(self.mktemp())
        with open(cgiFilename, 'wt') as cgiFile:
            cgiFile.write(READINPUT_CGI)

        portnum = self.startServer(cgiFilename)
        agent = client.Agent(reactor)
        url = "http://localhost:%d/cgi" % (portnum,)
        url = url.encode("ascii")
        d = agent.request(b"GET", url)
        d.addCallback(client.readBody)
        d.addCallback(self._test_ReadEmptyInput_1)
        return d
    test_ReadEmptyInput.timeout = 5


    def _test_ReadEmptyInput_1(self, res):
        expected = "readinput ok{}".format(os.linesep)
        expected = expected.encode("ascii")
        self.assertEqual(res, expected)


    def test_ReadInput(self):
        cgiFilename = os.path.abspath(self.mktemp())
        with open(cgiFilename, 'wt') as cgiFile:
            cgiFile.write(READINPUT_CGI)

        portnum = self.startServer(cgiFilename)
        agent = client.Agent(reactor)
        url = "http://localhost:%d/cgi" % (portnum,)
        url = url.encode("ascii")
        d = agent.request(
            uri=url,
            method=b"POST",
            bodyProducer=client.FileBodyProducer(
                BytesIO(b"Here is your stdin")),
        )
        d.addCallback(client.readBody)
        d.addCallback(self._test_ReadInput_1)
        return d
    test_ReadInput.timeout = 5


    def _test_ReadInput_1(self, res):
        expected = "readinput ok{}".format(os.linesep)
        expected = expected.encode("ascii")
        self.assertEqual(res, expected)


    def test_ReadAllInput(self):
        cgiFilename = os.path.abspath(self.mktemp())
        with open(cgiFilename, 'wt') as cgiFile:
            cgiFile.write(READALLINPUT_CGI)

        portnum = self.startServer(cgiFilename)
        url = "http://localhost:%d/cgi" % (portnum,)
        url = url.encode("ascii")
        d = client.Agent(reactor).request(
            uri=url,
            method=b"POST",
            bodyProducer=client.FileBodyProducer(
                BytesIO(b"Here is your stdin")),
        )
        d.addCallback(client.readBody)
        d.addCallback(self._test_ReadAllInput_1)
        return d
    test_ReadAllInput.timeout = 5


    def _test_ReadAllInput_1(self, res):
        expected = "readallinput ok{}".format(os.linesep)
        expected = expected.encode("ascii")
        self.assertEqual(res, expected)


    def test_useReactorArgument(self):
        """
        L{twcgi.FilteredScript.runProcess} uses the reactor passed as an
        argument to the constructor.
        """
        class FakeReactor:
            """
            A fake reactor recording whether spawnProcess is called.
            """
            called = False
            def spawnProcess(self, *args, **kwargs):
                """
                Set the C{called} flag to C{True} if C{spawnProcess} is called.

                @param args: Positional arguments.
                @param kwargs: Keyword arguments.
                """
                self.called = True

        fakeReactor = FakeReactor()
        request = DummyRequest(['a', 'b'])
        resource = twcgi.FilteredScript("dummy-file", reactor=fakeReactor)
        _render(resource, request)

        self.assertTrue(fakeReactor.called)



class CGIScriptTests(unittest.TestCase):
    """
    Tests for L{twcgi.CGIScript}.
    """

    def test_pathInfo(self):
        """
        L{twcgi.CGIScript.render} sets the process environment
        I{PATH_INFO} from the request path.
        """
        class FakeReactor:
            """
            A fake reactor recording the environment passed to spawnProcess.
            """
            def spawnProcess(self, process, filename, args, env, wdir):
                """
                Store the C{env} L{dict} to an instance attribute.

                @param process: Ignored
                @param filename: Ignored
                @param args: Ignored
                @param env: The environment L{dict} which will be stored
                @param wdir: Ignored
                """
                self.process_env = env

        _reactor = FakeReactor()
        resource = twcgi.CGIScript(self.mktemp(), reactor=_reactor)
        request = DummyRequest(['a', 'b'])
        _render(resource, request)

        self.assertEqual(_reactor.process_env["PATH_INFO"],
                         "/a/b")



class CGIDirectoryTests(unittest.TestCase):
    """
    Tests for L{twcgi.CGIDirectory}.
    """
    def test_render(self):
        """
        L{twcgi.CGIDirectory.render} sets the HTTP response code to I{NOT
        FOUND}.
        """
        resource = twcgi.CGIDirectory(self.mktemp())
        request = DummyRequest([''])
        d = _render(resource, request)
        def cbRendered(ignored):
            self.assertEqual(request.responseCode, NOT_FOUND)
        d.addCallback(cbRendered)
        return d


    def test_notFoundChild(self):
        """
        L{twcgi.CGIDirectory.getChild} returns a resource which renders an
        response with the HTTP I{NOT FOUND} status code if the indicated child
        does not exist as an entry in the directory used to initialized the
        L{twcgi.CGIDirectory}.
        """
        path = self.mktemp()
        os.makedirs(path)
        resource = twcgi.CGIDirectory(path)
        request = DummyRequest(['foo'])
        child = resource.getChild("foo", request)
        d = _render(child, request)
        def cbRendered(ignored):
            self.assertEqual(request.responseCode, NOT_FOUND)
        d.addCallback(cbRendered)
        return d



class CGIProcessProtocolTests(unittest.TestCase):
    """
    Tests for L{twcgi.CGIProcessProtocol}.
    """
    def test_prematureEndOfHeaders(self):
        """
        If the process communicating with L{CGIProcessProtocol} ends before
        finishing writing out headers, the response has I{INTERNAL SERVER
        ERROR} as its status code.
        """
        request = DummyRequest([''])
        protocol = twcgi.CGIProcessProtocol(request)
        protocol.processEnded(failure.Failure(error.ProcessTerminated()))
        self.assertEqual(request.responseCode, INTERNAL_SERVER_ERROR)



def discardBody(response):
    """
    Discard the body of a HTTP response.

    @param response: The response.

    @return: The response.
    """
    return client.readBody(response).addCallback(lambda _: response)