from unittest import mock
from test import support
from test.test_httpservers import NoLogRequestHandler
from unittest import TestCase
from wsgiref.util import setup_testing_defaults
from wsgiref.headers import Headers
from wsgiref.handlers import BaseHandler, BaseCGIHandler, SimpleHandler
from wsgiref import util
from wsgiref.validate import validator
from wsgiref.simple_server import WSGIServer, WSGIRequestHandler
from wsgiref.simple_server import make_server
from http.client import HTTPConnection
from io import StringIO, BytesIO, BufferedReader
from socketserver import BaseServer
from platform import python_implementation

import os
import re
import signal
import sys
import threading
import unittest


class MockServer(WSGIServer):
    """Non-socket HTTP server"""

    def __init__(self, server_address, RequestHandlerClass):
        BaseServer.__init__(self, server_address, RequestHandlerClass)
        self.server_bind()

    def server_bind(self):
        host, port = self.server_address
        self.server_name = host
        self.server_port = port
        self.setup_environ()


class MockHandler(WSGIRequestHandler):
    """Non-socket HTTP handler"""
    def setup(self):
        self.connection = self.request
        self.rfile, self.wfile = self.connection

    def finish(self):
        pass


def hello_app(environ,start_response):
    start_response("200 OK", [
        ('Content-Type','text/plain'),
        ('Date','Mon, 05 Jun 2006 18:49:54 GMT')
    ])
    return [b"Hello, world!"]


def header_app(environ, start_response):
    start_response("200 OK", [
        ('Content-Type', 'text/plain'),
        ('Date', 'Mon, 05 Jun 2006 18:49:54 GMT')
    ])
    return [';'.join([
        environ['HTTP_X_TEST_HEADER'], environ['QUERY_STRING'],
        environ['PATH_INFO']
    ]).encode('iso-8859-1')]


def run_amock(app=hello_app, data=b"GET / HTTP/1.0\n\n"):
    server = make_server("", 80, app, MockServer, MockHandler)
    inp = BufferedReader(BytesIO(data))
    out = BytesIO()
    olderr = sys.stderr
    err = sys.stderr = StringIO()

    try:
        server.finish_request((inp, out), ("127.0.0.1",8888))
    finally:
        sys.stderr = olderr

    return out.getvalue(), err.getvalue()

def compare_generic_iter(make_it,match):
    """Utility to compare a generic 2.1/2.2+ iterator with an iterable

    If running under Python 2.2+, this tests the iterator using iter()/next(),
    as well as __getitem__.  'make_it' must be a function returning a fresh
    iterator to be tested (since this may test the iterator twice)."""

    it = make_it()
    n = 0
    for item in match:
        if not it[n]==item: raise AssertionError
        n+=1
    try:
        it[n]
    except IndexError:
        pass
    else:
        raise AssertionError("Too many items from __getitem__",it)

    try:
        iter, StopIteration
    except NameError:
        pass
    else:
        # Only test iter mode under 2.2+
        it = make_it()
        if not iter(it) is it: raise AssertionError
        for item in match:
            if not next(it) == item: raise AssertionError
        try:
            next(it)
        except StopIteration:
            pass
        else:
            raise AssertionError("Too many items from .__next__()", it)


class IntegrationTests(TestCase):

    def check_hello(self, out, has_length=True):
        pyver = (python_implementation() + "/" +
                sys.version.split()[0])
        self.assertEqual(out,
            ("HTTP/1.0 200 OK\r\n"
            "Server: WSGIServer/0.2 " + pyver +"\r\n"
            "Content-Type: text/plain\r\n"
            "Date: Mon, 05 Jun 2006 18:49:54 GMT\r\n" +
            (has_length and  "Content-Length: 13\r\n" or "") +
            "\r\n"
            "Hello, world!").encode("iso-8859-1")
        )

    def test_plain_hello(self):
        out, err = run_amock()
        self.check_hello(out)

    def test_environ(self):
        request = (
            b"GET /p%61th/?query=test HTTP/1.0\n"
            b"X-Test-Header: Python test \n"
            b"X-Test-Header: Python test 2\n"
            b"Content-Length: 0\n\n"
        )
        out, err = run_amock(header_app, request)
        self.assertEqual(
            out.splitlines()[-1],
            b"Python test,Python test 2;query=test;/path/"
        )

    def test_request_length(self):
        out, err = run_amock(data=b"GET " + (b"x" * 65537) + b" HTTP/1.0\n\n")
        self.assertEqual(out.splitlines()[0],
                         b"HTTP/1.0 414 Request-URI Too Long")

    def test_validated_hello(self):
        out, err = run_amock(validator(hello_app))
        # the middleware doesn't support len(), so content-length isn't there
        self.check_hello(out, has_length=False)

    def test_simple_validation_error(self):
        def bad_app(environ,start_response):
            start_response("200 OK", ('Content-Type','text/plain'))
            return ["Hello, world!"]
        out, err = run_amock(validator(bad_app))
        self.assertTrue(out.endswith(
            b"A server error occurred.  Please contact the administrator."
        ))
        self.assertEqual(
            err.splitlines()[-2],
            "AssertionError: Headers (('Content-Type', 'text/plain')) must"
            " be of type list: <class 'tuple'>"
        )

    def test_status_validation_errors(self):
        def create_bad_app(status):
            def bad_app(environ, start_response):
                start_response(status, [("Content-Type", "text/plain; charset=utf-8")])
                return [b"Hello, world!"]
            return bad_app

        tests = [
            ('200', 'AssertionError: Status must be at least 4 characters'),
            ('20X OK', 'AssertionError: Status message must begin w/3-digit code'),
            ('200OK', 'AssertionError: Status message must have a space after code'),
        ]

        for status, exc_message in tests:
            with self.subTest(status=status):
                out, err = run_amock(create_bad_app(status))
                self.assertTrue(out.endswith(
                    b"A server error occurred.  Please contact the administrator."
                ))
                self.assertEqual(err.splitlines()[-2], exc_message)

    def test_wsgi_input(self):
        def bad_app(e,s):
            e["wsgi.input"].read()
            s("200 OK", [("Content-Type", "text/plain; charset=utf-8")])
            return [b"data"]
        out, err = run_amock(validator(bad_app))
        self.assertTrue(out.endswith(
            b"A server error occurred.  Please contact the administrator."
        ))
        self.assertEqual(
            err.splitlines()[-2], "AssertionError"
        )

    def test_bytes_validation(self):
        def app(e, s):
            s("200 OK", [
                ("Content-Type", "text/plain; charset=utf-8"),
                ("Date", "Wed, 24 Dec 2008 13:29:32 GMT"),
                ])
            return [b"data"]
        out, err = run_amock(validator(app))
        self.assertTrue(err.endswith('"GET / HTTP/1.0" 200 4\n'))
        ver = sys.version.split()[0].encode('ascii')
        py  = python_implementation().encode('ascii')
        pyver = py + b"/" + ver
        self.assertEqual(
                b"HTTP/1.0 200 OK\r\n"
                b"Server: WSGIServer/0.2 "+ pyver + b"\r\n"
                b"Content-Type: text/plain; charset=utf-8\r\n"
                b"Date: Wed, 24 Dec 2008 13:29:32 GMT\r\n"
                b"\r\n"
                b"data",
                out)

    def test_cp1252_url(self):
        def app(e, s):
            s("200 OK", [
                ("Content-Type", "text/plain"),
                ("Date", "Wed, 24 Dec 2008 13:29:32 GMT"),
                ])
            # PEP3333 says environ variables are decoded as latin1.
            # Encode as latin1 to get original bytes
            return [e["PATH_INFO"].encode("latin1")]

        out, err = run_amock(
            validator(app), data=b"GET /\x80%80 HTTP/1.0")
        self.assertEqual(
            [
                b"HTTP/1.0 200 OK",
                mock.ANY,
                b"Content-Type: text/plain",
                b"Date: Wed, 24 Dec 2008 13:29:32 GMT",
                b"",
                b"/\x80\x80",
            ],
            out.splitlines())

    def test_interrupted_write(self):
        # BaseHandler._write() and _flush() have to write all data, even if
        # it takes multiple send() calls.  Test this by interrupting a send()
        # call with a Unix signal.
        pthread_kill = support.get_attribute(signal, "pthread_kill")

        def app(environ, start_response):
            start_response("200 OK", [])
            return [b'\0' * support.SOCK_MAX_SIZE]

        class WsgiHandler(NoLogRequestHandler, WSGIRequestHandler):
            pass

        server = make_server(support.HOST, 0, app, handler_class=WsgiHandler)
        self.addCleanup(server.server_close)
        interrupted = threading.Event()

        def signal_handler(signum, frame):
            interrupted.set()

        original = signal.signal(signal.SIGUSR1, signal_handler)
        self.addCleanup(signal.signal, signal.SIGUSR1, original)
        received = None
        main_thread = threading.get_ident()

        def run_client():
            http = HTTPConnection(*server.server_address)
            http.request("GET", "/")
            with http.getresponse() as response:
                response.read(100)
                # The main thread should now be blocking in a send() system
                # call.  But in theory, it could get interrupted by other
                # signals, and then retried.  So keep sending the signal in a
                # loop, in case an earlier signal happens to be delivered at
                # an inconvenient moment.
                while True:
                    pthread_kill(main_thread, signal.SIGUSR1)
                    if interrupted.wait(timeout=float(1)):
                        break
                nonlocal received
                received = len(response.read())
            http.close()

        background = threading.Thread(target=run_client)
        background.start()
        server.handle_request()
        background.join()
        self.assertEqual(received, support.SOCK_MAX_SIZE - 100)


class UtilityTests(TestCase):

    def checkShift(self,sn_in,pi_in,part,sn_out,pi_out):
        env = {'SCRIPT_NAME':sn_in,'PATH_INFO':pi_in}
        util.setup_testing_defaults(env)
        self.assertEqual(util.shift_path_info(env),part)
        self.assertEqual(env['PATH_INFO'],pi_out)
        self.assertEqual(env['SCRIPT_NAME'],sn_out)
        return env

    def checkDefault(self, key, value, alt=None):
        # Check defaulting when empty
        env = {}
        util.setup_testing_defaults(env)
        if isinstance(value, StringIO):
            self.assertIsInstance(env[key], StringIO)
        elif isinstance(value,BytesIO):
            self.assertIsInstance(env[key],BytesIO)
        else:
            self.assertEqual(env[key], value)

        # Check existing value
        env = {key:alt}
        util.setup_testing_defaults(env)
        self.assertIs(env[key], alt)

    def checkCrossDefault(self,key,value,**kw):
        util.setup_testing_defaults(kw)
        self.assertEqual(kw[key],value)

    def checkAppURI(self,uri,**kw):
        util.setup_testing_defaults(kw)
        self.assertEqual(util.application_uri(kw),uri)

    def checkReqURI(self,uri,query=1,**kw):
        util.setup_testing_defaults(kw)
        self.assertEqual(util.request_uri(kw,query),uri)

    @support.ignore_warnings(category=DeprecationWarning)
    def checkFW(self,text,size,match):

        def make_it(text=text,size=size):
            return util.FileWrapper(StringIO(text),size)