#!/usr/bin/env python3

import collections
import slixmpp
import asyncio
import logging
import signal
import atexit
import lxml.etree
import sys
import io
from functools import partial
from slixmpp.xmlstream.matcher.base import MatcherBase


class MatchAll(MatcherBase):
    """match everything"""

    def match(self, xml):
        return True


class StanzaError(Exception):
    """
    Raised when a step fails.
    """
    pass


class SkipStepError(Exception):
    """
    Raised by a step when it needs to be skiped, by running
    the next available step immediately.
    """
    pass


class XMPPComponent(slixmpp.BaseXMPP):
    """
    XMPPComponent sending a “scenario” of stanzas, checking that the responses
    match the expected results.
    """

    def __init__(self, scenario, biboumi):
        super().__init__(jid="biboumi.localhost", default_ns="jabber:component:accept")
        self.is_component = True
        self.stream_header = '<stream:stream %s %s from="%s" id="%s">' % (
            'xmlns="jabber:component:accept"',
            'xmlns:stream="%s"' % self.stream_ns,
            self.boundjid, self.get_id())
        self.stream_footer = "</stream:stream>"

        self.register_handler(slixmpp.Callback('Match All',
                                               MatchAll(None),
                                               self.handle_incoming_stanza))

        self.add_event_handler("session_end", self.on_end_session)

        asyncio.async(self.accept_routine())

        self.scenario = scenario
        self.biboumi = biboumi
        # A callable, taking a stanza as argument and raising a StanzaError
        # exception if the test should fail.
        self.stanza_checker = None
        self.failed = False
        self.accepting_server = None

    def error(self, message):
        print("Failure: %s" % (message,))
        self.scenario.steps = []
        self.failed = True

    def on_end_session(self, event):
        self.loop.stop()

    def handle_incoming_stanza(self, stanza):
        if self.stanza_checker:
            try:
                self.stanza_checker(stanza)
            except StanzaError as e:
                self.error(e)
            except SkipStepError:
                # Run the next step and then re-handle this same stanza
                self.run_scenario()
                return self.handle_incoming_stanza(stanza)
            self.stanza_checker = None
        self.run_scenario()

    def run_scenario(self):
        if scenario.steps:
            step = scenario.steps.pop(0)
            step(self, self.biboumi)
        else:
            self.biboumi.stop()

    @asyncio.coroutine
    def accept_routine(self):
        self.accepting_server = yield from self.loop.create_server(lambda: self,
                                                                   "127.0.0.1", "8811", reuse_address=True)

    def check_stanza_against_all_expected_xpaths(self):
        pass


def check_xpath(xpaths, stanza):
    for xpath in xpaths:
        tree = lxml.etree.parse(io.StringIO(str(stanza)))
        matched = tree.xpath(xpath, namespaces={'re': 'http://exslt.org/regular-expressions',
                                                'muc_user': 'http://jabber.org/protocol/muc#user'})
        if not matched:
            raise StanzaError("Received stanza “%s” did not match expected xpath “%s”" % (stanza, xpath))


def check_xpath_optional(xpaths, stanza):
    try:
        check_xpath(xpaths, stanza)
    except StanzaError:
        raise SkipStepError()


class Scenario:
    """Defines a list of actions that are executed in sequence, until one of
    them throws an exception, or until the end.  An action can be something
    like “send a stanza”, “receive the next stanza and check that it matches
    the given XPath”, “send a signal”, “wait for the end of the process”,
    etc
    """

    def __init__(self, name, steps):
        """
        Steps is a list of 2-tuple:
        [(action, answer), (action, answer)]
        """
        self.name = name
        self.steps = []
        for elem in steps:
            if isinstance(elem, collections.Iterable):
                for step in elem:
                    self.steps.append(step)
            else:
                self.steps.append(elem)


class ProcessRunner:
    def __init__(self):
        self.process = None
        self.signal_sent = False

    @asyncio.coroutine
    def start(self):
        self.process = yield from self.create

    @asyncio.coroutine
    def wait(self):
        code = yield from self.process.wait()
        return code

    def stop(self):
        if not self.signal_sent:
            self.signal_sent = True
            if self.process:
                self.process.send_signal(signal.SIGINT)

    def __del__(self):
        self.stop()


class BiboumiRunner(ProcessRunner):
    def __init__(self, name, with_valgrind):
        super().__init__()
        self.name = name
        self.fd = open("biboumi_%s_output.txt" % (name,), "w")
        if with_valgrind:
            self.create = asyncio.create_subprocess_exec("valgrind", "--leak-check=full", "--show-leak-kinds=all",
                                                         "--errors-for-leak-kinds=all", "--error-exitcode=16",
                                                         "./biboumi", "test.conf", stdin=None, stdout=self.fd,
                                                         stderr=self.fd, loop=None, limit=None)
        else:
            self.create = asyncio.create_subprocess_exec("./biboumi", "test.conf", stdin=None, stdout=self.fd,
                                                         stderr=self.fd, loop=None, limit=None)


class IrcServerRunner(ProcessRunner):
    def __init__(self):
        super().__init__()
        self.create = asyncio.create_subprocess_exec("charybdis", "-foreground",
                                                     stderr=asyncio.subprocess.PIPE)


def send_stanza(stanza, xmpp, biboumi):
    xmpp.send_raw(stanza.format_map(common_replacements))
    asyncio.get_event_loop().call_soon(xmpp.run_scenario)


def expect_stanza(xpaths, xmpp, biboumi, optional=False):
    check_func = check_xpath if not optional else check_xpath_optional
    if isinstance(xpaths, str):
        xmpp.stanza_checker = partial(check_func, [xpaths.format_map(common_replacements)])
    elif isinstance(xpaths, tuple):
        xmpp.stanza_checker = partial(check_func, [xpath.format_map(common_replacements) for xpath in xpaths])
    else:
        print("Warning, from argument type passed to expect_stanza: %s" % (type(xpaths)))


class BiboumiTest:
    """
    Spawns a biboumi process and a fake XMPP Component that will run a
    Scenario.  It redirects the outputs of the subprocess into separated
    files, and detects any failure in the running of the scenario.
    """

    def __init__(self, scenario, expected_code=0):
        self.scenario = scenario
        self.expected_code = 0

    def run(self, with_valgrind=True):
        print("Running scenario: %s%s" % (self.scenario.name, " (with valgrind)" if with_valgrind else ''))
        # Redirect the slixmpp logging into a specific file
        output_filename = "slixmpp_%s_output.txt" % (self.scenario.name,)
        with open(output_filename, "w"):
            pass
        logging.basicConfig(level=logging.DEBUG,
                            format='%(levelname)-8s %(message)s',
                            filename=output_filename)

        with open("test.conf", "w") as fd:
            fd.write(confs['basic'])

        # Start the XMPP component and biboumi
        biboumi = BiboumiRunner(scenario.name, with_valgrind)
        xmpp = XMPPComponent(self.scenario, biboumi)
        asyncio.get_event_loop().run_until_complete(biboumi.start())

        asyncio.get_event_loop().call_soon(xmpp.run_scenario)

        xmpp.process()

        code = asyncio.get_event_loop().run_until_complete(biboumi.wait())
        failed = False
        if not xmpp.failed:
            if code != self.expected_code:
                xmpp.error("Wrong return code from biboumi's process: %d" % (code,))
                failed = True
            else:
                print("Success!")
        else:
            failed = True

        if xmpp.server:
            xmpp.accepting_server.close()

        return not failed


confs = {'basic':
"""hostname=biboumi.localhost
password=coucou
db_name=biboumi.sqlite
port=8811"""}

common_replacements = {
    'irc_server_one': 'irc.localhost@biboumi.localhost',
    'irc_host_one': 'irc.localhost',
    'resource_one': 'resource1',
    'nick_one': 'Nick',
    'jid_one': 'first@example.com',
    'jid_two': 'second@example.com',
    'nick_two': 'Bobby',
}


def handshake_sequence():
    return (partial(expect_stanza, "//handshake"),
            partial(send_stanza, "<handshake xmlns='jabber:component:accept'/>"))


def connection_sequence(irc_host, jid):
    jid = jid.format_map(common_replacements)
    xpath    = "/message[@to='" + jid + "'][@from='irc.localhost@biboumi.localhost']/body[text()='%s']"
    xpath_re = "/message[@to='" + jid + "'][@from='irc.localhost@biboumi.localhost']/body[re:test(text(), '%s')]"
    return (
    partial(expect_stanza,
          xpath % ('Connecting to %s:6697 (encrypted)' % irc_host)),
    partial(expect_stanza,
            xpath % 'Connection failed: Connection refused'),
    partial(expect_stanza,
          xpath % ('Connecting to %s:6670 (encrypted)' % irc_host)),
    partial(expect_stanza,
            xpath % 'Connection failed: Connection refused'),
    partial(expect_stanza,
          xpath % ('Connecting to %s:6667 (not encrypted)' % irc_host)),
    partial(expect_stanza,
            xpath % 'Connected to IRC server.'),
    # These two messages can be receive in any order
    partial(expect_stanza,
          xpath_re % (r'^%s: \*\*\* (Checking Ident|Looking up your hostname...)$' % irc_host)),
    partial(expect_stanza,
          xpath_re % (r'^%s: \*\*\* (Checking Ident|Looking up your hostname...)$' % irc_host)),
    # These three messages can be received in any order
    partial(expect_stanza,
          xpath_re % (r'^%s: (\*\*\* Found your hostname: .*|ACK multi-prefix|\*\*\* No Ident response)$' % irc_host)),
    partial(expect_stanza,
          xpath_re % (r'^%s: (\*\*\* Found your hostname: .*|ACK multi-prefix|\*\*\* No Ident response)$' % irc_host)),
    partial(expect_stanza,
          xpath_re % (r'^%s: (\*\*\* Found your hostname: .*|ACK multi-prefix|\*\*\* No Ident response)$' % irc_host)),
    partial(expect_stanza,
          xpath_re % (r'^%s: Your host is .*$' % irc_host)),
    partial(expect_stanza,
          xpath_re % (r'^%s: This server was created .*$' % irc_host)),
    partial(expect_stanza,
          xpath_re % (r'^%s: There are \d+ users and \d+ invisible on \d+ servers$' % irc_host)),
    partial(expect_stanza,
          xpath_re % (r'^%s: \d+ channels formed$' % irc_host), optional=True),
    partial(expect_stanza,
          xpath_re % (r'^%s: I have \d+ clients and \d+ servers$' % irc_host)),
    partial(expect_stanza,
          xpath_re % (r'^%s: \d+ \d+ Current local users \d+, max \d+$' % irc_host)),
    partial(expect_stanza,
          xpath_re % (r'^%s: \d+ \d+ Current global users \d+, max \d+$' % irc_host)),
    partial(expect_stanza,
          xpath_re % (r'^%s: Highest connection count: \d+ \(\d+ clients\) \(\d+ connections received\)$' % irc_host)),
    partial(expect_stanza,
            xpath % "- This is charybdis MOTD you might replace it, but if not your friends will\n- laugh at you.\n"),
    partial(expect_stanza,
            xpath_re % r'^User mode for \w+ is \[\+i\]$'),
    )


if __name__ == '__main__':

    atexit.register(asyncio.get_event_loop().close)

    # Start the test component, accepting connections on the configured
    # port.
    scenarios = (
        Scenario("basic_handshake_success",
                 [
                     handshake_sequence()
                 ]),
        Scenario("irc_server_connection",
                 [
                     handshake_sequence(),
                     partial(send_stanza,
                             "<presence from='{jid_one}/{resource_one}' to='#foo%{irc_server_one}/{nick_one}' />"),
                     connection_sequence("irc.localhost", '{jid_one}/{resource_one}'),
                 ]),
        Scenario("simple_channel_join",
                 [
                     handshake_sequence(),
                     partial(send_stanza,
                             "<presence from='{jid_one}/{resource_one}' to='#foo%{irc_server_one}/{nick_one}' />"),
                     connection_sequence("irc.localhost", '{jid_one}/{resource_one}'),
                     partial(expect_stanza,
                             "/message/body[text()='Mode #foo [+nt] by {irc_host_one}']"),
                     partial(expect_stanza,
                             ("/presence[@to='{jid_one}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_one}']/muc_user:x/muc_user:item[@affiliation='admin'][@role='moderator']",
                             "/presence/muc_user:x/muc_user:status[@code='110']")
                             ),
                     partial(expect_stanza, "/message[@from='#foo%{irc_server_one}'][@type='groupchat']/subject[not(text())]"),
                 ]),
        Scenario("channel_join_with_two_users",
                 [
                     handshake_sequence(),
                     # First user joins
                     partial(send_stanza,
                             "<presence from='{jid_one}/{resource_one}' to='#foo%{irc_server_one}/{nick_one}' />"),
                     connection_sequence("irc.localhost", '{jid_one}/{resource_one}'),
                     partial(expect_stanza,
                             "/message/body[text()='Mode #foo [+nt] by {irc_host_one}']"),
                     partial(expect_stanza,
                             ("/presence[@to='{jid_one}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_one}']/muc_user:x/muc_user:item[@affiliation='admin'][@jid='~nick@localhost'][@role='moderator']",
                             "/presence/muc_user:x/muc_user:status[@code='110']")
                             ),
                     partial(expect_stanza, "/message[@from='#foo%{irc_server_one}'][@type='groupchat']/subject[not(text())]"),

                     # Second user joins
                     partial(send_stanza,
                             "<presence from='{jid_two}/{resource_one}' to='#foo%{irc_server_one}/{nick_two}' />"),
                     connection_sequence("irc.localhost", '{jid_two}/{resource_one}'),
                     # Our presence, sent to the other user
                     partial(expect_stanza,
                             ("/presence[@to='{jid_one}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_two}']/muc_user:x/muc_user:item[@affiliation='none'][@jid='~bobby@localhost'][@role='participant']",)),
                     # The other user presence
                     partial(expect_stanza,
                             "/presence[@to='{jid_second}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_one}']/muc_user:x/muc_user:item[@affiliation='none'][@jid='~nick@localhost'][@role='participant']"),
                     # Our own presence
                     partial(expect_stanza,
                             ("/presence[@to='{jid_two}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_two}']/muc_user:x/muc_user:item[@affiliation='none'][@jid='~bobby@localhost'][@role='participant']",
                              "/presence/muc_user:x/muc_user:status[@code='110']")
                             ),
                     partial(expect_stanza, "/message[@from='#foo%{irc_server_one}'][@type='groupchat']/subject[not(text())]"),
                 ]),
        Scenario("channel_custom_topic",
                 [
                     handshake_sequence(),
                     # First user joins
                     partial(send_stanza,
                             "<presence from='{jid_one}/{resource_one}' to='#foo%{irc_server_one}/{nick_one}' />"),
                     connection_sequence("irc.localhost", '{jid_one}/{resource_one}'),
                     partial(expect_stanza,
                             "/message/body[text()='Mode #foo [+nt] by {irc_host_one}']"),
                     partial(expect_stanza,
                             ("/presence[@to='{jid_one}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_one}']/muc_user:x/muc_user:item[@affiliation='admin'][@jid='~nick@localhost'][@role='moderator']",
                             "/presence/muc_user:x/muc_user:status[@code='110']")
                             ),
                     partial(expect_stanza, "/message[@from='#foo%{irc_server_one}'][@type='groupchat']/subject[not(text())]"),

                     # First user sets the topic
                     partial(send_stanza,
                             "<message from='{jid_one}/{resource_one}' to='#foo%{irc_server_one}' type='groupchat'><subject>TOPIC TEST</subject></message>"),
                     partial(expect_stanza, "/message[@from='#foo%{irc_server_one}/{nick_one}'][@type='groupchat'][@to='{jid_one}/{resource_one}']/subject[text()='TOPIC TEST']"),

                     # Second user joins
                     partial(send_stanza,
                             "<presence from='{jid_two}/{resource_one}' to='#foo%{irc_server_one}/{nick_two}' />"),
                     connection_sequence("irc.localhost", '{jid_two}/{resource_one}'),
                     # Our presence, sent to the other user
                     partial(expect_stanza,
                             ("/presence[@to='{jid_one}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_two}']/muc_user:x/muc_user:item[@affiliation='none'][@jid='~bobby@localhost'][@role='participant']",)),
                     # The other user presence
                     partial(expect_stanza,
                             "/presence[@to='{jid_second}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_one}']/muc_user:x/muc_user:item[@affiliation='admin'][@jid='~nick@localhost'][@role='moderator']"),
                     # Our own presence
                     partial(expect_stanza,
                             ("/presence[@to='{jid_two}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_two}']/muc_user:x/muc_user:item[@affiliation='none'][@jid='~bobby@localhost'][@role='participant']",
                              "/presence/muc_user:x/muc_user:status[@code='110']")
                             ),
                     partial(expect_stanza, "/message[@from='#foo%{irc_server_one}/{nick_one}'][@type='groupchat']/subject[text()='TOPIC TEST']"),
                 ]),
    )

    failures = 0

    irc = IrcServerRunner()
    print("Starting irc server…")
    asyncio.get_event_loop().run_until_complete(irc.start())
    while True:
        res = asyncio.get_event_loop().run_until_complete(irc.process.stderr.readline())
        if b"now running in foreground mode" in res:
            break
    print("irc server started.")
    print("Running %s checks for biboumi." % (len(scenarios)))

    for scenario in scenarios:
        test = BiboumiTest(scenario)
        if not test.run(False):
            print("You can check the files slixmpp_%s_output.txt and biboumi_%s_output.txt to help you debug." %
                  (scenario.name, scenario.name))
            failures += 1

    print("Waiting for irc server to exit…")
    irc.stop()
    code = asyncio.get_event_loop().run_until_complete(irc.wait())

    if failures:
        print("%d test%s failed, please fix %s." % (failures, 's' if failures > 1 else '',
                                                    'them' if failures > 1 else 'it'))
        sys.exit(1)
    else:
        print("All tests passed successfully")