import os
import io
import time
import random
import subprocess
import imaplib
import smtplib
import itertools
from math import ceil
import pytest


def pytest_addoption(parser):
    parser.addoption(
        "--slow", action="store_true", default=False, help="also run slow tests"
    )


def pytest_configure(config):
    config._benchresults = {}
    config.addinivalue_line(
        "markers", "slow: mark test to require --slow option to run"
    )


def pytest_runtest_setup(item):
    markers = list(item.iter_markers(name="slow"))
    if markers:
        if not item.config.getoption("--slow"):
            pytest.skip("skipping slow test, use --slow to run")


@pytest.fixture
def maildomain():
    domain = os.environ.get("CHATMAIL_DOMAIN")
    if not domain:
        pytest.skip("set CHATMAIL_DOMAIN to a ssh-reachable chatmail instance")
    return domain


@pytest.fixture
def sshdomain(maildomain):
    return os.environ.get("CHATMAIL_SSH", maildomain)


@pytest.fixture
def maildomain2():
    domain = os.environ.get("CHATMAIL_DOMAIN2")
    if not domain:
        pytest.skip("set CHATMAIL_DOMAIN2 to a ssh-reachable chatmail instance")
    return domain


@pytest.fixture
def sshdomain2(maildomain2):
    return os.environ.get("CHATMAIL_SSH2", maildomain2)


def pytest_report_header():
    domain = os.environ.get("CHATMAIL_DOMAIN")
    if domain:
        text = f"chatmail test instance: {domain}"
        return ["-" * len(text), text, "-" * len(text)]


@pytest.fixture
def benchmark(request):
    def bench(func, num, name=None):
        if name is None:
            name = func.__name__
        durations = []
        for i in range(num):
            now = time.time()
            func()
            durations.append(time.time() - now)
        durations.sort()
        request.config._benchresults[name] = durations

    return bench


def pytest_terminal_summary(terminalreporter):
    tr = terminalreporter
    results = tr.config._benchresults
    if not results:
        return

    tr.section("benchmark results")
    float_names = 'median min max'.split()
    width = max(map(len, float_names))

    def fcol(parts):
        return " ".join(part.rjust(width) for part in parts)

    headers = f"{'benchmark name': <30} " + fcol(float_names)
    tr.write_line(headers)
    tr.write_line("-" * len(headers))
    for name, durations in results.items():
        measures = [
            sorted(durations)[len(durations) // 2],
            min(durations),
            max(durations),
        ]
        line = f"{name: <30} "
        line += fcol(f"{float: 2.2f}" for float in measures)
        tr.write_line(line)


@pytest.fixture
def imap(maildomain):
    return ImapConn(maildomain)


class ImapConn:
    AuthError = imaplib.IMAP4.error
    logcmd = "journalctl -f -u dovecot"
    name = "dovecot"

    def __init__(self, host):
        self.host = host

    def connect(self):
        print(f"imap-connect {self.host}")
        self.conn = imaplib.IMAP4_SSL(self.host)

    def login(self, user, password):
        print(f"imap-login {user!r} {password!r}")
        self.conn.login(user, password)

    def fetch_all(self):
        print("imap-fetch all")
        status, res = self.conn.select()
        if int(res[0]) == 0:
            raise ValueError("no messages in imap folder")
        status, results = self.conn.fetch("1:*", "(RFC822)")
        assert status == "OK"
        return results

    def fetch_all_messages(self):
        print("imap-fetch all messages")
        results = self.fetch_all()
        messages = []
        for item in results:
            if len(item) == 2:
                messages.append(item[1].decode())
        return messages


@pytest.fixture
def smtp(maildomain):
    return SmtpConn(maildomain)


class SmtpConn:
    AuthError = smtplib.SMTPAuthenticationError
    logcmd = "journalctl -f -t postfix/smtpd -t postfix/smtp -t postfix/lmtp"
    name = "postfix"

    def __init__(self, host):
        self.host = host

    def connect(self):
        print(f"smtp-connect {self.host}")
        self.conn = smtplib.SMTP_SSL(self.host)

    def login(self, user, password):
        print(f"smtp-login {user!r} {password!r}")
        self.conn.login(user, password)

    def sendmail(self, from_addr, to_addrs, msg):
        print(f"smtp-sendmail from={from_addr!r} to_addrs={to_addrs!r}")
        print(f"smtp-sendmail message size: {len(msg)}")
        return self.conn.sendmail(from_addr=from_addr, to_addrs=to_addrs, msg=msg)


@pytest.fixture(params=["imap", "smtp"])
def imap_or_smtp(request):
    return request.getfixturevalue(request.param)


@pytest.fixture
def gencreds(maildomain):
    count = itertools.count()
    next(count)

    def gen(domain=None):
        domain = domain if domain else maildomain
        while 1:
            num = next(count)
            alphanumeric = "abcdefghijklmnopqrstuvwxyz1234567890"
            user = "".join(random.choices(alphanumeric, k=10))
            user = f"ac{num}_{user}"
            password = "".join(random.choices(alphanumeric, k=10))
            yield f"{user}@{domain}", f"{password}"

    return lambda domain=None: next(gen(domain))


#
# Delta Chat testplugin re-use
# use the cmfactory fixture to get chatmail instance accounts
#


class ChatmailTestProcess:
    """Provider for chatmail instance accounts as used by deltachat.testplugin.acfactory"""

    def __init__(self, pytestconfig, maildomain, gencreds):
        self.pytestconfig = pytestconfig
        self.maildomain = maildomain
        assert "." in self.maildomain, maildomain
        self.gencreds = gencreds
        self._addr2files = {}

    def get_liveconfig_producer(self):
        while 1:
            user, password = self.gencreds(self.maildomain)
            config = {
                "addr": user,
                "mail_pw": password,
            }
            # speed up account configuration
            config["mail_server"] = self.maildomain
            config["send_server"] = self.maildomain
            yield config

    def cache_maybe_retrieve_configured_db_files(self, cache_addr, db_target_path):
        pass

    def cache_maybe_store_configured_db_files(self, acc):
        pass


@pytest.fixture
def cmfactory(request, gencreds, tmpdir, data, maildomain):
    # cloned from deltachat.testplugin.amfactory
    pytest.importorskip("deltachat")
    from deltachat.testplugin import ACFactory

    testproc = ChatmailTestProcess(request.config, maildomain, gencreds)
    am = ACFactory(request=request, tmpdir=tmpdir, testprocess=testproc, data=data)

    # nb. a bit hacky
    # would probably be better if deltachat's test machinery grows native support
    def switch_maildomain(maildomain2):
        am.testprocess.maildomain = maildomain2

    am.switch_maildomain = switch_maildomain

    yield am
    if hasattr(request.node, "rep_call") and request.node.rep_call.failed:
        if testproc.pytestconfig.getoption("--extra-info"):
            logfile = io.StringIO()
            am.dump_imap_summary(logfile=logfile)
            print(logfile.getvalue())
            # request.node.add_report_section("call", "imap-server-state", s)


@pytest.fixture
def remote(sshdomain):
    return Remote(sshdomain)


class Remote:
    def __init__(self, sshdomain):
        self.sshdomain = sshdomain

    def iter_output(self, logcmd=""):
        getjournal = f"journalctl -f" if not logcmd else logcmd
        self.popen = subprocess.Popen(
            ["ssh", f"root@{self.sshdomain}", getjournal],
            stdout=subprocess.PIPE,
        )
        while 1:
            line = self.popen.stdout.readline()
            res = line.decode().strip().lower()
            if res:
                yield res
            else:
                break


@pytest.fixture
def mailgen(request):
    class Mailgen:
        def get_encrypted(self, from_addr, to_addr):
            data = request.fspath.dirpath("mailgen/encrypted.eml").read()
            return data.format(from_addr=from_addr, to_addr=to_addr)

    return Mailgen()


@pytest.fixture
def cmsetup(maildomain, gencreds):
    return CMSetup(maildomain, gencreds)


class CMSetup:
    def __init__(self, maildomain, gencreds):
        self.maildomain = maildomain
        self.gencreds = gencreds

    def gen_users(self, num):
        print(f"Creating {num} online users")
        users = []
        for i in range(num):
            addr, password = self.gencreds()
            user = CMUser(self.maildomain, addr, password)
            assert user.smtp
            users.append(user)
        return users


class CMUser:
    def __init__(self, maildomain, addr, password):
        self.maildomain = maildomain
        self.addr = addr
        self.password = password
        self._smtp = None
        self._imap = None

    @property
    def smtp(self):
        if not self._smtp:
            handle = SmtpConn(self.maildomain)
            handle.connect()
            handle.login(self.addr, self.password)
            self._smtp = handle
        return self._smtp

    @property
    def imap(self):
        if not self._imap:
            imap = ImapConn(self.maildomain)
            imap.connect()
            imap.login(self.addr, self.password)
            self._imap = imap
        return self._imap