import unittest
import os
import shutil
import signal
import subprocess
import sys
import tempfile
import threading
import time

import psutil

from minode import shared
from minode.main import main as app


class TestProcessProto(unittest.TestCase):
    """Test process attributes, common flow"""
    _process_cmd = ['minode']
    _connection_limit = 4 if sys.platform.startswith('win') else 10
    _listen = False
    _listening_port = None

    home = None

    @classmethod
    def _build_app_args(cls, extra=None):
        if not cls.home:
            cls.home = tempfile.gettempdir()
        args = cls._process_cmd + [
            '--data-dir', cls.home,
            '--connection-limit', str(cls._connection_limit)
        ]
        if not cls._listen:
            args += ['--no-incoming']
        elif cls._listening_port:
            args += ['-p', str(cls._listening_port)]

        if extra:
            args += extra

        print('ARGS: %r' % args)
        return args

    @classmethod
    def _stop_process(cls, timeout=5):
        cls.process.send_signal(signal.SIGTERM)
        try:
            cls.process.wait(timeout)
        except psutil.TimeoutExpired:
            return False
        return True

    @classmethod
    def setUpClass(cls):
        cmd = cls._build_app_args()
        cls.process = psutil.Popen(cmd, stderr=subprocess.STDOUT)  # nosec

    @classmethod
    def tearDownClass(cls):
        """Ensures the process is stopped and removes files"""
        try:
            if not cls._stop_process(10):
                try:
                    cls.process.kill()
                except psutil.NoSuchProcess:
                    pass
        except psutil.NoSuchProcess:
            pass


class TestProcessShutdown(TestProcessProto):
    """Separate test case for SIGTERM"""
    def test_shutdown(self):
        """Send to minode SIGTERM and ensure it stopped"""
        # longer wait time because it's not a benchmark
        self.assertTrue(
            self._stop_process(20),
            '%s has not stopped in 20 sec' % ' '.join(self._process_cmd))


class TestProcess(TestProcessProto):
    """The test case for minode process"""
    _wait_time = 120
    _check_limit = False

    def test_connections(self):
        """Check minode process connections"""
        _started = time.time()

        def connections():
            return [
                c for c in self.process.connections()
                if c.status == 'ESTABLISHED']

        def continue_check_limit(extra_time):
            for t in range(extra_time * 2):
                self.assertLessEqual(
                    len(connections()),
                    # shared.outgoing_connections, one listening
                    # TODO: find the cause of one extra
                    (min(self._connection_limit, 8) if not self._listen
                     else self._connection_limit) + 1,
                    'Opened more connections than required'
                    ' by --connection-limit')
                time.sleep(1)

        for t in range(self._wait_time * 2):
            if len(connections()) > self._connection_limit / 2:
                _time_to_connect = round(time.time() - _started)
                break
            time.sleep(0.5)
        else:
            self.fail(
                'Failed establish at least %s connections in %s sec'
                % (self._connection_limit / 2, self._wait_time))

        if self._check_limit:
            continue_check_limit(_time_to_connect)

        for c in self.process.connections():
            if c.status == 'LISTEN':
                if self._listen is False:
                    return self.fail(
                        'Listening while started with --no-incoming')
                self.assertEqual(c.laddr[1], self._listening_port or 8444)
                break
        else:
            if self._listen:
                self.fail('No listening connection found')


class TestConnectivity(TestProcessProto):
    """Check connectivity between instances"""
    _process_cmd = [
        'minode', '--trusted-peer', '127.0.0.1:8445']
    # _listen = True

    @classmethod
    def setUpClass(cls):
        super(TestConnectivity, cls).setUpClass()

        cls._listen = True
        cls._listening_port = 8445
        cls.home = os.path.join(cls.home, 'client')
        os.mkdir(cls.home)
        # sys.argv = cls._build_app_args(['--trusted-peer', '127.0.0.1:8444'])
        cls._process_cmd = ['minode', '--no-outgoing']
        sys.argv = cls._build_app_args()
        cls.app = threading.Thread(name="minode", target=app, daemon=True)
        cls.app.start()

    @classmethod
    def tearDownClass(cls):
        super(TestConnectivity, cls).tearDownClass()
        shared.shutting_down = True
        shutil.rmtree(cls.home)

    def test_connections(self):
        """Check the connection with trusted peer"""
        time.sleep(5)
        for t in range(10):
            time.sleep(1)
            connection_count = len([
                c for c in shared.connections.copy()
                if c.status == 'fully_established'])
            if connection_count != 1:
                self.fail("Unexpected connection count: %i" % connection_count)