"""
Utilities and mock modules for unittests of statistics modules

"""
import os
import io
import time
import sys
import threading
import tempfile
import json

import msgq
import isc.config.cfgmgr
import stats
import stats_httpd

def send_command(command_name, module_name, params=None, session=None, nonblock=False, timeout=None):
    if session is not None:
        cc_session = session
    else:
        cc_session = isc.cc.Session()
    if timeout is not None:
        orig_timeout = cc_session.get_timeout()
        cc_session.set_timeout(timeout * 1000)
    command = isc.config.ccsession.create_command(command_name, params)
    seq = cc_session.group_sendmsg(command, module_name)
    try:
        (answer, env) = cc_session.group_recvmsg(nonblock, seq)
        if answer:
            return isc.config.ccsession.parse_answer(answer)
    except isc.cc.SessionTimeout:
        pass
    finally:
        if timeout is not None:
            cc_session.set_timeout(orig_timeout)
        if session is None:
            cc_session.close()

def send_shutdown(module_name, **kwargs):
    return send_command("shutdown", module_name, **kwargs)

class ThreadingServerManager:
    def __init__(self, server, *args, **kwargs):
        self.server = server(*args, **kwargs)
        self.server_name = server.__name__
        self.server._thread = threading.Thread(
            name=self.server_name, target=self.server.run)
        self.server._thread.daemon = True

    def run(self):
        self.server._thread.start()
        self.server._started.wait()
        self.server._started.clear()

    def shutdown(self):
        self.server.shutdown()
        self.server._thread.join(0) # timeout is 0

class MockMsgq:
    def __init__(self):
        self._started = threading.Event()
        self.msgq = msgq.MsgQ(verbose=True)
        result = self.msgq.setup()
        if result:
            sys.exit("Error on Msgq startup: %s" % result)

    def run(self):
        self._started.set()
        try:
            # any message is written to /dev/null
            sys.stderr = open(os.devnull, "w")
            self.msgq.run()
            sys.stderr.close()
        except Exception:
            pass
        finally:
            self.msgq.shutdown()

    def shutdown(self):
        self.msgq.shutdown()

class MockCfgmgr:
    def __init__(self):
        self._started = threading.Event()
        self.cfgmgr = isc.config.cfgmgr.ConfigManager(
            os.environ['CONFIG_TESTDATA_PATH'], "b10-config.db")
        self.cfgmgr.read_config()

    def run(self):
        self._started.set()
        self.cfgmgr.run()

    def shutdown(self):
        self.cfgmgr.running = False

class MockBoss:
    spec_str = """\
{
  "module_spec": {
    "module_name": "Boss",
    "module_description": "Mock Master process",
    "config_data": [],
    "commands": [
      {
        "command_name": "sendstats",
        "command_description": "Send data to a statistics module at once",
        "command_args": []
      }
    ],
    "statistics": [
      {
        "item_name": "boot_time",
        "item_type": "string",
        "item_optional": false,
        "item_default": "1970-01-01T00:00:00Z",
        "item_title": "Boot time",
        "item_description": "A date time when bind10 process starts initially",
        "item_format": "date-time"
      }
    ]
  }
}
"""
    _BASETIME = (2011, 6, 22, 8, 14, 8, 2, 173, 0)

    def __init__(self):
        self._started = threading.Event()
        self.running = False
        self.spec_file = io.StringIO(self.spec_str)
        # create ModuleCCSession object
        self.mccs = isc.config.ModuleCCSession(
            self.spec_file,
            self.config_handler,
            self.command_handler)
        self.spec_file.close()
        self.cc_session = self.mccs._session
        self.got_command_name = ''

    def run(self):
        self.mccs.start()
        self.running = True
        self._started.set()
        while self.running:
            self.mccs.check_command(False)

    def shutdown(self):
        self.running = False

    def config_handler(self, new_config):
        return isc.config.create_answer(0)

    def command_handler(self, command, *args, **kwargs):
        self._started.set()
        self.got_command_name = command
        if command == 'sendstats':
            params = { "owner": "Boss",
                       "data": {
                    'boot_time': time.strftime('%Y-%m-%dT%H:%M:%SZ', self._BASETIME)
                    }
                       }
            return send_command("set", "Stats", params=params, session=self.cc_session)
        return isc.config.create_answer(1, "Unknown Command")

class MockAuth:
    spec_str = """\
{
  "module_spec": {
    "module_name": "Auth",
    "module_description": "Mock Authoritative service",
    "config_data": [],
    "commands": [
      {
        "command_name": "sendstats",
        "command_description": "Send data to a statistics module at once",
        "command_args": []
      }
    ],
    "statistics": [
      {
        "item_name": "queries.tcp",
        "item_type": "integer",
        "item_optional": false,
        "item_default": 0,
        "item_title": "Queries TCP",
        "item_description": "A number of total query counts which all auth servers receive over TCP since they started initially"
      },
      {
        "item_name": "queries.udp",
        "item_type": "integer",
        "item_optional": false,
        "item_default": 0,
        "item_title": "Queries UDP",
        "item_description": "A number of total query counts which all auth servers receive over UDP since they started initially"
      }
    ]
  }
}
"""
    def __init__(self):
        self._started = threading.Event()
        self.running = False
        self.spec_file = io.StringIO(self.spec_str)
        # create ModuleCCSession object
        self.mccs = isc.config.ModuleCCSession(
            self.spec_file,
            self.config_handler,
            self.command_handler)
        self.spec_file.close()
        self.cc_session = self.mccs._session
        self.got_command_name = ''
        self.queries_tcp = 3
        self.queries_udp = 2

    def run(self):
        self.mccs.start()
        self.running = True
        self._started.set()
        while self.running:
            self.mccs.check_command(False)

    def shutdown(self):
        self.running = False

    def config_handler(self, new_config):
        return isc.config.create_answer(0)

    def command_handler(self, command, *args, **kwargs):
        self.got_command_name = command
        if command == 'sendstats':
            params = { "owner": "Auth",
                       "data": { 'queries.tcp': self.queries_tcp,
                                 'queries.udp': self.queries_udp } }
            return send_command("set", "Stats", params=params, session=self.cc_session)
        return isc.config.create_answer(1, "Unknown Command")

class MyStats(stats.Stats):
    def __init__(self):
        self._started = threading.Event()
        stats.Stats.__init__(self)

    def run(self):
        self._started.set()
        self.start()

    def shutdown(self):
        self.command_shutdown()

class MyStatsHttpd(stats_httpd.StatsHttpd):
    ORIG_SPECFILE_LOCATION = stats_httpd.SPECFILE_LOCATION
    def __init__(self, *server_address):
        self._started = threading.Event()
        if server_address:
            stats_httpd.SPECFILE_LOCATION = self.get_specfile(*server_address)
            try:
                stats_httpd.StatsHttpd.__init__(self)
            finally:
                stats_httpd.SPECFILE_LOCATION.close()
                stats_httpd.SPECFILE_LOCATION = self.ORIG_SPECFILE_LOCATION
        else:
            stats_httpd.StatsHttpd.__init__(self)

    def get_specfile(self, *server_address):
        spec = json.load(open(self.ORIG_SPECFILE_LOCATION))
        config = spec['module_spec']['config_data']
        for i in range(len(config)):
            if config[i]['item_name'] == 'listen_on':
                config[i]['item_default'] = \
                    [ dict(address=a[0], port=a[1]) for a in server_address ]
                break
        return io.StringIO(json.dumps(spec))

    def run(self):
        self._started.set()
        self.start()

    def shutdown(self):
        self.stop()

class BaseModules:
    def __init__(self):
        # Change value of BIND10_MSGQ_SOCKET_FILE in environment variables
        if 'BIND10_MSGQ_SOCKET_FILE' not in os.environ:
            os.environ['BIND10_MSGQ_SOCKET_FILE'] = tempfile.mktemp(prefix='msgq_socket_')
        # MockMsgq
        self.msgq = ThreadingServerManager(MockMsgq)
        self.msgq.run()
        # MockCfgmgr
        self.cfgmgr = ThreadingServerManager(MockCfgmgr)
        self.cfgmgr.run()
        # MockBoss
        self.boss = ThreadingServerManager(MockBoss)
        self.boss.run()
        # MockAuth
        self.auth = ThreadingServerManager(MockAuth)
        self.auth.run()

    def shutdown(self):
        # MockAuth
        self.auth.shutdown()
        # MockBoss
        self.boss.shutdown()
        # MockCfgmgr
        self.cfgmgr.shutdown()
        # MockMsgq
        self.msgq.shutdown()