# Microsoft Azure Linux Agent
#
# Copyright 2014 Microsoft Corporation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# Requires Python 2.4+ and Openssl 1.0+
#

import os
import sys
import time
import traceback

import azurelinuxagent.common.conf as conf
import azurelinuxagent.common.event as event
import azurelinuxagent.common.utils.fileutil as fileutil
import azurelinuxagent.common.logger as logger

from azurelinuxagent.common.future import ustr
from azurelinuxagent.common.event import add_event, WALAEventOperation
from azurelinuxagent.common.exception import ProtocolError
from azurelinuxagent.common.osutil import get_osutil
from azurelinuxagent.common.protocol import get_protocol_util
from azurelinuxagent.common.rdma import RDMADeviceHandler, setup_rdma_device
from azurelinuxagent.common.utils.textutil import parse_doc, find, getattrib
from azurelinuxagent.common.version import AGENT_LONG_NAME, AGENT_VERSION, \
                                     DISTRO_NAME, DISTRO_VERSION, \
                                     DISTRO_FULL_NAME, PY_VERSION_MAJOR, \
                                     PY_VERSION_MINOR, PY_VERSION_MICRO
from azurelinuxagent.daemon.resourcedisk import get_resourcedisk_handler
from azurelinuxagent.daemon.scvmm import get_scvmm_handler
from azurelinuxagent.pa.provision import get_provision_handler
from azurelinuxagent.pa.rdma import get_rdma_handler
from azurelinuxagent.ga.update import get_update_handler

def get_daemon_handler():
    return DaemonHandler()

class DaemonHandler(object):
    """
    Main thread of daemon. It will invoke other threads to do actual work
    """
    def __init__(self):
        self.running = True
        self.osutil = get_osutil()

    def run(self):
        logger.info("{0} Version:{1}", AGENT_LONG_NAME, AGENT_VERSION)
        logger.info("OS: {0} {1}", DISTRO_NAME, DISTRO_VERSION)
        logger.info("Python: {0}.{1}.{2}", PY_VERSION_MAJOR, PY_VERSION_MINOR,
            PY_VERSION_MICRO)

        self.check_pid()

        while self.running:
            try:
                self.daemon()
            except Exception as e:
                err_msg = traceback.format_exc()
                add_event("WALA", is_success=False, message=ustr(err_msg), 
                          op=WALAEventOperation.UnhandledError)
                logger.info("Sleep 15 seconds and restart daemon")
                time.sleep(15)


    def check_pid(self):
        """Check whether daemon is already running"""
        pid = None
        pid_file = conf.get_agent_pid_file_path()
        if os.path.isfile(pid_file):
            pid = fileutil.read_file(pid_file)

        if self.osutil.check_pid_alive(pid):
            logger.info("Daemon is already running: {0}", pid)
            sys.exit(0)
            
        fileutil.write_file(pid_file, ustr(os.getpid()))

    def daemon(self):
        logger.info("Run daemon") 

        self.protocol_util = get_protocol_util()
        self.scvmm_handler = get_scvmm_handler()
        self.resourcedisk_handler = get_resourcedisk_handler()
        self.rdma_handler = get_rdma_handler()
        self.provision_handler = get_provision_handler()
        self.update_handler = get_update_handler()

        # Create lib dir
        if not os.path.isdir(conf.get_lib_dir()):
            fileutil.mkdir(conf.get_lib_dir(), mode=0o700)
            os.chdir(conf.get_lib_dir())

        if conf.get_detect_scvmm_env():
            self.scvmm_handler.run()

        if conf.get_resourcedisk_format():
            self.resourcedisk_handler.run()

        # Always redetermine the protocol start (e.g., wireserver vs.
        # on-premise) since a VHD can move between environments        
        self.protocol_util.clear_protocol()

        self.provision_handler.run()

        # Enable RDMA, continue in errors
        if conf.enable_rdma():
            self.rdma_handler.install_driver()

            logger.info("RDMA capabilities are enabled in configuration")
            try:
                setup_rdma_device()
            except Exception as e:
                logger.error("Error setting up rdma device: %s" % e)
        else:
            logger.info("RDMA capabilities are not enabled, skipping")
        
        while self.running:
            self.update_handler.run_latest()