#!/usr/bin/env python

'''
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you 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.
'''
import tempfile

__all__ = ["Script"]

import os
import sys
import json
import logging
import platform
from ambari_commons.os_check import OSCheck
from resource_management.libraries.resources import XmlConfig
from resource_management.libraries.resources import PropertiesFile
from resource_management.core.resources import File, Directory
from resource_management.core.source import InlineTemplate
from resource_management.core.environment import Environment
from resource_management.core.logger import Logger
from resource_management.core.exceptions import Fail, ClientComponentHasNoStatus, ComponentIsNotRunning
from resource_management.core.resources.packaging import Package
from resource_management.libraries.functions.version_select_util import get_component_version
from resource_management.libraries.functions.version import compare_versions
from resource_management.libraries.functions.version import format_hdp_stack_version
from resource_management.libraries.script.config_dictionary import ConfigDictionary, UnknownConfiguration
from resource_management.core.resources.system import Execute

if OSCheck.is_windows_family():
  from resource_management.libraries.functions.install_hdp_msi import install_windows_msi
  from resource_management.libraries.functions.reload_windows_env import reload_windows_env
  from resource_management.libraries.functions.zip_archive import archive_dir
  from resource_management.libraries.resources import Msi
else:
  from resource_management.libraries.functions.tar_archive import archive_dir

USAGE = """Usage: {0} <COMMAND> <JSON_CONFIG> <BASEDIR> <STROUTPUT> <LOGGING_LEVEL> <TMP_DIR>

<COMMAND> command type (INSTALL/CONFIGURE/START/STOP/SERVICE_CHECK...)
<JSON_CONFIG> path to command json file. Ex: /var/lib/ambari-agent/data/command-2.json
<BASEDIR> path to service metadata dir. Ex: /var/lib/ambari-agent/cache/common-services/HDFS/2.1.0.2.0/package
<STROUTPUT> path to file with structured command output (file will be created). Ex:/tmp/my.txt
<LOGGING_LEVEL> log level for stdout. Ex:DEBUG,INFO
<TMP_DIR> temporary directory for executable scripts. Ex: /var/lib/ambari-agent/data/tmp
"""

_PASSWORD_MAP = {"/configurations/cluster-env/hadoop.user.name":"/configurations/cluster-env/hadoop.user.password"}

def get_path_from_configuration(name, configuration):
  subdicts = filter(None, name.split('/'))

  for x in subdicts:
    if x in configuration:
      configuration = configuration[x]
    else:
      return None

  return configuration

class Script(object):
  """
  Executes a command for custom service. stdout and stderr are written to
  tmpoutfile and to tmperrfile respectively.
  Script instances share configuration as a class parameter and therefore
  different Script instances can not be used from different threads at
  the same time within a single python process

  Accepted command line arguments mapping:
  1 command type (START/STOP/...)
  2 path to command json file
  3 path to service metadata dir (Directory "package" inside service directory)
  4 path to file with structured command output (file will be created)
  """
  structuredOut = {}
  command_data_file = ""
  basedir = ""
  stroutfile = ""
  logging_level = ""

  # Class variable
  tmp_dir = ""

  def get_stack_to_component(self):
    """
    To be overridden by subclasses.
    Returns a dictionary where the key is a stack name, and the value is the component name used in selecting the version.
    """
    return {}
    
  def load_structured_out(self):
    Script.structuredOut = {}
    if os.path.exists(self.stroutfile):
      with open(self.stroutfile, 'r') as fp:
        Script.structuredOut = json.load(fp)

    # version is only set in a specific way and should not be carried 
    if "version" in Script.structuredOut:
      del Script.structuredOut["version"]
    # reset security issues and errors found on previous runs
    if "securityIssuesFound" in Script.structuredOut:
      del Script.structuredOut["securityIssuesFound"]
    if "securityStateErrorInfo" in Script.structuredOut:
      del Script.structuredOut["securityStateErrorInfo"]

  def put_structured_out(self, sout):
    curr_content = Script.structuredOut.copy()
    Script.structuredOut.update(sout)
    try:
      with open(self.stroutfile, 'w') as fp:
        json.dump(Script.structuredOut, fp)
    except IOError, err:
      Script.structuredOut.update({"errMsg" : "Unable to write to " + self.stroutfile})

  def save_component_version_to_structured_out(self):
    """
    :param stack_name: One of HDP, HDPWIN, PHD, BIGTOP.
    :return: Append the version number to the structured out.
    """
    from resource_management.libraries.functions.default import default
    stack_name = default("/hostLevelParams/stack_name", None)
    stack_to_component = self.get_stack_to_component()
    if stack_to_component and stack_name:
      component_name = stack_to_component[stack_name] if stack_name in stack_to_component else None
      component_version = get_component_version(stack_name, component_name)

      if component_version:
        self.put_structured_out({"version": component_version})

  def should_expose_component_version(self, command_name):
    """
    Analyzes config and given command to determine if stack version should be written
    to structured out. Currently only HDP stack versions >= 2.2 are supported.
    :param command_name: command name
    :return: True or False
    """
    from resource_management.libraries.functions.default import default
    stack_version_unformatted = str(default("/hostLevelParams/stack_version", ""))
    hdp_stack_version = format_hdp_stack_version(stack_version_unformatted)
    if hdp_stack_version != "" and compare_versions(hdp_stack_version, '2.2') >= 0:
      if command_name.lower() == "status":
        request_version = default("/commandParams/request_version", None)
        if request_version is not None:
          return True
      else:
        # Populate version only on base commands
        return command_name.lower() == "start" or command_name.lower() == "install" or command_name.lower() == "restart"
    return False

  def execute(self):
    """
    Sets up logging;
    Parses command parameters and executes method relevant to command type
    """
    logger, chout, cherr = Logger.initialize_logger()
    
    # parse arguments
    if len(sys.argv) < 7:
     logger.error("Script expects at least 6 arguments")
     print USAGE.format(os.path.basename(sys.argv[0])) # print to stdout
     sys.exit(1)

    command_name = str.lower(sys.argv[1])
    self.command_data_file = sys.argv[2]
    self.basedir = sys.argv[3]
    self.stroutfile = sys.argv[4]
    self.load_structured_out()
    self.logging_level = sys.argv[5]
    Script.tmp_dir = sys.argv[6]

    logging_level_str = logging._levelNames[self.logging_level]
    chout.setLevel(logging_level_str)
    logger.setLevel(logging_level_str)

    # on windows we need to reload some of env variables manually because there is no default paths for configs(like
    # /etc/something/conf on linux. When this env vars created by one of the Script execution, they can not be updated
    # in agent, so other Script executions will not be able to access to new env variables
    if OSCheck.is_windows_family():
      reload_windows_env()

    try:
      with open(self.command_data_file) as f:
        pass
        Script.config = ConfigDictionary(json.load(f))
        # load passwords here(used on windows to impersonate different users)
        Script.passwords = {}
        for k, v in _PASSWORD_MAP.iteritems():
          if get_path_from_configuration(k, Script.config) and get_path_from_configuration(v, Script.config):
            Script.passwords[get_path_from_configuration(k, Script.config)] = get_path_from_configuration(v, Script.config)

    except IOError:
      logger.exception("Can not read json file with command parameters: ")
      sys.exit(1)

    # Run class method depending on a command type
    try:
      method = self.choose_method_to_execute(command_name)
      with Environment(self.basedir, tmp_dir=Script.tmp_dir) as env:
        env.config.download_path = Script.tmp_dir
        method(env)
        if command_name == "install":
          self.set_version()
    except ClientComponentHasNoStatus or ComponentIsNotRunning:
      # Support of component status checks.
      # Non-zero exit code is interpreted as an INSTALLED status of a component
      sys.exit(1)
    except Fail:
      logger.exception("Error while executing command '{0}':".format(command_name))
      sys.exit(1)
    finally:
      if self.should_expose_component_version(command_name):
        self.save_component_version_to_structured_out()

  def choose_method_to_execute(self, command_name):
    """
    Returns a callable object that should be executed for a given command.
    """
    self_methods = dir(self)
    if not command_name in self_methods:
      raise Fail("Script '{0}' has no method '{1}'".format(sys.argv[0], command_name))
    method = getattr(self, command_name)
    return method


  @staticmethod
  def get_config():
    """
    HACK. Uses static field to store configuration. This is a workaround for
    "circular dependency" issue when importing params.py file and passing to
     it a configuration instance.
    """
    return Script.config

  @staticmethod
  def get_password(user):
    return Script.passwords[user]

  @staticmethod
  def get_tmp_dir():
    """
    HACK. Uses static field to avoid "circular dependency" issue when
    importing params.py.
    """
    return Script.tmp_dir


  def install(self, env):
    """
    Default implementation of install command is to install all packages
    from a list, received from the server.
    Feel free to override install() method with your implementation. It
    usually makes sense to call install_packages() manually in this case
    """
    self.install_packages(env)

  def install_packages(self, env, exclude_packages=[]):
    """
    List of packages that are required< by service is received from the server
    as a command parameter. The method installs all packages
    from this list
    """
    config = self.get_config()
    if 'host_sys_prepped' in config['hostLevelParams']:
      # do not install anything on sys-prepped host
      if config['hostLevelParams']['host_sys_prepped'] == True:
        Logger.info("Node has all packages pre-installed. Skipping.")
        return
      pass
    try:
      package_list_str = config['hostLevelParams']['package_list']
      if isinstance(package_list_str, basestring) and len(package_list_str) > 0:
        package_list = json.loads(package_list_str)
        for package in package_list:
          if not package['name'] in exclude_packages:
            name = package['name']
            if OSCheck.is_windows_family():
              if name[-4:] == ".msi":
                #TODO all msis must be located in resource folder of server, change it to repo later
                Msi(name, http_source=os.path.join(config['hostLevelParams']['jdk_location']))
            else:
              Package(name)
    except KeyError:
      pass  # No reason to worry

    if OSCheck.is_windows_family():
      #TODO hacky install of windows msi, remove it or move to old(2.1) stack definition when component based install will be implemented
      install_windows_msi(os.path.join(config['hostLevelParams']['jdk_location'], "hdp.msi"),
                          config["hostLevelParams"]["agentCacheDir"], "hdp.msi", self.get_password("hadoop"),
                          str(config['hostLevelParams']['stack_version']))
      reload_windows_env()
    pass

  @staticmethod
  def fail_with_error(message):
    """
    Prints error message and exits with non-zero exit code
    """
    print("Error: " + message)
    sys.stderr.write("Error: " + message)
    sys.exit(1)


  def start(self, env, rolling_restart=False):
    """
    To be overridden by subclasses
    """
    self.fail_with_error('start method isn\'t implemented')

  def stop(self, env, rolling_restart=False):
    """
    To be overridden by subclasses
    """
    self.fail_with_error('stop method isn\'t implemented')

  def pre_rolling_restart(self, env):
    """
    To be overridden by subclasses
    """
    pass

  def restart(self, env):
    """
    Default implementation of restart command is to call stop and start methods
    Feel free to override restart() method with your implementation.
    For client components we call install
    """
    config = self.get_config()
    componentCategory = None
    try:
      componentCategory = config['roleParams']['component_category']
    except KeyError:
      pass

    restart_type = ""
    if config is not None:
      command_params = config["commandParams"] if "commandParams" in config else None
      if command_params is not None:
        restart_type = command_params["restart_type"] if "restart_type" in command_params else ""
        if restart_type:
          restart_type = restart_type.encode('ascii', 'ignore')

    rolling_restart = restart_type.lower().startswith("rolling")

    if componentCategory and componentCategory.strip().lower() == 'CLIENT'.lower():
      if rolling_restart:
        self.pre_rolling_restart(env)

      self.install(env)
    else:
      # To remain backward compatible with older stacks, only pass rolling_restart if True.
      if rolling_restart:
        self.stop(env, rolling_restart=rolling_restart)
      else:
        self.stop(env)

      if rolling_restart:
        self.pre_rolling_restart(env)

      # To remain backward compatible with older stacks, only pass rolling_restart if True.
      if rolling_restart:
        self.start(env, rolling_restart=rolling_restart)
      else:
        self.start(env)

      if rolling_restart:
        self.post_rolling_restart(env)

    if self.should_expose_component_version("restart"):
      self.save_component_version_to_structured_out()

  def post_rolling_restart(self, env):
    """
    To be overridden by subclasses
    """
    pass

  def configure(self, env, rolling_restart=False):
    """
    To be overridden by subclasses
    """
    self.fail_with_error('configure method isn\'t implemented')

  def security_status(self, env):
    """
    To be overridden by subclasses to provide the current security state of the component.
    Implementations are required to set the "securityState" property of the structured out data set
    to one of the following values:

      UNSECURED        - If the component is not configured for any security protocol such as
                         Kerberos
      SECURED_KERBEROS - If the component is configured for Kerberos
      UNKNOWN          - If the security state cannot be determined
      ERROR            - If the component is supposed to be secured, but there are issues with the
                         configuration.  For example, if the component is configured for Kerberos
                         but the configured principal and keytab file fail to kinit
    """
    self.put_structured_out({"securityState": "UNKNOWN"})

  def generate_configs_get_template_file_content(self, filename, dicts):
    config = self.get_config()
    content = ''
    for dict in dicts.split(','):
      if dict.strip() in config['configurations']:
        try:
          content += config['configurations'][dict.strip()]['content']
        except Fail:
          # 'content' section not available in the component client configuration
          pass

    return content

  def generate_configs_get_xml_file_content(self, filename, dict):
    config = self.get_config()
    return {'configurations':config['configurations'][dict],
            'configuration_attributes':config['configuration_attributes'][dict]}
    
  def generate_configs_get_xml_file_dict(self, filename, dict):
    config = self.get_config()
    return config['configurations'][dict]

  def generate_configs(self, env):
    """
    Generates config files and stores them as an archive in tmp_dir
    based on xml_configs_list and env_configs_list from commandParams
    """
    import params
    env.set_params(params)
    
    config = self.get_config()

    xml_configs_list = config['commandParams']['xml_configs_list']
    env_configs_list = config['commandParams']['env_configs_list']
    properties_configs_list = config['commandParams']['properties_configs_list']

    Directory(self.get_tmp_dir(), recursive=True)

    conf_tmp_dir = tempfile.mkdtemp(dir=self.get_tmp_dir())
    output_filename = os.path.join(self.get_tmp_dir(), config['commandParams']['output_file'])

    try:
      for file_dict in xml_configs_list:
        for filename, dict in file_dict.iteritems():
          XmlConfig(filename,
                    conf_dir=conf_tmp_dir,
                    **self.generate_configs_get_xml_file_content(filename, dict)
          )
      for file_dict in env_configs_list:
        for filename,dicts in file_dict.iteritems():
          File(os.path.join(conf_tmp_dir, filename),
               content=InlineTemplate(self.generate_configs_get_template_file_content(filename, dicts)))

      for file_dict in properties_configs_list:
        for filename, dict in file_dict.iteritems():
          PropertiesFile(os.path.join(conf_tmp_dir, filename),
            properties=self.generate_configs_get_xml_file_dict(filename, dict)
          )
      archive_dir(output_filename, conf_tmp_dir)
    finally:
      Directory(conf_tmp_dir, action="delete")

  def set_version(self):
    from resource_management.libraries.functions.default import default
    stack_name = default("/hostLevelParams/stack_name", None)
    version = default("/commandParams/version", None)
    stack_version_unformatted = str(default("/hostLevelParams/stack_version", ""))
    hdp_stack_version = format_hdp_stack_version(stack_version_unformatted)
    stack_to_component = self.get_stack_to_component()
    if stack_to_component:
      component_name = stack_to_component[stack_name] if stack_name in stack_to_component else None
      if component_name and stack_name and version and \
              compare_versions(format_hdp_stack_version(hdp_stack_version), '2.2.0.0') >= 0:
        Execute(('/usr/bin/hdp-select', 'set', component_name, version),
                sudo = True)