#!/usr/bin/env python3
# -*- encoding: utf-8 -*-

#  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.

''' execute.py '''
import contextlib
import os
import subprocess
import tarfile
import tempfile
import traceback

from heron.common.src.python.utils.log import Log

from heron.tools.cli.src.python.result import SimpleResult, ProcessResult, Status

import heron.common.src.python.pex_loader as pex_loader

import heron.tools.cli.src.python.opts as opts
import heron.tools.cli.src.python.jars as jars
import heron.tools.common.src.python.utils.config as config

################################################################################
def heron_class(class_name, lib_jars, extra_jars=None, args=None, java_defines=None):
  '''
  Execute a heron class given the args and the jars needed for class path
  :param class_name:
  :param lib_jars:
  :param extra_jars:
  :param args:
  :param java_defines:
  :return:
  '''
  # default optional params to empty list if not provided
  if extra_jars is None:
    extra_jars = []
  if args is None:
    args = []
  if java_defines is None:
    java_defines = []

  # Format all java -D options that need to be passed while running
  # the class locally.
  java_opts = ['-D' + opt for opt in java_defines]

  # Construct the command line for the sub process to run
  # Because of the way Python execute works,
  # the java opts must be passed as part of the list
  all_args = [config.get_java_path(), "-client", "-Xmx1g"] + \
             java_opts + \
             ["-cp", config.get_classpath(extra_jars + lib_jars)]

  all_args += [class_name] + list(args)

  # set heron_config environment variable
  heron_env = os.environ.copy()
  heron_env['HERON_OPTIONS'] = opts.get_heron_config()

  # print the verbose message
  Log.debug("Invoking class using command: ``%s''", ' '.join(all_args))
  Log.debug("Heron options: {%s}", str(heron_env["HERON_OPTIONS"]))

  # invoke the command with subprocess and print error message, if any
  process = subprocess.Popen(all_args, env=heron_env, stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE, bufsize=1)
  # stdout message has the information Java program sends back
  # stderr message has extra information, such as debugging message
  return ProcessResult(process)

def heron_tar(class_name, topology_tar, arguments, tmpdir_root, java_defines):
  '''
  :param class_name:
  :param topology_tar:
  :param arguments:
  :param tmpdir_root:
  :param java_defines:
  :return:
  '''
  # Extract tar to a tmp folder.
  tmpdir = tempfile.mkdtemp(dir=tmpdir_root, prefix='tmp')

  with contextlib.closing(tarfile.open(topology_tar)) as tar:
    tar.extractall(path=tmpdir)

  # A tar generated by pants has all dependency jars under libs/
  # in addition to the topology jar at top level. Pants keeps
  # filename for jar and tar the same except for extension.

  topology_jar = os.path.basename(topology_tar).replace(".tar.gz", "").replace(".tar", "") + ".jar"

  extra_jars = [
      os.path.join(tmpdir, topology_jar),
      os.path.join(tmpdir, "*"),
      os.path.join(tmpdir, "libs/*")
  ]

  lib_jars = config.get_heron_libs(jars.topology_jars())

  # Now execute the class
  return heron_class(class_name, lib_jars, extra_jars, arguments, java_defines)

def heron_pex(topology_pex, topology_class_name, args=None):
  Log.debug("Importing %s from %s", topology_class_name, topology_pex)
  if topology_class_name == '-':
    # loading topology by running its main method (if __name__ == "__main__")
    heron_env = os.environ.copy()
    heron_env['HERON_OPTIONS'] = opts.get_heron_config()
    cmd = [topology_pex]
    if args is not None:
      cmd.extend(args)
    Log.debug("Invoking class using command: ``%s''", ' '.join(cmd))
    Log.debug('Heron options: {%s}', str(heron_env['HERON_OPTIONS']))
    # invoke the command with subprocess and print error message, if any
    process = subprocess.Popen(cmd, env=heron_env, stdout=subprocess.PIPE,
                               stderr=subprocess.PIPE, bufsize=1)
    # todo(rli): improve python topology submission workflow
    return ProcessResult(process)
  else:
    try:
      # loading topology from Topology's subclass (no main method)
      # to support specifying the name of topology
      Log.debug("args: %s", args)
      if args is not None and isinstance(args, (list, tuple)) and len(args) > 0:
        opts.set_config('cmdline.topology.name', args[0])
      os.environ["HERON_OPTIONS"] = opts.get_heron_config()
      Log.debug("Heron options: {%s}", os.environ["HERON_OPTIONS"])
      pex_loader.load_pex(topology_pex)
      topology_class = pex_loader.import_and_get_class(topology_pex, topology_class_name)
      topology_class.write()
      return SimpleResult(Status.Ok)
    except Exception as ex:
      Log.debug(traceback.format_exc())
      err_context = "Topology %s failed to be loaded from the given pex: %s" %\
                (topology_class_name, ex)
      return SimpleResult(Status.HeronError, err_context)

# pylint: disable=superfluous-parens
def heron_cpp(topology_binary, args=None):
  Log.debug("Executing %s", topology_binary)
  heron_env = os.environ.copy()
  heron_env['HERON_OPTIONS'] = opts.get_heron_config()
  cmd = [topology_binary]
  if args is not None:
    cmd.extend(args)
  Log.debug("Invoking binary using command: ``%s''", ' '.join(cmd))
  Log.debug('Heron options: {%s}', str(heron_env['HERON_OPTIONS']))
  print("Invoking class using command: ``%s''" % ' '.join(cmd))
  print('Heron options: {%s}' % str(heron_env['HERON_OPTIONS']))
  # invoke the command with subprocess and print error message, if any
  proc = subprocess.Popen(cmd, env=heron_env, stdout=subprocess.PIPE,
                          stderr=subprocess.PIPE, bufsize=1)
  return ProcessResult(proc)