from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import os
import random
import subprocess
import time

def random_name():
  return str(random.randint(0, 99999999))

def start_local_scheduler(plasma_store_name,
                          plasma_manager_name=None,
                          worker_path=None,
                          plasma_address=None,
                          node_ip_address="127.0.0.1",
                          redis_address=None,
                          use_valgrind=False,
                          use_profiler=False,
                          stdout_file=None,
                          stderr_file=None,
                          static_resource_list=None,
                          num_workers=0):
  """Start a local scheduler process.

  Args:
    plasma_store_name (str): The name of the plasma store socket to connect to.
    plasma_manager_name (str): The name of the plasma manager to connect to.
      This does not need to be provided, but if it is, then the Redis address
      must be provided as well.
    worker_path (str): The path of the worker script to use when the local
      scheduler starts up new workers.
    plasma_address (str): The address of the plasma manager to connect to. This
      is only used by the global scheduler to figure out which plasma managers
      are connected to which local schedulers.
    node_ip_address (str): The address of the node that this local scheduler is
      running on.
    redis_address (str): The address of the Redis instance to connect to. If
      this is not provided, then the local scheduler will not connect to Redis.
    use_valgrind (bool): True if the local scheduler should be started inside of
      valgrind. If this is True, use_profiler must be False.
    use_profiler (bool): True if the local scheduler should be started inside a
      profiler. If this is True, use_valgrind must be False.
    stdout_file: A file handle opened for writing to redirect stdout to. If no
      redirection should happen, then this should be None.
    stderr_file: A file handle opened for writing to redirect stderr to. If no
      redirection should happen, then this should be None.
    static_resource_list (list): A list of integers specifying the local
      scheduler's resource capacities. The resources should appear in an order
      matching the order defined in task.h.
    num_workers (int): The number of workers that the local scheduler should
      start.

  Return:
    A tuple of the name of the local scheduler socket and the process ID of the
      local scheduler process.
  """
  if (plasma_manager_name == None) != (redis_address == None):
    raise Exception("If one of the plasma_manager_name and the redis_address is provided, then both must be provided.")
  if use_valgrind and use_profiler:
    raise Exception("Cannot use valgrind and profiler at the same time.")
  local_scheduler_executable = os.path.join(os.path.dirname(os.path.abspath(__file__)), "../core/src/photon/photon_scheduler")
  local_scheduler_name = "/tmp/scheduler{}".format(random_name())
  command = [local_scheduler_executable,
             "-s", local_scheduler_name,
             "-p", plasma_store_name,
             "-h", node_ip_address,
             "-n", str(num_workers)]
  if plasma_manager_name is not None:
    command += ["-m", plasma_manager_name]
  if worker_path is not None:
    assert plasma_store_name is not None
    assert plasma_manager_name is not None
    assert redis_address is not None
    start_worker_command = ("python {} "
                            "--node-ip-address={} "
                            "--object-store-name={} "
                            "--object-store-manager-name={} "
                            "--local-scheduler-name={} "
                            "--redis-address={}").format(worker_path,
                                                         node_ip_address,
                                                         plasma_store_name,
                                                         plasma_manager_name,
                                                         local_scheduler_name,
                                                         redis_address)
    command += ["-w", start_worker_command]
  if redis_address is not None:
    command += ["-r", redis_address]
  if plasma_address is not None:
    command += ["-a", plasma_address]
  if static_resource_list is not None:
    assert all([isinstance(resource, int) or isinstance(resource, float) for resource in static_resource_list])
    command += ["-c", ",".join([str(resource) for resource in static_resource_list])]

  if use_valgrind:
    pid = subprocess.Popen(["valgrind",
                            "--track-origins=yes",
                            "--leak-check=full",
                            "--show-leak-kinds=all",
                            "--error-exitcode=1"] + command,
                            stdout=stdout_file, stderr=stderr_file)
    time.sleep(1.0)
  elif use_profiler:
    pid = subprocess.Popen(["valgrind", "--tool=callgrind"] + command,
                           stdout=stdout_file, stderr=stderr_file)
    time.sleep(1.0)
  else:
    pid = subprocess.Popen(command, stdout=stdout_file, stderr=stderr_file)
    time.sleep(0.1)
  return local_scheduler_name, pid