""" Superuser Config API. """

import logging
import os
import signal
import subprocess

from flask import abort

from app import app, config_provider
from auth.permissions import SuperUserPermission
from endpoints.api.suconfig_models_pre_oci import pre_oci_model as model
from endpoints.api import (ApiResource, nickname, resource, internal_only, show_if, verify_not_prod)

import features


logger = logging.getLogger(__name__)


def database_is_valid():
  """ Returns whether the database, as configured, is valid. """
  if app.config['TESTING']:
    return False

  return model.is_valid()


def database_has_users():
  """ Returns whether the database has any users defined. """
  return model.has_users()


@resource('/v1/superuser/registrystatus')
@internal_only
@show_if(features.SUPER_USERS)
class SuperUserRegistryStatus(ApiResource):
  """ Resource for determining the status of the registry, such as if config exists,
      if a database is configured, and if it has any defined users.
  """
  @nickname('scRegistryStatus')
  @verify_not_prod
  def get(self):
    """ Returns the status of the registry. """

    # If we have SETUP_COMPLETE, then we're ready to go!
    if app.config.get('SETUP_COMPLETE', False):
      return {
        'provider_id': config_provider.provider_id,
        'requires_restart': config_provider.requires_restart(app.config),
        'status': 'ready'
      }

    # If there is no conf/stack volume, then report that status.
    if not config_provider.volume_exists():
      return {
        'status': 'missing-config-dir'
      }

    # If there is no config file, we need to setup the database.
    if not config_provider.config_exists():
      return {
        'status': 'config-db'
      }

    # If the database isn't yet valid, then we need to set it up.
    if not database_is_valid():
      return {
        'status': 'setup-db'
      }

    return {
      'status': 'create-superuser' if not database_has_users() else 'config'
    }


class _AlembicLogHandler(logging.Handler):
  def __init__(self):
    super(_AlembicLogHandler, self).__init__()
    self.records = []

  def emit(self, record):
    self.records.append({
      'level': record.levelname,
      'message': record.getMessage()
    })

# From: https://stackoverflow.com/a/44712205
def get_process_id(name):
    """Return process ids found by (partial) name or regex.

    >>> get_process_id('kthreadd')
    [2]
    >>> get_process_id('watchdog')
    [10, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61]  # ymmv
    >>> get_process_id('non-existent process')
    []
    """
    child = subprocess.Popen(['pgrep', name], stdout=subprocess.PIPE, shell=False)
    response = child.communicate()[0]
    return [int(pid) for pid in response.split()]


@resource('/v1/superuser/shutdown')
@internal_only
@show_if(features.SUPER_USERS)
class SuperUserShutdown(ApiResource):
  """ Resource for sending a shutdown signal to the container. """

  @verify_not_prod
  @nickname('scShutdownContainer')
  def post(self):
    """ Sends a signal to the phusion init system to shut down the container. """
    # Note: This method is called to set the database configuration before super users exists,
    # so we also allow it to be called if there is no valid registry configuration setup.
    if app.config['TESTING'] or not database_has_users() or SuperUserPermission().can():
      # Note: We skip if debugging locally.
      if app.config.get('DEBUGGING') == True:
        return {}

      os.kill(get_process_id('my_init')[0], signal.SIGINT)
      return {}

    abort(403)