# Copyright 2018, The Android Open Source Project
#
# 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.

"""Metrics base class."""

from __future__ import print_function

import getpass
import logging
import random
import socket
import subprocess
import time
import uuid

from atest import constants
from atest.metrics import clearcut_client
from atest.proto import clientanalytics_pb2
from atest.proto import external_user_log_pb2
from atest.proto import internal_user_log_pb2

INTERNAL_USER = 0
EXTERNAL_USER = 1

ATEST_EVENTS = {
    INTERNAL_USER: internal_user_log_pb2.AtestLogEventInternal,
    EXTERNAL_USER: external_user_log_pb2.AtestLogEventExternal,
}
# log source
ATEST_LOG_SOURCE = {INTERNAL_USER: 971, EXTERNAL_USER: 934}


def get_user_email():
  """Get user mail in git config.

  Returns:
      user's email.
  """
  try:
    output = subprocess.check_output(
        ['git', 'config', '--get', 'user.email'], universal_newlines=True
    )
    return output.strip() if output else ''
  except OSError:
    # OSError can be raised when running atest_unittests on a host
    # without git being set up.
    logging.debug(
        'Unable to determine if this is an external run, git is not found.'
    )
  except subprocess.CalledProcessError:
    logging.debug(
        'Unable to determine if this is an external run, email '
        'is not found in git config.'
    )
  return ''


def get_user_type():
  """Get user type.

  Determine the internal user by passing at least one check:
    - whose git mail domain is from google
    - whose hostname is from google
  Otherwise is external user.

  Returns:
      INTERNAL_USER if user is internal, EXTERNAL_USER otherwise.
  """
  email = get_user_email()
  if email.endswith(constants.INTERNAL_EMAIL):
    return INTERNAL_USER

  try:
    hostname = socket.getfqdn()
    if hostname and any((x in hostname) for x in constants.INTERNAL_HOSTNAME):
      return INTERNAL_USER
  except IOError:
    logging.debug(
        'Unable to determine if this is an external run, hostname is not found.'
    )
  return EXTERNAL_USER


def get_user_key():
  """Get user key

  Returns:
      A UUID.uuid5 keyed on the user's email
  """
  key = uuid.uuid5(uuid.NAMESPACE_DNS, get_user_email())
  return key


class MetricsBase:
  """Class for separating allowed fields and sending metric."""

  _run_id = str(uuid.uuid4())
  user_type = get_user_type()
  if user_type == INTERNAL_USER:
    _user_key = getpass.getuser()
  else:
    try:
      # pylint: disable=protected-access
      _user_key = str(get_user_key())
      # pylint: disable=broad-except
    except Exception:
      _user_key = str(uuid.UUID(int=0))

  _log_source = ATEST_LOG_SOURCE[user_type]
  cc = clearcut_client.Clearcut(_log_source)
  tool_name = None
  sub_tool_name = ''

  def __new__(cls, **kwargs):
    """Send metric event to clearcut.

    Args:
        cls: this class object.
        **kwargs: A dict of named arguments.

    Returns:
        A Clearcut instance.
    """
    # pylint: disable=no-member
    if not cls.tool_name:
      logging.debug('There is no tool_name, and metrics stops sending.')
      return None
    allowed = (
        {constants.EXTERNAL}
        if cls.user_type == EXTERNAL_USER
        else {constants.EXTERNAL, constants.INTERNAL}
    )
    fields = [
        k
        for k, v in vars(cls).items()
        if not k.startswith('_') and v in allowed
    ]
    fields_and_values = {}
    for field in fields:
      if field in kwargs:
        fields_and_values[field] = kwargs.pop(field)
    params = {
        'user_key': cls._user_key,
        'run_id': cls._run_id,
        'user_type': cls.user_type,
        'tool_name': cls.tool_name,
        'sub_tool_name': cls.sub_tool_name,
        cls._EVENT_NAME: fields_and_values,
    }
    log_event = cls._build_full_event(ATEST_EVENTS[cls.user_type](**params))
    cls.cc.log(log_event)
    return cls.cc

  @classmethod
  def get_run_id(cls) -> str:
    """Returns the unique run id set for the current invocation."""
    return cls._run_id

  @classmethod
  def _build_full_event(cls, atest_event):
    """This is all protobuf building you can ignore.

    Args:
        cls: this class object.
        atest_event: A client_pb2.AtestLogEvent instance.

    Returns:
        A clientanalytics_pb2.LogEvent instance.
    """
    log_event = clientanalytics_pb2.LogEvent()
    log_event.event_time_ms = int(time.time() * 1000)
    log_event.source_extension = atest_event.SerializeToString()
    return log_event