# -*- encoding:utf-8 -*-
# Copyright (c) Alibaba, Inc. and its affiliates.

import tensorflow as tf

from easy_rec.python.input.input import Input
from easy_rec.python.utils.tf_utils import get_tf_type

if tf.__version__ >= '2.0':
  tf = tf.compat.v1


class DummyInput(Input):
  """Dummy memory input.

  Dummy Input is used to debug the performance bottleneck of data pipeline.
  """

  def __init__(self,
               data_config,
               feature_config,
               input_path,
               task_index=0,
               task_num=1,
               check_mode=False,
               pipeline_config=None,
               input_vals={}):
    super(DummyInput,
          self).__init__(data_config, feature_config, input_path, task_index,
                         task_num, check_mode, pipeline_config)
    self._input_vals = input_vals

  def _build(self, mode, params):
    """Build fake constant input.

    Args:
      mode: tf.estimator.ModeKeys.TRAIN / tf.estimator.ModeKeys.EVAL / tf.estimator.ModeKeys.PREDICT
      params: parameters passed by estimator, currently not used

    Returns:
      features tensor dict
      label tensor dict
    """
    features = {}
    for field, field_type, def_val in zip(self._input_fields,
                                          self._input_field_types,
                                          self._input_field_defaults):
      tf_type = get_tf_type(field_type)
      def_val = self.get_type_defaults(field_type, default_val=def_val)

      if field in self._input_vals:
        tensor = self._input_vals[field]
      else:
        tensor = tf.constant([def_val] * self._batch_size, dtype=tf_type)

      features[field] = tensor
    parse_dict = self._preprocess(features)
    return self._get_features(parse_dict), self._get_labels(parse_dict)