# coding=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.
#

# pytype: skip-file

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


def combinevalues_simple(test=None):
  # [START combinevalues_simple]
  import apache_beam as beam

  with beam.Pipeline() as pipeline:
    total = (
        pipeline
        | 'Create produce counts' >> beam.Create([
            ('🥕', [3, 2]),
            ('🍆', [1]),
            ('🍅', [4, 5, 3]),
        ])
        | 'Sum' >> beam.CombineValues(sum)
        | beam.Map(print)
    )
    # [END combinevalues_simple]
    if test:
      test(total)


def combinevalues_function(test=None):
  # [START combinevalues_function]
  import apache_beam as beam

  def saturated_sum(values):
    max_value = 8
    return min(sum(values), max_value)

  with beam.Pipeline() as pipeline:
    saturated_total = (
        pipeline
        | 'Create plant counts' >> beam.Create([
            ('🥕', [3, 2]),
            ('🍆', [1]),
            ('🍅', [4, 5, 3]),
        ])
        | 'Saturated sum' >> beam.CombineValues(saturated_sum)
        | beam.Map(print)
    )
    # [END combinevalues_function]
    if test:
      test(saturated_total)


def combinevalues_lambda(test=None):
  # [START combinevalues_lambda]
  import apache_beam as beam

  with beam.Pipeline() as pipeline:
    saturated_total = (
        pipeline
        | 'Create plant counts' >> beam.Create([
            ('🥕', [3, 2]),
            ('🍆', [1]),
            ('🍅', [4, 5, 3]),
        ])
        | 'Saturated sum' >> beam.CombineValues(
            lambda values: min(sum(values), 8))
        | beam.Map(print)
    )
    # [END combinevalues_lambda]
    if test:
      test(saturated_total)


def combinevalues_multiple_arguments(test=None):
  # [START combinevalues_multiple_arguments]
  import apache_beam as beam

  with beam.Pipeline() as pipeline:
    saturated_total = (
        pipeline
        | 'Create plant counts' >> beam.Create([
            ('🥕', [3, 2]),
            ('🍆', [1]),
            ('🍅', [4, 5, 3]),
        ])
        | 'Saturated sum' >> beam.CombineValues(
            lambda values, max_value: min(sum(values), max_value),
            max_value=8)
        | beam.Map(print)
    )
    # [END combinevalues_multiple_arguments]
    if test:
      test(saturated_total)


def combinevalues_side_inputs_singleton(test=None):
  # [START combinevalues_side_inputs_singleton]
  import apache_beam as beam

  with beam.Pipeline() as pipeline:
    max_value = pipeline | 'Create max_value' >> beam.Create([8])

    saturated_total = (
        pipeline
        | 'Create plant counts' >> beam.Create([
            ('🥕', [3, 2]),
            ('🍆', [1]),
            ('🍅', [4, 5, 3]),
        ])
        | 'Saturated sum' >> beam.CombineValues(
            lambda values, max_value: min(sum(values), max_value),
            max_value=beam.pvalue.AsSingleton(max_value))
        | beam.Map(print)
    )
    # [END combinevalues_side_inputs_singleton]
    if test:
      test(saturated_total)


def combinevalues_side_inputs_iter(test=None):
  # [START combinevalues_side_inputs_iter]
  import apache_beam as beam

  def bounded_sum(values, data_range):
    min_value = min(data_range)
    result = sum(values)
    if result < min_value:
      return min_value
    max_value = max(data_range)
    if result > max_value:
      return max_value
    return result

  with beam.Pipeline() as pipeline:
    data_range = pipeline | 'Create data_range' >> beam.Create([2, 4, 8])

    bounded_total = (
        pipeline
        | 'Create plant counts' >> beam.Create([
            ('🥕', [3, 2]),
            ('🍆', [1]),
            ('🍅', [4, 5, 3]),
        ])
        | 'Bounded sum' >> beam.CombineValues(
            bounded_sum,
            data_range=beam.pvalue.AsIter(data_range))
        | beam.Map(print)
    )
    # [END combinevalues_side_inputs_iter]
    if test:
      test(bounded_total)


def combinevalues_side_inputs_dict(test=None):
  # [START combinevalues_side_inputs_dict]
  import apache_beam as beam

  def bounded_sum(values, data_range):
    min_value = data_range['min']
    result = sum(values)
    if result < min_value:
      return min_value
    max_value = data_range['max']
    if result > max_value:
      return max_value
    return result

  with beam.Pipeline() as pipeline:
    data_range = pipeline | 'Create data_range' >> beam.Create([
        ('min', 2),
        ('max', 8),
    ])

    bounded_total = (
        pipeline
        | 'Create plant counts' >> beam.Create([
            ('🥕', [3, 2]),
            ('🍆', [1]),
            ('🍅', [4, 5, 3]),
        ])
        | 'Bounded sum' >> beam.CombineValues(
            bounded_sum,
            data_range=beam.pvalue.AsDict(data_range))
        | beam.Map(print)
    )
    # [END combinevalues_side_inputs_dict]
    if test:
      test(bounded_total)

def combinevalues_combinefn(test=None):
  # [START combinevalues_combinefn]
  import apache_beam as beam

  class AverageFn(beam.CombineFn):
    def create_accumulator(self):
      return {}

    def add_input(self, accumulator, input):
      # accumulator == {}
      # input == '🥕'
      if input not in accumulator:
        accumulator[input] = 0  # {'🥕': 0}
      accumulator[input] += 1   # {'🥕': 1}
      return accumulator

    def merge_accumulators(self, accumulators):
      # accumulators == [
      #     {'🥕': 1, '🍅': 1},
      #     {'🥕': 1, '🍅': 1, '🍆': 1},
      # ]
      merged = {}
      for accum in accumulators:
        for item, count in accum.items():
          if item not in merged:
            merged[item] = 0
          merged[item] += count
      # merged == {'🥕': 2, '🍅': 2, '🍆': 1}
      return merged

    def extract_output(self, accumulator):
      # accumulator == {'🥕': 2, '🍅': 2, '🍆': 1}
      total = sum(accumulator.values())  # 5
      percentages = {item: count / total for item, count in accumulator.items()}
      # percentages == {'🥕': 0.4, '🍅': 0.4, '🍆': 0.2}
      return percentages

  with beam.Pipeline() as pipeline:
    percentages_per_season = (
        pipeline
        | 'Create produce' >> beam.Create([
            ('spring', ['🥕', '🍅', '🥕', '🍅', '🍆']),
            ('summer', ['🥕', '🍅', '🌽', '🍅', '🍅']),
            ('fall', ['🥕', '🥕', '🍅', '🍅']),
            ('winter', ['🍆', '🍆']),
        ])
        | 'Average' >> beam.CombineValues(AverageFn())
        | beam.Map(print)
    )
    # [END combinevalues_combinefn]
    if test:
      test(percentages_per_season)
