#!/bin/bash
#
#    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.
#

# This script will run sphinx to create documentation for python sdk
#
# Use "generate_pydocs.sh" to update documentation in the docs directory.
#
# The exit-code of the script indicates success or a failure.

# Check that the script is running in a known directory.
if [[ $PWD != *sdks/python* ]]; then
  echo 'Unable to locate Apache Beam Python SDK root directory'
  exit 1
fi

# Go to the Apache Beam Python SDK root
if [[ $PWD != *sdks/python ]]; then
  cd $(pwd | sed 's/sdks\/python.*/sdks\/python/')
fi

# Quit on any errors
set -e

# Create docs directory if it does not exist
mkdir -p target/docs
rm -rf target/docs/*

mkdir -p target/docs/source

# Sphinx apidoc autodoc options
export SPHINX_APIDOC_OPTIONS=\
members,\
undoc-members,\
show-inheritance

# Exclude internal, test, and Cython paths/patterns from the documentation.
excluded_patterns=(
    apache_beam/coders/stream.*
    apache_beam/coders/coder_impl.*
    apache_beam/examples/
    apache_beam/internal/clients/
    apache_beam/io/gcp/internal/
    # TODO(BEAM-4543): Remove datastore paths once they no longer exist.
    apache_beam/io/gcp/datastore/v1/
    apache_beam/io/gcp/datastore_write_it_*
    apache_beam/io/gcp/tests/
    apache_beam/metrics/execution.*
    apache_beam/runners/common.*
    apache_beam/runners/api/
    apache_beam/runners/test/
    apache_beam/runners/dataflow/internal/
    apache_beam/runners/portability/
    apache_beam/runners/worker/
    apache_beam/tools/map_fn_microbenchmark.*
    apache_beam/transforms/cy_combiners.*
    apache_beam/transforms/cy_dataflow_distribution_counter.*
    apache_beam/transforms/py_dataflow_distribution_counter.*
    apache_beam/utils/counters.*
    apache_beam/utils/windowed_value.*
    *_pb2.py
    *_test.py
    *_test_common.py
)

python $(type -p sphinx-apidoc) -fMeT -o target/docs/source apache_beam \
    "${excluded_patterns[@]}"

# Create the configuration and index files
#=== conf.py ===#
cat > target/docs/source/conf.py <<'EOF'
import os
import sys

import sphinx_rtd_theme

sys.path.insert(0, os.path.abspath('../../..'))

exclude_patterns = [
    '_build',
    'apache_beam.rst',
]

extensions = [
    'sphinx.ext.autodoc',
    'sphinx.ext.doctest',
    'sphinx.ext.intersphinx',
    'sphinx.ext.napoleon',
    'sphinx.ext.viewcode',
]
master_doc = 'index'
html_theme = 'sphinx_rtd_theme'
html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
project = 'Apache Beam'

autoclass_content = 'both'
autodoc_member_order = 'bysource'

doctest_global_setup = '''
import apache_beam as beam
'''

intersphinx_mapping = {
  'python': ('https://docs.python.org/2', None),
  'hamcrest': ('https://pyhamcrest.readthedocs.io/en/stable/', None),
  'google-cloud': ('https://googleapis.github.io/google-cloud-python/latest/', None),
}

# Since private classes are skipped by sphinx, if there is any cross reference
# to them, it will be broken. This can happen if a class inherits from a
# private class.
ignore_identifiers = [
  # Ignore "custom" builtin types
  '',
  'Any',
  'Dict',
  'Iterable',
  'List',
  'Set',
  'Tuple',

  # Ignore broken built-in type references
  'tuple',

  # Ignore future.builtin type references
  'future.types.newobject.newobject',

  # Ignore private classes
  'apache_beam.coders.coders._PickleCoderBase',
  'apache_beam.coders.coders.FastCoder',
  'apache_beam.io._AvroSource',
  'apache_beam.io.gcp.bigquery.RowAsDictJsonCoder',
  'apache_beam.io.gcp.datastore.v1.datastoreio._Mutate',
  'apache_beam.io.gcp.datastore.v1new.datastoreio._Mutate',
  'apache_beam.io.gcp.datastore.v1new.datastoreio.DatastoreMutateFn',
  'apache_beam.io.gcp.internal.clients.bigquery.'
      'bigquery_v2_messages.TableSchema',
  'apache_beam.io.iobase.SourceBase',
  'apache_beam.io.source_test_utils.ExpectedSplitOutcome',
  'apache_beam.metrics.metric.MetricResults',
  'apache_beam.pipeline.PipelineVisitor',
  'apache_beam.pipeline.PTransformOverride',
  'apache_beam.pvalue.AsSideInput',
  'apache_beam.pvalue.DoOutputsTuple',
  'apache_beam.pvalue.PValue',
  'apache_beam.runners.direct.executor.CallableTask',
  'apache_beam.transforms.core.CallableWrapperCombineFn',
  'apache_beam.transforms.ptransform.PTransformWithSideInputs',
  'apache_beam.transforms.trigger._ParallelTriggerFn',
  'apache_beam.transforms.trigger.InMemoryUnmergedState',
  'apache_beam.typehints.typehints.AnyTypeConstraint',
  'apache_beam.typehints.typehints.CompositeTypeHint',
  'apache_beam.typehints.typehints.TypeConstraint',
  'apache_beam.typehints.typehints.validate_composite_type_param()',
  'apache_beam.utils.windowed_value._IntervalWindowBase',

  # Private classes which are used within the same module
  'WindowedTypeConstraint',  # apache_beam.typehints.typehints

  # stdlib classes without documentation
  'unittest.case.TestCase',

  # DoFn param inner classes, due to a Sphinx misparsing of inner classes
  '_StateDoFnParam',
  '_TimerDoFnParam',
  '_BundleFinalizerParam',
  '_RestrictionDoFnParam',

  # Sphinx cannot find this py:class reference target
  'typing.Generic',
]

# When inferring a base class it will use ':py:class'; if inferring a function
# argument type or return type, it will use ':py:obj'. We'll generate both.
nitpicky = True
nitpick_ignore = []
nitpick_ignore += [('py:class', iden) for iden in ignore_identifiers]
nitpick_ignore += [('py:obj', iden) for iden in ignore_identifiers]
nitpick_ignore += [('py:exc', 'ValueError')]

# Monkey patch functools.wraps to retain original function argument signature
# for documentation.
# https://github.com/sphinx-doc/sphinx/issues/1711
import functools
def fake_wraps(wrapped):
  def wrapper(decorator):
    return wrapped
  return wrapper

functools.wraps = fake_wraps
EOF

#=== index.rst ===#
cat > target/docs/source/index.rst <<'EOF'
.. include:: ./apache_beam.rst
   :start-line: 2
EOF

# Build the documentation using sphinx
# Reference: http://www.sphinx-doc.org/en/stable/man/sphinx-build.html
python $(type -p sphinx-build) -v -a -E -j 8 -q target/docs/source \
  target/docs/_build -c target/docs/source \
  -w "target/docs/sphinx-build.warnings.log"

# Fail if there are errors or warnings in docs
! grep -q "ERROR:" target/docs/sphinx-build.warnings.log || exit 1
! grep -q "WARNING:" target/docs/sphinx-build.warnings.log || exit 1

# Run tests for code samples, these can be:
# - Code blocks using '.. testsetup::', '.. testcode::' and '.. testoutput::'
# - Interactive code starting with '>>>'
python -msphinx -M doctest target/docs/source \
  target/docs/_build -c target/docs/source \
  -w "target/docs/sphinx-doctest.warnings.log" -j 8

# Fail if there are errors or warnings in docs
! grep -q "ERROR:" target/docs/sphinx-doctest.warnings.log || exit 1
! grep -q "WARNING:" target/docs/sphinx-doctest.warnings.log || exit 1

# Message is useful only when this script is run locally.  In a remote
# test environment, this path will be removed when the test completes.
echo "Browse to file://$PWD/target/docs/_build/index.html"