# Copyright 2010-2022 Google LLC
# 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.

if(NOT BUILD_PYTHON)
  return()
endif()

# Use latest UseSWIG module (3.14) and Python3 module (3.18)
cmake_minimum_required(VERSION 3.18)

if(NOT TARGET ${PROJECT_NAMESPACE}::ortools)
  message(FATAL_ERROR "Python: missing ortools TARGET")
endif()

# Will need swig
set(CMAKE_SWIG_FLAGS)
find_package(SWIG REQUIRED)
include(UseSWIG)

if(${SWIG_VERSION} VERSION_GREATER_EQUAL 4)
  list(APPEND CMAKE_SWIG_FLAGS "-doxygen")
endif()

if(UNIX AND NOT APPLE)
  if (CMAKE_SIZEOF_VOID_P EQUAL 8)
    list(APPEND CMAKE_SWIG_FLAGS "-DSWIGWORDSIZE64")
  else()
    list(APPEND CMAKE_SWIG_FLAGS "-DSWIGWORDSIZE32")
  endif()
endif()

# Find Python 3
find_package(Python3 REQUIRED COMPONENTS Interpreter Development.Module)
list(APPEND CMAKE_SWIG_FLAGS "-py3" "-DPY3")

# Find if the python module is available,
# otherwise install it (PACKAGE_NAME) to the Python3 user install directory.
# If CMake option FETCH_PYTHON_DEPS is OFF then issue a fatal error instead.
# e.g
# search_python_module(
#   NAME
#     mypy_protobuf
#   PACKAGE
#     mypy-protobuf
#   NO_VERSION
# )
function(search_python_module)
  set(options NO_VERSION)
  set(oneValueArgs NAME PACKAGE)
  set(multiValueArgs "")
  cmake_parse_arguments(MODULE
    "${options}"
    "${oneValueArgs}"
    "${multiValueArgs}"
    ${ARGN}
  )
  message(STATUS "Searching python module: \"${MODULE_NAME}\"")
  if(${MODULE_NO_VERSION})
    execute_process(
      COMMAND ${Python3_EXECUTABLE} -c "import ${MODULE_NAME}"
      RESULT_VARIABLE _RESULT
      ERROR_QUIET
      OUTPUT_STRIP_TRAILING_WHITESPACE
    )
    set(MODULE_VERSION "unknown")
  else()
    execute_process(
      COMMAND ${Python3_EXECUTABLE} -c "import ${MODULE_NAME}; print(${MODULE_NAME}.__version__)"
      RESULT_VARIABLE _RESULT
      OUTPUT_VARIABLE MODULE_VERSION
      ERROR_QUIET
      OUTPUT_STRIP_TRAILING_WHITESPACE
      )
  endif()
  if(${_RESULT} STREQUAL "0")
    message(STATUS "Found python module: \"${MODULE_NAME}\" (found version \"${MODULE_VERSION}\")")
  else()
    if(FETCH_PYTHON_DEPS)
      message(WARNING "Can't find python module: \"${MODULE_NAME}\", install it using pip...")
      execute_process(
        COMMAND ${Python3_EXECUTABLE} -m pip install --user ${MODULE_PACKAGE}
        OUTPUT_STRIP_TRAILING_WHITESPACE
        )
    else()
      message(FATAL_ERROR "Can't find python module: \"${MODULE_NAME}\", please install it using your system package manager.")
    endif()
  endif()
endfunction()

# Find if a python builtin module is available.
# e.g
# search_python_internal_module(
#   NAME
#     mypy_protobuf
# )
function(search_python_internal_module)
  set(options "")
  set(oneValueArgs NAME)
  set(multiValueArgs "")
  cmake_parse_arguments(MODULE
    "${options}"
    "${oneValueArgs}"
    "${multiValueArgs}"
    ${ARGN}
  )
  message(STATUS "Searching python module: \"${MODULE_NAME}\"")
  execute_process(
    COMMAND ${Python3_EXECUTABLE} -c "import ${MODULE_NAME}"
    RESULT_VARIABLE _RESULT
    ERROR_QUIET
    OUTPUT_STRIP_TRAILING_WHITESPACE
    )
  if(${_RESULT} STREQUAL "0")
    message(STATUS "Found python internal module: \"${MODULE_NAME}\"")
  else()
    message(FATAL_ERROR "Can't find python internal module \"${MODULE_NAME}\", please install it using your system package manager.")
  endif()
endfunction()

##################
##  PROTO FILE  ##
##################
# Generate Protobuf py sources with mypy support
search_python_module(
  NAME mypy_protobuf
  PACKAGE mypy-protobuf
  NO_VERSION)
set(PROTO_PYS)
file(GLOB_RECURSE proto_py_files RELATIVE ${PROJECT_SOURCE_DIR}
  "ortools/bop/*.proto"
  "ortools/constraint_solver/*.proto"
  "ortools/glop/*.proto"
  "ortools/graph/*.proto"
  "ortools/linear_solver/*.proto"
  "ortools/packing/*.proto"
  "ortools/sat/*.proto"
  "ortools/scheduling/*.proto"
  "ortools/util/*.proto"
  )
if(USE_PDLP)
  file(GLOB_RECURSE pdlp_proto_py_files RELATIVE ${PROJECT_SOURCE_DIR} "ortools/pdlp/*.proto")
  list(APPEND proto_py_files ${pdlp_proto_py_files})
endif()
list(REMOVE_ITEM proto_py_files "ortools/constraint_solver/demon_profiler.proto")
foreach(PROTO_FILE IN LISTS proto_py_files)
  #message(STATUS "protoc proto(py): ${PROTO_FILE}")
  get_filename_component(PROTO_DIR ${PROTO_FILE} DIRECTORY)
  get_filename_component(PROTO_NAME ${PROTO_FILE} NAME_WE)
  set(PROTO_PY ${PROJECT_BINARY_DIR}/python/${PROTO_DIR}/${PROTO_NAME}_pb2.py)
  #message(STATUS "protoc py: ${PROTO_PY}")
  add_custom_command(
    OUTPUT ${PROTO_PY}
    COMMAND ${PROTOC_PRG}
    "--proto_path=${PROJECT_SOURCE_DIR}"
    ${PROTO_DIRS}
    "--python_out=${PROJECT_BINARY_DIR}/python"
    "--mypy_out=${PROJECT_BINARY_DIR}/python"
    ${PROTO_FILE}
    DEPENDS ${PROTO_FILE} ${PROTOC_PRG}
    COMMENT "Generate Python 3 protocol buffer for ${PROTO_FILE}"
    VERBATIM)
  list(APPEND PROTO_PYS ${PROTO_PY})
endforeach()
add_custom_target(Py${PROJECT_NAME}_proto
  DEPENDS
    ${PROTO_PYS}
    ${PROJECT_NAMESPACE}::ortools)

###################
##  Python Test  ##
###################
if(BUILD_VENV)
  search_python_module(NAME virtualenv PACKAGE virtualenv)
  # venv not working on github runners
  # search_python_internal_module(NAME venv)
  # Testing using a vitual environment
  set(VENV_EXECUTABLE ${Python3_EXECUTABLE} -m virtualenv)
  #set(VENV_EXECUTABLE ${Python3_EXECUTABLE} -m venv)
  set(VENV_DIR ${CMAKE_CURRENT_BINARY_DIR}/python/venv)
  if(WIN32)
    set(VENV_Python3_EXECUTABLE ${VENV_DIR}/Scripts/python.exe)
  else()
    set(VENV_Python3_EXECUTABLE ${VENV_DIR}/bin/python)
  endif()
endif()

if(BUILD_TESTING)
  # add_python_test()
  # CMake function to generate and build python test.
  # Parameters:
  #  the python filename
  # e.g.:
  # add_python_test(foo.py)
  function(add_python_test FILE_NAME)
    message(STATUS "Configuring test ${FILE_NAME} ...")
    get_filename_component(TEST_NAME ${FILE_NAME} NAME_WE)
    get_filename_component(WRAPPER_DIR ${FILE_NAME} DIRECTORY)
    get_filename_component(COMPONENT_DIR ${WRAPPER_DIR} DIRECTORY)
    get_filename_component(COMPONENT_NAME ${COMPONENT_DIR} NAME)

    add_test(
      NAME python_${COMPONENT_NAME}_${TEST_NAME}
      COMMAND ${VENV_Python3_EXECUTABLE} -m pytest ${FILE_NAME}
      WORKING_DIRECTORY ${VENV_DIR})
    message(STATUS "Configuring test ${FILE_NAME} done")
  endfunction()
endif()

#######################
##  PYTHON WRAPPERS  ##
#######################
# CMake will remove all '-D' prefix (i.e. -DUSE_FOO become USE_FOO)
#get_target_property(FLAGS ${PROJECT_NAMESPACE}::ortools COMPILE_DEFINITIONS)
set(FLAGS -DUSE_BOP -DUSE_GLOP -DABSL_MUST_USE_RESULT)
if(USE_COINOR)
  list(APPEND FLAGS "-DUSE_CBC" "-DUSE_CLP")
endif()
if(USE_GLPK)
  list(APPEND FLAGS "-DUSE_GLPK")
endif()
if(USE_HIGHS)
  list(APPEND FLAGS "-DUSE_HIGHS")
endif()
if(USE_PDLP)
  list(APPEND FLAGS "-DUSE_PDLP")
endif()
if(USE_SCIP)
  list(APPEND FLAGS "-DUSE_SCIP")
endif()
list(APPEND CMAKE_SWIG_FLAGS ${FLAGS} "-I${PROJECT_SOURCE_DIR}")

set(PYTHON_PROJECT ${PROJECT_NAME})
message(STATUS "Python project: ${PYTHON_PROJECT}")
set(PYTHON_PROJECT_DIR ${PROJECT_BINARY_DIR}/python/${PYTHON_PROJECT})
message(STATUS "Python project build path: ${PYTHON_PROJECT_DIR}")

# Swig wrap all libraries
foreach(SUBPROJECT IN ITEMS init algorithms graph linear_solver constraint_solver sat scheduling util)
  add_subdirectory(ortools/${SUBPROJECT}/python)
endforeach()

#######################
## Python Packaging  ##
#######################
#file(MAKE_DIRECTORY python/${PYTHON_PROJECT})
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/__init__.py CONTENT "__version__ = \"${PROJECT_VERSION}\"\n")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/algorithms/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/bop/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/constraint_solver/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/glop/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/graph/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/graph/python/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/init/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/linear_solver/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/linear_solver/python/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/packing/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/pdlp/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/sat/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/sat/python/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/scheduling/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/util/__init__.py CONTENT "")
file(GENERATE OUTPUT ${PYTHON_PROJECT_DIR}/util/python/__init__.py CONTENT "")

file(COPY
  ortools/linear_solver/linear_solver_natural_api.py
  DESTINATION ${PYTHON_PROJECT_DIR}/linear_solver)
file(COPY
  ortools/linear_solver/python/model_builder.py
  ortools/linear_solver/python/model_builder_helper.py
  DESTINATION ${PYTHON_PROJECT_DIR}/linear_solver/python)
file(COPY
  ortools/sat/python/cp_model.py
  ortools/sat/python/cp_model_helper.py
  ortools/sat/python/visualization.py
  DESTINATION ${PYTHON_PROJECT_DIR}/sat/python)

# setup.py.in contains cmake variable e.g. @PYTHON_PROJECT@ and
# generator expression e.g. $<TARGET_FILE_NAME:pyFoo>
configure_file(
  ${PROJECT_SOURCE_DIR}/ortools/python/setup.py.in
  ${PROJECT_BINARY_DIR}/python/setup.py.in
  @ONLY)
file(GENERATE
  OUTPUT ${PROJECT_BINARY_DIR}/python/setup.py
  INPUT ${PROJECT_BINARY_DIR}/python/setup.py.in)

#add_custom_command(
#  OUTPUT python/setup.py
#  DEPENDS ${PROJECT_BINARY_DIR}/python/setup.py
#  COMMAND ${CMAKE_COMMAND} -E copy setup.py setup.py
#  WORKING_DIRECTORY python)

configure_file(
  ${PROJECT_SOURCE_DIR}/tools/README.pypi.txt
  ${PROJECT_BINARY_DIR}/python/README.txt
  COPYONLY)

# Look for required python modules
search_python_module(
  NAME setuptools
  PACKAGE setuptools)
search_python_module(
  NAME wheel
  PACKAGE wheel)

add_custom_command(
  OUTPUT python/dist/timestamp
  COMMAND ${CMAKE_COMMAND} -E remove_directory dist
  COMMAND ${CMAKE_COMMAND} -E make_directory ${PYTHON_PROJECT}/.libs
  # Don't need to copy static lib on Windows.
  COMMAND ${CMAKE_COMMAND} -E $<IF:$<STREQUAL:$<TARGET_PROPERTY:ortools,TYPE>,SHARED_LIBRARY>,copy,true>
  $<$<STREQUAL:$<TARGET_PROPERTY:ortools,TYPE>,SHARED_LIBRARY>:$<TARGET_SONAME_FILE:ortools>>
  ${PYTHON_PROJECT}/.libs
  COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:pywrapinit> ${PYTHON_PROJECT}/init
  COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:pywrapknapsack_solver> ${PYTHON_PROJECT}/algorithms
  COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:linear_sum_assignment_pybind11> ${PYTHON_PROJECT}/graph/python
  COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:max_flow_pybind11> ${PYTHON_PROJECT}/graph/python
  COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:min_cost_flow_pybind11> ${PYTHON_PROJECT}/graph/python
  COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:pywrapcp> ${PYTHON_PROJECT}/constraint_solver
  COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:pywraplp> ${PYTHON_PROJECT}/linear_solver
  COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:pywrap_model_builder_helper> ${PYTHON_PROJECT}/linear_solver/python
  COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:swig_helper> ${PYTHON_PROJECT}/sat/python
  COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:pywraprcpsp> ${PYTHON_PROJECT}/scheduling
  COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:sorted_interval_list> ${PYTHON_PROJECT}/util/python
  #COMMAND ${Python3_EXECUTABLE} setup.py bdist_egg bdist_wheel
  COMMAND ${Python3_EXECUTABLE} setup.py bdist_wheel
  COMMAND ${CMAKE_COMMAND} -E touch ${PROJECT_BINARY_DIR}/python/dist/timestamp
  MAIN_DEPENDENCY
    ortools/python/setup.py.in
  DEPENDS
    python/setup.py
    Py${PROJECT_NAME}_proto
    ${PROJECT_NAMESPACE}::ortools
    pywrapinit
    pywrapknapsack_solver
    linear_sum_assignment_pybind11
    max_flow_pybind11
    min_cost_flow_pybind11
    pywrapcp
    pywraplp
    pywrap_model_builder_helper
    swig_helper
    pywraprcpsp
    sorted_interval_list
  BYPRODUCTS
    python/${PYTHON_PROJECT}
    python/${PYTHON_PROJECT}.egg-info
    python/build
    python/dist
  WORKING_DIRECTORY python
  COMMAND_EXPAND_LISTS)

# Main Target
add_custom_target(python_package ALL
  DEPENDS
    python/dist/timestamp
  WORKING_DIRECTORY python)

# Install rules
configure_file(
  ${PROJECT_SOURCE_DIR}/cmake/python-install.cmake.in
  ${PROJECT_BINARY_DIR}/python/python-install.cmake
  @ONLY)
install(SCRIPT ${PROJECT_BINARY_DIR}/python/python-install.cmake)

if(BUILD_VENV)
  # make a virtualenv to install our python package in it
  add_custom_command(TARGET python_package POST_BUILD
    # Clean previous install otherwise pip install may do nothing
    COMMAND ${CMAKE_COMMAND} -E remove_directory ${VENV_DIR}
    COMMAND ${VENV_EXECUTABLE} -p ${Python3_EXECUTABLE}
    $<IF:$<BOOL:${VENV_USE_SYSTEM_SITE_PACKAGES}>,--system-site-packages,-q>
      ${VENV_DIR}
    #COMMAND ${VENV_EXECUTABLE} ${VENV_DIR}
    # Must NOT call it in a folder containing the setup.py otherwise pip call it
    # (i.e. "python setup.py bdist") while we want to consume the wheel package
    COMMAND ${VENV_Python3_EXECUTABLE} -m pip install
      --find-links=${CMAKE_CURRENT_BINARY_DIR}/python/dist ${PYTHON_PROJECT}==${PROJECT_VERSION}
    # install modules only required to run examples
    COMMAND ${VENV_Python3_EXECUTABLE} -m pip install pandas matplotlib pytest
    BYPRODUCTS ${VENV_DIR}
    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
    COMMENT "Create venv and install ${PYTHON_PROJECT}"
    VERBATIM)
endif()

if(BUILD_TESTING)
  configure_file(
    ${PROJECT_SOURCE_DIR}/ortools/init/python/version_test.py.in
    ${PROJECT_BINARY_DIR}/python/version_test.py
    @ONLY)

  # run the tests within the virtualenv
  add_test(NAME python_init_version_test
    COMMAND ${VENV_Python3_EXECUTABLE} ${PROJECT_BINARY_DIR}/python/version_test.py)
endif()

#####################
##  Python Sample  ##
#####################
# add_python_sample()
# CMake function to generate and build python sample.
# Parameters:
#  the python filename
# e.g.:
# add_python_sample(foo.py)
function(add_python_sample FILE_NAME)
  message(STATUS "Configuring sample ${FILE_NAME} ...")
  get_filename_component(SAMPLE_NAME ${FILE_NAME} NAME_WE)
  get_filename_component(SAMPLE_DIR ${FILE_NAME} DIRECTORY)
  get_filename_component(COMPONENT_DIR ${SAMPLE_DIR} DIRECTORY)
  get_filename_component(COMPONENT_NAME ${COMPONENT_DIR} NAME)

  if(BUILD_TESTING)
    add_test(
      NAME python_${COMPONENT_NAME}_${SAMPLE_NAME}
      COMMAND ${VENV_Python3_EXECUTABLE} ${FILE_NAME}
      WORKING_DIRECTORY ${VENV_DIR})
  endif()
  message(STATUS "Configuring sample ${FILE_NAME} done")
endfunction()

######################
##  Python Example  ##
######################
# add_python_example()
# CMake function to generate and build python example.
# Parameters:
#  the python filename
# e.g.:
# add_python_example(foo.py)
function(add_python_example FILE_NAME)
  message(STATUS "Configuring example ${FILE_NAME} ...")
  get_filename_component(EXAMPLE_NAME ${FILE_NAME} NAME_WE)
  get_filename_component(COMPONENT_DIR ${FILE_NAME} DIRECTORY)
  get_filename_component(COMPONENT_NAME ${COMPONENT_DIR} NAME)

  if(BUILD_TESTING)
    add_test(
      NAME python_${COMPONENT_NAME}_${EXAMPLE_NAME}
      COMMAND ${VENV_Python3_EXECUTABLE} ${FILE_NAME}
      WORKING_DIRECTORY ${VENV_DIR})
  endif()
  message(STATUS "Configuring example ${FILE_NAME} done")
endfunction()