# Copyright (C) 2023 The Qt Company Ltd.
# SPDX-License-Identifier: BSD-3-Clause

cmake_minimum_required(VERSION 3.18)
cmake_policy(VERSION 3.18)

# Enable policy to not use RPATH settings for install_name on macOS.
if(POLICY CMP0068)
  cmake_policy(SET CMP0068 NEW)
endif()

# Enable policy to run automoc on generated files.
if(POLICY CMP0071)
  cmake_policy(SET CMP0071 NEW)
endif()

# Consider changing the project name to something relevant for you.
project(wiggly LANGUAGES CXX)
set(CMAKE_INCLUDE_CURRENT_DIR ON)
set(CMAKE_AUTOMOC ON)

find_package(Qt6 COMPONENTS Core Gui Widgets)

# ================================ General configuration ======================================

# Set CPP standard to C++17 minimum.
set(CMAKE_CXX_STANDARD 17)

# The wiggly library for which we will create bindings. You can change the name to something
# relevant for your project.
set(wiggly_library "libwiggly")

# The name of the generated bindings module (as imported in Python). You can change the name
# to something relevant for your project.
set(bindings_library "wiggly")

# The header file with all the types and functions for which bindings will be generated.
# Usually it simply includes other headers of the library you are creating bindings for.
set(wrapped_header ${CMAKE_SOURCE_DIR}/bindings.h)

# The typesystem xml file which defines the relationships between the C++ types / functions
# and the corresponding Python equivalents.
set(typesystem_file ${CMAKE_SOURCE_DIR}/bindings.xml)

# Specify which C++ files will be generated by shiboken. This includes the module wrapper
# and a '.cpp' file per C++ type. These are needed for generating the module shared
# library.
set(generated_sources
    ${CMAKE_CURRENT_BINARY_DIR}/${bindings_library}/wiggly_module_wrapper.cpp
    ${CMAKE_CURRENT_BINARY_DIR}/${bindings_library}/wigglywidget_wrapper.cpp)


# ================================== Dependency detection ======================================

# Find required packages
find_package(Python COMPONENTS Interpreter Development REQUIRED)
# On RHEL and some other distros, Python wheels and site-packages may be installed under 'lib64'
# instead of 'lib'. The FindPython CMake module may set Python_SITELIB to 'lib', which is incorrect
# for these cases. To ensure compatibility, we override Python_SITELIB by querying Python directly.
# This guarantees the correct site-packages path is used regardless of platform or Python build.
execute_process(
    COMMAND ${Python_EXECUTABLE} -c
    "import site; print(next(p for p in site.getsitepackages() if 'site-packages' in p))"
    OUTPUT_VARIABLE Python_SITELIB
    OUTPUT_STRIP_TRAILING_WHITESPACE
)
list(APPEND CMAKE_PREFIX_PATH
    "${Python_SITELIB}/shiboken6_generator/lib/cmake"
)
find_package(Shiboken6Tools REQUIRED)

# ==================================== RPATH configuration ====================================


# =============================================================================================
# !!! (The section below is deployment related, so in a real world application you will want to
# take care of this properly with some custom script or tool).
# =============================================================================================
# Enable rpaths so that the built shared libraries find their dependencies.
set(CMAKE_SKIP_BUILD_RPATH FALSE)
set(CMAKE_BUILD_WITH_INSTALL_RPATH TRUE)
set(CMAKE_INSTALL_RPATH ${CMAKE_CURRENT_SOURCE_DIR})
set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
# =============================================================================================
# !!! End of dubious section.
# =============================================================================================


# =============================== CMake target - wiggly_library ===============================


# Get the relevant Qt include dirs, to pass them on to shiboken.
get_property(QT_WIDGETS_INCLUDE_DIRS TARGET Qt6::Widgets PROPERTY INTERFACE_INCLUDE_DIRECTORIES)
set(INCLUDES "")
foreach(INCLUDE_DIR ${QT_WIDGETS_INCLUDE_DIRS})
    list(APPEND INCLUDES "-I${INCLUDE_DIR}")
endforeach()

# On macOS, check if Qt is a framework build. This affects how include paths should be handled.
get_target_property(QtCore_is_framework Qt6::Core FRAMEWORK)
if (QtCore_is_framework)
    get_target_property(qt_core_library_location Qt6::Core LOCATION)
    get_filename_component(qt_core_library_location_dir "${qt_core_library_location}" DIRECTORY)
    get_filename_component(lib_dir "${qt_core_library_location_dir}/../" ABSOLUTE)
    list(APPEND INCLUDES "--framework-include-paths=${lib_dir}")
endif()

# We need to include the headers for the module bindings that we use.
set(pyside_additional_includes "")
foreach(INCLUDE_DIR ${pyside_include_dir})
    list(APPEND pyside_additional_includes "${INCLUDE_DIR}/QtCore")
    list(APPEND pyside_additional_includes "${INCLUDE_DIR}/QtGui")
    list(APPEND pyside_additional_includes "${INCLUDE_DIR}/QtWidgets")
endforeach()


# Define the wiggly shared library for which we will create bindings.
set(${wiggly_library}_sources  wigglywidget.cpp)
add_library(${wiggly_library} SHARED ${${wiggly_library}_sources})
set_property(TARGET ${wiggly_library} PROPERTY PREFIX "")

# Needed mostly on Windows to export symbols, and create a .lib file, otherwise the binding
# library can't link to the wiggly library.
target_compile_definitions(${wiggly_library} PRIVATE BINDINGS_BUILD)

target_link_libraries(${wiggly_library} PRIVATE Qt6::Widgets)


# ====================== Shiboken target for generating binding C++ files  ====================

# Define Qt modules needed
set(qt_modules Core Gui Widgets)

# Create Python bindings using Shiboken6Tools function
shiboken_generator_create_binding(
    EXTENSION_TARGET ${bindings_library}
    GENERATED_SOURCES ${generated_sources}
    HEADERS ${wrapped_header}
    TYPESYSTEM_FILE ${typesystem_file}
    LIBRARY_TARGET ${wiggly_library}
    QT_MODULES Core Gui Widgets
)

# ================================= Dubious deployment section ================================

set(windows_shiboken_shared_libraries)

if(WIN32)
    # =========================================================================================
    # !!! (The section below is deployment related, so in a real world application you will
    # want to take care of this properly (this is simply to eliminate errors that users usually
    # encounter.
    # =========================================================================================
    # Circumvent some "#pragma comment(lib)"s in "include/pyconfig.h" which might force to link
    # against a wrong python shared library.

    set(python_versions_list 3 36 37 38 39)
    set(python_additional_link_flags "")
    foreach(ver ${python_versions_list})
        set(python_additional_link_flags
            "${python_additional_link_flags} /NODEFAULTLIB:\"python${ver}_d.lib\"")
        set(python_additional_link_flags
            "${python_additional_link_flags} /NODEFAULTLIB:\"python${ver}.lib\"")
    endforeach()

    set_target_properties(${bindings_library}
                           PROPERTIES LINK_FLAGS "${python_additional_link_flags}")

    # Get the correct DLL path for the current build type
    if(CMAKE_BUILD_TYPE STREQUAL "Debug")
        get_target_property(dll_path Shiboken6::libshiboken IMPORTED_LOCATION_DEBUG)
    else()
        get_target_property(dll_path Shiboken6::libshiboken IMPORTED_LOCATION_RELEASE)
    endif()
    file(TO_CMAKE_PATH "${dll_path}" dll_path)
    set(windows_shiboken_shared_libraries "${dll_path}")
    # =========================================================================================
endif()

# =============================================================================================
# !!! (The section below is deployment related, so in a real world application you will want to
# take care of this properly with some custom script or tool).
# =============================================================================================
# Install the library and the bindings module into the source folder near the main.py file, so
# that the Python interpeter successfully imports the used module.
install(TARGETS ${bindings_library} ${wiggly_library}
        LIBRARY DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}
        RUNTIME DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}
        )
install(FILES ${windows_shiboken_shared_libraries} DESTINATION ${CMAKE_CURRENT_SOURCE_DIR})
# =============================================================================================
# !!! End of dubious section.
# =============================================================================================