#
# All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
# its licensors.
#
# For complete copyright and license terms please see the LICENSE at the root of this
# distribution (the "License"). All use of this software is governed by the License,
# or, if provided, by the license below or the license accompanying this file. Do not
# remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#

# Do not overcomplicate searching for the 3rdParty path, if it is not easy to find,
# the user should define it.

set(LY_3RDPARTY_PATH "" CACHE PATH "Path to the 3rdParty folder")

if(LY_3RDPARTY_PATH)
    file(TO_CMAKE_PATH ${LY_3RDPARTY_PATH} LY_3RDPARTY_PATH)
endif()
if(NOT EXISTS ${LY_3RDPARTY_PATH})
    message(FATAL_ERROR "3rdParty folder: ${LY_3RDPARTY_PATH} does not exist, call cmake defining a valid LY_3RDPARTY_PATH or use cmake-gui to configure it")
endif()

#! ly_add_external_target_path: adds a path to module path so 3rdparty Find files can be added from paths different than cmake/3rdParty
#
# \arg:PATH path to add
#
function(ly_add_external_target_path PATH)
    list(APPEND CMAKE_MODULE_PATH ${PATH})
    set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} PARENT_SCOPE)
    set_property(GLOBAL APPEND PROPERTY LY_ADDITIONAL_MODULE_PATH ${PATH})
endfunction()

#! ly_add_external_target: adds a library interface that exposes external libraries to be used as cmake dependencies.
#
# \arg:NAME name of the external library
# \arg:VERSION version of the external library. Location will be defined by 3rdPartyPath/NAME/VERSION
# \arg:3RDPARTY_DIRECTORY overrides the path to use when searching in the 3rdPartyPath (instead of NAME).
#                         If not indicated, PACKAGE will be used, if not indicated, NAME will be used.
# \arg:3RDPARTY_ROOT_DIRECTORY overrides the root path to the external library directory. This will be used instead of ${LY_3RDPARTY_PATH}.
# \arg:INCLUDE_DIRECTORIES include folders (relative to the root path where the external library is: ${LY_3RDPARTY_PATH}/${NAME}/${VERSION})
# \arg:PACKAGE if defined, defines the name of the external library "package". This is used when a package exposes multiple interfaces
#              if not defined, NAME is used
# \arg:COMPILE_DEFINITIONS compile definitions to be added to the interface
# \arg:BUILD_DEPENDENCIES list of interfaces this target depends on (could be a compilation dependency if the dependency is only
#                         exposing an include path, or could be a linking dependency is exposing a lib)
# \arg:RUNTIME_DEPENDENCIES list of files this target depends on (could be a dynamic libraries, text files, executables,
#                           applications, other 3rdParty targets, etc)
# \arg:OUTPUT_SUBDIRECTORY Subdirectory within bin/<Profile/Debug>/ where the ${PACKAGE_AND_NAME}_RUNTIME_DEPENDENCIES exported by the target will be copied to.
#                          If not specified, then the ${PACKAGE_AND_NAME}_RUNTIME_DEPENDENCIES will be copied directly under bin/<Profile/Debug>/.
#                          Each file listed in runtime dependencies can also customize its own output subfolder
#                          by adding "\n<subfolder path>" at the end of each listed file. OUTPUT_SUBDIRECTORY only works
#                          if such customized subfolder per file is NOT specified.
#                          Examples:
#                          1- If there are 5 files listed in ${PACKAGE_AND_NAME}_RUNTIME_DEPENDENCIES, and all of them
#                             should be copied to the same output subfolder named "My/Output/Subfolder" then it is advisable
#                             to set OUTPUT_SUBDIRECTORY to "My/Output/Subfolder" instead of appending: "\nMy/Output/Subfolder"
#                             at the end of each listed file.
#                          2- Assume there are 2 files listed in ${PACKAGE_AND_NAME}_RUNTIME_DEPENDENCIES, "fileA" must go to
#                             subdirectory "My/Output/Subfolder/lib" and "fileB" must go to subdirectory "My/Output/Subfolder/bin".
#                             In this case OUTPUT_SUBDIRECTORY should NOT be used, instead the files can be listed as:
#                             "fileA\nMy/Output/Subfolder/lib"
#                             "fileB\nMy/Output/Subfolder/bin"
#
function(ly_add_external_target)

    set(options)
    set(oneValueArgs NAME VERSION 3RDPARTY_DIRECTORY PACKAGE 3RDPARTY_ROOT_DIRECTORY OUTPUT_SUBDIRECTORY)
    set(multiValueArgs HEADER_CHECK COMPILE_DEFINITIONS INCLUDE_DIRECTORIES BUILD_DEPENDENCIES RUNTIME_DEPENDENCIES)

    cmake_parse_arguments(ly_add_external_target "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})

    # Validate input arguments
    if(NOT ly_add_external_target_NAME)
        message(FATAL_ERROR "You must provide a name for the 3rd party library")
    endif()

    if(NOT ly_add_external_target_PACKAGE)
        set(ly_add_external_target_PACKAGE ${ly_add_external_target_NAME})
        set(PACKAGE_AND_NAME "${ly_add_external_target_NAME}")
        set(NAME_WITH_NAMESPACE "${ly_add_external_target_NAME}")
        set(has_package FALSE)
    else()
        set(PACKAGE_AND_NAME "${ly_add_external_target_PACKAGE}_${ly_add_external_target_NAME}")
        set(NAME_WITH_NAMESPACE "${ly_add_external_target_PACKAGE}::${ly_add_external_target_NAME}")
        set(has_package TRUE)
    endif()
    string(TOUPPER ${PACKAGE_AND_NAME} PACKAGE_AND_NAME)
    string(TOUPPER ${ly_add_external_target_PACKAGE} PACKAGE)

    if(NOT TARGET 3rdParty::${NAME_WITH_NAMESPACE})

        if(NOT DEFINED ly_add_external_target_VERSION AND NOT VERSION IN_LIST ly_add_external_target_KEYWORDS_MISSING_VALUES)
            message(FATAL_ERROR "You must provide a version of the \"${ly_add_external_target_PACKAGE}\" 3rd party library")
        endif()

        if(NOT ly_add_external_target_3RDPARTY_ROOT_DIRECTORY)
            if(NOT ly_add_external_target_3RDPARTY_DIRECTORY)
                if(ly_add_external_target_PACKAGE)
                    set(ly_add_external_target_3RDPARTY_DIRECTORY ${ly_add_external_target_PACKAGE})
                else()
                    set(ly_add_external_target_3RDPARTY_DIRECTORY ${ly_add_external_target_NAME})
                endif()
            endif()
            set(BASE_PATH "${LY_3RDPARTY_PATH}/${ly_add_external_target_3RDPARTY_DIRECTORY}")

        else()
            ly_install_external_target(${ly_add_external_target_3RDPARTY_ROOT_DIRECTORY})
            set(BASE_PATH "${ly_add_external_target_3RDPARTY_ROOT_DIRECTORY}")
        endif()

        if(ly_add_external_target_VERSION)
            set(BASE_PATH "${BASE_PATH}/${ly_add_external_target_VERSION}")
        endif()

        # Setting BASE_PATH variable in the parent scope to allow for the Find<3rdParty>.cmake scripts to use them
        set(BASE_PATH ${BASE_PATH} PARENT_SCOPE)

        add_library(3rdParty::${NAME_WITH_NAMESPACE} INTERFACE IMPORTED GLOBAL)

        if(ly_add_external_target_INCLUDE_DIRECTORIES)
            list(TRANSFORM ly_add_external_target_INCLUDE_DIRECTORIES PREPEND ${BASE_PATH}/)
            foreach(include_path ${ly_add_external_target_INCLUDE_DIRECTORIES})
                if(NOT EXISTS ${include_path})
                    message(FATAL_ERROR "Cannot find include path ${include_path} for 3rdParty::${NAME_WITH_NAMESPACE}")
                endif()
            endforeach()
            ly_target_include_system_directories(TARGET 3rdParty::${NAME_WITH_NAMESPACE}
                INTERFACE ${ly_add_external_target_INCLUDE_DIRECTORIES}
            )
        endif()

        # Check if there is a pal file
        ly_get_absolute_pal_filename(pal_file ${CMAKE_CURRENT_LIST_DIR}/Platform/${PAL_PLATFORM_NAME}/${ly_add_external_target_PACKAGE}_${PAL_PLATFORM_NAME_LOWERCASE}.cmake)
        if(NOT EXISTS ${pal_file})
            set(pal_file ${CMAKE_CURRENT_LIST_DIR}/Platform/${PAL_PLATFORM_NAME}/${ly_add_external_target_PACKAGE}_${PAL_PLATFORM_NAME_LOWERCASE}.cmake)
        endif()
        if(EXISTS ${pal_file})
            include(${pal_file})
        endif()

        if(${PACKAGE_AND_NAME}_INCLUDE_DIRECTORIES)
            list(TRANSFORM ${PACKAGE_AND_NAME}_INCLUDE_DIRECTORIES PREPEND ${BASE_PATH}/)
            foreach(include_path ${${PACKAGE_AND_NAME}_INCLUDE_DIRECTORIES})
                string(GENEX_STRIP ${include_path} include_genex_expr)
                if(include_genex_expr STREQUAL include_path AND NOT EXISTS ${include_path}) # Exclude include paths that have generation expressions from validation
                    message(FATAL_ERROR "Cannot find include path ${include_path} for 3rdParty::${NAME_WITH_NAMESPACE}")
                endif()
            endforeach()
            ly_target_include_system_directories(TARGET 3rdParty::${NAME_WITH_NAMESPACE}
                INTERFACE ${${PACKAGE_AND_NAME}_INCLUDE_DIRECTORIES}
            )
        endif()

        if(has_package AND ${PACKAGE}_LIBS)
            set_property(TARGET 3rdParty::${NAME_WITH_NAMESPACE}
                APPEND PROPERTY
                    INTERFACE_LINK_LIBRARIES "${${PACKAGE}_LIBS}"
            )
        endif()

        if(${PACKAGE_AND_NAME}_LIBS)
            set_property(TARGET 3rdParty::${NAME_WITH_NAMESPACE}
                APPEND PROPERTY
                    INTERFACE_LINK_LIBRARIES "${${PACKAGE_AND_NAME}_LIBS}"
            )
        endif()

        if(has_package AND ${PACKAGE}_LINK_OPTIONS)
            set_property(TARGET 3rdParty::${NAME_WITH_NAMESPACE}
                APPEND PROPERTY
                    INTERFACE_LINK_OPTIONS "${${PACKAGE}_LINK_OPTIONS}"
            )
        endif()
        if(${PACKAGE_AND_NAME}_LINK_OPTIONS)
            set_property(TARGET 3rdParty::${NAME_WITH_NAMESPACE}
                APPEND PROPERTY
                    INTERFACE_LINK_OPTIONS "${${PACKAGE_AND_NAME}_LINK_OPTIONS}"
            )
        endif()

        if(has_package AND ${PACKAGE}_COMPILE_OPTIONS)
            set_property(TARGET 3rdParty::${NAME_WITH_NAMESPACE}
                APPEND PROPERTY
                    INTERFACE_COMPILE_OPTIONS "${${PACKAGE}_COMPILE_OPTIONS}"
            )
        endif()
        if(${PACKAGE_AND_NAME}_COMPILE_OPTIONS)
            set_property(TARGET 3rdParty::${NAME_WITH_NAMESPACE}
                APPEND PROPERTY
                    INTERFACE_COMPILE_OPTIONS "${${PACKAGE_AND_NAME}_COMPILE_OPTIONS}"
            )
        endif()

        unset(all_dependencies)
        if(ly_add_external_target_RUNTIME_DEPENDENCIES)
            list(APPEND all_dependencies ${ly_add_external_target_RUNTIME_DEPENDENCIES})
        endif()
        if(has_package AND ${PACKAGE}_RUNTIME_DEPENDENCIES)
            list(APPEND all_dependencies ${${PACKAGE}_RUNTIME_DEPENDENCIES})
        endif()
        if(${PACKAGE_AND_NAME}_RUNTIME_DEPENDENCIES)
            list(APPEND all_dependencies ${${PACKAGE_AND_NAME}_RUNTIME_DEPENDENCIES})
        endif()

        unset(locations)
        unset(manual_dependencies)
        if(all_dependencies)
            foreach(dependency ${all_dependencies})
                if(dependency MATCHES "3rdParty::")
                    list(APPEND manual_dependencies ${dependency})
                else()
                    if(ly_add_external_target_OUTPUT_SUBDIRECTORY)
                        string(APPEND dependency "\n${ly_add_external_target_OUTPUT_SUBDIRECTORY}")
                    endif()
                    list(APPEND locations ${dependency})
                endif()
            endforeach()
        endif()
        if(locations)
            set_property(TARGET 3rdParty::${NAME_WITH_NAMESPACE}
                APPEND PROPERTY
                    INTERFACE_IMPORTED_LOCATION "${locations}"
            )
        endif()
        if(manual_dependencies)
            ly_add_dependencies(3rdParty::${NAME_WITH_NAMESPACE} ${manual_dependencies})
        endif()
        get_property(additional_dependencies GLOBAL PROPERTY LY_DELAYED_DEPENDENCIES_3rdParty::${NAME_WITH_NAMESPACE})
        if(additional_dependencies)
            ly_add_dependencies(3rdParty::${NAME_WITH_NAMESPACE} ${additional_dependencies})
            # Clear the variable so we can track issues in case some dependency is added after
            set_property(GLOBAL PROPERTY LY_DELAYED_DEPENDENCIES_3rdParty::${NAME_WITH_NAMESPACE})
        endif()

        if(ly_add_external_target_COMPILE_DEFINITIONS)
            target_compile_definitions(3rdParty::${NAME_WITH_NAMESPACE}
                INTERFACE ${ly_add_external_target_COMPILE_DEFINITIONS}
            )
        endif()
        if(has_package AND ${PACKAGE}_COMPILE_DEFINITIONS)
            set_property(TARGET 3rdParty::${NAME_WITH_NAMESPACE}
                APPEND PROPERTY
                    INTERFACE_COMPILE_DEFINITIONS "${${PACKAGE}_COMPILE_DEFINITIONS}"
            )
        endif()
        if(${PACKAGE_AND_NAME}_COMPILE_DEFINITIONS)
            set_property(TARGET 3rdParty::${NAME_WITH_NAMESPACE}
                APPEND PROPERTY
                    INTERFACE_COMPILE_DEFINITIONS "${${PACKAGE_AND_NAME}_COMPILE_DEFINITIONS}"
            )
        endif()

        if(has_package AND ${PACKAGE}_BUILD_DEPENDENCIES)
            list(APPEND ly_add_external_target_BUILD_DEPENDENCIES "${${PACKAGE}_BUILD_DEPENDENCIES}")
            list(REMOVE_DUPLICATES ly_add_external_target_BUILD_DEPENDENCIES)
        endif()
        if(${PACKAGE_AND_NAME}_BUILD_DEPENDENCIES)
            list(APPEND ly_add_external_target_BUILD_DEPENDENCIES "${${PACKAGE_AND_NAME}_BUILD_DEPENDENCIES}")
            list(REMOVE_DUPLICATES ly_add_external_target_BUILD_DEPENDENCIES)
        endif()

        # Interface dependencies may require to find_packages. So far, we are just using packages for 3rdParty, so we will
        # search for those and automatically bring those packages. The naming convention used is 3rdParty::PackageName::OptionalInterface
        foreach(dependency ${ly_add_external_target_BUILD_DEPENDENCIES})
            string(REPLACE "::" ";" dependency_list ${dependency})
            list(GET dependency_list 0 dependency_namespace)
            if(${dependency_namespace} STREQUAL "3rdParty")
                list(GET dependency_list 1 dependency_package)
                ly_download_associated_package(${dependency_package})
                find_package(${dependency_package} REQUIRED MODULE)
            endif()
        endforeach()

        if(ly_add_external_target_BUILD_DEPENDENCIES)
            target_link_libraries(3rdParty::${NAME_WITH_NAMESPACE}
                INTERFACE
                    ${ly_add_external_target_BUILD_DEPENDENCIES}
            )
        endif()

    endif()

endfunction()

#! ly_install_external_target: external libraries which are not part of 3rdParty need to be installed
#
# \arg:3RDPARTY_ROOT_DIRECTORY custom 3rd party directory which needs to be installed
function(ly_install_external_target 3RDPARTY_ROOT_DIRECTORY)

    # Install the Find file to our <install_location>/cmake directory
    install(FILES ${CMAKE_CURRENT_LIST_FILE}
        DESTINATION cmake
    )

    # We only want to install external targets that are part of our source tree
    # Checking for relative path beginning with "../" also works when the path
    # given is on another drive letter on windows(i.e., RELATIVE_PATH returns an absolute path)
    file(RELATIVE_PATH rel_path ${CMAKE_SOURCE_DIR} ${3RDPARTY_ROOT_DIRECTORY})
    if (NOT ${rel_path} MATCHES "^../")
        get_filename_component(rel_path ${rel_path} DIRECTORY)
        install(DIRECTORY ${3RDPARTY_ROOT_DIRECTORY}
            DESTINATION ${rel_path}
        )
    endif()

endfunction()

# Add the 3rdParty folder to find the modules
list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR}/3rdParty)
ly_get_absolute_pal_filename(pal_dir ${CMAKE_CURRENT_LIST_DIR}/3rdParty/Platform/${PAL_PLATFORM_NAME})
list(APPEND CMAKE_MODULE_PATH ${pal_dir})

if(NOT INSTALLED_ENGINE)
    # Add the 3rdParty cmake files to the IDE
    ly_include_cmake_file_list(cmake/3rdParty/cmake_files.cmake)
    ly_get_absolute_pal_filename(pal_3rdparty_dir ${CMAKE_CURRENT_SOURCE_DIR}/cmake/3rdParty/Platform/${PAL_PLATFORM_NAME})
    ly_include_cmake_file_list(${pal_3rdparty_dir}/cmake_${PAL_PLATFORM_NAME_LOWERCASE}_files.cmake)
endif()