# SPDX-FileCopyrightText: 2014 Rohan Garg <rohan16garg@gmail.com>
# SPDX-FileCopyrightText: 2014 Alex Merry <alex.merry@kde.org>
# SPDX-FileCopyrightText: 2014-2016 Aleix Pol <aleixpol@kde.org>
# SPDX-FileCopyrightText: 2017 Friedrich W. H. Kossebau <kossebau@kde.org>
# SPDX-FileCopyrightText: 2022 Ahmad Samir <a.samir78@gmail.com>
#
# SPDX-License-Identifier: BSD-3-Clause
#[=======================================================================[.rst:
ECMQueryQt
---------------
This module can be used to query the installation paths used by Qt.

For Qt5 this uses ``qmake``, and for Qt6 this used ``qtpaths`` (the latter has built-in
support to query the paths of a target platform when cross-compiling).

This module defines the following function:
::

    ecm_query_qt(<result_variable> <qt_variable> [TRY])

Passing ``TRY`` will result in the method not making the build fail if the executable
used for querying has not been found, but instead simply print a warning message and
return an empty string.

Example usage:

.. code-block:: cmake

    include(ECMQueryQt)
    ecm_query_qt(bin_dir QT_INSTALL_BINS)

If the call succeeds ``${bin_dir}`` will be set to ``<prefix>/path/to/bin/dir`` (e.g.
``/usr/lib64/qt/bin/``).

Since: 5.93
#]=======================================================================]

cmake_policy(VERSION 3.16)

include(${CMAKE_CURRENT_LIST_DIR}/QtVersionOption.cmake)
include(CheckLanguage)
check_language(CXX)
if (CMAKE_CXX_COMPILER)
    # Enable the CXX language to let CMake look for config files in library dirs.
    # See: https://gitlab.kitware.com/cmake/cmake/-/issues/23266
    enable_language(CXX)
endif()

if (QT_MAJOR_VERSION STREQUAL "5")
    # QUIET to accommodate the TRY option
    find_package(Qt${QT_MAJOR_VERSION}Core QUIET)
    set(_exec_name_text "Qt5 qmake")
    if(TARGET Qt5::qmake)
        get_target_property(_qmake_executable_default Qt5::qmake LOCATION)

        set(QUERY_EXECUTABLE ${_qmake_executable_default})
        set(_cli_option "-query")
    endif()
elseif(QT_MAJOR_VERSION STREQUAL "6")
    # QUIET to accommodate the TRY option
    find_package(Qt6 COMPONENTS CoreTools QUIET CONFIG)
    set(_exec_name_text "Qt6 qtpaths")
    if (TARGET Qt6::qtpaths)
        get_target_property(_qtpaths_executable Qt6::qtpaths LOCATION)

        set(QUERY_EXECUTABLE ${_qtpaths_executable})
        set(_cli_option "--query")
    endif()
endif()

function(ecm_query_qt result_variable qt_variable)
    set(options TRY)
    set(oneValueArgs)
    set(multiValueArgs)

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

    if(NOT QUERY_EXECUTABLE)
        if(ARGS_TRY)
            set(${result_variable} "" PARENT_SCOPE)
            message(STATUS "No ${_exec_name_text} executable found. Can't check ${qt_variable}")
            return()
        else()
            message(FATAL_ERROR "No ${_exec_name_text} executable found. Can't check ${qt_variable} as required")
        endif()
    endif()
    execute_process(
        COMMAND ${QUERY_EXECUTABLE} ${_cli_option} "${qt_variable}"
        RESULT_VARIABLE return_code
        OUTPUT_VARIABLE output
    )
    if(return_code EQUAL 0)
        string(STRIP "${output}" output)
        file(TO_CMAKE_PATH "${output}" output_path)
        set(${result_variable} "${output_path}" PARENT_SCOPE)
    else()
        message(WARNING "Failed call: ${QUERY_EXECUTABLE} ${_cli_option} ${qt_variable}")
        message(FATAL_ERROR "${_exec_name_text} call failed: ${return_code}")
    endif()
endfunction()
