cmake_minimum_required (VERSION 3.10 FATAL_ERROR)
project (Spectra VERSION 1.2.0 LANGUAGES CXX)

# Make CMake look into the ./cmake/ folder for configuration files
list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)

include(CPM)
include(FeatureSummary)
include(CheckCXXCompilerFlag)
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF) # Without compiler extensions like gnu++11
set(CMAKE_CXX_FLAGS_DEBUG "-O1 -g") # Use slight optimization to speed up tests
set(CMAKE_CXX_FLAGS_RELEASE "-O2")

# Supported options
# -----------------
option(ENABLE_COVERAGE_BUILD "Do a coverage build" OFF)
option(BUILD_TESTS "Build tests" OFF)
option(BUILD_EXAMPLES "Build examples" OFF)
include(FeatureSummary) # More verbose Output for libraries using set_package_properties

# Look for supporting libraries
# -----------------------------
if(NOT TARGET Eigen3::Eigen)
    CPMFindPackage(
        NAME Eigen3
        VERSION 3.4.0
        URL https://gitlab.com/libeigen/eigen/-/archive/3.4.0/eigen-3.4.0.tar.gz
        # Eigen's CMakelists are not intended for library use
        DOWNLOAD_ONLY YES
    )

    if(Eigen3_ADDED)
        add_library(Eigen3::Eigen INTERFACE IMPORTED)
        target_include_directories(Eigen3::Eigen INTERFACE ${Eigen3_SOURCE_DIR})
    endif()
endif()

# Setup library
# -------------
add_library(Spectra INTERFACE)
target_include_directories(
    Spectra
    INTERFACE
    $<INSTALL_INTERFACE:include>
    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
)
target_link_libraries(Spectra INTERFACE Eigen3::Eigen)

# Parse additional options
# ------------------------
if(ENABLE_COVERAGE_BUILD)
    message(STATUS "Enabling coverage build")
    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} --coverage")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} --coverage")
    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --coverage")
    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} --coverage")
endif()

if(BUILD_EXAMPLES)
    add_subdirectory(examples)
endif()

if(BUILD_TESTS)
    enable_testing()
    add_subdirectory(test)
endif()

# Install the library (relative to the CMAKE_INSTALL_PREFIX)
# ----------------------------------------------------------
include(GNUInstallDirs)

install(
    TARGETS Spectra
    EXPORT Spectra-targets
    INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
)

install(DIRECTORY ${PROJECT_SOURCE_DIR}/include/ DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})

install(
    EXPORT Spectra-targets
    FILE Spectra-targets.cmake
    NAMESPACE Spectra::
    DESTINATION ${CMAKE_INSTALL_DATADIR}/cmake/Spectra
)

# Configure package
# -----------------
include(CMakePackageConfigHelpers)

configure_package_config_file(
    ${PROJECT_SOURCE_DIR}/cmake/spectra-config.cmake.in
    ${CMAKE_BINARY_DIR}/cmake/spectra-config.cmake
    INSTALL_DESTINATION ${CMAKE_INSTALL_DATADIR}/cmake/Spectra
)

write_basic_package_version_file(
    ${CMAKE_BINARY_DIR}/cmake/spectra-config-version.cmake
    VERSION ${Spectra_VERSION}
    COMPATIBILITY AnyNewerVersion
)

install(
    FILES
        ${CMAKE_BINARY_DIR}/cmake/spectra-config.cmake
        ${CMAKE_BINARY_DIR}/cmake/spectra-config-version.cmake
    DESTINATION ${CMAKE_INSTALL_DATADIR}/cmake/Spectra
)

find_package(CLANG_FORMAT 16)
if(CLANG_FORMAT_FOUND)
    file(GLOB_RECURSE FORMAT_SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/*.cpp ${CMAKE_CURRENT_SOURCE_DIR}/*.h)
    add_custom_target(
        format
        COMMAND ${CLANG_FORMAT_EXECUTABLE} -i -style=file ${FORMAT_SOURCES}
        DEPENDS ${FORMAT_SOURCES}
    )
endif()



# Print out summary of all detected packages
feature_summary(INCLUDE_QUIET_PACKAGES WHAT ALL)