#===============================================================================
#      The main build file for building ale using CMake.
#===============================================================================
# CMake initialization

# Specify the required version of CMake.
# cmake 3.15 required for findPython virtualenv configuration
cmake_minimum_required(VERSION 3.15)
project(ale VERSION 0.10.0 DESCRIPTION "Abstraction Library for Ephemerides ")

list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")

message(STATUS "CMake Module Path: " ${CMAKE_MODULE_PATH})

# include what we need
include(GNUInstallDirs)

set(CMAKE_CXX_STANDARD 11)

option(ALE_BUILD_LOAD "If the C++ Python load interface should be built." ON)
option(ALE_USE_EXTERNAL_JSON "If an external nlohmann JSON library should be used" ON)
option(ALE_USE_EXTERNAL_EIGEN "If an external EIGEN library should be used" ON)

# Third Party Dependencies
if(ALE_USE_EXTERNAL_JSON)
  find_package(nlohmann_json REQUIRED)
else()
  set(JSON_BuildTests OFF CACHE INTERNAL "")
  add_subdirectory(json)
endif()

if(ALE_USE_EXTERNAL_EIGEN)
  find_package(Eigen3 3.3 REQUIRED NO_MODULE)
else()
  add_library (eigen INTERFACE)
  add_library (Eigen3::Eigen ALIAS eigen)
  target_include_directories (eigen INTERFACE
    ${CMAKE_CURRENT_SOURCE_DIR}/eigen)
endif()

if(ALE_BUILD_LOAD)
  # If there is an Anaconda environment activated, search that for Python first
  if(EXISTS $ENV{CONDA_PREFIX})
    message("Searching Anaconda environment at $ENV{CONDA_PREFIX} for Python libraries")
    set(Python_FIND_VIRTUALENV FIRST)
    set(Python_FIND_REGISTRY LAST)
    set(Python_FIND_FRAMEWORK LAST)
    set(Python_FIND_STRATEGY LOCATION)
  endif()
  find_package(Python REQUIRED COMPONENTS Development)
endif()

# Library setup
set(ALE_BUILD_INCLUDE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/include/ale")
set(ALE_INSTALL_INCLUDE_DIR "include/ale")
set(ALE_SRC_FILES ${CMAKE_CURRENT_SOURCE_DIR}/src/InterpUtils.cpp
                  ${CMAKE_CURRENT_SOURCE_DIR}/src/Rotation.cpp
                  ${CMAKE_CURRENT_SOURCE_DIR}/src/Orientations.cpp
                  ${CMAKE_CURRENT_SOURCE_DIR}/src/States.cpp
                  ${CMAKE_CURRENT_SOURCE_DIR}/src/Isd.cpp
                  ${CMAKE_CURRENT_SOURCE_DIR}/src/Util.cpp
                  ${CMAKE_CURRENT_SOURCE_DIR}/src/Vectors.cpp)
set(ALE_HEADER_FILES ${ALE_BUILD_INCLUDE_DIR}/InterpUtils.h
                     ${ALE_BUILD_INCLUDE_DIR}/Rotation.h
                     ${ALE_BUILD_INCLUDE_DIR}/Orientations.h
                     ${ALE_BUILD_INCLUDE_DIR}/States.h
                     ${ALE_BUILD_INCLUDE_DIR}/Isd.h
                     ${ALE_BUILD_INCLUDE_DIR}/Distortion.h
                     ${ALE_BUILD_INCLUDE_DIR}/Vectors.h
                     ${ALE_BUILD_INCLUDE_DIR}/Util.h)
set(ALE_PRIVATE_LINKS Eigen3::Eigen)
set(ALE_PUBLIC_LINKS nlohmann_json::nlohmann_json)

if(ALE_BUILD_LOAD)
  list(APPEND ALE_SRC_FILES    ${CMAKE_CURRENT_SOURCE_DIR}/src/Load.cpp)
  list(APPEND ALE_HEADER_FILES ${ALE_BUILD_INCLUDE_DIR}/Load.h)
  list(APPEND ALE_PRIVATE_LINKS Python::Python)
endif()

add_library(ale SHARED ${ALE_SRC_FILES})

set_target_properties(ale PROPERTIES
                      VERSION   ${PROJECT_VERSION}
                      SOVERSION 0)
# Use generator expressions so that downstream projects can use this target
target_include_directories(ale
                           PUBLIC
                           $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
                           $<INSTALL_INTERFACE:include>
                           PRIVATE)

target_link_libraries(ale PRIVATE ${ALE_PRIVATE_LINKS}
                          PUBLIC ${ALE_PUBLIC_LINKS})

# Optional build tests
option (ALE_BUILD_TESTS "Build tests" ON)
if(ALE_BUILD_TESTS)
    include(cmake/gtest.cmake)
    include(GoogleTest)
    include(CTest)

    find_package (Threads)
    enable_testing()
    add_subdirectory(tests/ctests)

    # Setup for code coverage
    # default to off
    set(COVERAGE OFF CACHE BOOL "Coverage")
    if(COVERAGE)
        target_compile_options(ale PRIVATE --coverage -O0)
        target_link_libraries(ale PRIVATE --coverage -O0)
    endif()
endif()

# Generate the package config
configure_file(cmake/config.cmake.in
               ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config.cmake
               @ONLY)

# Install the package config
install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config.cmake
              DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME})

# Install the headers
install(FILES ${ALE_HEADER_FILES} DESTINATION ${ALE_INSTALL_INCLUDE_DIR})

# Install the library
install(TARGETS ale
        EXPORT aleTargets
        LIBRARY  DESTINATION ${CMAKE_INSTALL_LIBDIR}
        INCLUDES DESTINATION ${ALE_INSTALL_INCLUDE_DIR})

# Install the target
install(EXPORT aleTargets
        NAMESPACE ale::
        DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME})

option (ALE_BUILD_DOCS "Build the ALE Docs" ON)
if(ALE_BUILD_DOCS)
  add_subdirectory ("docs")
else()
  message(STATUS "Skipping Docs")
endif()