CMAKE_MINIMUM_REQUIRED(VERSION 3.16)
PROJECT("Photo Compress Archiver")

################################################################################
# Check GCC version
################################################################################
IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
   # Require at least gcc 10.3 for C++20 support
   IF (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 10.3)
      MESSAGE(FATAL_ERROR "GCC version must be at least 10.3!")
   ENDIF()
ENDIF()

# This is a neat trick to prevent in source builds
IF (CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR)
   MESSAGE(FATAL_ERROR "Prevented in-tree build. This is bad practice; you "
           "should be running cmake from inside a build directory.")
ENDIF()


################################################################################
# Build configuration options
################################################################################

IF (NOT CMAKE_BUILD_TYPE)
   SET(CMAKE_BUILD_TYPE ReleaseWithDebug CACHE STRING
           "Choose the type of build, options are: None Debug ReceiverRelease ReleaseWithDebug."
           FORCE )
ENDIF()

MESSAGE(STATUS "Build Type: " ${CMAKE_BUILD_TYPE})

ADD_CUSTOM_TARGET(Debug
        COMMAND ${CMAKE_COMMAND} -DCMAKE_BUILD_TYPE=Debug ${CMAKE_SOURCE_DIR}
        COMMAND ${CMAKE_COMMAND} --build ${CMAKE_BINARY_DIR} --target all
        COMMENT "Switch CMAKE_BUILD_TYPE to Debug"
)

ADD_CUSTOM_TARGET(ReceiverRelease
        COMMAND ${CMAKE_COMMAND} -DCMAKE_BUILD_TYPE=PCARelease ${CMAKE_SOURCE_DIR}
        COMMAND ${CMAKE_COMMAND} --build ${CMAKE_BINARY_DIR} --target all
        COMMENT "Switch CMAKE_BUILD_TYPE to ReceiverRelease"
)

ADD_CUSTOM_TARGET(ReleaseWithDebug
        COMMAND ${CMAKE_COMMAND} -DCMAKE_BUILD_TYPE=ReleaseWithDebug ${CMAKE_SOURCE_DIR}
        COMMAND ${CMAKE_COMMAND} --build ${CMAKE_BINARY_DIR} --target all
        COMMENT "Switch CMAKE_BUILD_TYPE to ReleaseWithDebug"
)


# Use /etc/os-release to determine Linux flavor and version
EXECUTE_PROCESS(COMMAND bash -c "grep \"^NAME=\" /etc/os-release | cut -c7- | rev | cut -c2- | rev"
        OUTPUT_VARIABLE DISTRIB_ID
        OUTPUT_STRIP_TRAILING_WHITESPACE
)

EXECUTE_PROCESS(COMMAND bash -c "grep \"^VERSION_ID=\" /etc/os-release | cut -c13- | rev | cut -c2- | rev"
        OUTPUT_VARIABLE DISTRIB_RELEASE
        OUTPUT_STRIP_TRAILING_WHITESPACE
)

# Output the parsed ID and release version
MESSAGE(STATUS "DISTRIB_ID:      " ${DISTRIB_ID})
MESSAGE(STATUS "DISTRIB_RELEASE: " ${DISTRIB_RELEASE})

# Do not let CMake add the build directory path to RPATH. This means that CL/SL
# cannot be run from the build directory and must be properly installed.
SET(CMAKE_SKIP_BUILD_RPATH  TRUE)

# Uncomment this line to enable AddressSanitizer
# SET(CMAKE_CXX_FLAGS "-fsanitize=address -fno-omit-frame-pointer")

# Detect presence of mold linker and use it if found
IF (EXISTS "/usr/bin/mold")
   MESSAGE(STATUS "Using mold linker!")
   # Note this only works on gcc >= 12.1
   SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fuse-ld=mold")
   SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -fuse-ld=mold")
ELSE()
   MESSAGE(WARNING "Mold linker not detected. Consider installing mold (add BL APT repo: "
           "https://athena.blacklynx.tech/apt/): sudo apt install mold")
ENDIF()

#
# Set the compile flags
#
SET(CMAKE_CXX_STANDARD 20)
SET(CMAKE_CXX_STANDARD_REQUIRED ON)
SET(CMAKE_CXX_EXTENSIONS OFF)
# SET(CMAKE_CXX_VISIBILITY_PRESET hidden)

# This length is used along with the __FILE__ macro for logging
STRING(LENGTH ${CMAKE_CURRENT_SOURCE_DIR} BPLEN)
ADD_DEFINITIONS("-DBUILD_PATH_LEN=${BPLEN}")

# Ensure symbols from statically linked libraries are hidden
SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wl,--exclude-libs=ALL")

# Enable warnings
SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wno-unused-parameter")
SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wno-unused-parameter")

IF (CMAKE_BUILD_TYPE STREQUAL "PCARelease")

   # Tune for Skylake minimum
   SET(COMPILE_FLAGS "-O3 -flto=auto -march=skylake")

   SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${COMPILE_FLAGS}")
   SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${COMPILE_FLAGS}")

ELSEIF (CMAKE_BUILD_TYPE STREQUAL "ReleaseWithDebug")

   # Tune for Skylake minimum
   SET(COMPILE_FLAGS "-g -O3 -flto=auto -march=skylake ")

   SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${COMPILE_FLAGS}")
   SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${COMPILE_FLAGS}")

ELSEIF (CMAKE_BUILD_TYPE STREQUAL "Debug")

   SET(COMPILE_FLAGS "-g -O0 -march=skylake -mtune=generic")

   SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${COMPILE_FLAGS}")
   SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${COMPILE_FLAGS}")

ENDIF()

# Set the library install path depending on the Linux flavor
SET(LIBRARY_INSTALL_PATH "")
IF ((DISTRIB_ID STREQUAL "Ubuntu") OR (DISTRIB_ID STREQUAL "Linux Mint"))
   SET(LIBRARY_INSTALL_PATH "usr/lib/x86_64-linux-gnu/")
ELSE()
   # CentOS/RedHat/Scientific
   SET(LIBRARY_INSTALL_PATH "usr/lib64/")
ENDIF()

IF(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
   set(CMAKE_INSTALL_PREFIX "/" CACHE PATH "..." FORCE)
ENDIF()


################################################################################
# Library Dependencies
################################################################################
SET(EXTERNAL_LIBS)

FIND_PACKAGE(Threads)


################################################################################
# External projects
################################################################################
INCLUDE(ExternalProject)

#
# libpackjpg
#
SET(PACKJPG_PREFIX ${CMAKE_BINARY_DIR}/libpackjpg)

# TODO: only build/install libpackjpg.a
ExternalProject_Add(libpackjpg_local
        GIT_REPOSITORY      "https://brutus.gleeze.com/git/libpackjpg"
        PREFIX              ${PACKJPG_PREFIX}
        INSTALL_DIR         ${PACKJPG_PREFIX}/install
        SOURCE_SUBDIR       lib_src
        CMAKE_ARGS          -DCMAKE_INSTALL_PREFIX=${PACKJPG_PREFIX}/install -DCMAKE_BUILD_TYPE=Release)


INCLUDE_DIRECTORIES(${PACKJPG_PREFIX}/install/usr/include)

SET(libpackjpg_static_lib ${PACKJPG_PREFIX}/install/${LIBRARY_INSTALL_PATH}/libpackjpg.a)
MESSAGE(STATUS "libpackjpg path: ${libpackjpg_static_lib}")

SET_SOURCE_FILES_PROPERTIES(
        ${libpackjpg_static_lib} PROPERTIES
        EXTERNAL_OBJECT TRUE  # Identifies this as an object file (static lib)
        GENERATED TRUE        # Avoids need for file to exist at configure-time
)


################################################################################
# Source
################################################################################
INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR}/src)
INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR}/external)

SET(pca_sources
   ${CMAKE_CURRENT_SOURCE_DIR}/src/PhotoCompressArchiver.cc
)


################################################################################
# Target: pca executable
################################################################################

ADD_EXECUTABLE(pca
   ${pca_sources}
   ${CMAKE_CURRENT_SOURCE_DIR}/src/main.cc)

ADD_DEPENDENCIES(pca libpackjpg_local)

TARGET_LINK_LIBRARIES(pca ${EXTERNAL_LIBS} ${libpackjpg_static_lib})