cmake_minimum_required(VERSION 3.14 FATAL_ERROR)

project(
        photon
        VERSION 0.6
        LANGUAGES C CXX ASM
)

# Utility Modules and Find Modules
include(FindPackageHandleStandardArgs)
include(CheckCXXCompilerFlag)
include(FetchContent)
include(ProcessorCount)
include(ExternalProject)
include(CMake/build-from-src.cmake)
find_package(PkgConfig REQUIRED)

# Options
set(PHOTON_CXX_STANDARD "14" CACHE STRING "C++ standard")
option(PHOTON_BUILD_TESTING "enable build testing" OFF)
option(PHOTON_ENABLE_URING "enable io_uring function" OFF)
option(PHOTON_ENABLE_FUSE "enable fuse function" OFF)
option(PHOTON_ENABLE_SASL "enable sasl" OFF)
option(PHOTON_ENABLE_MIMIC_VDSO "enable mimic vdso" OFF)
option(PHOTON_ENABLE_FSTACK_DPDK "Use f-stack + DPDK as the event engine" OFF)
option(PHOTON_ENABLE_EXTFS "enable extfs" OFF)

option(PHOTON_BUILD_DEPENDENCIES "" OFF)
set(PHOTON_AIO_SOURCE "https://pagure.io/libaio/archive/libaio-0.3.113/libaio-0.3.113.tar.gz" CACHE STRING "")
set(PHOTON_ZLIB_SOURCE "https://github.com/madler/zlib/releases/download/v1.2.13/zlib-1.2.13.tar.gz" CACHE STRING "")
set(PHOTON_OPENSSL_SOURCE "" CACHE STRING "")
set(PHOTON_CURL_SOURCE "" CACHE STRING "")
set(PHOTON_URING_SOURCE "https://github.com/axboe/liburing/archive/refs/tags/liburing-2.3.tar.gz" CACHE STRING "")
set(PHOTON_FUSE_SOURCE "" CACHE STRING "")
set(PHOTON_GSASL_SOURCE "" CACHE STRING "")
set(PHOTON_FSTACK_SOURCE "" CACHE STRING "")
set(PHOTON_E2FS_SOURCE "" CACHE STRING "")
set(PHOTON_GFLAGS_SOURCE "https://github.com/gflags/gflags/archive/refs/tags/v2.2.2.tar.gz" CACHE STRING "")
set(PHOTON_GOOGLETEST_SOURCE "https://github.com/google/googletest/archive/refs/tags/release-1.12.1.tar.gz" CACHE STRING "")

# Get CPU arch and number
execute_process(COMMAND uname -m OUTPUT_VARIABLE ARCH OUTPUT_STRIP_TRAILING_WHITESPACE)
if (NOT (${ARCH} STREQUAL x86_64) AND NOT (${ARCH} STREQUAL aarch64) AND NOT (${ARCH} STREQUAL arm64))
    message(FATAL_ERROR "Unknown CPU architecture ${ARCH}")
endif ()
ProcessorCount(NumCPU)

# Compiler options
add_compile_options(-Wall)  # -Werror is not enable yet

set(CMAKE_CXX_STANDARD ${PHOTON_CXX_STANDARD})
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
# CMake didn't provide an abstraction of optimization level for now.
set(CMAKE_CXX_FLAGS_DEBUG "-O0 -g")
set(CMAKE_CXX_FLAGS_RELEASE "-O2 -DNDEBUG")
set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -DNDEBUG -g")
set(CMAKE_CXX_FLAGS_MINSIZEREL "-O2 -g")    # Only for CI test
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
set(CMAKE_BUILD_RPATH_USE_ORIGIN ON)
set(CMAKE_POSITION_INDEPENDENT_CODE ON)
set(CMAKE_BUILD_PARALLEL_LEVEL ${NumCPU})

if (${ARCH} STREQUAL x86_64)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -msse4.2")
elseif (${ARCH} STREQUAL aarch64)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mcpu=generic+crc -fsigned-char -fno-stack-protector -fomit-frame-pointer")
endif ()

check_cxx_compiler_flag(-mcrc32 COMPILER_HAS_MCRC32_FLAG)
if (COMPILER_HAS_MCRC32_FLAG)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mcrc32")
endif ()

set(CMAKE_C_FLAGS ${CMAKE_CXX_FLAGS})
set(CMAKE_C_FLAGS_DEBUG ${CMAKE_CXX_FLAGS_DEBUG})
set(CMAKE_C_FLAGS_RELEASE ${CMAKE_CXX_FLAGS_RELEASE})

# Default build type is Release
if (NOT CMAKE_BUILD_TYPE)
    set(CMAKE_BUILD_TYPE Release)
endif ()

# If ccache exists, use it to speed up compiling
find_program(CCACHE_FOUND ccache)
if(CCACHE_FOUND)
    set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE ccache)
endif(CCACHE_FOUND)

# CMake dirs
list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/CMake)
set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/output)
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/output)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/output)

################################################################################

# There are two ways to handle dependencies:
#   1. Find locally installed packages. (Static lib is suggested)
#   2. Build it from source. (Only when PHOTON_BUILD_DEPENDENCIES is set, and PHOTON_XXX_SOURCE is not empty)
#
# The naming conventions MUST obey:
#   name:       xxx
#   include:    XXX_INCLUDE_DIRS
#   lib:        XXX_LIBRARIES
#   source:     PHOTON_XXX_SOURCE

set(dependencies zlib openssl curl)

if (CMAKE_SYSTEM_NAME MATCHES "Linux")
    LIST(APPEND dependencies aio)
    if (PHOTON_ENABLE_FUSE)
        LIST(APPEND dependencies fuse)
    endif ()
    if (PHOTON_ENABLE_URING)
        LIST(APPEND dependencies uring)
    endif ()
endif ()
if (PHOTON_ENABLE_SASL)
    LIST(APPEND dependencies gsasl)
endif ()
if (PHOTON_ENABLE_FSTACK_DPDK)
    LIST(APPEND dependencies fstack)
endif ()
if (PHOTON_ENABLE_EXTFS)
    LIST(APPEND dependencies e2fs)
endif()
if (PHOTON_BUILD_TESTING)
    LIST(APPEND dependencies gflags googletest)
endif ()

FOREACH (dep ${dependencies})
    string(TOUPPER ${dep} DEP)
    set(source_url "${PHOTON_${DEP}_SOURCE}")
    if (PHOTON_BUILD_DEPENDENCIES AND (NOT source_url STREQUAL ""))
        message(STATUS "Will build ${dep} from source")
        message(STATUS "    URL: ${source_url}")
        build_from_src(dep)
    else ()
        message(STATUS "Will find ${dep}")
        find_package(${dep} REQUIRED)
    endif ()
endforeach ()

################################################################################

add_subdirectory(third_party)

# Compile photon objects
file(GLOB PHOTON_SRC
        photon.cpp
        common/*.cpp
        common/checksum/*.cpp
        common/executor/*.cpp
        common/memory-stream/*.cpp
        common/stream-messenger/*.cpp
        fs/aligned-file.cpp
        fs/async_filesystem.cpp
        fs/exportfs.cpp
        fs/filecopy.cpp
        fs/localfs.cpp
        fs/path.cpp
        fs/subfs.cpp
        fs/throttled-file.cpp
        fs/virtual-file.cpp
        fs/xfile.cpp
        fs/httpfs/*.cpp
        io/signal.cpp
        net/*.cpp
        net/http/*.cpp
        net/security-context/tls-stream.cpp
        rpc/*.cpp
        thread/*.cpp
        )
if (APPLE)
    list(APPEND PHOTON_SRC io/kqueue.cpp)
else ()
    list(APPEND PHOTON_SRC io/aio-wrapper.cpp io/epoll.cpp)
    if (PHOTON_ENABLE_URING)
        list(APPEND PHOTON_SRC io/iouring-wrapper.cpp)
    endif ()
endif ()
if (PHOTON_ENABLE_FUSE)
    list(APPEND PHOTON_SRC io/fuse-adaptor.cpp)
endif ()
if (PHOTON_ENABLE_SASL)
    list(APPEND PHOTON_SRC net/security-context/sasl-stream.cpp)
endif ()
if (PHOTON_ENABLE_FSTACK_DPDK)
    list(APPEND PHOTON_SRC io/fstack-dpdk.cpp)
endif ()
if (PHOTON_ENABLE_EXTFS)
    file(GLOB EXTFS_SRC fs/extfs/*.cpp)
    list(APPEND PHOTON_SRC ${EXTFS_SRC})
endif ()

# An object library compiles source files but does not archive or link their object files.
add_library(photon_obj OBJECT ${PHOTON_SRC})
target_include_directories(photon_obj PUBLIC include ${OPENSSL_INCLUDE_DIRS} ${AIO_INCLUDE_DIRS}
        ${ZLIB_INCLUDE_DIRS} ${CURL_INCLUDE_DIRS})
target_compile_definitions(photon_obj PRIVATE _FILE_OFFSET_BITS=64 FUSE_USE_VERSION=29)
if (PHOTON_ENABLE_URING)
    target_include_directories(photon_obj PUBLIC ${URING_INCLUDE_DIRS})
    target_compile_definitions(photon_obj PRIVATE PHOTON_URING=on)
endif()
if (PHOTON_ENABLE_MIMIC_VDSO)
    target_compile_definitions(photon_obj PRIVATE ENABLE_MIMIC_VDSO=on)
endif()
if (PHOTON_ENABLE_FSTACK_DPDK)
    target_include_directories(photon_obj PUBLIC ${FSTACK_INCLUDE_DIRS})
endif()
if (PHOTON_ENABLE_EXTFS)
    target_include_directories(photon_obj PUBLIC ${LIBE2FS_INCLUDE_DIRS})
endif()
if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 8.0)
    # This option is enabled by default after -std=c++17
    target_compile_options(photon_obj PRIVATE -faligned-new)
endif()

if (actually_built)
    add_dependencies(photon_obj ${actually_built})
endif ()

################################################################################

set(static_deps
        easy_weak
        fstack_weak
        ${ZLIB_LIBRARIES}
        ${OPENSSL_LIBRARIES}
        ${CURL_LIBRARIES}
)
set(shared_deps
        -lpthread
)
if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
    list(APPEND shared_deps -lgcc)  # solve [hidden symbol `__cpu_model'] problem
endif ()
if (NOT APPLE)
    list(APPEND static_deps ${AIO_LIBRARIES})
    list(APPEND shared_deps -lrt -ldl)
endif ()
if (PHOTON_ENABLE_URING)
    list(APPEND static_deps ${URING_LIBRARIES})
endif ()
if (PHOTON_ENABLE_FUSE)
    list(APPEND static_deps ${FUSE_LIBRARIES})
endif ()
if (PHOTON_ENABLE_SASL)
    list(APPEND static_deps ${GSASL_LIBRARIES})
endif ()
if (PHOTON_ENABLE_FSTACK_DPDK)
    list(APPEND static_deps ${FSTACK_LIBRARIES})
endif ()
if (PHOTON_ENABLE_EXTFS)
    list(APPEND static_deps ${E2FS_LIBRARIES})
endif ()

# It's OK to have some `shared_deps` duplicated in `static_deps`.
# Even though .a is suggested, we may still probably find .so in local installed dir.
# This is for the max compatability.
if (NOT APPLE)
    set(suffix "\.so$")
else ()
    set(suffix "\.dylib$" "\.tbd$")
endif ()
foreach (dep ${static_deps})
    foreach (suf ${suffix})
        if (dep MATCHES "${suf}")
            list(APPEND shared_deps ${dep})
            break()
        endif ()
    endforeach ()
    if (dep MATCHES "\.a$")
        list(APPEND static_deps_archive ${dep})
    endif ()
endforeach ()

set(version_scripts)
list(APPEND version_scripts "-Wl,--version-script=${PROJECT_SOURCE_DIR}/tools/libaio.map")

################################################################################

# Link photon shared lib
add_library(photon_shared SHARED $<TARGET_OBJECTS:photon_obj>)
set_target_properties(photon_shared PROPERTIES OUTPUT_NAME photon)
if (NOT APPLE)
    target_link_libraries(photon_shared
            PRIVATE ${version_scripts} -Wl,--whole-archive ${static_deps} -Wl,--no-whole-archive
            PUBLIC ${shared_deps}
    )
else ()
    target_link_libraries(photon_shared
            PUBLIC ${shared_deps}
            PRIVATE -Wl,-force_load ${static_deps}
    )
endif ()

# Link photon static lib
add_library(photon_static STATIC $<TARGET_OBJECTS:photon_obj>)
set_target_properties(photon_static PROPERTIES OUTPUT_NAME photon_sole)
target_link_libraries(photon_static
        PUBLIC ${shared_deps}
        PRIVATE ${static_deps}
)

# Merge static libs into libphoton.a
# Do NOT use this target directly.
if (NOT APPLE)
    set(merge_command ar -crT libphoton.a)
else ()
    set(merge_command libtool -static -o libphoton.a)
endif ()
add_custom_target(_photon_static_archive ALL
        COMMAND rm -rf libphoton.a
        COMMAND ${merge_command} $<TARGET_FILE:photon_static> $<TARGET_FILE:easy_weak> $<TARGET_FILE:fstack_weak>
        DEPENDS photon_static
        WORKING_DIRECTORY ${CMAKE_ARCHIVE_OUTPUT_DIRECTORY}
        VERBATIM
)

# Build test cases
if (PHOTON_BUILD_TESTING)
    include(CTest)

    set(testing_libs ${GFLAGS_LIBRARIES} ${GOOGLETEST_LIBRARIES})
    include_directories(${GFLAGS_INCLUDE_DIRS} ${GOOGLETEST_INCLUDE_DIRS})

    add_subdirectory(examples)
    add_subdirectory(common/checksum/test)
    add_subdirectory(common/test)
    add_subdirectory(fs/test)
    add_subdirectory(io/test)
    add_subdirectory(net/test)
    add_subdirectory(net/http/test)
    add_subdirectory(rpc/test)
    add_subdirectory(thread/test)
    add_subdirectory(net/security-context/test)
    if (PHOTON_ENABLE_EXTFS)
        add_subdirectory(fs/extfs/test)
    endif ()
endif ()