# Copyright (C) 2019-2020 Zilliz. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
# or implied. See the License for the specific language governing permissions and limitations under the License.


message(STATUS "Using ${MILVUS_DEPENDENCY_SOURCE} approach to find dependencies")

# For each dependency, set dependency source to global default, if unset
foreach (DEPENDENCY ${MILVUS_THIRDPARTY_DEPENDENCIES})
    if ("${${DEPENDENCY}_SOURCE}" STREQUAL "")
        set(${DEPENDENCY}_SOURCE ${MILVUS_DEPENDENCY_SOURCE})
    endif ()
endforeach ()

# ----------------------------------------------------------------------
# Identify OS
if (UNIX)
    if (APPLE)
        set(CMAKE_OS_NAME "osx" CACHE STRING "Operating system name" FORCE)
    else (APPLE)
        ## Check for Debian GNU/Linux ________________
        find_file(DEBIAN_FOUND debian_version debconf.conf
                PATHS /etc
                )
        if (DEBIAN_FOUND)
            set(CMAKE_OS_NAME "debian" CACHE STRING "Operating system name" FORCE)
        endif (DEBIAN_FOUND)
        ##  Check for Fedora _________________________
        find_file(FEDORA_FOUND fedora-release
                PATHS /etc
                )
        if (FEDORA_FOUND)
            set(CMAKE_OS_NAME "fedora" CACHE STRING "Operating system name" FORCE)
        endif (FEDORA_FOUND)
        ##  Check for RedHat _________________________
        find_file(REDHAT_FOUND redhat-release inittab.RH
                PATHS /etc
                )
        if (REDHAT_FOUND)
            set(CMAKE_OS_NAME "redhat" CACHE STRING "Operating system name" FORCE)
        endif (REDHAT_FOUND)
        ## Extra check for Ubuntu ____________________
        if (DEBIAN_FOUND)
            ## At its core Ubuntu is a Debian system, with
            ## a slightly altered configuration; hence from
            ## a first superficial inspection a system will
            ## be considered as Debian, which signifies an
            ## extra check is required.
            find_file(UBUNTU_EXTRA legal issue
                    PATHS /etc
                    )
            if (UBUNTU_EXTRA)
                ## Scan contents of file
                file(STRINGS ${UBUNTU_EXTRA} UBUNTU_FOUND
                        REGEX Ubuntu
                        )
                ## Check result of string search
                if (UBUNTU_FOUND)
                    set(CMAKE_OS_NAME "ubuntu" CACHE STRING "Operating system name" FORCE)
                    set(DEBIAN_FOUND FALSE)

                    find_program(LSB_RELEASE_EXEC lsb_release)
                    execute_process(COMMAND ${LSB_RELEASE_EXEC} -rs
                            OUTPUT_VARIABLE LSB_RELEASE_ID_SHORT
                            OUTPUT_STRIP_TRAILING_WHITESPACE
                            )
                    STRING(REGEX REPLACE "\\." "_" UBUNTU_VERSION "${LSB_RELEASE_ID_SHORT}")
                endif (UBUNTU_FOUND)
            endif (UBUNTU_EXTRA)
        endif (DEBIAN_FOUND)
    endif (APPLE)
endif (UNIX)

# ----------------------------------------------------------------------
# thirdparty directory
set(THIRDPARTY_DIR "${MILVUS_SOURCE_DIR}/thirdparty")

# ----------------------------------------------------------------------
# ExternalProject options

#string(TOUPPER ${CMAKE_BUILD_TYPE} UPPERCASE_BUILD_TYPE)

set(EP_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_${UPPERCASE_BUILD_TYPE}}")
set(EP_C_FLAGS "${CMAKE_C_FLAGS} ${CMAKE_C_FLAGS_${UPPERCASE_BUILD_TYPE}}")

# Set -fPIC on all external projects
set(EP_CXX_FLAGS "${EP_CXX_FLAGS} -fPIC")
set(EP_C_FLAGS "${EP_C_FLAGS} -fPIC")

# CC/CXX environment variables are captured on the first invocation of the
# builder (e.g make or ninja) instead of when CMake is invoked into to build
# directory. This leads to issues if the variables are exported in a subshell
# and the invocation of make/ninja is in distinct subshell without the same
# environment (CC/CXX).
set(EP_COMMON_TOOLCHAIN -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
        -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER})

if (CMAKE_AR)
    set(EP_COMMON_TOOLCHAIN ${EP_COMMON_TOOLCHAIN} -DCMAKE_AR=${CMAKE_AR})
endif ()

if (CMAKE_RANLIB)
    set(EP_COMMON_TOOLCHAIN ${EP_COMMON_TOOLCHAIN} -DCMAKE_RANLIB=${CMAKE_RANLIB})
endif ()

# External projects are still able to override the following declarations.
# cmake command line will favor the last defined variable when a duplicate is
# encountered. This requires that `EP_COMMON_CMAKE_ARGS` is always the first
# argument.
set(EP_COMMON_CMAKE_ARGS
        ${EP_COMMON_TOOLCHAIN}
        -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
        -DCMAKE_C_FLAGS=${EP_C_FLAGS}
        -DCMAKE_C_FLAGS_${UPPERCASE_BUILD_TYPE}=${EP_C_FLAGS}
        -DCMAKE_CXX_FLAGS=${EP_CXX_FLAGS}
        -DCMAKE_CXX_FLAGS_${UPPERCASE_BUILD_TYPE}=${EP_CXX_FLAGS})

if (NOT MILVUS_VERBOSE_THIRDPARTY_BUILD)
    set(EP_LOG_OPTIONS LOG_CONFIGURE 1 LOG_BUILD 1 LOG_INSTALL 1 LOG_DOWNLOAD 1)
else ()
    set(EP_LOG_OPTIONS)
endif ()

# Ensure that a default make is set
if ("${MAKE}" STREQUAL "")
    find_program(MAKE make)
endif ()

if (NOT DEFINED MAKE_BUILD_ARGS)
    set(MAKE_BUILD_ARGS "-j8")
endif ()
message(STATUS "Third Party MAKE_BUILD_ARGS = ${MAKE_BUILD_ARGS}")

# ----------------------------------------------------------------------
# Find pthreads

set(THREADS_PREFER_PTHREAD_FLAG ON)
find_package(Threads REQUIRED)

# ----------------------------------------------------------------------
# Versions and URLs for toolchain builds, which also can be used to configure
# offline builds

# Read toolchain versions from cpp/thirdparty/versions.txt
file(STRINGS "${THIRDPARTY_DIR}/versions.txt" TOOLCHAIN_VERSIONS_TXT)
foreach (_VERSION_ENTRY ${TOOLCHAIN_VERSIONS_TXT})
    # Exclude comments
    if (NOT _VERSION_ENTRY MATCHES "^[^#][A-Za-z0-9-_]+_VERSION=")
        continue()
    endif ()

    string(REGEX MATCH "^[^=]*" _LIB_NAME ${_VERSION_ENTRY})
    string(REPLACE "${_LIB_NAME}=" "" _LIB_VERSION ${_VERSION_ENTRY})

    # Skip blank or malformed lines
    if (${_LIB_VERSION} STREQUAL "")
        continue()
    endif ()

    # For debugging
    #message(STATUS "${_LIB_NAME}: ${_LIB_VERSION}")

    set(${_LIB_NAME} "${_LIB_VERSION}")
endforeach ()

