################################################################################
#    HPCC SYSTEMS software Copyright (C) 2014 HPCC Systems®.
#
#    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.
################################################################################

# - Try to find the libmemcached library # Once done this will define #
#  LIBMEMCACHED_FOUND - system has the libmemcached library
#  LIBMEMCACHED_INCLUDE_DIR - the libmemcached include directory(s)
#  LIBMEMCACHED_LIBRARIES - The libraries needed to use libmemcached

#  If the memcached libraries are found on the system, we assume they exist natively and dependencies
#  can be handled through package management.  If the libraries are not found, and if
#  MEMCACHED_USE_EXTERNAL_LIBRARY is ON, we will fetch, build, and include a copy of the neccessary
#  Libraries.

option(MEMCACHED_USE_EXTERNAL_LIBRARY "Pull and build source from external location if local is not found" OFF)

# Search for native library to build against
if(WIN32)
    set(libmemcached_lib "libmemcached")
    set(libmemcachedUtil_lib "libmemcachedutil")
else()
    set(libmemcached_lib "memcached")
    set(libmemcachedUtil_lib "memcachedutil")
endif()

find_path(LIBMEMCACHED_INCLUDE_DIR libmemcached/memcached.hpp PATHS /usr/include /usr/share/include /usr/local/include PATH_SUFFIXES libmemcached)
find_library(LIBMEMCACHEDCORE_LIBRARY NAMES ${libmemcached_lib} PATHS /usr/lib usr/lib/libmemcached /usr/share /usr/lib64 /usr/local/lib /usr/local/lib64)
find_library(LIBMEMCACHEDUTIL_LIBRARY NAMES ${libmemcachedUtil_lib} PATHS /usr/lib /usr/share /usr/lib64 /usr/local/lib /usr/local/lib64)

set(LIBMEMCACHED_LIBRARIES ${LIBMEMCACHEDCORE_LIBRARY} ${LIBMEMCACHEDUTIL_LIBRARY})

if(LIBMEMCACHED_INCLUDE_DIR)
    if(EXISTS "${LIBMEMCACHED_INCLUDE_DIR}/libmemcached-1.0/configure.h")
        file(STRINGS "${LIBMEMCACHED_INCLUDE_DIR}/libmemcached-1.0/configure.h" version REGEX "#define LIBMEMCACHED_VERSION_STRING")
        string(REGEX REPLACE "#define LIBMEMCACHED_VERSION_STRING " "" version "${version}")
        string(REGEX REPLACE "\"" "" version "${version}")
        set(LIBMEMCACHED_VERSION_STRING ${version})
        if("${LIBMEMCACHED_VERSION_STRING}" VERSION_EQUAL "${LIBMEMCACHED_FIND_VERSION}" OR "${LIBMEMCACHED_VERSION_STRING}" VERSION_GREATER "${LIBMEMCACHED_FIND_VERSION}")
            set(LIBMEMCACHED_VERSION_OK 1)
            set(MSG "${DEFAULT_MSG}")
        else()
            set(LIBMEMCACHED_VERSION_OK 0)
            set(MSG "libmemcached version '${LIBMEMCACHED_VERSION_STRING}' incompatible with min version>=${LIBMEMCACHED_FIND_VERSION}")
        endif()
    endif()
endif()

if((LIBMEMCACHEDCORE_LIBRARY STREQUAL "LIBMEMCACHEDCORE_LIBRARY-NOTFOUND"
    OR LIBMEMCACHEDUTIL_LIBRARY STREQUAL "LIBMEMCACHEDUTIL_LIBRARY-NOTFOUND"
    OR LIBMEMCACHED_INCLUDE_DIR STREQUAL "LIBMEMCACHED_INCLUDE_DIR-NOTFOUND"
    OR NOT LIBMEMCACHED_VERSION_OK)
    AND MEMCACHED_USE_EXTERNAL_LIBRARY)
    # Currently libmemcached versions are not sufficient on ubuntu 12.04 and 14.04 LTS
    # until then, we build the required libraries from source
    if(NOT TARGET generate-libmemcached)
        set(LIBMEMCACHED_URL https://launchpad.net/libmemcached/1.0/${LIBMEMCACHED_FIND_VERSION}/+download/libmemcached-${LIBMEMCACHED_FIND_VERSION}.tar.gz)
        include(ExternalProject)
        ExternalProject_Add(
            generate-libmemcached
            URL ${LIBMEMCACHED_URL}
            DOWNLOAD_NO_PROGRESS 1
            TIMEOUT 15
            DOWNLOAD_DIR ${CMAKE_BINARY_DIR}/downloads
            SOURCE_DIR ${CMAKE_BINARY_DIR}/downloads/libmemcached
            CONFIGURE_COMMAND "${CMAKE_BINARY_DIR}/downloads/libmemcached/configure" --prefix=${INSTALL_DIR} LDFLAGS=-L${LIB_PATH}
            BUILD_COMMAND ${CMAKE_MAKE_PROGRAM} CXXFLAGS='-fpermissive' LDFLAGS='-Wl,-rpath-link,${LIB_PATH}'
            BINARY_DIR ${CMAKE_BINARY_DIR}/build-libmemcached
            INSTALL_COMMAND "")
        add_library(libmemcached SHARED IMPORTED GLOBAL)
        add_library(libmemcachedutil SHARED IMPORTED GLOBAL)
        set_property(TARGET libmemcached
            PROPERTY IMPORTED_LOCATION ${CMAKE_BINARY_DIR}/build-libmemcached/libmemcached/.libs/libmemcached.so.11.0.0)
        set_property(TARGET libmemcachedutil
            PROPERTY IMPORTED_LOCATION ${CMAKE_BINARY_DIR}/build-libmemcached/libmemcached/.libs/libmemcachedutil.so.2.0.0)
        set_property(TARGET libmemcached
            PROPERTY IMPORTED_LINK_DEPENDENT_LIBRARIES libmemcachedutil)
        add_dependencies(libmemcached generate-libmemcached)
        add_dependencies(libmemcachedutil generate-libmemcached)

        if(PLATFORM)
            install(CODE "set(ENV{LD_LIBRARY_PATH} \"\$ENV{LD_LIBRARY_PATH}:${CMAKE_BINARY_DIR}:${CMAKE_BINARY_DIR}/build-libmemcached/libmemcached/.libs\")")
            install(PROGRAMS
                ${CMAKE_BINARY_DIR}/build-libmemcached/libmemcached/.libs/libmemcached.so
                ${CMAKE_BINARY_DIR}/build-libmemcached/libmemcached/.libs/libmemcached.so.11
                ${CMAKE_BINARY_DIR}/build-libmemcached/libmemcached/.libs/libmemcached.so.11.0.0
                ${CMAKE_BINARY_DIR}/build-libmemcached/libmemcached/.libs/libmemcachedutil.so
                ${CMAKE_BINARY_DIR}/build-libmemcached/libmemcached/.libs/libmemcachedutil.so.2
                ${CMAKE_BINARY_DIR}/build-libmemcached/libmemcached/.libs/libmemcachedutil.so.2.0.0
                DESTINATION lib)
        endif()
    endif()

    set(LIBMEMCACHEDCORE_LIBRARY $<TARGET_FILE:libmemcached>)
    set(LIBMEMCACHEDUTIL_LIBRARY $<TARGET_FILE:libmemcachedutil>)
    set(LIBMEMCACHED_LIBRARIES $<TARGET_FILE:libmemcached> $<TARGET_FILE:libmemcachedutil>)
    set(LIBMEMCACHED_INCLUDE_DIR ${CMAKE_BINARY_DIR}/downloads/libmemcached)
    # always assumed to be ok
    set(LIBMEMCACHED_VERSION_OK 1)
else()
    set(MEMCACHED_USE_EXTERNAL_LIBRARY OFF)
endif()

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(
    LIBMEMCACHED DEFAULT_MSG
    LIBMEMCACHEDCORE_LIBRARY
    LIBMEMCACHEDUTIL_LIBRARY
    LIBMEMCACHED_INCLUDE_DIR
    LIBMEMCACHED_VERSION_OK)
mark_as_advanced(LIBMEMCACHED_INCLUDE_DIR LIBMEMCACHED_LIBRARIES LIBMEMCACHEDCORE_LIBRARY LIBMEMCACHEDUTIL_LIBRARY)