# SPDX-License-Identifier: Apache-2.0
#
# Copyright (C) 2023 The Falco Authors.
#
# 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.
#
cmake_minimum_required(VERSION 3.5.1)

project(falco)

option(USE_BUNDLED_DEPS "Bundle hard to find dependencies into the Falco binary" OFF)
option(USE_DYNAMIC_LIBELF "Dynamically link libelf" ON)
option(BUILD_WARNINGS_AS_ERRORS "Enable building with -Wextra -Werror flags" OFF)
option(MINIMAL_BUILD "Build a minimal version of Falco, containing only the engine and basic input/output (EXPERIMENTAL)" OFF)
option(MUSL_OPTIMIZED_BUILD "Enable if you want a musl optimized build" OFF)
option(BUILD_FALCO_UNIT_TESTS "Build falco unit tests" OFF)

if(WIN32)
	set(CPACK_GENERATOR "NSIS") # this needs NSIS installed, and available
elseif (APPLE)
	set(CPACK_GENERATOR "DragNDrop")
elseif(EMSCRIPTEN)
  set(USE_BUNDLED_DEPS ON CACHE BOOL "" FORCE)
  set(BUILD_DRIVER OFF CACHE BOOL "" FORCE)
  set(ENABLE_DKMS OFF CACHE BOOL "" FORCE)
  set(BUILD_BPF OFF CACHE BOOL "" FORCE)
  set(CPACK_GENERATOR TGZ CACHE BOOL "" FORCE)
endif()

# gVisor is currently only supported on Linux x86_64
if(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64" AND CMAKE_SYSTEM_NAME MATCHES "Linux" AND NOT MINIMAL_BUILD)
  option(BUILD_FALCO_GVISOR "Build gVisor support for Falco" ON)
  if (BUILD_FALCO_GVISOR)
    add_definitions(-DHAS_GVISOR)
  endif()
endif()

# Modern BPF is not supported on not Linux systems and in MINIMAL_BUILD
if(CMAKE_SYSTEM_NAME MATCHES "Linux" AND NOT MINIMAL_BUILD)
  option(BUILD_FALCO_MODERN_BPF "Build modern BPF support for Falco" OFF)
  if(BUILD_FALCO_MODERN_BPF)
    add_definitions(-DHAS_MODERN_BPF)
  endif()
endif()

# We shouldn't need to set this, see https://gitlab.kitware.com/cmake/cmake/-/issues/16419
option(EP_UPDATE_DISCONNECTED "ExternalProject update disconnected" OFF)
if (${EP_UPDATE_DISCONNECTED})
  set_property(
    DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
    PROPERTY EP_UPDATE_DISCONNECTED TRUE)
endif()

# Elapsed time
# set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CMAKE_COMMAND} -E time") # TODO(fntlnz, leodido): add a flag to enable this

# Make flag for parallel processing
include(ProcessorCount)
processorcount(PROCESSOR_COUNT)
if(NOT PROCESSOR_COUNT EQUAL 0)
  set(PROCESSOUR_COUNT_MAKE_FLAG -j${PROCESSOR_COUNT})
endif()

# Custom CMake modules
list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules")

# GNU standard installation directories' definitions
include(GNUInstallDirs)

if(NOT DEFINED FALCO_ETC_DIR)
  set(FALCO_ETC_DIR "${CMAKE_INSTALL_FULL_SYSCONFDIR}/falco")
endif()

# This will be used to print the architecture for which Falco is compiled.
if (EMSCRIPTEN)
  set(FALCO_TARGET_ARCH "wasm")
else()
  set(FALCO_TARGET_ARCH ${CMAKE_SYSTEM_PROCESSOR})
endif()

include(CompilerFlags)

set(PACKAGE_NAME "falco")
set(DRIVER_NAME "falco")
set(DRIVER_DEVICE_NAME "falco")
set(DRIVERS_REPO "https://download.falco.org/driver")

# If no path is provided, try to search the BPF probe in: `home/.falco/falco-bpf.o`
# This is the same fallback that we had in the libraries: `SCAP_PROBE_BPF_FILEPATH`.
set(FALCO_PROBE_BPF_FILEPATH ".${DRIVER_NAME}/${DRIVER_NAME}-bpf.o")
add_definitions(-DFALCO_PROBE_BPF_FILEPATH="${FALCO_PROBE_BPF_FILEPATH}")

if(NOT DEFINED FALCO_COMPONENT_NAME)
    set(FALCO_COMPONENT_NAME "${CMAKE_PROJECT_NAME}")
endif()

if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
  set(CMAKE_INSTALL_PREFIX
      /usr
      CACHE PATH "Default install path" FORCE)
endif()

set(CMD_MAKE make)

include(ExternalProject)

# libs
include(falcosecurity-libs)

# compute FALCO_VERSION (depends on libs)
include(falco-version)

# nlohmann-json
include(njson)

# yaml-cpp
include(yaml-cpp)

if(NOT WIN32 AND NOT APPLE AND NOT MINIMAL_BUILD AND NOT EMSCRIPTEN)
  # OpenSSL
  include(openssl)

  # libcurl
  include(curl)

  # todo(jasondellaluce,rohith-raju): support webserver for non-linux builds too
  # cpp-httlib
  include(cpp-httplib)
endif()

include(cxxopts)

# One TBB
if (NOT EMSCRIPTEN)
  include(tbb)
endif()

include(zlib)
if (NOT MINIMAL_BUILD)
  if (NOT WIN32 AND NOT APPLE AND NOT EMSCRIPTEN)
    include(cares)
    include(protobuf)
    # gRPC
    include(grpc)
  endif()
endif()

# Installation
if(WIN32)
	set(FALCO_INSTALL_CONF_FILE "%PROGRAMFILES%/${PACKAGE_NAME}-${FALCO_VERSION}/etc/falco/falco.yaml")
	install(FILES falco.yaml DESTINATION etc/falco/ COMPONENT "${FALCO_COMPONENT_NAME}")
elseif(APPLE)
	set(FALCO_INSTALL_CONF_FILE "/etc/falco/falco.yaml")
	install(FILES falco.yaml DESTINATION etc/falco/ COMPONENT "${FALCO_COMPONENT_NAME}")
else()
	set(FALCO_INSTALL_CONF_FILE "/etc/falco/falco.yaml")
	install(FILES falco.yaml DESTINATION "${FALCO_ETC_DIR}" COMPONENT "${FALCO_COMPONENT_NAME}")
endif()

if(NOT MINIMAL_BUILD)
  # Coverage
  include(Coverage)
endif()

# Rules
include(rules)

# Clang format
# add_custom_target(format COMMAND clang-format --style=file -i $<TARGET_PROPERTY:falco,SOURCES> COMMENT "Formatting ..." VERBATIM)

# Static analysis
include(static-analysis)

# Shared build variables
set(FALCO_SINSP_LIBRARY sinsp)
set(FALCO_SHARE_DIR share/falco)
set(FALCO_ABSOLUTE_SHARE_DIR "${CMAKE_INSTALL_PREFIX}/${FALCO_SHARE_DIR}")
set(FALCO_BIN_DIR bin)

add_subdirectory(scripts)
add_subdirectory(userspace/engine)
add_subdirectory(userspace/falco)

if(NOT WIN32 AND NOT APPLE AND NOT EMSCRIPTEN AND NOT MUSL_OPTIMIZED_BUILD)
  include(falcoctl)
endif()

# Packages configuration
include(CPackConfig)

if(BUILD_FALCO_UNIT_TESTS)
  add_subdirectory(unit_tests)
endif()