#!/bin/sh
set -e

# Convenience wrapper for easily setting options that the project's CMake
# scripts will recognize.

Command="$0 $*"
CommandDirname=`dirname $0`
SourceDir=`cd $CommandDirname && pwd`

usage="\
Usage:

  $0 [--<variable>=<value>...]

General CMake options:

  --cmake=PATH              set a custom path to the CMake binary
  --build-dir=PATH          set build directory [build]
  --build-type=STRING       set build type of single-configuration generators
  --generator=STRING        set CMake generator (see cmake --help)
  --cxx-flags=STRING        set CMAKE_CXX_FLAGS when running CMake
  --prefix=PATH             set installation directory
  --debug-postfix           set CMAKE_DEBUG_POSTFIX

Locating packages in non-standard locations:

  --openssl-root-dir=PATH   set root directory of an OpenSSL installation

Debugging options:

  --log-level=STRING      build with debugging output, possible values:
                            - ERROR
                            - WARNING
                            - INFO
                            - DEBUG
                            - TRACE
  --sanitizers=STRING     build with this list of sanitizers enabled

Convenience options:

  --dev-mode                shortcut for passing:
                              --build-type=Debug
                              --log-level=TRACE
                              --sanitizers=address,undefined
                              --disable-examples
                              --disable-tools
                              --disable-shared-libs
                              --enable-utility-targets
                              --enable-runtime-checks

Flags (use --enable-<name> to activate and --disable-<name> to deactivate):

  cpack                     build with CPack package description [OFF]
  shared-libs               build shared library targets [ON]
  export-compile-commands   write JSON compile commands database [ON]
  prefer-pthread-flag       prefer -pthread flag if available  [ON]
  curl-examples             build examples with libcurl [OFF]
  protobuf-examples         build examples with Google Protobuf [OFF]
  qt6-examples              build examples with the Qt6 framework [OFF]
  runtime-checks            build CAF with extra runtime assertions [OFF]
  utility-targets           include targets like consistency-check [OFF]
  examples                  build small programs showcasing CAF features [ON]
  io-module                 build networking I/O module [ON]
  openssl-module            build OpenSSL module [ON]
  testing                   build unit test suites [ON]
  with-exceptions           build CAF with support for exceptions [ON]

Influential Environment Variables (only on first invocation):

  CXX                       C++ compiler command
  CXXFLAGS                  Additional C++ compiler flags
  LDFLAGS                   Additional linker flags
"

# Appends a CMake cache entry definition to the CMakeCacheEntries variable.
#   $1: variable name
#   $2: CMake type
#   $3: value
append_cache_entry() {
  case "$3" in
    *\ * )
      # string contains whitespace
      CMakeCacheEntries="$CMakeCacheEntries -D \"$1:$2=$3\""
      ;;
    *)
      # string contains no whitespace
      CMakeCacheEntries="$CMakeCacheEntries -D $1:$2=$3"
      ;;
  esac
}

# Appends a BOOL cache entry to the CMakeCacheEntries variable.
#   $1: flag name
#   $2: value (ON or OFF)
set_build_flag() {
  FlagName=''
  case "$1" in
    cpack)                   FlagName='CAF_ENABLE_CPACK' ;;
    shared-libs)             FlagName='BUILD_SHARED_LIBS' ;;
    export-compile-commands) FlagName='CMAKE_EXPORT_COMPILE_COMMANDS' ;;
    prefer-pthread-flag)     FlagName='THREADS_PREFER_PTHREAD_FLAG' ;;
    curl-examples)           FlagName='CAF_ENABLE_CURL_EXAMPLES' ;;
    protobuf-examples)       FlagName='CAF_ENABLE_PROTOBUF_EXAMPLES' ;;
    qt6-examples)            FlagName='CAF_ENABLE_QT6_EXAMPLES' ;;
    runtime-checks)          FlagName='CAF_ENABLE_RUNTIME_CHECKS' ;;
    utility-targets)         FlagName='CAF_ENABLE_UTILITY_TARGETS' ;;
    examples)                FlagName='CAF_ENABLE_EXAMPLES' ;;
    io-module)               FlagName='CAF_ENABLE_IO_MODULE' ;;
    net-module)              FlagName='CAF_ENABLE_NET_MODULE' ;;
    openssl-module)          FlagName='CAF_ENABLE_OPENSSL_MODULE' ;;
    testing)                 FlagName='CAF_ENABLE_TESTING' ;;
    exceptions)              FlagName='CAF_ENABLE_EXCEPTIONS' ;;
    *)
      echo "Invalid flag '$1'.  Try $0 --help to see available options."
      exit 1
      ;;
  esac
  append_cache_entry $FlagName BOOL $2
}

# Set defaults.
CMakeBuildDir="$SourceDir/build"
CMakeCacheEntries=""

# Parse user input.
while [ $# -ne 0 ]; do
  # Fetch the option argument.
  case "$1" in
    --*=*) optarg=`echo "$1" | sed 's/[-_a-zA-Z0-9]*=//'` ;;
    --enable-*) optarg=`echo "$1" | sed 's/--enable-//'` ;;
    --disable-*) optarg=`echo "$1" | sed 's/--disable-//'` ;;
    *) ;;
  esac
  # Consume current input.
  case "$1" in
    --help|-h)
      echo "${usage}" 1>&2
      exit 1
      ;;
    --cmake=*)
      CMakeCommand="$optarg"
      ;;
    --build-dir=*)
      CMakeBuildDir="$optarg"
      ;;
    --generator=*)
      CMakeGenerator="$optarg"
      ;;
    --build-type=*)
      append_cache_entry CMAKE_BUILD_TYPE STRING "$optarg"
      ;;
    --cxx-flags=*)
      append_cache_entry CMAKE_CXX_FLAGS STRING "$optarg"
      ;;
    --prefix=*)
      append_cache_entry CMAKE_INSTALL_PREFIX PATH "$optarg"
      ;;
    --log-level=*)
      append_cache_entry CAF_LOG_LEVEL STRING "$optarg"
      ;;
    --sanitizers=*)
      append_cache_entry CAF_SANITIZERS STRING "$optarg"
      ;;
    --dev-mode)
      append_cache_entry CAF_LOG_LEVEL STRING 'TRACE'
      append_cache_entry CAF_SANITIZERS STRING 'address,undefined'
      append_cache_entry CMAKE_BUILD_TYPE STRING 'Debug'
      set_build_flag examples OFF
      set_build_flag shared-libs OFF
      set_build_flag tools OFF
      set_build_flag runtime-checks ON
      set_build_flag utility-targets ON
      ;;
   --enable-*)
      set_build_flag $optarg ON
      ;;
    --disable-*)
      set_build_flag $optarg OFF
      ;;
    --openssl-root-dir=*)
      append_cache_entry OPENSSL_ROOT_DIR PATH "$optarg"
      ;;
    --debug-postfix=*)
      append_cache_entry CMAKE_DEBUG_POSTFIX STRING "$optarg"
      ;;
    *)
      echo "Invalid option '$1'. Try $0 --help to see available options."
      exit 1
      ;;
  esac
  # Get next input.
  shift
done

# Check for `cmake` command.
if [ -z "$CMakeCommand" ]; then
  # Prefer cmake3 over "regular" cmake (cmake == cmake2 on RHEL).
  if command -v cmake3 >/dev/null 2>&1 ; then
    CMakeCommand="cmake3"
  elif command -v cmake >/dev/null 2>&1 ; then
    CMakeCommand="cmake"
  else
    echo "This package requires CMake, please install it first."
    echo "Then you may use this script to configure the CMake build."
    echo "Note: pass --cmake=PATH to use cmake in non-standard locations."
    exit 1
  fi
fi

# Make sure the build directory is an absolute path.
case "$CMakeBuildDir" in
  /*)
    CMakeAbsoluteBuildDir="$CMakeBuildDir"
    ;;
  *)
    CMakeAbsoluteBuildDir="$SourceDir/$CMakeBuildDir"
    ;;
esac

# If a build directory exists, delete any existing cache to have a clean build.
if [ -d "$CMakeAbsoluteBuildDir" ]; then
  if [ -f "$CMakeAbsoluteBuildDir/CMakeCache.txt" ]; then
    rm -f "$CMakeAbsoluteBuildDir/CMakeCache.txt"
  fi
else
  mkdir -p "$CMakeAbsoluteBuildDir"
fi

# Run CMake.
cd "$CMakeAbsoluteBuildDir"
if [ -n "$CMakeGenerator" ]; then
  "$CMakeCommand" -G "$CMakeGenerator" $CMakeCacheEntries "$SourceDir"
else
  "$CMakeCommand" $CMakeCacheEntries "$SourceDir"
fi

# Generate a config.status file that allows re-running a clean build.
printf "#!/bin/sh\n\n" > config.status
printf "# Switch to the source of this build directory.\n" >> config.status
printf "cd \"%s\"\n\n" "$SourceDir" >> config.status
printf "# Invoke the command to configure this build.\n" >> config.status
if [ -n "$CXX" ]; then
  printf "CXX=\"%s\"\n" "$CXX" >> config.status
fi
if [ -n "$CXXFLAGS" ]; then
  printf "CXXFLAGS=\"%s\"\n" "$CXXFLAGS" >> config.status
fi
if [ -n "$LDFLAGS" ]; then
  printf "LDFLAGS=\"%s\"\n" "$LDFLAGS" >> config.status
fi
echo $Command >> config.status
chmod u+x config.status