#!/bin/sh

## CMake build mode with auto configuring.
##
## Search the source dir in order:
##   - $ENV{CMAKE_SOURCE_DIR} if non empty
##   - current working dir
##
## Presets:
##   - when build with a preset 'X', the configurePreset field should also be 'X'
##   - when no build dir and no preset is specified, use the 'default' preset
##
## Environments:
##   CMAKE_SOURCE_DIR
##   CMAKE_COMMAND
## When leave this script, these environments will be unset.

set -euf
[ "${DEBUG-}" != true ] || set -x

if ! hash -- "${CMAKE_COMMAND:=cmake}" 2>/dev/null; then
  echo "[ERROR] no cmake command!" >&2
  exit 1
fi

unset __b_mode __b_p_or_d
__b_mode=fallback # fallback/dir/preset/no-build/list-presets

exec_cbuild() {
  case "$__b_mode" in
  no-build) set -- --build "$@" ;;
  dir) set -- --build "$__b_p_or_d" "$@" ;;
  fallback)
    set -- --build --preset default "$@"
    [ -z "${CMAKE_SOURCE_DIR:-}" ] || cd -- "${CMAKE_SOURCE_DIR}" || exit $?
    ;;
  preset | list-presets)
    set -- --build "$@"
    [ -z "${CMAKE_SOURCE_DIR:-}" ] || cd -- "${CMAKE_SOURCE_DIR}" || exit $?
    ;;
  *)
    echo "[ERROR] invalid build mode ${__b_mode-}" >&2
    exit 1
    ;;
  esac

  unset __bin
  __bin="$CMAKE_COMMAND"
  unset CMAKE_COMMAND CMAKE_SOURCE_DIR

  if which -- "$__bin" >/dev/null 2>&1; then
    exec "$__bin" "$@"
  else
    "$__bin" "$@"
  fi
  exit $?
}

# --test to enable ctest mode
[ "${1-}" != --test ] || {
  shift
  exec "${CMAKE_CTEST_COMMAND:-ctest}" "$@" --preset default
}

# --build if present must be the first argument
[ "${1-}" != --build ] || shift

if [ $# != 0 ]; then
  # parse dir mode
  case "${1-}" in
  -*) # for some corner cases which the build dir is a relative dir starting with a dash
    # use `cmake --build ./-build-dir-with-dash` format
    ;;
  *)
    __b_mode=dir
    __b_p_or_d="${1-.}"
    shift
    ;;
  esac
fi

parse_cli() {
  __argc=$#
  __i=0
  while [ $__i -lt $__argc ]; do
    __v="${1-}"
    shift
    case "${__v-}" in
    --) break ;;
    --list-presets)
      __b_mode=list-presets
      break
      ;;

    # last preset wins
    --preset)
      __b_p_or_d="${1-}"
      shift || :
      __i=$((__i + 1))
      case "${__b_p_or_d-}" in
      '' | -*)
        __b_mode=no-build
        break
        ;; # invalid preset name
      *) __b_mode=preset ;;
      esac
      ;;
    --preset=*)
      __b_p_or_d="${__v#--preset=}"
      case "${__b_p_or_d-}" in
      '' | -*)
        __b_mode=no-build
        break
        ;; # invalid preset name
      *) __b_mode=preset ;;
      esac
      ;;

    -j[0-9]* | --parallel[0-9]*) ;;
    -j | --parallel)
      case "${1-}" in
      '' | [0-9]*)
        shift || :
        __i=$((__i + 1))
        ;;
      *)
        __b_mode=no-build
        break
        ;; # invalid job number
      esac
      ;;
    -j* | --parallel*)
      __b_mode=no-build
      break
      ;; # invalid job number

    -t | --target | --config)
      shift || :
      __i=$((__i + 1))
      ;;

    --clean-first | --resolve-package-references=* | --use-stderr | -v | --verbose) ;;

    *)
      __b_mode=no-build
      break
      ;; # invalid build options
    esac

    __i=$((__i + 1))
  done
}

configure_if_needed() (
  case "$__b_mode" in
  no-build | list-presets) return ;;
  dir) set -- "${__b_p_or_d}" ;;
  *)
    [ -z "${CMAKE_SOURCE_DIR:-}" ] || cd -- "${CMAKE_SOURCE_DIR}" || exit $?
    set -- --preset "${__b_p_or_d:-default}"
    ;;
  esac

  # try build the 'help' target to verify previous configure result.
  __ok=true
  __err_msg=$(LANG=C "${CMAKE_COMMAND}" --build "$@" --target help 2>&1 >/dev/null) || __ok=false

  if ! $__ok; then
    case "${__err_msg}" in
    *"No such build preset"*) return ;; # invalid preset
    esac

    # initial configure
    if [ "$__b_mode" = dir ]; then
      set -- -S "${CMAKE_SOURCE_DIR:-.}" -B "$@"
    else
      set -- -S . "$@"
    fi
    "${CMAKE_COMMAND}" "$@"
  fi
)

parse_cli "$@"
configure_if_needed && exec_cbuild "$@"