# shellcheck shell=ksh
# If SH_LIBPATH is not set or null, then we try to build it
if [ -z "${SH_LIBPATH+x}" ] || [ "${#SH_LIBPATH}" -eq "0" ]; then
  for _path in /usr/local/lib/sh "${HOME}"/.local/lib/sh; do
    [ -d "${_path}" ] && SH_LIBPATH="${SH_LIBPATH}:${_path}"
  done
fi
unset -v _path
# Remove any leading colons from the construction process and export
SH_LIBPATH="${SH_LIBPATH#:}"
export SH_LIBPATH

# We want SH_LIBPATH to be expanded for printf
# shellcheck disable=SC2086
import() {
  while read -r _path; do
    if [ -r "${_path}"/"${1:?No target specified}" ]; then
      # shellcheck disable=SC1090
      . "${_path}"/"${1}"
      unset -v _path
      return 0
    fi
  done < <(IFS=':'; printf -- '%s ' ${SH_LIBPATH})
  unset -v _path
  return 1
}

# Function to work through a list of commands and/or files
# and fail on any unmet requirements.  Example usage:
# requires curl sed awk /etc/someconf.cfg
requires() {
  # shellcheck disable=SC2048
  for _fsobj in ${*}; do
    # First try to determine if it's a command
    command -v "${_fsobj}" >/dev/null 2>&1 && continue

    # Next, see if it's an executable file e.g. a script to call
    [ -x ./"${_fsobj}" ] && continue

    # Next, let's see if it's a readable file e.g. a cfg file to load
    [ -r "${_fsobj}" ] && continue

    # If we get to this point, add it to our list of failures
    _failures="${_failures} ${_fsobj}"
  done
  # Strip any leading space from the construction of _failures
  _failures="${_failures# }"

  # If we have no failures, then no news is good news - return quietly
  if [ "${#_failures}" -eq "0" ]; then
    unset -v _fsobj _failures
    return 0
  # Otherwise, we error out and exit immediately
  else
    printf -- '%s\n' "The following requirements were not met" "${_failures}" >&2
    unset -v _fsobj _failures
    exit 1
  fi
}

# Sometimes you might want to load a file only if it exists,
# but otherwise it's not critical and your script can move on.
load_if_found() {
  _fstarget="${1:?No target specified}"
  if [ -e "${_fstarget}" ]; then
    if [ -r "${_fstarget}" ]; then
      # shellcheck disable=SC1090
      . "${_fstarget}"
      unset -v _fstarget
    else
      printf -- '%s\n' "${_fstarget} exists but isn't readable" >&2
      unset -v _fstarget
      return 1
    fi
  fi
}