###############################################################################
#
#    medley_utils.sh - script containing various useful functions for medley.sh script.
#
#   !!!! This script is meant to be SOURCEd from the scripts/medley.sh script.
#   !!!! It should not be run as a standlone script.
#
#   2023-01-23 Frank Halasz
#
#   Copyright 2023 Interlisp.org
#
###############################################################################

is_tput=$(which tput)
output_error_msg() {
  local lines=("$@")
  for line in "${lines[@]}"
  do
    if [ -n "${is_tput}" ];
    then
      echo "$(${is_tput} setab 1)$(${is_tput} setaf 7)${line}$(${is_tput} sgr0)"
    else
      echo "${line}"
    fi
  done
}

check_for_dash_or_end() {
  local err_msg;
  if [[ -z "$2" || "$2" = "--" ]];
  then
    err_msg=(
      "Error: the flag \"$1\" requires a value."
      "Value is missing."
    )
    usage "${err_msg[@]}"
  elif [ "${2:0:1}" = "-" ];
  then
     err_msg=(
       "Error: either the value for flag \"${1}\" is missing OR"
       "the value begins with a \"-\", which is not allowed."
     )
     usage "${err_msg[@]}"
  fi
}

check_file_writeable_or_creatable() {
  local msg_core="\"$2\" given as the value of the \"$1\" flag"
  local err_msg;
  if [[ -e "$%2" ]];
  then
    if [[ ! -f "$2" ]];
    then
      err_msg=(
        "Error: File ${msg_core} is not a regular file."
        "It is either a directory or a device file of some sort."
        "Exiting"
      )
      output_error_msg "${err_msg[@]}"
      exit 1
    elif [[ ! -w "$2" ]];
    then
      err_msg=(
        "Error: File ${msg_core} exists but is not writeable"
        "Exiting"
      )
      output_error_msg "${err_msg[@]}"
      exit 1
    fi
  else
    if [[ ! -w "$(dirname -- $2)" ]];
    then
      err_msg=(
        "Error: File ${msg_core} cannot be created because"
        "its directory either doen't exist or is not writeable."
        "Exiting"
      )
      output_error_msg "${err_msg[@]}"
      exit 1
    fi
  fi
}

check_file_readable() {
  local msg_core="\"$2\" given as the value of the \"$1\" flag"
  if [[ ! -r "$2" ]];
  then
    err_msg=(
      "Error: File ${msg_core}"
      "either doesn't exist or is not readable."
      "Exiting"
    )
    output_error_msg "${err_msg[@]}"
    exit 1
  fi
}

check_dir_writeable_or_creatable() {
  local msg_core="\"$2\" given as the value of the \"$1\" flag"
  if [[ -e "$2" ]];
  then
    if [[ ! -d "$2" ]];
    then
      err_msg=(
        "Error: Pathname ${msg_core} exists but is not a directory."
        "Exiting"
      )
      output_error_msg "${err_msg[@]}"
      exit 1
    elif [[ ! -w "$2" ]];
    then
      err_msg=(
        "Error: Directory ${msg_core} exists but is not writeable."
        "Exiting"
      )
      output_error_msg "${err_msg[@]}"
      exit 1
    fi
  else
    if [[ ! -w "$(dirname -- $2)" ]];
    then
      err_msg=(
        "Error: Directory ${msg_core} cannot be created because"
        "its parent directory either doesn't exist or is not writeable."
        "Exiting"
      )
      output_error_msg "${err_msg[@]}"
      exit 1
    fi
  fi
}