#!/usr/bin/env bash

set -euo pipefail

# @describe Remove empty values from JSON
# @meta require-tools jq
# @arg file=- <PATH> input file name
# @flag -n --remove-nulls remove nulls
# @flag -N --keep-nulls keep nulls
# @flag -e --remove-empty-strings remove empty strings
# @flag -E --keep-empty-strings keep empty strings
# @flag -b --remove-blank-strings remove blank strings
# @flag -B --keep-blank-strings keep blank strings
# @flag -a --remove-empty-arrays remove empty arrays
# @flag -A --keep-empty-arrays keep empty arrays
# @flag -o --remove-empty-objects remove empty objects
# @flag -O --keep-empty-objects keep empty objects
# @flag --keep-all keep all
# @flag --print-filter print used JQ filter

join_by() {
  local delimiter="$1"
  local result
  shift
  result=$(printf "%s$delimiter" "$@")
  result=${result%"$delimiter"}
  echo "$result"
}

print_jq_filter() {
  local filters
  [ "${argc_keep_nulls:-0}" = 0 ] && filters+=(". == null")
  [ "${argc_keep_empty_strings:-0}" = 0 ] && filters+=('. == ""')
  [ "${argc_keep_blank_strings:-0}" = 0 ] && filters+=('(. | tostring | test("^[[:space:]]*$"))')
  [ "${argc_keep_empty_arrays:-0}" = 0 ] && filters+=('. == []')
  [ "${argc_keep_empty_objects:-0}" = 0 ] && filters+=('. == {}')

  echo "del(..|select($(join_by " or " "${filters[@]}")))"
}

main() {
  local jq_filter
  jq_filter=$(print_jq_filter)

  [ "${argc_print_filter:-}" = 1 ] && echo "JQ Filter: $jq_filter" >&2

  jq "$jq_filter" "${argc_file?}"
}

eval "$(argc --argc-eval "$0" "$@")"