#!/usr/bin/env bash
set -euo pipefail

main() {
  [[ $(type -t _verify-prerequisites) == "function" ]] && ! _verify-prerequisites && exit 1

  redefine-functions-defined-with-selector-16

  if [[ $(type -t "⚡${1:-}") == "function" ]]; then
    command="$1"
    shift
    _task_args=( "$@" )
    ⚡$command "$@"
  else
    ⚡help
  fi
}

redefine-functions-defined-with-selector-16() {
  for function in $(compgen -c $(printf "⚡\uFE0F")); do
    original_definition="$(typeset -f $function)"
    eval "${original_definition//$(printf "⚡\uFE0F")/⚡}"
    unset $function
  done
}

⚡help() {
  _help-line "Show this list"
  export HELP_LINE=please
  echo Usage: "$0" SUBCOMMAND
  echo
  echo "Available subcommands:"
  for subcommand in $(_subcommands); do
    if [[ $(type ⚡$subcommand) =~ _help-line ]]; then
      printf "\t%-20s - %s\n" "$subcommand" "$(⚡$subcommand help-line)"
    else
      printf "\t%-20s\n" $subcommand
    fi
  done
}

_subcommands() {
  prefix_length=1
  while [[ "$(cut -c ${prefix_length}- <<< "⚡tomato")" != "tomato" ]]; do
    prefix_length=$((prefix_length + 1))
  done

  compgen -c ⚡ | cut -c ${prefix_length}-
}

_help-line() {
  if [[ "${HELP_LINE:-}" == "please" ]]; then
    echo "$1" && exit 0
  fi
}

_argument() {
  for arg in "${_task_args[@]}"; do
    key="$(<<< "$arg" cut -d= -f1)"
    value="$(<<< "$arg" cut -d= -f2-)"
    if [[ "$key" == "$1" ]]; then
      declare -g "_arg_$key"="$value"
    fi
  done
}

_required_argument() {
  _argument "$@"
  if [[ ! -v "_arg_$1" ]]; then
    _bad-message "'hello' is a required argument" >&2
    exit 1
  fi
}

_good-message() {
  echo -e "\e[32m$@\e[0m"
}

_bad-message() {
  echo -e "\e[31m$@\e[0m"
}

_wrapper() {
  unset OPTIND
  while getopts "l:d:n:v:" opt; do
    case $opt in
      l) linux_url=$OPTARG ;;
      d) darwin_url=$OPTARG ;;
      n) name=$OPTARG ;;
      v) version=$OPTARG ;;
    esac
  done

  while [[ -n "${1:-}" && "$1" != "--" ]]; do
    shift
  done
  shift

  if [[ $(uname -s) == Linux ]]; then
    url=$linux_url
  else
    url=$darwin_url
  fi

  wrapper_root=".generated/wrapper/$name/$version/"
  mkdir -p $wrapper_root
  [[ -f $wrapper_root/bin ]] || curl --location ${url//VERSION/$version} > $wrapper_root/bin
  chmod +x $wrapper_root/bin
  ./$wrapper_root/bin "$@"
}

main "$@"