sly

#!/usr/bin/env bash

## Colors
red=31
green=32
yellow=33
bold=$(tput smul)
reset=$(tput sgr0)


# Utils
sly_print_color() {
  printf "\e[%sm%s\e[m" "$1" "$2"
}

sly_prepend() {
  color="${2-$yellow}"
  prefix="$(sly_print_color "$color" "$(printf "%-3s | " "${1-${sly_prefix-SLY}}")")"
  while IFS= read -r line; do
    >&2 echo -e "${prefix}${line}"
  done
}

sly_error() {
  printf '\a%s\n' "$1" | sly_prepend "ERROR" $red >&2
}

sly_done() {
  printf '\a%s\n' "$1" | sly_prepend "DONE " $green >&2
}

sly_available_functions() {
  # Ignore functions starting with `sly_` or with an underscore
  declare -F | awk '{print $NF}' | sort | grep -Ev "^(sly)?_"
}


# Commands
sly_exec() {
  # if [ -z "$(command -v "$1")" ]; then
  if [ -z "$(sly_available_functions | grep "$1")" ]; then
    sly_error "There is no function called ${bold}${1}${reset}"
    exit 1
  fi

  echo "Executing function: ${bold}${1}${reset}" | sly_prepend
  if [ "$verbose" = true ]; then
    declare -f "$1" | sly_prepend
  fi

  "$@"
}

sly_list() {
  echo "Available commands:" | sly_prepend
  echo "" | sly_prepend
  sly_available_functions | sly_prepend
  exit 0
}


# Execution
[[ "$1" =~ ^(-v|--verbose)$ ]] && verbose=true && shift

cmd="$1"
[ -z "$cmd" ] && sly_error "Missing argument COMMAND" && cmd="--help"
[[ "$cmd" =~ ^sly_ ]] && sly_error "The sly_ prefix is reserved for sly internal functions" && exit 1
[[ "$cmd" =~ ^_ ]] && sly_error "Functions prefixed with an underscore are considered \"private\" and shouldn't be called directly" && exit 1
[[ "$cmd" =~ ^(-l|--list)$ ]] && sly_list

(sly_exec "$@")