barg-parser/arg_parser.sh

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

# ===== SPEC =====
SPEC=(
  "command;build;Build a dev container"
  "argument;name;type:positional;required;help:Name of the container"
  "argument;image,i;type:option;required;map:image_name;help:Base image"
  "argument;include,I;type:option;repeatable;map:include_paths;help:Include paths"
  "argument;verbose,v;type:flag;repeatable;default:0;help:Increase verbosity (-v, -vv, ...)"
  "argument;quiet,q;type:flag;default:false;help:Suppress all output"
  "argument;cmd;type:rest;map:cmd_rest;help:Command and args to run inside the container"

  "command;stop;Stop a dev container"
  "argument;name;type:positional;required;help:Name of the container"
  "argument;kill,k;type:flag;default:false;help:Force kill the container"
)

# ===== CONSTANTS =====
ENTRY_COMMAND="command"
ENTRY_ARGUMENT="argument"

ATTR_REQUIRED="required"
ATTR_HELP="help"
ATTR_DEFAULT="default"
ATTR_MAP="map"
ATTR_TYPE="type"
ATTR_REPEATABLE="repeatable"

ATTR_TYPE_POSITIONAL="positional"
ATTR_TYPE_OPTION="option"
ATTR_TYPE_FLAG="flag"

# ===== STORAGE =====
declare -A SPEC_DATA
declare -A SPEC_ALIASES

# ===== GENERATE IDS =====
cmd_id=0
arg_id=0
get_cmd_id() { echo $((cmd_id++)); }
get_arg_id() { echo $((arg_id++)); }

# ===== PARSE SPEC ENTRY =====
parse_spec_entry() {
  local raw_entry="$1"
  IFS=';' read -r type alias_str rest <<<"$raw_entry"
  IFS=',' read -r -a aliases <<<"$alias_str"

  declare -A attr

  if [[ "$type" == "$ENTRY_COMMAND" ]]; then
    attr["$ATTR_HELP"]="$rest"
  else
    attr["$ATTR_REQUIRED"]=false
    attr["$ATTR_REPEATABLE"]=false
    attr["$ATTR_TYPE"]="$ATTR_TYPE_POSITIONAL"
    attr["$ATTR_MAP"]=""
    attr["$ATTR_DEFAULT"]=""
    attr["$ATTR_HELP"]=""

    # Re-split rest on ';'
    IFS=';' read -r -a elements <<<"$rest"
    for element in "${elements[@]}"; do
      [[ -z "$element" ]] && continue
      IFS=':' read -r attribute value <<<"$element"
      case "$attribute" in
      "$ATTR_REQUIRED") attr["$ATTR_REQUIRED"]=true ;;
      "$ATTR_REPEATABLE") attr["$ATTR_REPEATABLE"]=true ;;
      "$ATTR_TYPE") attr["$ATTR_TYPE"]="$value" ;;
      "$ATTR_MAP") attr["$ATTR_MAP"]="$value" ;;
      "$ATTR_DEFAULT") attr["$ATTR_DEFAULT"]="$value" ;;
      "$ATTR_HELP") attr["$ATTR_HELP"]="$value" ;;
      esac
    done
  fi

  # Serialize attributes to string
  local attr_str=""
  for k in "${!attr[@]}"; do
    attr_str+="$k=${attr[$k]}|"
  done
  attr_str="${attr_str%|}"

  echo "$type;$alias_str;$attr_str"
}

# ===== PARSE SPEC =====
parse_spec() {
  local command_filter="${1:-}"
  local skip_cmd=false
  local exit_on_next_cmd=false
  local current_cmd_id=""

  for raw_entry in "${SPEC[@]}"; do
    local entry
    entry="$(parse_spec_entry "$raw_entry")"
    IFS=';' read -r type alias_str attr_str <<<"$entry"
    IFS=',' read -r -a aliases <<<"$alias_str"

    if [[ "$type" == "$ENTRY_COMMAND" ]]; then
      if [[ "$exit_on_next_cmd" == true ]]; then
        break
      fi

      if [[ -n "$command_filter" ]]; then
        local found=false
        for a in "${aliases[@]}"; do
          [[ "$a" == "$command_filter" ]] && found=true && break
        done
        if [[ "$found" == false ]]; then
          skip_cmd=true
          continue
        fi
        skip_cmd=false
        exit_on_next_cmd=true
      fi

      current_cmd_id="$(get_cmd_id)"
      SPEC_DATA["$current_cmd_id.type"]="$type"
      SPEC_DATA["$current_cmd_id.aliases"]="$alias_str"
      SPEC_DATA["$current_cmd_id.attr"]="$attr_str"
      SPEC_DATA["$current_cmd_id.id"]="$current_cmd_id"

      for a in "${aliases[@]}"; do
        SPEC_ALIASES["$a"]="$current_cmd_id"
      done
    elif [[ "$type" == "$ENTRY_ARGUMENT" ]]; then
      if [[ "$skip_cmd" == true ]]; then
        continue
      fi
      local this_arg_id
      this_arg_id="$(get_arg_id)"
      SPEC_DATA["$current_cmd_id.$this_arg_id.type"]="$type"
      SPEC_DATA["$current_cmd_id.$this_arg_id.aliases"]="$alias_str"
      SPEC_DATA["$current_cmd_id.$this_arg_id.attr"]="$attr_str"
      SPEC_DATA["$current_cmd_id.$this_arg_id.id"]="$this_arg_id"

      for a in "${aliases[@]}"; do
        SPEC_ALIASES["$current_cmd_id.$a"]="$this_arg_id"
      done
    fi
  done
}

# ===== MAIN =====
parse_spec

# Print results as JSON-like structure
echo "{"
echo "  \"spec_data\": {"
for k in "${!SPEC_DATA[@]}"; do
  printf '    "%s": "%s",\n' "$k" "${SPEC_DATA[$k]}"
done
echo "  },"
echo "  \"spec_aliases\": {"
for k in "${!SPEC_ALIASES[@]}"; do
  printf '    "%s": "%s",\n' "$k" "${SPEC_ALIASES[$k]}"
done
echo "  }"
echo "}"