rowbot/rowbot

#!/usr/bin/env bash

###
# feature switch toggling
###

shopt -s dotglob extglob lastpipe nullglob

###
# configure rowbot
###

# default config

declare -A config=(
  # connection settings
  [server]=irc.libera.chat [port]="" [tls]=no [client-cert]=""
  # irc registration settings
  [nick]=rowbot-dev [ident]=rowbot [realname]=rowbot [chan]=""
  # bot control settings
  [owner]="${USER:-uplime}" [trigger]=\` [dev]=yes
  # log settings
  [log]="" [overwrite]=no [log-level]=info
)

# parse command line arguments

declare -A opts
# This code is not used yet, but will be later.
# shellcheck disable=SC2034
cmd_line=( "${@:0}" )

while (( $# )); do
  case $1 in
  --*=*)
    key=${1#--} key=${key%%=*}
    opts[$key]=${1#--*=}
    ;;
  --no-*)
    key=${1#--no-}
    opts[$key]=no
    ;;
  --)
    shift
    break
    ;;
  --*)
    key=${1#--}
    opts[$key]=yes
    ;;
  *)
    break
  esac

  shift
done

# apply custom configuration files

for file do
  if [[ -f $file ]]; then
    # These files (if any) are provided dynamically at run-time.
    # shellcheck disable=SC1090
    . "$file" # ha, dot file
  else
    die "could not locate config file %s" "$file"
  fi
done

for setting in "${!config[@]}"; do
  if [[ -v ${setting//-/_} ]]; then
    declare -n setting_var=${setting//-/_}
    config[$setting]=$setting_var
  fi
done

# apply command line arguments

for setting in "${!config[@]}"; do
  # This is a false positive.
  # shellcheck disable=SC2102
  if [[ -v opts[$setting] ]]; then
    config[$setting]=${opts[$setting]}
  fi
done

# apply default port if one isn't provided

if [[ -z ${config[port]} ]]; then
  if [[ ${config[tls]} = yes ]]; then
    config[port]=6697
  else
    config[port]=6667
  fi
fi

# apply any reloaded values

for setting in "${!config[@]}"; do
  env_name=${setting//-/_} env_name=${env_name^^}
  declare -n env_var=$env_name

  if [[ -v $env_name ]]; then
    # This variable is only used for assignment.
    # shellcheck disable=SC2034
    config[$setting]=$env_var
  fi
done

# cleanup

unset key file setting setting_var env_name env_var

###
# utility and helper functions
###

any_file() {
  local files=( "${1:-.}"/* ) max idx

  if (( ${#files[@]} > 1 )); then
    (( max = ${#files[@]} - 1 ))
    idx=$(random 0 "$max")
    printf %s "${files[$idx]}"
  fi
}

die() {
  # error "$@"
  exit "${STATUS:-42}"
}

get_option() {
  if (( $# != 2 )); then
    return 1
  fi

  local option_name=${1//-/_}
  declare -n option_var=$option_name

  if [[ -v opts[$1] ]]; then
    option_var=${opts[log-level]}
  elif [[ ! -v $option_name ]]; then
    # This variable is only used for assignment.
    # shellcheck disable=SC2034
    option_var=$2
  fi
}

has() {
  if (( $# )); then
    hash "$1" 2>/dev/null
  else
    return 1
  fi
}

is_parent() {
  (( BASHPID == $$ ))
}

is_reloaded() {
  [[ $RELOADED = yes ]] || (( LORE_LIVES > 1 ))
}

random() {
  local min=$1 max=$2
  (( (RANDOM % max) + min ))
}

run_callbacks() {
  if (( ! $# )); then
    return 1
  fi

  local filter=$1
  shift

  while IFS= read -r; do
    "$REPLY" "$@"
  done < <(compgen -A function "$filter")

  return 0
}

###
# live code reloader
###

reload() {
  run_callbacks on_before_reload_
  exec "${cmd_line[@]}"
}

hup_reload() {
  reload
}

trap hup_reload HUP

on_init_debug() {
  declare -p config
}

###
# initialization sequence
###

run_callbacks on_init_

if is_reloaded; then
  run_callbacks on_after_reload_
else
  run_callbacks on_first_
fi