rowbot/rowbot

#!/usr/bin/env bash

###
# logger
###

declare -A levels=(
  [debug]=1 [info]=2
  [warn]=3 [error]=4
)

log() {
  if [[ -v LEVEL ]] && (( levels[$level] <= levels[$LEVEL] )); then
    printf "%s: $1\n" "${LEVEL^^}" "${@:2}" >&"$log"
  fi
}

debug() {
  LEVEL=debug log "$@"
}

info() {
  LEVEL=info log "$@"
}

warn() {
  LEVEL=warn log "$@"
}

error() {
  LEVEL=error log "$@"
}

###
# argument parser for parsing arguments
##

original_args=("$0" "$@")
declare -A opts

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

###
# default config
##

server=${opts[server]:-irc.libera.chat}
tls=${opts[tls]:-no}

if [[ $tls = yes ]]; then
  if ! hash socat 2>/dev/null; then
    printf 'please install socat to use tls with rowbot.\n' >&2
    exit 1
  fi

  port=${opts[port]:-6697}
else
  port=${opts[port]:-6667}
fi

nick=${opts[nick]:-rowbot-dev}
ident=${opts[ident]:-rowbot}
realname=${opts[realname]:-rowbot}
chan=${opts[chan]:-}
trigger=${opts[trigger]:-\`}
fact_root=${opts[fact-root]:-.}
reload=${opts[reload]:-no}
dev=${opts[dev]:-no}

if [[ -v USER ]]; then
  owner=${opts[owner]:-"$USER"}
else
  owner=${opts[owner]:-uplime}
fi

level=${opts[log-level]:-info}

if [[ $reload = yes ]]; then
  log=$LOG_FD
elif [[ ${opts[log]} ]]; then
  exec {log}>"${opts[log]}"
else
  log=1
fi

###
# utilities
###

cleanup() {
  exec {in_sock}>&- {out_sock}>&- {log}>&-

  if [[ $tls = yes ]]; then
    kill "$tls_pid"
    rm -rf "$sock_dir"
  fi

  if [[ -v ping_pid ]]; then
    kill "$ping_pid"
  fi
}

trap cleanup EXIT

###
# net code
###

if [[ $reload = yes ]]; then
  in_sock=$IN_SOCK out_sock=$OUT_SOCK

  if [[ $tls = yes ]]; then
    sock_dir=$SOCK_DIR
    tls_pid=$tls_pid
  fi

  if [[ -v PING_PID ]]; then
    ping_pid=$PING_PID
  fi
elif [[ $tls = yes ]]; then
  sock_dir=$(mktemp -d)
  mkfifo "$sock_dir"/rb{in,out}
  socat OPENSSL:"$server":"$port" - <"$sock_dir"/rbin >"$sock_dir"/rbout &
  tls_pid=$!
  exec {out_sock}>"$sock_dir"/rbin {in_sock}<"$sock_dir"/rbout
else
  exec {sock}<>/dev/tcp/"$server"/"$port"
  in_sock=$sock out_sock=$sock
fi

send() {
  local fmt
  printf -v fmt "$1" "${@:2}"
  printf '%s\r\n' "$fmt" >&"$out_sock"
  debug "sending line: %s" "$fmt"
}

recv() {
  declare -n sock_line=$1
  IFS= read -r "$1" <&"$in_sock"
  sock_line=${sock_line%$'\r'}
  debug "received line: %s" "$sock_line"
}

###
# irc recv code
###

on_ERROR() {
  error "${params[0]}"
  exit
}

on_JOIN() {
  info "%s has joined %s" "$from" "${params[0]}"
}

on_MODE() {
  if (( ${#params[@]} == 2 )); then
    info "%s sets mode(s) %s on %s" "$from" "${params[1]}" "${params[0]}"
  else
    warn "mode line was not handled: %s" "$orig_line"
  fi
}

on_NOTICE() {
  info "[%s/%s] %s" "$from" "${params[0]}" "${params[1]}"
}

on_PING() {
  pong "${params[1]}"
  debug "received ping: %s" "${params[0]}"
}

on_PONG() {
  debug "received pong: %s" "${params[1]}"
}

on_PRIVMSG() {
  info "<%s/%s> %s" "$from" "${params[0]}" "${params[1]}"
}

on_QUIT() {
  info "%s has disconnected: %s" "$from" "${params[0]}"
}

on_001() {
  info %s "${params[1]}"

  if [[ $chan ]]; then
    join "$chan"
  fi

  while true; do
    ping "row your bot gently down the stream"
    sleep 10
  done &

  ping_pid=$!
}

on_002() {
  info %s "${params[1]}"
}

on_003() {
  info %s "${params[1]}"
}

on_004() {
  debug "%s " "${params[@]:1}"
}

declare -A isupport

on_005() {
  local param key value

  for param in "${params[@]:1:${#params[@]}-2}"; do
    IFS== read -r key value <<< "$param"
    isupport[$key]=$value
    debug "isupport: %s = %s" "$key" "$value"
  done
}

on_250() {
  info %s "${params[1]}"
}

on_251() {
  info %s "${params[1]}"
}

on_252() {
  info "There are %d operators online" "${params[1]}"
}

on_253() {
  info "There are %d unknown connections" "${params[1]}"
}

on_254() {
  info "There are %d channels formed" "${params[1]}"
}

on_255() {
  info %s "${params[1]}"
}

on_265() {
  info %s "${params[3]}"
}

on_266() {
  info %s "${params[3]}"
}

on_332() {
  info "topic for %s is %s" "${params[1]}" "${params[2]}"
}

on_333() {
  local date
  printf -v date '%(%c)T' "${params[3]}"
  info "topic for %s set by %s at %s" "${params[1]}" "${params[2]}" "$date"
}

on_353() {
  info "members of %s: %s" "${params[2]}" "${params[3]}"
}

on_366() {
  debug "%s: end of NAMES list" "${params[1]}"
}

on_372() {
  info %s "${params[1]}"
}

on_375() {
  debug %s "${params[1]}"
}

on_376() {
  debug %s "${params[1]}"
}

on_473() {
  error "%s: %s" "${params[1]}" "${params[2]}"
}

###
# irc send code
###

join() {
  send "JOIN %s" "$1"
}

nick() {
  send "NICK %s" "$1"
  info "changing nickname to %s" "$1"
}

ping() {
  send "PING :%s" "$1"
}

pong() {
  send "PONG %s" "$1"
}

privmsg() {
  send "PRIVMSG %s :\u200b%s" "$1" "$2"
  info "<%s/%s> %s" "$nick" "$1" "$2"
}

user() {
  send "USER %s * * :%s" "$ident" "$realname"
}

###
# app hooks
##

hook_post_PRIVMSG_factoids() {
  if [[ ${params[0]:0:1} != \# ]]; then
    return 0
  elif [[ ${words[0]} = "$trigger"* ]]; then
    case ${words[0]:${#trigger}} in
    is)
      if (( ${#words[@]} < 3 )); then
        return 0
      fi

      local key val
      key=${params[1]#*"$trigger"is} key=${key# }
      val=${key#* } key=${key%% *}

      info "%s said in %s to remember %s as %s" "$from" "${params[0]}" "$key" "$val"
      privmsg "${params[0]}" "I'm sure I'll remember that."
      mkdir -p "$fact_root"/"${params[0]}"
      printf %s "$val" > "$fact_root"/"${params[0]}"/"$key"
      ;;
    isnt)
      if (( ${#words[@]} < 2 )); then
        return 0
      fi

      local key
      key=${params[1]#*"$trigger"isnt} key=${key# }

      if [[ -f $fact_root/${params[0]}/$key ]]; then
        info "%s said in %s to delete %s" "$from" "${params[0]}" "$key"
        privmsg "${params[0]}" "I forgot what that was anyways."
        rm -f "$fact_root"/"${params[0]}"/"$key"
      fi
      ;;
    ls)
      local facts=( "$fact_root"/"${params[0]}"/* )
      privmsg "${params[0]}" "${facts[*]##*/}"
      ;;
    *)
      local key=${params[1]:1}

      if [[ -f $fact_root/${params[0]}/$key ]]; then
        privmsg "${params[0]}" "$from: $(<"$fact_root"/"${params[0]}"/"$key")"
      fi
    esac
  fi
}

hook_post_PRIVMSG_control_panel() {
  if [[ ${words[0]} = "$trigger"* ]]; then
    if [[ $from != $owner && $dev != yes ]]; then
      return 0
    fi

    local to=${params[0]}

    if [[ ${params[0]:0:1} != \# ]]; then
      to=$from
    fi

    case ${words[0]:${#trigger}} in
    raw)
      local cmd
      cmd=${params[1]#*"$trigger"raw} cmd=${cmd# }
      info "%s is executing command: %s" "$from" "$cmd"
      send "$cmd"
      ;;
    join)
      join "${words[1]}"
      ;;
    reload)
      export IN_SOCK=$in_sock OUT_SOCK=$out_sock LOG_FD=$log

      if [[ $tls = yes ]]; then
        export SOCK_DIR=$sock_dir
        export TLS_PID=$tls_pid
      fi

      if [[ -v ping_pid ]]; then
        export PING_pid=$ping_pid
      fi

      privmsg "$to" "reloading..."
      exec "${original_args[@]}" --reload
      ;;
    esac
  fi
}

###
# driver
###

if [[ $reload != yes ]]; then
  nick "$nick"
  user "$ident" "$realname"
fi

while recv line; do
  params=( )
  has_words=no
  orig_line=$line

  if [[ ${line:0:1} = : ]]; then
    src=${line%% *} src=${src#:}
    line=${line#:"$src"} line=${line# }
    from=${src%@*} ident=${from#*!}
    from=${from%!*} host=${src#*@}
  fi

  cmd=${line%% *}
  line=${line#"$cmd"}
  line=${line# }

  while [[ $line ]]; do
    if [[ ${line:0:1} = : ]]; then
      params+=("${line:1}")
      line=""
      has_words=yes
    else
      param=${line%% *}
      params+=("$param")
      line=${line#"$param"} line=${line# }
    fi
  done

  if [[ $has_words = yes ]]; then
    read -ra words <<< "${params[@]:(-1)}"
  else
    words=( )
  fi

  skip_handler=0

  while IFS= read -r hook; do
    "$hook"
    (( skip_handler |= $? ))
  done < <(compgen -A function "hook_pre_${cmd^^}_")

  if hash "on_${cmd^^}" 2>/dev/null; then
    if (( ! skip_handler )); then
      "on_${cmd^^}"
    else
      debug "handler for %s was skipped" "${cmd^^}"
    fi
  else
    warn "unhandled line: %s" "$orig_line"
  fi

  while IFS= read -r hook; do
    "$hook"
  done < <(compgen -A function "hook_post_${cmd^^}_")
done