From dece4203b4a0fd5e69bc8872d5a994917b6762e8 Mon Sep 17 00:00:00 2001
From: Nick Chambers <uplime@spookyinternet.com>
Date: Sun, 4 Jul 2021 06:25:08 -0500
Subject: [PATCH] Add a logging interface

---
 rowbot | 306 +++++++++++++++++++++++++++++++++++----------------------
 1 file changed, 186 insertions(+), 120 deletions(-)

diff --git a/rowbot b/rowbot
index 314d260..b49394f 100755
--- a/rowbot
+++ b/rowbot
@@ -6,111 +6,6 @@
 
 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
 ###
@@ -126,7 +21,12 @@ any_file() {
 }
 
 die() {
-  # error "$@"
+  local fmt=$1
+  shift
+  # This is a wrapper around printf so the format string isn't known ahead of
+  # time.
+  # shellcheck disable=SC2059
+  printf "$fmt\n" "$@" >&2
   exit "${STATUS:-42}"
 }
 
@@ -135,15 +35,17 @@ get_option() {
     return 1
   fi
 
-  local option_name=${1//-/_}
-  declare -n option_var=$option_name
+  local var_name=${1//-/_}
+  local env_var=${var_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
+  if [[ -v $env_var ]]; then
+    config[$1]=${!env_var}
+  elif [[ -v opts[$1] ]]; then
+    config[$1]=${opts[$1]}
+  elif [[ -v $var_name ]]; then
+    config[$1]=${!var_name}
+  else
+    config[$1]=$2
   fi
 }
 
@@ -183,25 +85,187 @@ run_callbacks() {
   return 0
 }
 
+###
+# configure rowbot's environment
+###
+
+# parse command line arguments
+
+declare -A opts
+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
+
+# load 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
+
+# cleanup
+
+unset key file
+
+###
+# load default config
+###
+
+declare -A config
+
+# connection settings
+
+get_option server irc.libera.chat
+get_option tls no
+
+if [[ ${config[tls]} = no ]]; then
+  get_option port 6667
+else
+  get_option client-cert ""
+  get_option port 6697
+fi
+
+# irc registration settings
+
+get_option nick rowbot-dev
+get_option ident rowbot
+get_option realname rowbot
+get_option chan ""
+
+# bot control settings
+
+get_option owner "${USER:-uplime}"
+get_option trigger \`
+get_option dev yes
+
+###
+# logger
+###
+
+log() {
+  if [[ -v LOG_LEVEL ]] && (( log_levels[$log_level] <= log_levels[$LOG_LEVEL] )); then
+    printf "%s: $1\n" "${LOG_LEVEL^^}" "${@:2}" >&"$log_fd"
+  fi
+}
+
+log_debug() {
+  LOG_LEVEL=debug log "$@"
+}
+
+log_info() {
+  LOG_LEVEL=info log "$@"
+}
+
+log_warn() {
+  LOG_LEVEL=warn log "$@"
+}
+
+log_error() {
+  LOG_LEVEL=error log "$@"
+}
+
+log_has_level() {
+  local level
+
+  for level in "${!log_levels[@]}"; do
+    if [[ ${1,,} = "$level" ]]; then
+      return 0
+    fi
+  done
+
+  return 1
+}
+
+on_init_001_log() {
+  declare -gA log_levels=( [debug]=1 [info]=2 [warn]=3 [error]=4 )
+  get_option log-level info
+
+  if ! log_has_level "${config[log-level]}"; then
+    die "%s is not a valid logging level" "${config[log-level]}"
+  fi
+
+  get_option log ""
+  get_option overwrite no
+  log_level=${config[log-level]}
+
+  if [[ ${config[log]} ]]; then
+    if [[ ${config[overwrite]} = yes ]]; then
+      exec {log_fd}>"${config[log]}"
+    else
+      exec {log_fd}>>"${config[log]}"
+    fi
+  else
+    log_fd=1
+  fi
+}
+
+on_exit_log() {
+  if [[ -v log_fd ]] && (( log_fd != 1 )); then
+    exec {log_fd}>&-
+  fi
+}
+
+###
+# cleanup
+###
+
+cleanup() {
+  run_callbacks on_exit_
+}
+
+trap cleanup EXIT
+
 ###
 # live code reloader
 ###
 
 reload() {
-  run_callbacks on_before_reload_
+  local setting setting_name
+  run_callbacks on_before_
+
+  for setting in "${!config[@]}"; do
+    setting_name=${setting//-/_}
+    export "${setting_name^^}"="${config[$setting]}"
+  done
+
   exec "${cmd_line[@]}"
 }
 
 hup_reload() {
+  log_info "received reload signal (HUP)"
   reload
 }
 
 trap hup_reload HUP
 
-on_init_debug() {
-  declare -p config
-}
-
 ###
 # initialization sequence
 ###
@@ -209,7 +273,9 @@ on_init_debug() {
 run_callbacks on_init_
 
 if is_reloaded; then
-  run_callbacks on_after_reload_
+  run_callbacks on_after_
 else
   run_callbacks on_first_
 fi
+
+declare -p config