lager

#!/usr/bin/env bash

#!/usr/bin/env bash
Usage() { cat <<'EOL'
_________/\\\_______________/\\\\\\\ _______/\\\\\\\\ ___/\\\\\\\\\\\ __/\\\\\\\\\\\
_________\/\\\ ____________/\\\////\\\ ____/\\\/////\\\ _\/\\\/////// __\/\\\//////\\\
__________\/\\\ __________/\\\ ___\/\\\ ___\/\\\ __\///___\/\\\ _________\/\\\ ___/\\\
___________\/\\\ _________\/\\\\\\\\\\\\\ __\/\\\ _________\/\\\\\\\\\ ___\/\\\\\\\\\/
____________\/\\\ _________\/\\\///////\\\ __\/\\\ _/\\\\\ _\/\\\/////_____\/\\\////\\\\
_____________\/\\\ _________\/\\\ ____\/\\\ __\/\\\ \///\\\ _\/\\\ _________\/\\\ _\///\\\
______________\/\\\ _________\/\\\ ____\/\\\ __\/\\\ __\/\\\ _\/\\\ _________\/\\\ ___\//\\\
_______________\/\\\\\\\\\\\ _\/\\\ ____\/\\\ __\//\\\\\\\\/ __\/\\\\\\\\\\ __\/\\\ ____\/\\\
USAGE __________\///////////___\/// _____\///_____\////////_____\//////////____\///______\///
         lager.sh  <start|stop>  [<option>]  [<route ...>]
SYNOPSIS
         Activate/deactivate logging for optionally specifiable route(s).
         After logging has been activated,
          the default behavior is to display a simple log-count monitor.
PARAMETERS
       install:   install middleware and route loggers.
     uninstall:   uninstall middleware and route loggers.
         start:   activate logging for [specified||all] routes.
         stop :   manually deactivate logging for [specified||all] routes.
    `route(s)`:   relative path(s) to files in the routes directory.
OPTIONS
      -h, --help   :   reveal this helpful usage information.
      -a, --all    :   activate|deactive logging for all routes/endpoints.
      -q, --quiet  :   do not display monitor after activating logging.
      -s, --status :   get current log counts and list of actively logged routes.
      -m, --monitor:   activate monitoring mode.
NOTES
   * to [un]install: be in project root directory, call script from relative path (`../../wherever/lager install`)
   * logging is automatically deactivated during cleanup of the monitoring process.
   * if invoked with the `-q` flag, do not forget to manually deactivate with `stop`.
   * the clock displayed during monitoring will be set to UTC (or the server's locale)
      this can be adjusted by passing the desired timezone as an environment variable
      at runtime.  for example: ` TZ='America/New_York' ./lager.sh ... `
                                ` TZ='America/Kentucky/Louisville' ./lager.sh ... `

EOL

	exit ${1:-0}
}
[[ "${1,,}" != +(\-)@(h)?(elp) ]] || Usage

_viewer() {
	#echo 'USAGE:      lager view [<OPTIONS>] <ROUTE> [<ENDPOINT>] *WIP'
	#echo '                                    (dir)   (log file)'
	viewerUsage() {
		echo 'USAGE:   lager view <LOGFILE> (.logs/...)'
		echo 'OPTIONS:'
		echo '         -p          : pretty print (default is line-oriented (`jq -c`))'
		echo '         -n <NUMBER> : only print the last <N> entries'
		echo ''
	}
	viewReq() {
		local -i n=${1}
		if [[ "${3:-}" == 'Pretty' ]]; then
			if ((n == 0)); then
				jq '.' -- "$2"
			else
				tail -n${n} "$2" | jq '.'
			fi
		else
			if ((n == 0)); then
				jq -c '.' -- "$2"
			else
				tail -n${n} "$2" | jq -c '.'
			fi
		fi
	}
	viewRes() {
		local -i i=${1}
		if ((i == 0)); then
			jq '.' -- "$2"
		else
			tail -n${i} "$2" | jq '.'
		fi
	}
	viewPrettyRes() {
		local -i len=$(wc -l < "$2")
		((len != 0)) || return 1
		local -i n=${1}
		if ((n==0)); then
			# whole file
			((n = 1))
		else
			# last <n> lines
			(( n = len - n ))
			(( n = n <= 0 ? 1 : n + 1 ))
		fi
		for((i=n;i<=len;i++)){
			sed -n "${i}p" "$2" | jq '.timestamp, .method, .url'
			sed -n "${i}p" "$2" | jq -r '.responseBody' | jq -c
			echo ""
		}
	}
	local Log='' Kind=''
	local -i N=0
	for((x=1;x<=$#;x++)){
		[[ "${!x,,}" != *(\-)@(h)?(elp) ]] || { viewerUsage; break; }
		case "${!x}" in
		'-n') ((++x)); [[ "${!x}" != +([[:digit:]]) ]] || N=${!x} ;;
		'-p'|'--pretty') Kind='Pretty' ;;
		*) [[ ! -f "${!x}" ]] || Log="${!x}"
		esac
	}
	[[ -f "$Log" ]] || return 1
	if [[ "${Log,,}" == *'responses.json' ]]; then
		view${Kind}Res $N "$Log"
	else
		viewReq $N "$Log" ${Kind:-}
	fi
}

ALL=false
QUIET=false
declare -ga Routes=()
unset Action 2>/dev/null
mkdir -p .logs

## activate|deactivate logging for a given route/endpoint
enablager() { sed -i '/Lager/s/^\/\///' "$1"; }
disablager() { sed -i '/Lager/s/^/\/\//' "$1"; }
_start() { grep -sIqE "^[^\/\/].*(Request|Response)Lager" "$1" || enablager "$1"; }
_stop() { grep -qvIsE "^[^\/\/].*(Request|Response)Lager" "$1" || disablager "$1"; }

## returns list of logfiles
countLogs() { find $1 -type f -name "*.log" -exec wc -l '{}' \; | awk '!/^0/ && !/lager/ { print $0 }' | sort -k 2 | column -t; }

## updates .logs/lager.log with the current log counts (same info displayed during monitoring)
updateCount() { { date ; countLogs '.logs/' ; echo "" ; } | tee .logs/lager.log ; }

## deactivate logging on exit (unless ran with `-q`)
onExit() {
	tput reset
	for((r=0;r<${#Routes[@]};r++)){ _stop "${Routes[r]}"; }
	updateCount >/dev/null
	exit 0
}
trap onExit SIGINT

## generates log counts
showLogs() {
	local -i i=0 x=$(shize x)
	while read line; do
		tput cup $((++i)) 0; printf "${line}%$((x-${#line}-1))s\n"
	done < <(if ((${#Routes[@]} != 0)); then
			for((r=0;r<${#Routes[@]};r++)){
				routeName="$(basename -s '.js' ${Routes[r]})";
				mkdir -p .logs/${routeName}
				countLogs ".logs/${routeName}/"
			}
		else countLogs '.logs/'; fi
	)
}

## reports which if any routes are being monitored
chkStatus() {
	updateCount
	local -i i=0
	local -a Active=()
	for r in routes/*.js ; do ((++i))
		grep -qvIsE "^[^\/].*(Request|Response)Lager" $r >/dev/null || Active[${#Active[@]}]="$(basename -s '.js' $r)"
	done
	case ${#Active[@]} in
	0) printf '\nNo routes are being logged.\n' ;;
	$i) printf '\nActively logging all routes.\n' ;;
	*)
		printf 'Actively logging:\n'
		for((r=0;r<${#Active[@]};r++)){ echo "${Active[r]}"; }
	esac
	exit 0
}

## display the real-time log monitor
Monitor() {
	tput clear civis
	while :; do
		tput setaf 3 cup 0 0; date; tput sgr0
		showLogs; tput sgr0
		sleep 3
	done
}
iRoutes() {
	local GREP_OPTIONS='-m1 -sHIniE' GREP_TARGET="${1:-routes}"
	[[ -d "$1" || $# == 0 && -d routes ]] && GREP_OPTIONS+='R'
	[[ ! -e $GREP_TARGET ]] || { grep $GREP_OPTIONS '\s*const\s*router\s*\=\s*express\.' "$GREP_TARGET" | awk -F\: '!a[$1]++ {print $2,$1}'; }
}
uRoutes() { grep -m1 -slIR "Lager" routes ; }
insertLager() { local -ai x=( $1 $1 ); local -a Insertions;
	Insertions[0]="import { RequestLager, ResponseLager } from '../middlewares/Lager.js';"
	Insertions[1]="router.use(RequestLager('${2}'));"
	Insertions[2]="router.use(ResponseLager('${2}'));"
	! { sed -n "$((++x[1]))p" "$3" | grep -Esq "(r|R)outer\.use\(cors"; } || ((++x[1]))
	sed -i.bak "$((++x[1]))i${Insertions[1]}\n${Insertions[2]}" "$3"
	sed -i "$((x>1?x-1:1))i${Insertions[0]}" "$3"
}
installagers() {
	local lagerSource="$(realpath ${BASH_SOURCE[0]})"
	cp -vf ${lagerSource%\/*}/middleware/Lager.js middlewares/Lager.js || exit 2
	while read n f ; do
		cp -vf "$f" "${f%\/*}/.${f##*\/}"
		insertLager $n "$(basename -s '.js' "$f")" "$f"
	done < <(iRoutes ${1:-routes} )
	echo $'\n'{"middlewares/Lager.js",".logs","routes/*.bak",} >> .gitignore
	[[ -x $(which lager) ]] 2>/dev/null || { cp -fv "${lagerSource}" ./ ; chmod +x lager ; }
}
uninstallagers() {
	for r in $(grep -m1 -lIRs "Lager" routes); do sed -i '/Lager/d' "$r"; done
	rm -f middlewares/Lager.js
	[[ ! -f lager ]] || rm -f lager
}

## parse commandline options
for((a=1;a<=$#;a++)){
	case "${!a,,}" in
	'-v'|*'view') Action='viewer' && break ;;
	'stop'|'--stop') Action='stop' ;;
	'start'|'--start') Action='start' ;;
	'-i'|'--install'|'install') Action='installagers' ;;
	\-[ru]|*'remove'|*'uninstall') Action='uninstallagers' ;;
	'-a'|*'all') Routes=(routes/*.js) ;;
	'-q'|*'quiet') QUIET=true ;;
	'-s'|*'status') Action='chkStatus' ;;
	'-m'|*'monitor') Action='Monitor' ;;
	*)
		[[ -f "${!a}" ]] && Routes[${#Routes[@]}]="${!a}" || {
			[[ -f "routes/${!a}" ]] && Routes[${#Routes[@]}]="routes/${!a}" || {
				[[ ! -f "routes/${!a}.js" ]] || Routes[${#Routes[@]}]="routes/${!a}.js"
			}
		}
	esac
}

## perform action(s)
[[ -n ${Action} ]] || Usage 1
case "${Action}" in
'viewer') _viewer ${@:a+1} ;;
'chkStatus'|'Monitor'|'installagers'|'uninstallagers') $Action ;;
*)
	((${#Routes[@]} != 0)) || Usage 1
	for((r=0;r<${#Routes[@]};r++)){ _${Action} "${Routes[r]}"; }
	${QUIET} || { [[ "$Action" == 'stop' ]] || Monitor ; }
esac