#!/bin/bash
#
# backup-script system for cloning systems using rsync
# Copyright (c)2008-2016 Alexander Barton, alex@barton.de
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
# Please read the file COPYING, README and AUTHORS for more information.
#

NAME=$(basename "$0")
PIDFILE="/var/run/backup-script.pid"
QUICK=0
ONLY_ERRORS=0
ONLY_LATEST=0

export LC_ALL=C

declare -i count=0
declare -i snapshots=0

# Default settings, can be overwritten in backup-script.conf:
[ -d "/usr/local/etc/backup-script.d" ] \
	&& conf_d="/usr/local/etc/backup-script.d" \
	|| conf_d="/etc/backup-script.d"
default_backup_type="rsync"
default_generations=0
default_target="/var/backups"

# Search configuration file (last one is used as default!)
for conf in \
	"/usr/local/etc/backup-script.conf" \
	"/etc/backup-script.conf" \
	"${conf_d}/backup-script.conf" \
	"/usr/local/etc/backup-script.conf" \
; do
	if [ -r "$conf" ]; then
		# shellcheck source=/dev/null
		source "$conf"
		break
	fi
done

Usage() {
	echo "Usage: $NAME [--errors|--latest] [--quick] [<job> [<job> [...]]]"
	echo "       $NAME --running"
	echo
	echo "  -e, --errors    Only show current backups with errors (implies \"--latest\")."
	echo "  -l, --latest    Only show latest backup generations."
	echo "  -q, --quick     Don't calculate backup sizes."
	echo "  -r, --running   Check if an \"backup-script\" task is currently running."
	echo
	echo "When no <job> is given, all defined jobs are listed."
	echo
	exit 2
}

Check_Size() {
	# $1: directory
	# $2: padding

	if [ "$QUICK" = "0" ]; then
		size=$(du -Hhs "$1" | cut -f1)
		# shellcheck disable=SC2086
		echo "$2  - Size:" $size
	fi
}

Check_Stamp() {
	# $1: stamp file
	# $2: padding

	if [ -f "$1" ]; then
		declare -i code=-1
		declare -i start_t=-1
		start=""
		declare -i end_t=-1
		end=""
		declare -i duration_t=-1

		# Read in "stamp file"
		# shellcheck source=/dev/null
		source "$1"

		if [ $start_t -gt 0 ] && [ $end_t -gt 0 ]; then
			if [ "$(uname)" = "Linux" ]; then
				start=$(date -d @"$start_t")
				end=$(date -d @"$end_t")
			else
				start=$(date -r "$start_t")
				end=$(date -r "$end_t")
			fi
			duration_t=$end_t-$start_t
		else
			if [ "$(uname)" = "Linux" ]; then
				end=$(LC_ALL=C stat "$1" | grep "^Modify: " \
				 | cut -d':' -f2- | cut -d. -f1)
			else
				end=$(LC_ALL=C stat -f "%Sc" "$1")
			fi
		fi
		# shellcheck disable=SC2086
		[ -n "$start" ] && echo "$2  - Start date:" $start
		# shellcheck disable=SC2086
		[ -n "$end" ] && echo "$2  - End date:" $end
		if [ $duration_t -gt -1 ]; then
			declare -i s=$duration_t
			if [ $s -ge 60 ]; then
				declare -i m=$((s / 60))
				declare -i s=$((s % 60))
				if [ $m -ge 60 ]; then
					declare -i h=$((m / 60))
					declare -i m=$((m % 60))
					if [ $h -ge 24 ]; then
						declare -i d=$((h / 24))
						declare -i h=$((h % 24))
						duration="${d}d${h}h${m}m${s}s"
					else
						duration="${h}h${m}m${s}s"
					fi
				else
					duration="${m}m${s}s"
				fi
			else
				duration="${s}s"
			fi
			echo "$2  - Duration:" $duration
		fi

		case "$code" in
		  0)	txt=", OK"; ;;
		  24)	txt=", WARNING (some files vanished during backup)"; ;;
		  *)	txt=", ERROR"
		esac
		[ $code -ge 0 ] && echo "$2  - Result code: ${code}${txt}"
	else
		echo "$2  - No timestamp recorded! Backup currently running or aborted?"
	fi
}

Snapshot_Info() {
	echo "  - Snapshot: $1"
	Check_Size "$1" "  "
	Check_Stamp "$1/.stamp" "  "
}

Get_Result_Code() {
	code=1
	# shellcheck source=/dev/null
	[ -r "$1" ] && source "$1"
	[ -z "$code" ] && code=1
	echo $code
}

if [[ "$1" == "-r" || "$1" == "--running" ]]; then
	pid="$(cat "$PIDFILE" 2>/dev/null)"
	if [ -n "$pid" ]; then
		if kill -0 "$pid" >/dev/null 2>&1; then
			echo "Backup job running with PID $pid."
			echo
			pstree -ap "$pid" 2>/dev/null
			exit 0
		else
			echo "No backup running (invalid PID $pid in \"$PIDFILE\")."
			exit 1
		fi
	fi
	echo "No backup running (no PID file \"$PIDFILE\" found)."
	exit 1
fi

while [ $# -gt 0 ]; do
	case "$1" in
		"--errors"|"-e")
			ONLY_ERRORS=1
			ONLY_LATEST=1
			;;
		"--latest"|"-l")
			ONLY_LATEST=1
			;;
		"--quick"|"-q")
			QUICK=1
			;;
		"-"*)
			Usage
			;;
		*)
			break
	esac
	shift
done

if [ $# -ge 1 ]; then
	for s in "$@"; do
		if [ ! -r "${conf_d}/$s" ]; then
			echo "$NAME: Can' read \"${conf_d}/$s\"!"
			exit 1
		fi
		sys+=("${conf_d}/$s")
	done
else
	sys=("${conf_d}/"*)
fi

for f in "${sys[@]}"; do
	[[ -r "$f" && -f "$f" ]] || continue

	fname=$(basename "$f")
	case "$fname" in
		"backup-script.conf"|*.sh)
			continue
			;;
	esac

	# Set global defaults
	system="$fname"
	target="$default_target"
	generations="$default_generations"
	backup_type="$default_backup_type"

	# Read in system configuration file
	# shellcheck source=/dev/null
	source "$f"

	target="$target/$(basename "$f")"

	[ -d "$target" ] || continue

	if [ "$ONLY_ERRORS" != "0" ]; then
		[[ "$backup_type" = "disabled" ]] && continue
		[ $generations -gt 0 ] \
			&& result=$(Get_Result_Code "$target/latest/.stamp") \
			|| result=$(Get_Result_Code "$target/.stamp")
		[[ $result -eq 0 || $result -eq 24 ]] && continue
	fi

	# System name
	[ "$system" = "$fname" ] && echo "$fname" || echo "$fname [$system]"

	# System target directory
	echo "- Target: $target"

	if [ $generations -gt 0 ]; then
		if [ "$ONLY_LATEST" = "0" ]; then
			for s in $target/[0-9]*-[0-9]* $target/current; do
				[ -e "$s" ] || continue
				Snapshot_Info "$s"
				snapshots=$snapshots+1
			done
		elif [ -e "$target/latest" ]; then
			Snapshot_Info "$target/latest"
			snapshots=$snapshots+1
		fi
	else
		# Timestamp and result code
		Check_Size "$target"
		Check_Stamp "$target/.stamp"
		snapshots=$snapshots+1
	fi

	count=$count+1
	echo
done

if [ "$ONLY_ERRORS" != "0" ]; then
	status="failed "; p0="."; pN="!"
else
	status=""; p0="!"; pN="."
fi
if [ $count -lt 1 ]; then
	echo "No ${status}backups found${p0}"
	exit 1
fi
[ $count -eq 1 ] && sc="" || sc="s"
[ $snapshots -eq 1 ] && ss="" || ss="s"
echo "$count ${status}system backup$sc found, $snapshots snapshot$ss${pN}"

# -eof-