#!/bin/bash

function delete_older_backups {
	typeset host="$1"

	typeset year=$(date '+%Y')
	typeset month=$(date '+%m')
	typeset day=$(date '+%d')

	# Strip leading 0 off days
	month=${month#0}
	day=${day#0}

	# Remove all except 5th day backups for early portion of this month
	if [ $day -gt 20 ]
	then
		rm -rf $(printf "$host/%04d-%02d-0[02-57-9].*" $year $month)
	fi

	# Remove all except 5th day backups for last month
	let month=month-1
	[ $month -lt 1 ] && let month=month+12 && let year=year-1
	if [ $day -gt 10 ]
	then
		rm -rf $(printf "$host/%04d-%02d-?[02-57-9].*" $year $month)
	else
		rm -rf $(printf "$host/%04d-%02d-[01][02-57-9].*" $year $month)
	fi

	# Remove all except 10th day backups for 2-5 months ago
	for x in 1 2 3 4
	do
		let month=month-1
		[ $month -lt 1 ] && let month=month+12 && let year=year-1
		rm -rf $(printf "$host/%04d-%02d-?[02-9].*" $year $month)
	done

	# Remove all except monthly backups (1st of month) for
	#  6 months ago & beyond
	for x in 1 2 3 4 5 6
	do
		let month=month-1
		[ $month -lt 1 ] && let month=month+12 && let year=year-1
		rm -rf $(printf "$host/%04d-%02d-[1-3][0-9].*" $year $month)
	done
}

# Set up paths and stuff
arg0=$(basename $0)
PATH="$HOME/bin:$PATH"
cd ~/Backups || exit 1
d="[0-9]"
status=0
weekday=$(date '+%a')

for host in *
do
	# Locate the last successful backup done
	priorbackup=$(eval "ls -1d $host/$d$d$d$d-$d$d-$d$d.$d 2>/dev/null" | tail -1)
	if [ "$priorbackup" = "" ] 
	then
		echo "$host: No prior backup found; please check."
		continue
	fi
	# Get today's date, then if we're backing up twice on the same
	# day then locate the sequence number for this backup.
	date=$(date '+%Y-%m-%d')
	sequence=0

	priordate=$(basename "$priorbackup" | cut -c1-10)
	priorsequence=$(basename "$priorbackup" | cut -c12)
	if [ "$date" = "$priordate" ]
	then
		let sequence=priorsequence+1
		if [ $sequence -gt 9 ]
		then
			echo "$host: Out of sequence numbers for today."
			continue
		fi
	fi
	
	# Pull the backup from the remote host to the current server.
	# This varies a lot, so run a script to do it for each backup
	# directory if present.
	if [ -x $host/get-backup ]
	then
		mkdir -p "$host/Logs"
		$host/get-backup "$host" "$host/$date.$sequence" \
				 "../$priordate.$priorsequence" \
				 > "$host/Logs/get-backup.$weekday"
		backupstatus=$?
	else
		echo "$host: no get-backup script, or not executable."
		backupstatus=1
	fi

	if [ $backupstatus -eq 0 ]
	then
		delete_older_backups "$host"
	else
		[ -f "$host/$date.$sequence" ] &&
			mv $host/$date.$sequence $host/$date.$sequence.incomplete
		status=1
	fi
done

exit $status