#!/bin/bash

MAX_VERSIONS=5

BASE_DIR="/home/backy/sw-backups"

DB_BACKUPS="$BASE_DIR/db"
DIR_BACKUPS="$BASE_DIR/dir"

MODE="0600"
OWNER="backy"
EXCLUDE_LIST="/etc/backup.exclude"

mkdir -p "$DB_BACKUPS" "$DIR_BACKUPS"
chown -R "$OWNER" "$DB_BACKUPS" "$DIR_BACKUPS"

rotate(){
    local dir="$1"
    local pattern="$2"
    local versions="$3"

    local files=($(find "$dir" -name "$pattern" -printf "%C@ %p\n" | sort -n | cut -d' ' -f2-))
    while [[ "${#files[@]}" -ge "$versions" ]]
    do
        rm -rf "${files[0]}"
        unset files[0]
        backups=( "${files[@]}" )
    done
}

store_compressed(){
    local dir="$1"
    local name="$2"
    local ext="$3"
    local versions="$4"
    shift 4

    local tmpfile="`mktemp`"

    $@ | bzip2 -9 -c > "$tmpfile"

    [[ "${PIPESTATUS[0]}" -eq 0 ]] || {
        rm -f "$tmpfile"
        return 1
    }

    rotate "$dir" "${name}_*$ext" "$versions"

    local bname="$dir/${name}_`date +"%d.%m.%Y_%H.%M"`.$ext"
    mv "$tmpfile" "$bname" || {
        rm -f "$tmpfile"
        return 1
    }

    chmod "$MODE" "$bname"
    chown "$OWNER" "$bname"
}

backup_db(){
    local dbname="$1"
    local user="$2"
    local password="$3"

    store_compressed "$DB_BACKUPS" "$dbname" "sql.bz2" "$MAX_VERSIONS" mysqldump -u "$user" --password="$password" -B "$dbname"
}

backup_dir(){
    local dir="$1"
    local parent="`dirname "$dir"`"
    local fname="`basename "$dir"`"

    store_compressed "$DIR_BACKUPS" "$fname" "tar.bz2" "$MAX_VERSIONS" tar -X "$EXCLUDE_LIST" -C "$parent" -cf - "$fname"
}

backup_db dbname dbuser dbpassword
backup_db dbname dbuser dbpassword

backup_dir /home/site1/public_html
backup_dir /home/site1/public_html

# now run the syncer
su - backy -c "sh -c 'cd dropbox-syncer && ruby cron.rb'"