#!/bin/bash
# -*- coding: utf-8 -*-
# 
# Copyright by Scott Severance
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

# file-insurance-cleanup
# Deletes all but the most recent backup files created by file-insurance.

prog="$(basename $0)"
backupDir="$HOME/.file-insurance"
escDir="$(echo "$backupDir" | sed 's/\//\\\//g')\/"
counter="0"
quiet=

FILE_COLOR="\033[4;34m"
ERROR_COLOR="\033[0;31m"
MSG_COLOR="\033[0;32m"
NO_COLOR="\033[0m" #Transparent - don't change
TITLEBAR_START="\033]0;"
TITLEBAR_END="\007"

E_USAGE=65
E_NORMAL=0
E_CANCEL=66

function cleanDir {
    local dir="$1"
    local oldPwd="$(pwd)"
    local bakFile=
    if [[ "$dir" =~ "$backupDir" ]]; then
        local fullDir="$dir"
    else
        local fullDir="$oldPwd/$dir"
    fi
    counter="0"

    builtin cd "$dir" 2> /dev/null
    IFS="\n" ls -1 --reverse | while read bakFile; do
                                   cleanFiles "$bakFile"
                               done
    builtin cd "$oldPwd" 2> /dev/null
    rmdir "$dir" 2> /dev/null
}

function cleanFiles {
    local bakFile="$1"

    if [ -d "$bakFile" ]; then
        cleanDir "$bakFile"
        return
    fi

    local fullFile="$(pwd)/$bakFile"
    local abbrFile="$(echo "$fullFile" | sed "s/${escDir}//g")"

    if [[ ! "$bakFile" =~ '^file-insurance\.[0-9]{4}-[0-9]{2}-[0-9]{2}_[0-9]{2}-[0-9]{2}-[0-9]{2}\.bz2$' ]]; then
        echo -e "${ERROR_COLOR}WARNING: Skipping file with unexpected name: ${FILE_COLOR}$abbrFile${NO_COLOR}" 1>&2
        return
    fi
    if [ "$counter" = "0" ]; then
        (( counter++ ))
        [ -z "$quiet" ] && echo -e "${MSG_COLOR}Preserving ${FILE_COLOR}$abbrFile${MSG_COLOR}...${NO_COLOR}"
    else
        [ -z "$quiet" ] && echo -e "Removing ${FILE_COLOR}$abbrFile${NO_COLOR}..."
        rm "$bakFile"
        (( counter++ ))
    fi
}

function usage {
    echo -e "${MSG_COLOR}Usage:"
    echo -e "$prog [--quiet|--help]${NO_COLOR}"
    echo -e "\n$prog cleans up after file-insurance by deleting all backup"
    echo -e "files it created except the most recent.\n"
    echo "With the --quiet option, $prog is silent except for errors."
}

function main {
    local i=

    case "$1" in
        "--help")
            usage
            exit $E_USAGE
            ;;
        "--quiet")
            quiet="true"
            FILE_COLOR=
            ERROR_COLOR=
            ;;
    esac

    if [ -z "$quiet" ]; then
        backupDirAbbr="$(echo "$backupDir" | sed "s/^$(echo "$HOME" | sed 's/[\/[{?.+*]/\\&/g')/~/g")"
        echo -n "Do you want to prune file-insurance's backup directory ($backupDirAbbr)? [y/N] "
        read answer
        if [[ ! "$answer" =~ '[Yy]' ]]; then
            echo "Exiting..."
            exit $E_CANCEL
        fi
    fi

    cleanDir "$backupDir"

    exit $E_NORMAL 
}

main "$@"