#!/bin/sh

#  Copyright (c) 2013 Yanhui Shen, shen.elf@gmail.c0m
#  All rights reserved.
#
#  Redistribution and use in source and binary forms, with or without
#  modification, are permitted provided that the following conditions
#  are met:
#  1. Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer.
#  2. Redistributions in binary form must reproduce the above copyright
#     notice, this list of conditions and the following disclaimer in the
#     documentation and/or other materials provided with the distribution.
#
#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
#  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
#  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
#  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
#  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
#  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
#  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
#  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
#  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
#  SUCH DAMAGE.

#Twiddle="echo '|/-\\' | cut -c"
PkgQuery="pkg query -e \"%#r=0\" \"%o#%c\" | sort"
PkgDelete="pkg delete -y"
DialogList="dialog --stdout --checklist \"leaf packages (%s)\" 30 90 30"

KeptLeaves=""
while true; do
    #==== refresh leaves ====
    echo "Calculating..."
    AllLeaves=`eval $PkgQuery`
    NewLeaves=""
    nNewLeaves="0"
    #n="0"
    IFS=$'\n'
    for line in $AllLeaves; do
        # print twiddle will be a little slower
        #n=$(($n % 4 + 1))
        #ch=`eval "$Twiddle $n"`
        #printf "Calculating...%s\r" "$ch"

        port=`echo "$line" | cut -d'#' -f1`
        desc=`echo "$line" | cut -d'#' -f2 | sed -e 's/\"/\\\"/g'`
        ret=`echo "$KeptLeaves" | grep "$port"`
        if [ -z "$ret" ]; then
            NewLeaves="$NewLeaves $port \"$desc\" off"
            nNewLeaves=$(($nNewLeaves + 1))
        fi
    done

    #==== show dialog ====
    if [ -z "$NewLeaves" ]; then
        echo "Nothing to do!"
        exit
    fi
    cmd=`printf $DialogList "$nNewLeaves"`
    selections=`eval "$cmd $NewLeaves"`
    if [ $? -ne 0 ]; then
        echo "Canceled."
        exit
    fi

    #==== record old leaves ====
    KeptLeaves="$AllLeaves"

    #==== deinstall selected ====
    if [ -z $selections ]; then
        echo "No selection, quit."
        exit
    fi
    eval "$PkgDelete $selections"
done
