#!/bin/bash
# Copyright 2012 Nicolás Reynolds <fauno@parabola.nu> Licensed under GPLv3
#
# Smart cleanup of the chroot, restores chroot to its original state but also
# leaves the dependencies already installed that are needed by the current
# package. In other words, it removes everything that's left.
#
# Useful when you're building a lot of packages one after another and they
# share some dependencies.
#
# Logic: tap into `makepkg -sr`, collect required packages and remove the
# leftovers
#
# Use it as the PACMAN var for makepkg: `PACMAN=$0 makepkg`

set -e
set -x

cleanup_log=/tmp/libretools-cleanup.log
cmd="$1"; shift
# make -Rn respect PACMAN_OPTS
flags=($(echo "$@" | grep -o "\-\-no\(confirm\|progressbar\)" || true))
args="$@"

case $cmd in

# Collect the packages that are going to be installed, but use a clean database
# to get the full needed list.
# See update-cleansystem
    -T)
# Use sudo because $0 is run as normal user
# TODO -Sy only once
        sudo pacman -b "${BD:-/var/lib/libretools/clean}" -Sy >/dev/null 2>&1
        sudo pacman -b "${BD:-/var/lib/libretools/clean}" \
                    -Sp \
                    --print-format "%n" \
                    ${args[@]} >>${cleanup_log} 2>/dev/null
    ;;

# Diff against previously installed packages and remove the unneeded ones
#
# We don't collect during -S because we never get here if depencies are met
# during -T
    -S)
        cleanup=($(comm -23 \
                        <(pacman -Qq | sort) \
                        <(cat /etc/libretools.d/cleansystem ${cleanup_log} | sort -u)
                ))

        if [ ${#cleanup[@]} -gt 0 ]; then
# At this point $0 is run as root
            pacman -Rn ${flags[@]} ${cleanup[@]}
        fi

# Remove the cleanup log at the end
        rm ${cleanup_log}
    ;;
# DON'T LET MAKEPKG DO REMOVALS OF ITS OWN
    -R) exit 0;;
esac

# Make makepkg dreams come true
pacman $cmd ${args[@]}