#!/bin/bash

package_etc_update="/etc/portage/package.etc-update"
# remove previously created etc-update temp files
rm -rf /var/tmp/etc-update-*
# run etc-update with -p, so that it will do trivial merges, and -7 to create tmp files
etc-update -p --automode -7 > /dev/null
files=$(find /var/tmp/etc-update-*/files/ -type f)
for file in $files; do
    orig_config=$(head -n 1 $file)
    cfg_list=($(tail -n +2 $file))
    IFS=$'\n'
    RULES=( $(grep ${orig_config} ${package_etc_update}) )
    for rule in ${RULES[@]}; do
        IFS=$' '
        rule=(${rule})
        if [[ ${#rule[@]} > 2 ]]; then
            # MD5sums are included in the rule
            for cfg in ${cfg_list[@]}; do
                md5sum_cfg=$(md5sum $cfg | cut -d' ' -f1)
                for md5 in ${rule[@]:3}; do
                    if [[ $md5 == $md5sum_cfg ]]; then
                        if [[ ${rule[0]} == "accept" ]]; then
                            mv $cfg $orig_config
                            rm ${cfg_list[@]} > /dev/null
                        elif [[ ${rule[0]} == "reject" ]]; then
                            rm $cfg > /dev/null
                        fi
                        break
                    fi
                done
            done
        else
            # No MD5sums are in the rule
            if [[ ${rule[0]} == "accept" ]]; then
                mv ${cfg_list[${#cfg_list[@]}-1]} $orig_config
                rm ${cfg_list[@]} > /dev/null
            elif [[ ${rule[0]} == "reject" ]]; then
                rm ${cfg_list[@]} > /dev/null
            fi
        fi
    done
    unset IFS
done