#!/bin/bash

database=/etc/portage/package.keywords
tempfile=/tmp/keywords.$$

cleanup() {
    rm -f ${tempfile}
}

die() {
    echo "${0//#*\//}: $*" >&2
    exit 1
}

append-package() {
    local package=${1}
    local keyword=${2:-~x86}

    test -z "${package}" && die "No package specified"
    echo "${package} ${keyword}" >> ${database}
}

remove-packages() {
    if show-packages "$@"
    then
        echo "Press RETURN to remove those packages."
        read

        GREPFLAGS=-v show-packages "$@" > ${tempfile}
        diff -u "${database}" "${tempfile}" 
        
        echo "Press RETURN to apply this changes."
        read

        mv "${tempfile}" "${database}"
    else
        echo "No matches found."
    fi
}

show-packages() {
    test $# = 0 && die "No packages specified"

    local pattern="$*"

    pattern="${pattern// /\\|}"
    pattern="${pattern//./\\.}"

    grep ${GREPFLAGS} "^\(=\|>=\|<=\)\?\(${pattern}\)" < ${database}
}

check-keyword() {
    local keyword=$1; shift
    grep -q "^KEYWORDS=.*[\"[:space:]]${keyword}\>" "$@"
}

check-packages() {
    sed -ne 's|^=\(\S\+\)/\(\S*\)-\([0-9.*]\+[a-z]\?\(_\w\+[0-9]\+\)\?\(-r[0-9]\+\)\?\)\s.*|\1 \2 \3|p' < ${database} |
    while read category package version
    do
        test -d "/usr/portage/${category}" || echo "Bad category: ${category}"

        local cdirs=$(find /usr/{portage,local/overlay/*} -type d -name ${category} -maxdepth 1)
        local pdirs=$(find ${cdirs} -type d -maxdepth 1 -name ${package})
        
        if test -n "${pdirs}" 
        then
            local efiles=$(find ${pdirs} -type f -maxdepth 1 -name "${package}-${version}.ebuild")
            
            if test -z "${efiles}"
            then
                local stable= unstable=

                for ebuild in $(
                    find ${pdirs} -type f -maxdepth 1 -name "*.ebuild")
                do
                    ev=$(echo ${ebuild} | sed -e "s|.*/||" -e "s|^${package}-||" -e "s|\.ebuild$||g")
                    { check-keyword 'x86' ${ebuild} && stable="${stable} ${ev}"; } ||
                    { check-keyword '~x86' ${ebuild} && unstable="${unstable} ${ev}"; }
                done

                stable=${stable/# /}
                unstable=${unstable/# /}

                echo "No ebuild found: ${category}/${package}-${version} [${stable:-none}][${unstable:-none}]"
            elif echo "${version}" | fgrep -q -v '*'
            then
                check-keyword '~x86' ${efiles} || {
                    check-keyword 'x86' ${efiles} &&
                    echo "Ebuild is stable: ${category}/${package}-${version}" || 
                    echo "Platform not supported: ${category}/${package}-${version}"
                }
            fi
        else
            echo "Bad package: ${category}/${package}"
        fi
        
    done
}

show-usage() {
    cat <<END
Usage: ${0//#*\//} COMMAND [ARGS...]
Utility for working with Gentoo package keywords.

COMMANDS

  check                 Searches for obsolete keywords
  add PACKAGE [KEYWORD] Adds a keyword for the given package
  remove PACKAGE        Removes package
  show PACKAGE          Lists packages

END

}

trap cleanup EXIT

case "$1" in
    add) shift; append-package "$@";;
    remove) shift; remove-packages "$@";;
    show) shift; show-packages "$@";;
    check) check-packages;;
    *) show-usage;;
esac

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