#!/bin/sh -e

BINARYONLY=false
if [ "$1" = "-b" ]; then
    BINARYONLY=:
    shift
fi

pkg="$1"
rel="$2"

[ -n "$pkg" -a -n "$rel" ] || {
    echo "Usage: $0 {-b <binary package>|<source package>} <release>"
    exit 1
}

T=`mktemp -d`
trap "rm -rf $T" 0 1 2 3 4 5 6 7 8 10 11 12 13 15

for pocket in '' -updates -security -backports; do
    # get source/package lists
    for comp in main restricted universe multiverse; do
        wget -q -O - http://archive.ubuntu.com/ubuntu/dists/$rel$pocket/$comp/source/Sources.gz | gunzip > "$T/$rel${pocket}_${comp}_Sources"
    done

    # get lists of debs
    if $BINARYONLY; then
        debs="$pkg"
    else
        debs=`grep-dctrl -sBinary -n -X -P $pkg $T/*_Sources`|| {
            echo Unknown source package $pkg
            exit 1
        }
        debs=`echo "$debs" | sed 's/,//g'`
    fi

    for comp in main restricted universe multiverse; do
        for deb in $debs; do
            # build dependencies
            if d=`grep-dctrl -e -n -sPackage -FBuild-Depends "(,| |^)$(echo "$deb" | sed 's/+/\\\\+/g')(,| |$|\()" $T/$rel${pocket}_${comp}_Sources`; then
                echo "-- $rel$pocket/$comp build deps on $deb:"
                echo "$d"
            fi

            # binary dependencies
            for arch in amd64 i386 powerpc; do
                if d=`wget -q -O - http://archive.ubuntu.com/ubuntu/dists/$rel$pocket/$comp/binary-$arch/Packages.gz | gunzip \
                    | grep-dctrl -e -n -sPackage -FDepends "(,| |^)$(echo "$deb" | sed 's/+/\\\\+/g')(,| |$|\()"`; then  
                    echo "-- $rel$pocket/$comp $arch deps on $deb:"
                    echo "$d"
                fi
            done
            for arch in hppa ia64 sparc; do
                if d=`wget -q -O - http://ports.ubuntu.com/ubuntu-ports/dists/$rel$pocket/$comp/binary-$arch/Packages.gz | gunzip \
                    | grep-dctrl -e -n -sPackage -FDepends "(,| |^)$(echo "$deb" | sed 's/+/\\\\+/g')(,| |$|\()"`; then  
                    echo "-- $rel$pocket/$comp $arch deps on $deb:"
                    echo "$d"
                fi
            done
        done
    done
done