#!/bin/sh
name0=`basename "$0"`

get_name()
{
    echo "$1" | sed -e 's/_.*$//'
}

get_version()
{
    echo "$1" | sed -e 's/^[^_]*_//' -e 's/-.*$//'
}

get_arch()
{
    echo "$1" | sed -e 's/^.*_\([a-z0-9-]*\)\.deb$/\1/'
}

get_multiarch()
{
    pkg="$1"
    dpkg --info "$pkg" | sed -e 's/^ *Multi-Arch: *//' -e t -e d
}

get_properties()
{
    _pkg="$1"
    _name=`get_name "$_pkg"`
    _version=`get_version "$_pkg"`
    _arch=`get_arch "$_pkg"`
    if [ -z "$_pkg" -o -z "$_name" -o -z "$_version" -o -z "$_arch" ]
    then
        echo "prepare_package bug: pkg='$_pkg' name='$_name' version='$_version' arch='_$arch'" >&2
        exit 1
    fi
}

prepare_package()
{
    _pkg="$1"
    get_properties "$_pkg"

    # alien may have left its working directory behind
    rm -rf "$_name-$_version"
    if ! alien --to-tgz "$_pkg" >"/tmp/$name0.$$" 2>&1
    then
        echo "$name0:error: alien --to-tgz '$_pkg' failed" >&2
        cat "/tmp/$name0.$$" >&2
        rm -f "/tmp/$name0.$$"
        exit 1
    fi

    _dir="$_name-$_arch"
    rm -rf "$_dir"
    mkdir "$_dir"
    tar xfz $_name-*.tgz -C "$_dir"
    rm $_name-*.tgz

    _include=`get_arch_include "$_dir"`
    [ -n "$_include" ] && mv "$_include" "$_dir/usr/include/ARCH"
    echo "$_dir"
}

get_arch_include()
{
    _dir="$1"
    for _i in "$_dir"/usr/include/*-linux-gnu* \
              "$_dir"/usr/include/*-kfreebsd-gnu* \
              "$_dir"/usr/include/*-gnu
    do
        if [ -d "$_i" ]
        then
            if [ -z "$_include" ]
            then
                _include="$_i"
            elif [ "$_i" != "$_include" ]
            then
                echo "ambiguous include directory: $_include != $_i" >&2
                return
            fi
        fi
    done
    echo "$_include"
}

done=""
is_done()
{
    if echo "$done" | grep "$1" >/dev/null
    then
       return 0
    fi
    done="$done $1"
    return 1
}

check_packages()
{
    pkg1="$1"
    doforeign="$2"

    is_done "$pkg1" && return

    arch1=`get_arch "$pkg1"`
    multiarch1=`get_multiarch "$pkg1"`
    dir1=`prepare_package "$pkg1"` || exit 1

    glob=`echo "$pkg1" | sed -e 's/_.*$/_*.deb/'`
    for pkg2 in $glob
    do
        is_done "$pkg2" && continue

        arch2=`get_arch "$pkg2"`
        multiarch2=`get_multiarch "$pkg2"`
        if [ "$multiarch1" != "$multiarch2" ]
        then
            echo "The $arch1 package is '$multiarch1' but the $arch2 one is '$multiarch2'"
        fi

        case "$doforeign" in
            no)  [ "$multiarch1" = "foreign" ] && continue ;;
            only) [ "$multiarch1" != "foreign" ] && continue ;;
            *) ;;
        esac

        dir2=`prepare_package "$pkg2"` || exit 1
        diff -ur "$dir1" "$dir2" | egrep -v "/usr/lib: [a-z0-9_]*-((linux|kfreebsd)-gnu[a-z]*|gnu)$"
    done
}

clean_package()
{
    pkg="$1"
    get_properties "$pkg"
    rm -rf "$_name-$_version"
    rm -rf "$_name-$_arch"
}

if [ "$1" = "--help" ]
then
    echo "Usage: $name0 [debfile] [yes|no|only]"
    echo "or     $name0 clean"
    echo
    echo "Checks whether files differ that could prevent the packages from being marked Multi-Arch: same"
    echo
    echo "Where:".
    echo "  debfile      Is a Debian package file. All architectures of that package are then"
    echo "               tested. If omitted, all package files found in the current directory"
  echo "                 are checked."
    echo "  yes|no|only  Indicates whether to also process multiarch foreign packages, skip"
    echo "               them or only process them."
    echo "  clean        Removes the package trees created for the checks."

elif [ "$1" = "clean" ]
then
    for deb in *.deb
    do
        clean_package "$deb"
    done

elif [ -n "$1" ]
then
    check_packages "$1" "yes"

else
    for deb in *.deb
    do
        check_packages "$deb" "no"
    done

    echo
    echo "Foreign packages:"
    for deb in *.deb
    do
        check_packages "$deb" "only"
    done
fi