#!/bin/bash
# -*- coding: utf-8 -*-

# rpmdev-diff -- Diff contents of two archives
#
# Copyright (c) 2004-2010 Ville Skyttä <ville.skytta@iki.fi>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

set -e

unset CDPATH
tmpdir=
diffopts=
list=
long=
contents=
meta=
diffcopts=-Nup
diffoopts=-U0

trap cleanup EXIT
cleanup()
{
    set +e
    [ -z "$tmpdir" -o ! -d "$tmpdir" ] || rm -rf "$tmpdir"
}

version()
{
    cat <<EOF
rpmdev-diff version 1.4

Copyright (c) 2004-2010 Ville Skyttä <ville.skytta@iki.fi>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
EOF
}

help()
{
    cat <<EOF
rpmdev-diff diffs contents of two archives.

See rpmdev-extract(1) for information about supported archive types.
EOF
    usage
    echo ""
    echo "Report bugs to <https://bugzilla.redhat.com/>."
}

usage()
{
    cat <<EOF
Usage: rpmdev-diff [OPTION]... [DIFF-OPTIONS] FROM-ARCHIVE TO-ARCHIVE

Options:
  -c, --contents   Diff contents of files in archives.  This is the default.
  -l, --list       Diff lists of files in archives.
  -L, --long-list  Diff long lists (akin to 'find -ls') of files in archives.
  -m, --metadata   Diff archive metadata (only implemented for rpms for now).
  -h, --help       Print help message and exit.
  -v, --version    Print version information and exit.
  diff-options     Options passed to diff(1).  The first repeated argument of
                   the above or the first argument starting with a '-' but not
                   one of the above starts diff-options, the first one not
                   starting with it ends them.  Default: $diffcopts for contents
                   (in addition to -r which will always be passed), -U0 for
                   others.

More than one of -c, -l, -L, and -m may be specified.
EOF
}

rpm_meta()
{
    rpm -qp --nodigest --nosignature --info --changelog --scripts --triggers \
        --qf='[Requires: %{REQUIRENAME} %{REQUIREFLAGS:depflags} %{REQUIREVERSION}\n][Provides: %{PROVIDENAME} %{PROVIDEFLAGS:depflags} %{PROVIDEVERSION}\n][Obsoletes: %{OBSOLETENAME} %{OBSOLETEFLAGS:depflags} %{OBSOLETEVERSION}\n][Conflicts: %{CONFLICTNAME} %{CONFLICTFLAGS:depflags} %{CONFLICTVERSION}\n]' \
        "$@" 2>/dev/null
}

while true ; do
    case $1 in
        -l|--list)
            if [[ $list$diffopts ]] ; then
                diffopts+=" $1"
            else
                list=true
            fi
            ;;
        -L|--long-list)
            if [[ $long$diffopts ]] ; then
                diffopts+=" $1"
            else
                long=true
            fi
            ;;
        -c|--contents)
            if [[ $contents$diffopts ]] ; then
                diffopts+=" $1"
            else
                contents=true
            fi
            ;;
        -m|--metadata)
            if [[ $meta$diffopts ]] ; then
                diffopts+=" $1"
            else
                meta=true
            fi
            ;;
        -h|--help)
            if [[ $diffopts ]] ; then
                diffopts+=" $1"
            else
                help
                exit 0
            fi
            ;;
        -v|--version)
            if [[ $diffopts ]] ; then
                diffopts+=" $1"
            else
                version
                exit 0
            fi
            ;;
        -*)
            diffopts+=" $1"
            ;;
        *)
            break
            ;;
    esac
    shift
done
if [[ $# -lt 2 ]] ; then
    usage
    exit 1
fi
for file in "$1" "$2" ; do
    if [[ ! -f $file ]] ; then
        [[ -e $file ]] && \
            echo "Error: not a regular file: '$file'" >&2 ||
            echo "Error: file does not exist: '$file'" >&2
        exit 1
    fi
done

tmpdir=`mktemp -d ${TMPDIR:-/tmp}/rpmdev-diff.XXXXXX`

mkdir "$tmpdir/old" "$tmpdir/new"
rpmdev-extract -q -C "$tmpdir/old" "$1"
rpmdev-extract -q -C "$tmpdir/new" "$2"
if ${meta:-false} ; then
    set +e
    rpm_meta "$1" > "$tmpdir/old.meta"
    rpm_meta "$2" > "$tmpdir/new.meta"
    set -e
fi

# It would be nice if rpmdev-extract could do some of the chmods.
find "$tmpdir"/* -type d -exec chmod u+rx {} ';' # Note: -exec, not xargs here.
chmod -R u+rw "$tmpdir"/*
cd "$tmpdir"

# Did the archives uncompress into base dirs?
if [[ $(ls -1d old/* | wc -l) -eq 1 ]] ; then
  old=$(ls -1d old/*)
else
  old=old
fi
if [[ $(ls -1d new/* | wc -l) -eq 1 ]] ; then
  new=$(ls -1d new/*)
else
  new=new
fi

# Fixup base dirs to the same level.
if [[ $(basename "$old") != $(basename "$new") ]] ; then
  if [[ $old != old ]] ; then
    mv "$old" .
    old=`basename "$old"`
  fi
  if [[ $new != new ]] ; then
    mv "$new" .
    new=`basename "$new"`
  fi
fi

# Contents mode is the default.
if [[ -z $list$long$meta$contents ]] ; then
    contents=true
else
    contents=${contents:-false}
fi
list=${list:-false}
long=${long:-false}
meta=${meta:-false}

# Here we go.

if $meta ; then
    set +e
    diff ${diffopts:-$diffoopts} old.meta new.meta
    [[ $? -eq 0 || $? -eq 1 ]] || exit $?
    set -e
fi

if $list ; then
    find "$old" | sort | cut -d/ -f 2- -s > "$old.files"
    find "$new" | sort | cut -d/ -f 2- -s > "$new.files"
    set +e
    diff ${diffopts:-$diffoopts} "$old.files" "$new.files"
    [[ $? -eq 0 || $? -eq 1 ]] || exit $?
    set -e
fi

if $long ; then
    find "$old" -ls | \
        perl -pe "s|^(?:[\d\s]*)(\S+)(?:\s+\d+)(.+)$|\1\2| ;
                  s|.*\s\Q$old\E$|| ; s|(\s)\Q$old/\E|\1|" | \
        sort > "$old.files"
    find "$new" -ls | \
        perl -pe "s|^(?:[\d\s]*)(\S+)(?:\s+\d+)(.+)$|\1\2| ;
                  s|.*\s\Q$new\E$|| ; s|(\s)\Q$new/\E|\1|" | \
        sort > "$new.files"
    set +e
    diff ${diffopts:-$diffoopts} "$old.files" "$new.files"
    [[ $? -eq 0 || $? -eq 1 ]] || exit $?
    set -e
fi

if $contents ; then
    set +e
    diff -r ${diffopts:-$diffcopts} "$old" "$new"
    [[ $? -eq 0 || $? -eq 1 ]] || exit $?
    set -e
fi