#!/usr/bin/perl -w

# Rebuild an RPM .spec file from a package
# Waider July 25 2000
#
# 03/11/2004 Add changelog
#            Check for other packages built from the same source file
#            Clean up file listing a little
use POSIX;
use Data::Dumper;

# Get the basics
$rpm = "/bin/rpm";
$file = shift;
die unless $file;

# Find out if this is an installed package or something on disk
open( INFO, "$rpm -q $file|" );
@info = <INFO>;
close( INFO );

if ( grep /^package $file is not installed$/, @info ) {
  $pkg = "p";
} else {
  $pkg = "";
}

# Handy variable to have around
$thispkg = `$rpm -q$pkg --queryformat '[%{NAME}-%{VERSION}]' $file`;

# see if there's anything else built from the same src.rpm as this
my @allpkgs = ( $thispkg );
my $srcrpm = `$rpm -q$pkg --queryformat '[%{SOURCERPM}]' $file`;
print STDERR "Source came from $srcrpm, looking for other packages built from that...\n";
for my $line ( split( /\n/, `$rpm -qa --queryformat '%{SOURCERPM} %{NAME}-%{VERSION}\n'` )) {
    my ( $s, $p ) = split( ' ', $line );
    if ( $s eq $srcrpm ) {
        push @allpkgs, $p unless grep /^$p$/, @allpkgs;
    }
}

# Some of this is bloody EVIL.
$format =<<"EOF";
Summary: %{SUMMARY}
Name: %{NAME}
Version: %{VERSION}
Release: %{RELEASE}
Copyright: %{COPYRIGHT}%|COPYRIGHT?{}:{ DELETEME}|
Group: %{GROUP}
Source: %{SOURCE}%|SOURCE?{}:{ DELETEME}|
%|SOURCE?{ DELETEME}:{Source: $thispkg.tar.gz}|
Url: %{URL}%|URL?{}:{ DELETEME}|
Packager: %{PACKAGER}%|PACKAGER?{}:{ DELETEME}|
Vendor: %{VENDOR}%|VENDOR?{}:{ DELETEME}|
Requires: [%{REQUIRENAME} %{REQUIREFLAGS} %{REQUIREVERSION} ]%|REQUIRENAME?{}:{ DELETEME}|
Provides: [%{PROVIDES} ]

%%description
%{DESCRIPTION}

%%prep

%%setup

%%build

%%install

%%clean

%%pre%|PREIN?{}:{ DELETEME}|
%{PREIN}%|PREIN?{\n}:{ DELETEME}|
%%post%|POSTIN?{}:{ DELETEME}|
%{POSTIN}%|POSTIN?{\n}:{ DELETEME}|
%%preun%|PREUN?{}:{ DELETEME}|
%{PREUN}%|PREUN?{\n}:{ DELETEME}|
%%postun%|POSTUN?{}:{ DELETEME}|
%{POSTUN}%|POSTUN?{\n}:{ DELETEME}|
%%files
EOF

print "Recovering huge lumpy chunks\n";
@lines = grep !/ DELETEME$/, `$rpm -q$pkg --queryformat '$format' $file`;

# MAGIC!
@lines = map { if ( /^Requires\: / ) {
    s/\s+0\s+/ /g;
    s/12/>=/g;
    s/16396/>=/g;
    s/ (16384|64|1344|4416) //g; # no version specified
    s/(16777290|74)/<=/g;
} $_; } @lines;

# Ideally, we could slim down the above by figuring out what provides
# each requirement, and sorting and uniquing that.

# Now figure out the %files section
print STDERR "recovering files list...\n";
@lines2 = `$rpm -q$pkg --queryformat '[%{FILEFLAGS} %{FILENAMES}\n]' $file`;

# Fix the flags for each file
@lines2 = map { s|^2 (/usr/(share/)?doc/$thispkg/)?|\%doc |;
				s|^1 |\%config |;
				s|^0 ||;
				s|/usr/doc/$thispkg\n||; # throw away
				$_ } @lines2;

# clean up the files list a bit
my @docs = grep /^\%doc/, @lines2;
my @files = grep !/^\%doc/, @lines2;

my @man = grep /\/man\d/, @docs;
@docs = grep !/\/man\d/, @docs;
@man = map { s|\%doc ||; $_ } @man;

push @lines, join( " ", "\%doc", map { s|^\%doc (.*)\n|$1|; $_ } @docs ) . "\n";

push @lines, ( @files, @man );

# add in the changelog
push @lines, "\n";
push @lines, "\%changelog\n";

for my $cl ( split( '\n', `$rpm -q$pkg --queryformat '[* %{CHANGELOGTIME} %{CHANGELOGNAME}\n%{CHANGELOGTEXT}\n\n]' $file` )) {
    if ( $cl =~ /^\* (\d+) (.*)$/ ) {
        $cl = strftime( "* %a %b %e %Y $2", gmtime( $1 ));
    }
    push @lines, $cl . "\n";
}

open( SPEC, ">$thispkg-rebuilt.spec" );
print SPEC @lines;
close( SPEC );