#!/usr/bin/perl

use strict;

chdir('patches') if -d 'patches';

if (!-f 'verify-patches') {
    die <<EOT;
Please run this script from the root of the rsync dir or
from inside the patches subdir.
EOT
}

$ENV{'TZ'} = 'GMT';

my($has_dependencies, @new);

END {
    &restore_cvsdir;
};

my $root;
open(IN, '../CVS/Root') or die $!;
chomp($root = <IN>);
close IN;

my $tmpdir = ',tmp-for-patch-tests';

mkdir($tmpdir, 0777) unless -d $tmpdir;
chdir($tmpdir) or die "Unable to chdir to $tmpdir";

mkdir('workdir') unless -d 'workdir';
open(OUT, '>exclude') or die $!;
print OUT <<EOT;
proto.h
configure
config.h.in
rsync.1
rsyncd.conf.5
EOT
close OUT;

print "Using CVS to update the $tmpdir/cvsdir copy of the source.\n";
system qq|cvs -d "$root" co -d cvsdir rsync|;

@ARGV = glob('../*.diff') unless @ARGV;

DIFF:
foreach my $diff (@ARGV) {
    next unless $diff =~ /\.diff$/;
    next if $diff =~ /gzip-rsyncable\.diff$/;
    $diff =~ s#^(patches|\.\.)/##;

    open(IN, "../$diff") or die $!;
    while (<IN>) {
	last if /^--- /;
	if (/^Depends-On-Patch: (\S+.diff)$/) {
	    my $dep = $1;
	    $has_dependencies = 1;
	    print "\nApplying dependency patch $dep\n";
	    if (system("patch -d cvsdir -p0 -b -Vt -Z <../$dep") != 0) {
		print "Unable to cleanly apply depenency patch -- skipping $diff\n";
		&restore_cvsdir;
		next DIFF;
	    }
	}
    }
    close IN;

    my $apply = 1;
    my(@rejects, $default);
    while (1) {
	print "\n----------- $diff ------------\n";
	if ($apply) {
	    undef @new;
	    $default = 'N';
	    system "rsync -a --delete cvsdir/ workdir";
	    open(IN, "patch -d workdir -p0 --no-backup-if-mismatch -Z <../$diff |") or die $!;
	    while (<IN>) {
		print $_;
		chomp;
		if (s/^patching file //) {
		    push(@new, $_) unless -f "cvsdir/$_";
		} elsif (s/.* saving rejects to file //) {
		    push(@rejects, $_);
		} elsif (/^Hunk #\d+ FAILED/) {
		    $default = 'F';
		} elsif (/^Hunk #\d+ succeeded/) {
		    $default = 'E' unless $default eq 'F';
		}
	    }
	    close IN;
	    if ($default eq 'N') {
		generate_new_patch($diff);
		if (system("diff ../$diff new.patch >/dev/null") == 0) {
		    print "\n(New patch is identical to old.)\n";
		}
	    }
	    $apply = 0;
	}
	print "\nFix rejects, Edit both diffs, Update patch,\n",
	    "Apply patch again, Next, Quit: [$default] ";
	my $ans = <STDIN>;
	chomp $ans;
	$ans = $default unless $ans =~ s/^(\w)/$1/;
	if ($ans =~ /E/i) {
	    generate_new_patch($diff);
	    chdir('workdir') or die $!;
	    system "vim -d ../../$diff ../new.patch";
	    chdir('..') or die $!;
	    $default = 'U';
	} elsif ($ans =~ /F/i) {
	    chdir('workdir') or die $!;
	    system "vim @rejects";
	    chdir('..') or die $!;
	    $default = 'E';
	} elsif ($ans =~ /U/i) {
	    system "cp -p new.patch ../$diff";
	    print "\nUpdated $diff from new.patch\n";
	    $default = 'A';
	} elsif ($ans =~ /A/i) {
	    $apply = 1;
	} elsif ($ans =~ /N/i) {
	    last;
	} elsif ($ans =~ /Q/i) {
	    exit;
	}
    }

    &restore_cvsdir;
}

exit;


sub generate_new_patch
{
    my($diff) = @_;

    foreach (@new) {
	system "touch -r workdir/$_ cvsdir/$_";
    }
    open(IN, "../$diff") or die $!;
    open(OUT, '>new.patch') or die $!;
    while (<IN>) {
	last if /^--- /;
	print OUT $_;
    }
    close IN;
    open(IN, 'diff --exclude-from=exclude -upr cvsdir workdir |') or die $!;
    while (<IN>) {
	next if /^(diff -|Index: |Only in )/;
	s#^\Q--- cvsdir/\E#--- orig/#;
	s#^\Q+++ workdir/\E#+++ #;
	s#(\.000000000)? \+0000$##;
	print OUT $_;
    }
    close IN;
    close OUT;
    foreach (@new) {
	unlink("cvsdir/$_");
    }
}

sub restore_cvsdir
{
    return unless $has_dependencies;
    $has_dependencies = 0;

    foreach (glob('*.~[1-9]~'), glob('*/*.~[1-9]~')) {
	my $fn;
	($fn = $_) =~ s/\.~1~$//;
	if ($fn eq $_) {
	    unlink($_);
	} elsif (-r $fn) {
	    rename($_,  $fn);
	} else {
	    unlink($_);
	    unlink($fn);
	}
    }
}