#!/usr/bin/perl
#
# usage: fix-includes file_to_add.h before_file.h <files>
#

$toadd = shift @ARGV;
$before = shift @ARGV;

# build the dependency list
system("./tools/makedep -fdeps -Iinclude -Idlls/ddraw `find . -name \\*.h`");
open DEPS, "deps" or die "cannot open deps";
while (<DEPS>)
{
    chomp;
    while (/\\$/) { chop; $_ .= <DEPS>; }
    my ($obj,@deps) = split;
    for (my $i = 0; $i <= $#deps; $i++) { $deps[$i] =~ s/.*\///; }
    my $header = $deps[0];
    foreach my $f (@deps) { $includes{$header}{$f} = 1; }
}
close DEPS;
unlink "deps";

foreach $file (@ARGV)
{
    open IN, "$file" or die "cannot open $file";
    @lines = ();
    $added = 0;

    while (<IN>)
    {
        chomp;
        if (/^\s*\#\s*include\s+([<"])(.*)[>"]/)
        {
            my $quote = $1;
            my $incl = $2;

            if ($includes{$incl}{$toadd})
            {
                # the header includes the one we want
                last unless $added;  # not added yet, nothing to do
                next if ($incl eq $toadd);  # don't add it twice
            }
            elsif ($includes{$incl}{$before})
            {
                push @lines, ($quote eq "<") ? "#include <$toadd>\n" : "#include \"$toadd\"\n" unless $added;
                $added = 1;
            }
        }
        push @lines, $_ . "\n";
    }
    close IN;

    if ($added)
    {
        open OUT, ">$file.new" or die "cannot create $file.new";
        print OUT @lines;
        close OUT;
        print "changed $file\n";
        system "chmod --reference=$file $file.new";
        system "diff -u $file $file.new";
        rename "$file.new", "$file";
    }
}