#!/usr/bin/perl -w
#
# The FreeBSD Japanese Documentation Project
#
# This is a preprocessor for HTML docs.
#
# usage: prehtml [-revcheck <localtop> <relative to localtop>] <SGML filename>
#   (ex. % prehtml -revcheck ../.. news/1996 index.sgml)
#
# $FreeBSD: www/ja/prehtml,v 1.1 2000/10/02 09:16:04 kuriyama Exp $

my $revcheck;
my $topdir;
my $reldir;

my %file;
my %rev;

### parse options ....................................................
###
sub sOPT {1};
sub sARG {2};

my $opt_state = sOPT;
my $argv;

while(defined($_ = $ARGV[0])) {

    if ($opt_state eq sOPT) {
        # option expected        
        if(/^-(.+)/) {
            shift @ARGV; # discard option itself;
            local $_ = $1;
            /revcheck/ and do {
                $topdir = shift @ARGV;
                $reldir = shift @ARGV;
                if($reldir ne '' and $reldir !~ /\/$/) {
                    $reldir .= "/";
                }
                $revcheck = 1;
                next;
            };
        } else {
            # this is not a option but an argument
            $opt_state = sARG;
            next;
        }
    } elsif ($opt_state eq sARG) {
        $file{target} = $_;
        if($revcheck) {
            s/.sgml$//;
            my $basename = $_;
            $file{cvsweb}  = "www/en/${reldir}${basename}.sgml";
            $file{orgbase} = "${topdir}/../en/${reldir}${basename}";
            $rev{org} = get_rev_org($file{orgbase}.".sgml");
        }
        last;
    }
    die "internal error: option parsing abnormally terminated.\n";
}

### add and replace entities .........................................
###
open TARGET,"<$file{target}" or die "cannot open a target file: $!\n";
my $pos_date;
### first, get date string and rev_target
while(defined($_ = <TARGET>)) {
    if(/<!ENTITY\s+date/) {
        $pos_date = tell(TARGET);
        if(m/\"\$Free[B]SD: [^\s]+ [.0-9]+ ([\/0-9]+)[^\$]*\$\"/) {
            $date = "<!ENTITY date \"Last modified: $1\">";
        } else {
            $date = "<!ENTITY date \"Last modified: UNKNOWN\">";
        }
    }
    if(/<!ENTITY\s+title/) {
        $pos_title = tell(TARGET);
    }

    if($revcheck) {
        if(/[Oo]riginal [Rr]evision:[ \t]*([0-9.]+)/) {
            $rev{target} = $1;
        }
        last if($revcheck and $rev{target} and $date);
    } else {
        last if($date);
    }
}

$rev{target} ||= "TARGET revision not found";
$rev{org}    ||= "ORG revision not found";

### if offset of "date" string is not found,
### use "title"'s instead.
if(not defined $pos_date) {
    if(not defined $pos_title) {
        die qq/element "date" or "title" is not defined.\n/;
    }
    $pos_date = $pos_title;
}

### next, put lines and replace the line with
### $date + entity difinitions for revcheck 
seek TARGET,0,0;
while(defined($_ = <TARGET>)) {
    if(tell(TARGET) == $pos_date) {
        print $date,"\n";
        if($revcheck) {
            #print STDERR "$rev{org} -> $rev{target}\n";
            print "<!ENTITY base CDATA '$topdir'>\n";
            print "<!ENTITY file.cvsweb  CDATA '$file{cvsweb}'>\n";
            print "<!ENTITY file.orgbase CDATA '$file{orgbase}'>\n";
            print "<!ENTITY rev.latest CDATA '$rev{org}'>\n";
            print "<!ENTITY rev.target CDATA '$rev{target}'>\n";
            printf "<!ENTITY %% rev.diff '%s'>\n", ($rev{org} eq $rev{target}) ? "IGNORE" : "INCLUDE";
        }
    } else {
        # for backward compatibility
        s/<!ENTITY \% rev.incl SYSTEM "[-a-zA-Z0-9]+.revinc"> \%rev.incl;//;
        print;
    }
}
close TARGET;

exit 0;

sub get_rev_org 
{
    my $infile = shift @_;
    my $rev_org;

    open ORG,"<$infile" or return undef;
    while(defined($_ = <ORG>)) {
        if(/\$Free[B]SD: [^\s]+ ([.0-9]+) [\/0-9]+[^\$]*\$/) {
            $rev_org = $1;
            last;
        }
    }
    close ORG;
    return $rev_org;
}

__END__