#!/usr/bin/perl

use strict;
use IO::File;
use Getopt::Std;
our %opts = (W => 2);

getopts('ohwW:', \%opts) || usage();

usage() if ($opts{'h'});

usage() if ($#ARGV != 1);

# should be the feature-details.h file
my $inputfile = shift @ARGV;
my $outputfile = shift @ARGV;

my %features;
my %top;
my %files;
my $reqfile;

gather_data($inputfile);
if ($opts{'w'}) {
    print_wiki_mode($outputfile);
} else {
    print_org_mode($outputfile);
}

sub gather_data {
    my ($inputfile) = @_;

    open(I, $inputfile);
    while(<I>) {
	if (/(required|provided|wanted) by (.*) \*/) {
	    $reqfile = $2;
	} elsif (/define NETSNMP_FEATURE_PROVIDE_(.*) 1/) {
	    my $lc = lc($1);
	    die "no reqfile currently set; bug!" if (!defined($reqfile));

	    add($lc);

	    push @{$files{$reqfile}{'provides'}}, $lc;
	    push @{$features{$lc}{'providedby'}}, $reqfile;

	} elsif (/define NETSNMP_FEATURE_REQUIRE_(.*) 1/) {
	    my $lc = lc($1);
	    die "no reqfile currently set; bug!" if (!defined($reqfile));

	    add($lc);

	    push @{$files{$reqfile}{'requires'}}, $lc;
	    push @{$features{$lc}{'requiredby'}}, $reqfile;

	} elsif (/define NETSNMP_FEATURE_WANT_(.*) 1/) {
	    my $lc = lc($1);
	    die "no reqfile currently set; bug!" if (!defined($reqfile));

	    add($lc);

	    push @{$files{$reqfile}{'wants'}}, $lc;
	    push @{$features{$lc}{'wantedby'}}, $reqfile;
	} elsif (/define NETSNMP_FEATURE_(.*)_CHILD_OF_(.*) 1/) {
	    my $child = lc($1);
	    my $parent = lc($2);

	    add_child($child, $parent);
	}
    }
}

sub add {
    my ($name) = @_;
    if (!exists($features{$name})) {
	# new feature entirely, mark it as a top node
	$top{$name} = 1;
    }
}

sub add_child {
    my ($child, $parent) = @_;

    add($parent);

    if (exists($top{$child})) {
	# it's no longer a top node if it's a child of something else
	delete $top{$child};
    }
    $features{$parent}{'children'}{$child}++;

    $features{$child}{'providedby'}, $reqfile;
}

######################################################################
# org-mode output
#
sub print_org_mode {
    my ($outputfile) = @_;

    my $fh = new IO::File;

    if (!$fh->open("> $outputfile")) {
	die "error!\n";
    }

    foreach my $node (sort keys(%top)) {
	print_org_node($fh, $node, "*");
    }
}

sub print_org_node {
    my ($fh, $node, $prefix) = @_;

    my $spaces = $prefix;
    $spaces =~ s/./ /g;

    print $fh "$prefix $node\n";
    if (exists($features{$node}{'providedby'})) {
	print $fh "$spaces + provided in file: " .
	    join(", ", org_link_files(@{$features{$node}{'providedby'}})) . "\n";
    }
    if (exists($features{$node}{'requiredby'})) {
	print $fh "$spaces + required in file: " .
	    join(", ", org_link_files(@{$features{$node}{'requiredby'}})) . "\n";
    }
    if (exists($features{$node}{'wantedby'})) {
	print $fh "$spaces + wanted in file: " .
	    join(", ", org_link_files(@{$features{$node}{'wantedby'}})) . "\n";
    }
    if (exists($features{$node}{'children'})) {
	foreach my $child (sort keys(%{$features{$node}{'children'}})) {
	    print_org_node($fh, $child, $prefix . "*");
	}
    }
}

sub org_link_files {
    my @files = @_;
    map { $_ = "[[file:$_][$_]]"; } @files;
    return @files;
}

######################################################################
# wiki output
#
sub print_wiki_mode {
    my ($outputfile) = @_;

    my $fh = new IO::File;
    my $depth = 0;

    if (!$fh->open("> $outputfile")) {
	die "error!\n";
    }

    print $fh "'''The contents of this page is auto-generated from local/minimalist/feature-makedocs; do not edit by hand (changes will be lost)'''\n\n";
    print $fh "Details of the feature marking system and how it is used can be found at [[Feature Marking and Selection]]\n\n";

    foreach my $node (sort keys(%top)) {
	print_wiki_node($fh, $node, $depth+1);
    }
}

sub print_wiki_node {
    my ($fh, $node, $depth) = @_;

    my $dataheader;
    my $depthincrease = 1;

    if ($depth > $opts{'W'}) {
	print $fh "*" x ($depth - $opts{'W'} + 1) . " $node\n";
	$dataheader = "*" x ($depth - $opts{'W'} + 2);
	$depthincrease++;
    } else {
	print $fh "=" x $depth . " $node " . "=" x $depth . "\n";
	$dataheader = "*";
    }

    if (exists($features{$node}{'providedby'})) {
	print $fh "$dataheader provided in file: " .
	    join(", ", wiki_link_files(@{$features{$node}{'providedby'}})) ."\n";
    }
    if (exists($features{$node}{'requiredby'})) {
	print $fh "$dataheader required in file: " .
	    join(", ", wiki_link_files(@{$features{$node}{'requiredby'}})) ."\n";
    }
    if (exists($features{$node}{'wantedby'})) {
	print $fh "$dataheader wanted in file: " .
	    join(", ", wiki_link_files(@{$features{$node}{'wantedby'}})) . "\n";
    }
    if (exists($features{$node}{'children'})) {
	if ($depth >= $opts{'W'}) {
	    print $fh "$dataheader Children:\n";
	}
	foreach my $child (sort keys(%{$features{$node}{'children'}})) {
	    print_wiki_node($fh, $child, $depth + $depthincrease);
	}
    }
}

sub wiki_link_files {
    my @files = @_;
    map { $_ = "[http://net-snmp.svn.sourceforge.net/viewvc/net-snmp/trunk/net-snmp/$_?view=markup $_]"; } @files;
    return @files;
}

######################################################################
# help output
#
sub usage {
    print "Usage: $0 [FLAGS] INPUTFILE OUTPUTFILE\n\n";
    print "FLAGS:\n";
    print "\t-h\thelp\n";
    print "\t-o\tOutput style: Org-Mode [default]\n";
    print "\t-w\tOutput style: wiki\n";
    print "\t-W DEPTH\tWiki header to bullet list depth (default 2)\n";
    print "\nINPUT/OUTPUT\n";
    print "\tINPUTFILE:\tlocation of the include/net-snmp/feature-details.h file\n";
    print "\tOUTPUTFILE:\tthe file to write the results to\n";
    exit;
}