#!/usr/bin/perl

use strict;
use warnings;
use Getopt::Long;
use File::Path;
use File::Basename;
use IO::File;

use JSON;

my $release = '@RELEASE@';

my $clicmd = shift or
    die "no command specified\n";

my $data_str = "";
while (<main::DATA>) { $data_str .= $_; }

my $fileinfo = decode_json($data_str);

my $tmpprefix = ".asciidoc-pve-tmp_";

my $adoc_source_dir = "/usr/share/pve-doc-generator";

# inside pve-docs source dir?
if (-f "attributes.txt" && -f "pve-admin-guide.adoc") {
    $adoc_source_dir = "."
}

my $prepared_files = {};

my $env_stack = [];
my $env_skip = 0;

sub push_environment {
    my ($env, $skip) = @_;

    $skip = 1 if $env_skip;
    $skip = 0 if !defined($skip);

    push @$env_stack, [$env, $skip];

    $env_skip = $skip;
}

sub pop_environment {
    my ($env) = @_;

    my $last_stack_entry = pop @$env_stack;
    die "unable to pop env '$env'" if !defined($last_stack_entry);

    my ($last_env, $skip) = @$last_stack_entry;
    die "environment missmatch (${last_env} != $env)\n" if $last_env ne $env;

    if (!scalar(@$env_stack)) {
	$env_skip = 0;
    } else {
	my (undef, $skip) = @{$env_stack->[-1]};
	$env_skip = $skip;
    }
}

sub replace_wiki_xref {
    my ($blockid, $text) = @_;

    my $link = $fileinfo->{blockid_target}->{wiki}->{$blockid};
    my $reftext = $fileinfo->{reftext}->{wiki}->{$blockid};

    die "unable to resolve wiki link (xref:$blockid)\n"
	if !defined($link);

    $text = $reftext if !length($text);

    die "xref: no text for '$blockid'\n" if !$text;

    return "$link\[$text\]";
}

sub prepare_adoc_file {
    my ($filename, $attributes) = @_;


    return if $prepared_files->{$filename};

    print "PREPARE $filename\n";

    $prepared_files->{$filename} = 1;

    my $dirname = dirname($filename);
    my $basename = basename($filename);

    my $outfilename = "$dirname/${tmpprefix}$basename";

    my $fh = IO::File->new("$filename", "r") or
	die "unable to open file '$filename' - $!\n";

    my $outfh = IO::File->new("$outfilename", "w") or
	die "unable to open temporary file '$outfilename'\n";

    while (defined (my $line = <$fh>)) {
	if ($line =~ m/^if(n?)def::(\S+)\[(.*)\]\s*$/) {
	    my ($not, $env, $text) = ($1, $2, $3);
	    die "unsuported ifdef usage - implement me" if $text;

	    my $skip = !exists($attributes->{$env}) ? 1 : 0;
	    $skip = ($skip ? 0 : 1 ) if $not;

	    push_environment($env, $skip);
	    next;
	} elsif ($line =~ m/^endif::(\S+)\[(.*)\]\s*$/) {
	    my ($env, $text) = ($1, $2);
	    die "unsuported ifdef usage - implement me" if $text;
	    pop_environment($env);
	    next;
	}

	next if $env_skip;

	if ($line =~ m/^include::(\S+)(\[.*\]\s*)$/) {
	    my ($fn, $rest) = ($1, $2);
	    print "INCLUDE: $fn\n";
	    my $new_fn = prepare_adoc_file($fn, $attributes);
	    $line = "include::${new_fn}$rest\n";
	}

	# fix xrefs
	$line =~ s/xref:([^\s\[\]]+)\[([^\]]*)\]/replace_wiki_xref($1,$2)/ge;

	$line =~ s/<<([^\s,\[\]]+)(?:,(.*?))?>>/replace_wiki_xref($1,$2)/ge;

	print $outfh $line;
    }

    return $outfilename;
}

sub compile_wiki {

    my $verbose;
    my $outfile;
    my $target_env;

    GetOptions ("outfile=s" => \$outfile,
		"verbose"   => \$verbose) or
		    die("Error in command line arguments\n");

    my $infile = shift(@ARGV) or
	die "no input file specified\n";

    scalar(@ARGV) == 0 or
	die "too many arguments...\n";

    my $env = 'wiki';


    my $title = $fileinfo->{titles}->{$env}->{$infile} or
	die "unable to get title for '$infile'\n";


    print "compile: $title\n";

    my $leveloffset = 0;

    my $doctype = $fileinfo->{doctype}->{$env}->{$infile} // 0;
    $leveloffset = - $doctype;

    my $date = `date`;
    chomp $date;

    my $attributes = {
	$env => undef,
	icons => undef,
	'data-uri' => undef,
	date => $date,
	leveloffset => $leveloffset,
	revnumber => $release,
    };

    my $cmd = ['asciidoc', '-s'];

    foreach my $key (keys %$attributes) {
	my $value = $attributes->{$key};
	if (defined($value)) {
	    push @$cmd, '-a', "$key=$value";
	} else {
	    push @$cmd, '-a', $key;
	}
    }

    push @$cmd, '--verbose' if $verbose;

    if (!defined($outfile)) {
	$outfile = $infile;
	$outfile =~ s/\.adoc$//;
	$outfile .= ".html";
    }

    push @$cmd, '--out-file', $outfile;

    my $new_infile = prepare_adoc_file($infile, $attributes);

    push @$cmd, $new_infile;

    print "RUN " . join(' ', @$cmd) . "\n";

    system(@$cmd) == 0 or
	die "aciidoc error";
}

if ($clicmd eq 'compile-wiki') {

    eval { compile_wiki(); };
    my $err = $@;

    # cleanup

    die $err if $err;

} else {

    die "unknown command '$clicmd'\n";

}






exit 0;

__END__