#! /usr/bin/perl
use strict;
use warnings;

my ($elinks, $option) = @ARGV;

if ($option =~ /command/) {
    open my $pipe, "-|", $elinks, "--long-help" or die;
    my $version = <$pipe>;
    chomp $version;
    $version =~ s/^ELinks ([-.\w]+).*$/$1/ or die "unusual version: $version";
    my $blank = 1;
    while (<$pipe>) {
	if (/^ {4}(-.*?) *$/) {
	    # '    -anonymous [0|1] (default: 0)'
	    # '    -config-dir <str> (default: "")'
	    $_ = $1;
	    s/ {2,}/ /g;
	    print "${_}::\n";
	} elsif (/^ {12}\t(-eval .*)$/) {
	    print "\n\t$1\n";
	} elsif (/^ {12}\t(\w+\(.*\)) +: (.*)$/) {
	    # '            	openURL(URL, new-tab)     : open URL in new tab'
	    print "\t- `$1`: $2\n";
	} elsif (/^ {12}\t(\d+) (means .+)$/) {
	    # '            	0 means only show serious errors'
	    print "\t- $1:\t$2\n";
	} elsif (s/^ {12}//) {
	    s/'([^']+)'/\\'$1\\'/g;
	    s((~/\.elinks|-dump|-default-mime-type|text/html|-touch-files|-no-connect|-session-ring))(`$1`)g;
	    s/(ELinks|HOME)/'$1'/g;
	    print "\t$_";
	} else {
	    print "\n" unless $blank;
	    $blank = 2;
	}
	$blank = ($blank == 2);
    }
    print "Generated using output from ELinks version $version.\n";
} elsif ($option =~ /config/) {
    open my $pipe, "-|", $elinks, "--config-help" or die;
    my $version = <$pipe>;
    chomp $version;
    $version =~ s/^ELinks ([-.\w]+).*$/$1/ or die "unusual version: $version";
    my $blank = 1;
    my $continued = 0;
    while (<$pipe>) {
	if (/^ {2}[^ ].*: \(([-.\w]+)\)$/) {
	    # '  Active link: (document.browse.links.active_link)'
	    print "$1::\n";
	} elsif (/^ {4}([^ ].*?)$/) {
	    # '    bookmarks.file_format <num> (default: 0)'
	    print "$1::\n";
	} elsif (/^ {12,}$/) {
	    print "+\n";
	    $continued = 1;
	} elsif (s/^ {12,}//) {
	    # escape things that might look like AsciiDoc markup
	    s/'(.*?)'/\\'$1\\'/g;
	    s/\{(.*?)\}/\\{$1\\}/g;
	    # add the actual AsciiDoc markup
	    s/(ELinks|WWW_HOME)/'$1'/g;
	    s((~/\.elinks))(`$1`)g;
	    if (/^(-?\d[-+\d]*?) +(.*)$/) {
		# '            1+ is use cookie's expiration date, but limit age to the given'
		print "\t- $1:\t$2\n";
	    } elsif ($continued) {
		print "$_";
	    } else {
		print "\t$_";
	    }
	} else {
	    print "\n" unless $blank;
	    $blank = 2;
	    $continued = 0;
	}
	$blank = ($blank == 2);
    }
    print "Generated using output from ELinks version $version.\n";
} else {
    die "usage: $0 ELINKS-EXECUTABLE option-command.txt\n"
      . "   or: $0 ELINKS-EXECUTABLE option-config.txt\n";
}