#!@PERL@
###############################################################################
##
## $Id: gift-setup.in,v 1.7 2004/11/14 22:44:25 hexwab Exp $
##
## Wrapper for the configuration templates installed in ${datadir}/giFT.
##
## Copyright (C) 2001-2003 giFT project (gift.sourceforge.net)
##
## This program is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by the
## Free Software Foundation; either version 2, or (at your option) any
## later version.
##
## This program is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
###############################################################################

use strict;
use Data::Dumper;
use IO::File;

###############################################################################

my $datadir = '@giftdatadir@';
my $confdir = "$ENV{HOME}/.giFT";

###############################################################################

main();

sub main
{
	return if (!check_uid ());
		
	my $templates = find_templates ($datadir);
	my $configed  = find_configured ($confdir);

	# no available templates, bogus install
	if (scalar @$templates == 0)
	{
		print <<"__EOF__";

 *** ERROR ***

No available configuration templates were found.  This could mean that you
legitimately have none and need to install the giFT daemon properly or that
you have placed them in an alternate data directory than this script is
looking.  The configuration template path being used is:

	$datadir

__EOF__

		return;
	}

	#
	# Configuration modules which will be read from the available templates.
	# This basically creates a new data structure which is a hash of module
	# entries, including ->{path_cfg} and ->{path_tpl}.  This data
	# structure may be further trimmed through the condition below.
	#
	my $modules_hash = build_modules ($configed, $templates);

	#
	# If there have been previously configured modules, we need to ask the
	# user if they'd like us to rebuild from available templates or only
	# add new configuration templates to the confdir.
	#
	if (scalar @$configed > 0)
	{
		print <<"__EOF__";

 *** WARNING ***

Previous configuration has been detected.  This script is capable of
preserving that configuration and only adding from new available templates.
If you choose no, all presently installed configuration modules will be used
in place of any custom configuration you have.  In the future, previous
configuration will be read and used as defaults, but this script does not
currently have such a feature.

__EOF__

 gotos_are_bad:
		print "Would you like to preserve old configuration? [Yn] ";

		chomp (my $yesno = <>); $yesno = 'y' unless $yesno;
		goto gotos_are_bad unless $yesno =~ m/[yn]/i;

		# print a little separator to help the user organize this output
		print_sep();

		if ($yesno =~ m/y/i)
		{
			#
			# Iterate through each configured entry and remove it from the
			# modules hash constructed above.  This is a horribly hackish
			# approach, but hey, it works and this is perl :)
			#
			foreach my $cfg (@$configed)
			{
				delete $modules_hash->{$cfg->{name}};
			}
		}
	}

	#
	# Convert the hash data structure to a list now that we don't need
	# the delete/exists hack.  This will also take care of fudging the
	# order so that gift and ui are before plugins.
	#
	my @modules = get_modules_list ($modules_hash);

	if (scalar @modules == 0)
	{
		print <<'__EOF__';
No configuration modules are available for processing.  This could be because
you have chosen to preserve old configuration and no new modules have been
added since last configuration.

__EOF__

		return;
	}

	# and away we go...
	my $n = process_modules (@modules);
	printf ("%d module(s) successfully processed.\n", $n);
}

###############################################################################

sub print_sep
{
	print "\n", '#' x 78, "\n\n";
}

###############################################################################

#
# Construct a list of all templates that are installed and available.
#
sub find_templates
{
	return find_conf_modules (shift, "*.conf.template");
}

#
# Construct a list of all configuration files that currently exist in the
# supplied config directory.
#
sub find_configured
{
	return find_conf_modules (shift, "*.conf");
}

sub find_conf_modules
{
	my $dir = shift;
	my $glob = shift;

	my @modules = ();

	#
	# Quick and dirty hack to access all template files in the supplied data
	# dir and the first depth underneath.  I would prefer to avoid using
	# File::Find, if possible.
	#
	foreach my $path ((glob ("$dir/$glob"), glob ("$dir/*/$glob")))
	{
		# just making sure...
		die "Cannot read $path: $!" unless -f $path && -r $path;

		#
		# Expose only the module name, that is the configuration object
		# name, instead of the path and file extension.  For example,
		# if given /usr/local/share/giFT/OpenFT/OpenFT.conf.template,
		# 'OpenFT' should be added as the module.
		#
		my @pathelem = split ('/', $path); my $file = pop @pathelem;
		my ($module) = $file =~ m/^(\w+)/;

		push @modules, { 'name' => $module, 'path' => $path };
	}

	return \@modules;
}

###############################################################################

sub build_modules
{
	my $cfg = shift;
	my $tpl = shift;

	my $modules = {};

	foreach my $template (@$tpl)
	{
		my $module = construct_module ($modules, $template->{name});
		$module->{path_tpl} = $template->{path};

		# try to guess the configuration path, in case no real config
		# module is present by that name...
		$module->{path_cfg} = guess_config_path ($module->{name});
	}

	foreach my $config (@$cfg)
	{
		#
		# Only templates are allowed to construct new module elements, because
		# we dont want to present configuration when no template exists
		# for parsing...
		#
		next unless exists $modules->{$config->{name}};

		# add the path_cfg member to the module object
		my $module = $modules->{$config->{name}};
		$module->{path_cfg} = $config->{path};
	}

	return $modules;
}

# simple short-hand to reduce code duplication
sub construct_module
{
	my $modules = shift;
	my $name    = shift;

	$modules->{$name} = {} unless exists $modules->{$name};

	$modules->{$name}->{name} = $name;
	return $modules->{$name};
}

sub guess_config_path
{
	my $name = shift;

	return "$confdir/giftd.conf" if ($name eq 'giftd');
	return "$confdir/$name/$name.conf";
}

###############################################################################

sub get_modules_list
{
	my $hash = shift;
	my @modules = ();

	# fudge the order
	push @modules, delete $hash->{'giftd'} if exists $hash->{'giftd'};
	push @modules, delete $hash->{'ui'} if exists $hash->{'ui'};

	push @modules, values %$hash;

	return @modules;
}

###############################################################################

sub process_modules
{
	my @modules = @_;

	# number of successfully processed modules
	my $ret = 0;

	foreach my $module (@modules)
	{
		# process this module atomically and flush all configuration
		$ret += process_module ($module);
	}

	return $ret;
}

sub process_module
{
	my $module = shift;

	printf ("Configuring %s (%s):\n", $module->{name}, $module->{path_tpl});
	print_sep();

	my $cfg_ents = parse_template ($module->{path_tpl});
	my $cfg_tbl  = {};

	foreach my $ent (@$cfg_ents)
	{
		my $dont_ask = 0;

		# WARNING: This is an absolutely terrible hack!  This functionality
		# needs to exist in the config template itself!
		if ($module->{name} eq 'OpenFT')
		{
			# if the user has configured as something other than a search
			# node, do not present relevant configuration switches to them.
			$dont_ask = 1 if ($ent->{key} =~ m%^/search/% &&
			                  !($cfg_tbl->{'/main/class'} & 0x2));
		}

		if ($ent->{default} =~ m/^random \((\d+), (\d+)\)/)
		{
			# create a random number and pretend the default value was that
			$ent->{value} = get_random_port ($1, $2);
		}

		my $resp;

		unless ($dont_ask)
		{
			printf ("%s\n\n", $ent->{label}) if $ent->{label};
			printf ("%s [%s] ", $ent->{key}, $ent->{value});

			$resp = <>; chomp $resp;
		}

		$resp = $ent->{value} unless $resp;
		$cfg_tbl->{$ent->{key}} = $resp;

		print_sep() unless $dont_ask;
	}

	write_config ($cfg_tbl, $module->{path_cfg}, $module->{path_tpl});

	1;
}

sub write_config
{
	my $cfg_tbl  = shift;
	my $path_cfg = shift;
	my $path_tpl = shift;

	my ($path_cfg_dir) = $path_cfg =~ m/^(.*)\/[^\/]+$/;
	mkdir ($path_cfg_dir, 0755) unless (-d $path_cfg_dir);
	
	my $fcfg = new IO::File;
	my $ftpl = new IO::File;

	open ($fcfg, ">$path_cfg") or
	  die "Cannot open $path_cfg: $!";

	open ($ftpl, $path_tpl) or
	  die "Cannot open $path_tpl: $!";

	my $cfg_hdr;

	while (<$ftpl>)
	{
		$cfg_hdr = $1 if m/^\[(\w+)\]$/;

		if (m/^\#?(\w+) =\s?(.*)$/)
		{
			die unless defined $cfg_hdr;
			printf $fcfg ("%s = %s\n", $1, $cfg_tbl->{"/$cfg_hdr/$1"});
		}
		else
		{
			print $fcfg $_;
		}
	}

	close $fcfg;
	close $ftpl;

	printf ("Wrote %s.\n", $path_cfg);
}

###############################################################################

sub parse_template
{
	my $template = shift;
	my @cfg_tbl = ();
	my $cfg_ent = {};
	my $cfg_hdr = undef;
	
	my $fhandle = new IO::File;

	open ($fhandle, $template) or
	  die "Cannot open $template: $!";

	#
	# Special flag used to switch on reading of the leading config switch
	# documentation.  This is switched on as soon as a blank comment line
	# is observed, which by convention begins the comment.  It is turned off
	# once the actual configuration switch is seen.
	#
	my $reading = 0;

	while (<$fhandle>)
	{
		$cfg_hdr = $1 if m/^\[(\w+)\]$/;

		# determine when to begin processing a single config switch
		$reading = 1 if m/^\#\s*$/ or m/^\w+ =/;
		next unless $reading;

		if (m/^\#\s(.*)$/ or m/^\#(\s*)$/)
		{
			$cfg_ent->{label} .= "$1\n";
			$cfg_ent->{default} = $1 if ($1 =~ m/^Default: (.*)$/);
		}
		else
		{
			if (m/^\#?(\w+) =\s?(.*)$/)
			{
				$cfg_ent->{key} = "/$cfg_hdr/$1";
				$cfg_ent->{value} = $2;

				# tidy up
				$cfg_ent->{label} =~ s/^\s*//;
				$cfg_ent->{label} =~ s/\s*$//;
				$cfg_ent->{default} = undef if ($cfg_ent->{default} eq 'none');

				push @cfg_tbl, $cfg_ent;
			}
			else
			{
				print "shouldnt happen, bogus template, something!\n\n$_\n\n";
				print Dumper $cfg_ent;
			}

			$cfg_ent = {};
			$reading = 0;
		}
	}

	close $fhandle;

	return \@cfg_tbl;
}

###############################################################################

sub get_random_port
{
	my ($min, $max) = @_;

	# TODO: should we do any checks on the value before we spit it back out?
	my $num = int (rand (($max - $min)) + $min);

	return $num;
}

###############################################################################

sub check_uid
{
	return 1 if $<;

	print <<"__EOF__";

 *** WARNING ***

You are running this script as root.  Instead, you should run it as the
user you intend to run giFT as (setup files are created in the user's
home directory).  If you intend to run giFT as root (not advised), or
if your system does not support multiple users, you may continue at
your own risk.

__EOF__

	my $yesno;
	do {
		print "Do you want to continue anyway? [yN] ";
	} while (($yesno = <>) !~ m/^[yn]?$/i);

	return ($yesno =~ m/y/i);
}