#!/usr/bin/perl
######################################################################
# This is a simple shell for the AI::ExpertSystem::Simple inference
# engine class. The -t switch is used to provide an interface for the 
# consult tcl/tk interface that allows the users to run the program
# with a tk based gui.
######################################################################
use strict;
use warnings;
$| = -1;
use Getopt::Std;
use AI::ExpertSystem::Simple;
my %opts;
getopts('t',\%opts);
my $tkinterface = defined $opts{t};
if ( scalar(@ARGV) != 1 ) { die "usage: $0 [-t] <file.xml>"; }
my $filename = $ARGV[0];
if ( !-f $filename ) { die "The file '$filename' is not a file"; }
if ( !-r $filename ) { die "The file '$filename' is not readable"; }
######################################################################
# The main loop
######################################################################
my $s = AI::ExpertSystem::Simple->new();
$s->load($filename);
say_status("Consulting $filename");
my $continue = 'yes';
while($continue eq 'yes') {
        my $running = 1;
        while ($running) {
                my $r = $s->process();
                process_log();
                if ( $r eq 'question' ) {
                        $s->answer( ask_question( $s->get_question() ) );
                }
                elsif ( $r eq 'finished' ) {
                        say_status('The answer is : ' . $s->get_answer());
                        $s->explain();
                        process_log( 'explaination' , 1);
                        $running = undef;
                }
                elsif ( $r eq 'failed' ) {
                        say_status("Unable to answer your question");
                        $running = undef;
                }
        }
        if($tkinterface) {
                $continue = 'no';
        } else {
                $continue = ask_question( 'Another consoltation', 'yes', 'no' );
                $s->reset();
        }
}
######################################################################
# Ask a question of the user showing the available responses
######################################################################
sub ask_question {
        my ( $text, @responses ) = @_;
        my $number = scalar(@responses);
        my $x      = 0;
        while ( $x < 1 or $x > $number ) {
                say_question($text);
                for ( my $y = 1 ; $y <= $number ; $y++ ) {
                        say_something('response', " $y : ", $responses[$y - 1]);
                }
                if($tkinterface) {
                        say_something('response', '', '*');
                } else { 
                        print '** ';
                }
                $x = <STDIN>;
                $x = 0 if $x !~ m#^[0-9]+$#;
        }
        return $responses[ $x - 1 ];
}
######################################################################
# The various ways of printing out a message
######################################################################
sub say_status   { say_something('status',   '>> ', shift) }
sub say_question { say_something('question', '',    shift) }
sub say_something {
        my ($tag1, $tag2, $text) = @_;
        if($tkinterface) {
                print "$tag1:$text\n";
        } else {
                print "$tag2$text\n";
        }
}
######################################################################
# The various ways of printing out a message
######################################################################
sub process_log {
        my ($prefix, $override) = @_;
        $prefix = 'information' unless $prefix;
        my @log = $s->log();
        if($tkinterface or $override) {
                foreach my $line (@log) {
                        say_something($prefix, '', $line);
                }
        }
}