#!/usr/bin/perl

#this is a perl implementation of the radoteur from the book "Théorie du Bordel
#Ambiant" authored by the french researcher Roland Moreno
#It will take a word list as input and output giberrish-y words from it, after
#a while it will cycle, this program has been specially written to identify
#the relationship between the wordlist and the size of the cycles
#next thing would be to do some stat works on the word size, their numbers
#inside the wordlist to find the equation that models the word list - cycle
#size the most accurately

use strict;
use warnings;
use autodie;
my($evt,$niter);
my $cycled = 0;
$niter= 0;

#this is a double hash, the first level keys are line numbers, the second
#its values are another hash which keys are letter coordinates inside the 
#line's word, if we have the same letter in the same word on the same line
#appear twice then we have cycled
my %letter_lines;
if(!defined $ARGV[0]){
    die "to use me, give me the word list file as argument\n";
}
while($cycled == 0){
	open my $fh, '<',$ARGV[0];
	FILE_ITER: while(<$fh>){
			#here I take in the new word and split it into its letters
			#I also count the iteration number
		my $word = $_;
		$niter++;
		my @letters = split("", $word);

			#if evt is undefined, that's because we were looking for a newline
			#in the previous event or its the first iteration, in any case
			#the new event will be the first letter of the current word
		if(!defined($evt)){

			if(defined $letter_lines{$.}{0}){
							warn "we have cycled: doing line $. letter 0
							again\n";
				$cycled = 1;
				last FILE_ITER;
			}

			else{
				$letter_lines{$.}{0} = 1;
							warn "adding to hash line $. letter 0\n";
			}
			$evt = shift @letters;
			print $evt;
			next FILE_ITER;
		}
		else{
			WORD_ITER:foreach my $i (0 .. $#letters){
				if($evt eq $letters[$i]){
					my $j = $i+1;
					$evt = $i < $#letters?$letters[$j]:undef;
					if(defined $evt){
						if(defined $letter_lines{$.}{$j}){
							warn "we have cycled :
							line $. letter $j \n";
							$cycled = 1;
							last FILE_ITER;
						}
						else{
							warn "adding to hash line $.
							letter $j\n";
							$letter_lines{$.}{$j} = 1;
							print $evt;
						}
					}
					last WORD_ITER;
				}
			}
		}
	}
	close($fh);
	warn "going back to the beginning\n";
}
warn "cycled in $niter iterations\n";