#!/usr/bin/env perl

# for https://perlmonks.org/?node_id=1221711

use strict;
use warnings;

select(STDERR); $| = 1;
select(STDOUT); $| = 1;

srand(1234);

# read a text or a dictionary
# find each word and filter out rubbish (numbers, initials, etc)
# enter the words in a hash keyed on their last N chars
# - an attempt to rhyme.
# TeX::Hyphen hyphenates the words so it's better but misses
# out a lot of words.
# create a pattern for the sentence, (0,1,0,0,1,0)
# meaning: pick random word for first word,
# second word change the ending, (1) so pick up
# a random word with different ending.
# 3rd word continue with same ending as previous (0)
# etc.

my $num_sentences = 100;
#my $dict_filename = '/usr/share/dict/words';
#my $dict_filename = './words';
#my $dict_filename = './dict.txt';
#my $dict_filename = './KingJamesBible.txt';
my $dict_filename = './ShelleyFrankenstein.txt';
#my $dict_filename = './wordlist';

open(my $dfh, '<', $dict_filename) || die "dict file: $!";
my %words_keyed_on_ending = ();
my ($aword, $aline);
my $progress = 1;
print "reading dict: ";
while( $aline = <$dfh> ){
        chomp($aline);
        $aline =~ s/[0-9]+\:[0-9]*//g;
        foreach my $aword (split/\W+/, $aline){
                if( $aword =~ /^[0-9A-Z\.,]+$/ ){ next }
                my $last_syl = substr($aword, -3);
                $words_keyed_on_ending{$last_syl} = [] unless exists $words_keyed_on_ending{$last_syl};
                push(@{$words_keyed_on_ending{$last_syl}}, $aword);
        }
        print "$progress " if ++$progress % 10000 == 0;
#       if( $progress > 100 ){ last }
}
print "\n";
my @keys_of_words_keyed_on_ending = keys %words_keyed_on_ending;
#for (sort @keys_of_words_keyed_on_ending){ print "$_ : ".join("---", @{$words_keyed_on_ending{$_}})."\n"; } exit(0);

for(1..$num_sentences){
        print join(" ", @{make_sentence()})."\n";
}
exit(0);

sub     make_sentence {
        my @pat = (0,1,0,0,1,1,0,0);
        my $current_ending = $keys_of_words_keyed_on_ending[rand @keys_of_words_keyed_on_ending];
        my $bag_of_words = $words_keyed_on_ending{$current_ending};
        my $current_word = ucfirst $bag_of_words->[rand @$bag_of_words];
        my @sent = ($current_word);
        #print "current word: $current_word (ending in $current_ending)\n";
        #print "bag of words: ".join(", ", @$bag_of_words)."\n";
        my $last_word = $current_word;
        for(1..$#pat){
                if( $pat[$_] ){
                        #print "changing ending to ";
                        # change the ending
                        $current_ending = $keys_of_words_keyed_on_ending[rand @keys_of_words_keyed_on_ending];
                        $bag_of_words = $words_keyed_on_ending{$current_ending};
                        $current_word = $bag_of_words->[rand @$bag_of_words];
                } else {
                        # use same ending
                        $current_word = $bag_of_words->[rand @$bag_of_words];
                }
                if( $current_word ne $last_word ){
                        $last_word = $current_word;
                        push(@sent, $current_word);
                }
                #print "current word: $current_word (ending in $current_ending)\n";
                #print "bag of words: ".join(", ", @$bag_of_words)."\n";
        }
        #print "num words: ".scalar(@sent)."\n";
        return \@sent;
}