Implementation of Four Letters Word Game from BJ Homer's flash talk at Division Meetup

fourletters.php

<?php

define( 'DICT_FILE', '/usr/share/dict/words' );

$allwords = file_get_contents( DICT_FILE );
$qty = preg_match_all( '/^\w{4}$/m', $allwords, $matches );
echo "\r\n\e[32mLoaded \e[37m{$qty}\e[32m four-letter words in from \e[37m" . DICT_FILE . "\e[32m ...\r\n\e[0m";

$fourletter = $matches[0];

// Build our frequency chart ...
$frequency = array_count_values(
	str_split(
		strtolower(
			implode(
				'',
				$fourletter
			)
		)
	)
);
arsort( $frequency );

// Pick the word for the user to guess ...
$word = $fourletter[ array_rand( $fourletter ) ];
echo "\e[39mWord Selected!\r\n";
echo "\e[32mIf you'd like to quit, submit an empty guess.  Happy guessing!\r\n\e[0m";

$guess_history = '';
$guess = '';

while ( strtolower( $guess ) !== strtolower( $word ) ) {
	$guessed_letters = array_unique( str_split( strtoupper( $guess_history ) ) );
	print_frequency_chart( $frequency, $guessed_letters );

	$prev_guesses = strlen( $guess_history ) / 4;
	$guess = readline( "\e[39mGuess #\e[37m" . ( $prev_guesses + 1 ) . "\e[39m: " );

	if ( $guess === $word ) {
		echo "\e[37mYou got it!\r\n";
		break;
	} elseif ( '' === $guess ) {
		if ( 'y' === strtolower( readline( "\r\n\e[39mDid you want to give up? [y/N] " ) ) ) {
			break;
		}
	} elseif ( ! preg_match( '/^[a-z]{4}$/i', $guess ) ) {
		echo "\t\e[31m‼️  Guesses must be four characters. Try again.\r\n\e[39m";
		continue;
	} elseif ( ! in_array( strtolower( $guess ), array_map( 'strtolower', $fourletter ) ) ) {
		echo "\t\e[31m⁉️  That's not a known word. Try again.\r\n\e[39m";
		continue;
	}
	
	$guess_history .= $guess;
	echo "\t\e[37m=> \e[37m" . calculate_number( $guess, $word ) . "\r\n";
}

echo "\r\n\e[32mThe word was \e[37m{$word}\e[0m\r\n";

/**
 * Custom Functions:
 */

function print_frequency_chart( $frequency_array, $guessed = array() ) {
	echo "\r\n\e[39mLetter Frequency Chart:\r\n";

	$guessed = array_map( 'strtoupper', $guessed );
	foreach ( $frequency_array as $letter => $frequency ) {
		if ( in_array( strtoupper( $letter ), $guessed ) ) {
			echo "\e[31m";
		} else {
			echo "\e[37m";
		}
		echo strtoupper( $letter );
		
	}
	echo "\r\n\e[0m";
}

function calculate_number( $guess, $solution ) {
	$number = 0;
	$guess_arr = str_split( $guess );
	
	foreach ( $guess_arr as $letter ) {
		if ( str_contains( strtolower( $solution ), strtolower( $letter ) ) ) {
			$number++;
		}
	}

	return $number;
}