advent 2 - php

<?php
function testmove($currentposition, $direction) {
    $boolarray = Array(false => 'false', true => 'true');
    if (($currentposition === 1 || $currentposition === 4 || $currentposition === 7) && $direction === "L") {
        return $boolarray[false];
    }
    if (($currentposition === 3 || $currentposition === 6 || $currentposition === 9) && $direction === "R") {
        return $boolarray[false];
    }
    if (($currentposition === 1 || $currentposition === 2 || $currentposition === 3) && $direction === "U") {
        return $boolarray[false];
    }
    if (($currentposition === 7 || $currentposition === 8 || $currentposition === 9) && $direction === "D") {
        return $boolarray[false];
    }
    return $boolarray[true];
}

function move($currentposition, $line) {
    $line = str_split($line);
    foreach ($line as $key => $movement) {
        echo "A1: Start position for action is " . $currentposition . "<br>";
        echo "A2: Movement required is " . $movement . "<br>";
        $acceptmove = testmove($currentposition, $movement);
        echo "A3: Result of testmove() for this movement is " . $acceptmove . "<br>";
        if (testmove($currentposition, $movement) === "true") {
            switch ($movement) {
                case "U":
                    $currentposition = ($currentposition - 3);
                    break;
                case "D":
                    $currentposition = ($currentposition + 3);
                    break;
                case "L":
                    $currentposition = ($currentposition - 1);
                    break;
                case "R":
                    $currentposition = ($currentposition + 1);
                    break;
            }
        }
        echo "A4: Result position for action is " . $currentposition . "<br>";
    }
    echo "Notice: Result position for line is " . $currentposition . "<br>";
    return $currentposition;
}

$inputstring = 'DULUDRDDDRLUDURUUULRRRURDRDULRUDDUDRULUDDUDRLDULRRLRDRUDUUULUUDLRURDUDDDDRDLLLLULRDLDRDLRLULRUURDDUULUDLRURRDDRDDRDDLDRDLLUURDRUULRRURURRDLRLLLUDULULULULUDRLLRUDUURLDRLRLRDRRDRLLLDURRDULDURDDRLURRDURLRRRLDLLLDRUUURLRDLDLLLLRDURRLDLULRLDDLDLURLRRDDRUDDUULRURRUDLRDLDUURDDDDRLRURUDULUDLRRLLLLLRDRURLLDLDULUUDLUDDDRLLDRRUDLLURRUUDDRRLLRRLDDDURLDRDRLURRRRDRRRDDUDULULDURRUUURRRDULUUUDDRULDRLLRDLDURLURRLLRUUUULRDURLLDDRLLDLRLRULUUDRURUDLLURUDDRDURLRDRRRDURLDDRDRLRLLURULUUULUDDDULDLRDDDRDLLRRLDRDULLUUUDLDDLDDDLLLLLLLDUDURURDURDRUURRRDDRDUDLULDURDUDURDDDRULDURURURRLURLURLUURLULDLLRUULURDDRLRDDLRDLRRR
LUURLRUDRRUDLLDLUDDURULURLUUDUUDDRLUULRDUDDUULDUUDRURDDRRDRLULLRDRDLRLLUURRUULRLDRULUDLDUUDDDRDDLRDLULDRLDUULDLRDLLLDLDLRDUULUDURRULLRLDUDRLLLULUUUULUUDUUURRRDULLUURUDRRLDURRUULDRDULDUDRDUUULUUDDRLUDRLDLDRUUURDLDUDRUDUURLLRRLRLLRRLDULDDULUDUUURULDDUDUDRURRDLULRUDDURDLDLLRRRLDRLULLLRUULDUDLUUDURRLLLRLUDURRDDLDRDDDLURDLDRRUDUDLUDULULRUUUDLUURLLRLDDLURULDURDLRRDDDDURLDDLLDDULLLRLDLDULDUUDDRLDUURDDLDLUUDULRRLRLUURURUURLRLURUURLDRUURLLRDDUUUDULUDDDRDRLDRDRRLRLDULLRRUDLURULULRDRURURLULDUDLRURLRDDRULDDLRD
LUDRULUULRRDDDDRRDUURUDDRLDDLDRDURRURULRDLDLDUUDRRDUUDUDLLLRRLDUDDRLDDLRRLRDRLUDLULUDDUUDULDUUULUDLDDURLDURUDLDRUUDRLRRLDLDDULDUUDDLDDLLURDRLRUURDDRUDDUDLDRRLRUDRUULRRRLRULULURDLRRURDRLRULDDDRDUULLURUUUURUDDLRRRRRDURLULDLUULUDRRUDUDRRDDRURDURLRLUDDLDLRRULUDLDDRLDDLDDDLLLLRDLLUULDDLULDLDRDDUDLURUDLDLDDRRUUDDDLRLLLDRRDDDUURDUDURUURRDRLLDUDLDUULLDLDLLUULLRRULDLDRURLDULDRUURDURRURDLRDLLLDRRUDRUUDRURLUDDRURLDURRDLUUDLUUDULLLDDDDRRDLLLDLURULDDRDLUUURRDRRUUDDUL
DUUULDUDDDURLLULDDLLUDURLLLURULULURUURDRURLRULLLLDRDDULRRDRRLLLRDDDUULLRRURRULLDDURRRLRDDLULDULLDUDLURRDLDDLURDLRLLDRURLLRLLRRRDRRRURURUUDDLLDDLDDDLRLURUUUULRDLUDDDURLLDDRLDRRLLUDUUULRLLDRRRLRUUDLDUULRLUDRULLLLDUDLLUUDDRUURLURUDRDDDLRURUDRLULLULUUDLDURDULRRDRLDURUULRDRRRDRDRRLRLRDDUULLRDLDURDDDULURRLULDDURDURDDUDURDLLUUULUDULRDDLDRDRUDLLUURDLRDURURULURULLDRLLRRULDLULULDLULRURLRRLUDLLLRLUDLURLULDULDRLLLDLDDDDRDRLRRLRDULUUDULDDLDURDLLLDDDDLLUURRDURLDLUDDLULRUUUDDRRLDLLLRDLLDRRRDDLULLURDDRRRRLDLRLLLRL
LULLRRDURRLDUUDRRURLURURRRLRDRUULUULURLLURRDRULRDURDDDDUULLLLDUULDLULURDRLDLULULDRLLDLLRLRULURUDRUUDULRULLLUDRULUDRLLUDLDRRDRUUURURLRDURDRLRDDDURLURRDLRUUUDUURULULDLUULRDLRRRDRDRLLLDLRRDRLLDDULDRUDRRLULLRDLDUDDULRDDLULRURULRLLLULDLLLLRDLDRURUDUURURLDRLUULLDUDULUDDDULUDLRUDDUDLULLUULUUURULURRULRDDURDDLURLRRDRDLDULRLRDRRRULRDDDRLLDDDDRRRRDRDLULUURDURULDLRDULDUDLDURUDLUDLUDDDUDURDURDDURLLRUDUURRRUDRRRRULLLLDDDLUULLUULRRRULDLURDLULRULDRLR';
$currentposition = 5;
$inputarray = explode(PHP_EOL, $inputstring);

foreach ($inputarray as $key => $line) {
    echo "Notice: Processing line (" . ($key + 1) . ")<br>";
    $currentposition = move($currentposition, $line);
}

echo "Notice: Final position is " . $currentposition;
?>