// ================== TASK 2(a) ==================
// Odd and Even Numbers using while loop

if (isset($_GET['submit_odd_even']) && isset($_GET['num'])) {
    $n = intval($_GET['num']);
    if ($n > 0) {
        // Odd numbers using while loop
        echo "<p><strong>Odd numbers:</strong> ";
        $count = 0;
        $num = 1;
        while ($count < $n) {
            echo $num;
            $count++;
            if ($count < $n) echo ", ";
            $num += 2;
        }
        echo " ($n odd numbers)</p>";
        
        // Even numbers using while loop
        echo "<p><strong>Even numbers:</strong> ";
        $count = 0;
        $num = 2;
        while ($count < $n) {
            echo $num;
            $count++;
            if ($count < $n) echo ", ";
            $num += 2;
        }
        echo " ($n even numbers)</p>";
    }
}

// ================== TASK 2(b) ==================
// Year Mark Calculation and Exam Admission

function calculateYearMark($a1, $a2, $a3, $a4) {
    $yearMark = ($a1 * 0.10) + ($a2 * 0.35) + ($a3 * 0.45) + ($a4 * 0.10);
    // Using ternary operator for exam admission
    $hasAdmission = ($yearMark >= 40) ? "has exam admission." : "does NOT have exam admission.";
    $admissionClass = ($yearMark >= 40) ? "admitted" : "not-admitted";
    
    echo "<div class='result'>";
    echo "<p><strong>Assignment 1:</strong> $a1%</p>";
    echo "<p><strong>Assignment 2:</strong> $a2%</p>";
    echo "<p><strong>Assignment 3:</strong> $a3%</p>";
    echo "<p><strong>Assignment 4:</strong> $a4%</p>";
    echo "<p><strong>Year Mark:</strong> " . number_format($yearMark, 2) . "%</p>";
    echo "<p class='$admissionClass'><strong>Result:</strong> Student $hasAdmission</p>";
    echo '</div>';
}

// Test cases
$testData = [
    [93, 0, 96, 95],
    [62, 60, 93, 55],
    [60, 65, 70, 60]
];

foreach ($testData as $data) {
    calculateYearMark($data[0], $data[1], $data[2], $data[3]);
}

// ================== TASK 2(c) ==================
// Province ISO Codes using switch statement

if (isset($_GET['submit_province']) && isset($_GET['province']) && !empty($_GET['province'])) {
    $province = $_GET['province'];
    $isoCode = '';
    
    switch ($province) {
        case 'Eastern Cape':
            $isoCode = 'EC';
            break;
        case 'Free State':
            $isoCode = 'FS';
            break;
        case 'Gauteng':
            $isoCode = 'GP';
            break;
        case 'KwaZulu-Natal':
            $isoCode = 'KZN';
            break;
        case 'Limpopo':
            $isoCode = 'LP';
            break;
        case 'Mpumalanga':
            $isoCode = 'MP';
            break;
        case 'North West':
            $isoCode = 'NW';
            break;
        case 'Northern Cape':
            $isoCode = 'NC';
            break;
        case 'Western Cape':
            $isoCode = 'WC';
            break;
        default:
            $isoCode = 'Invalid province';
    }
    
    echo "<p><strong>Province:</strong> $province</p>";
    echo "<p><strong>ISO/Conventional Code:</strong> $isoCode</p>";
}