0UT1S's

<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $uploadDir = __DIR__ . '/../uploads/';
    $allowedExtensions = ['png', 'jpg', 'jpeg', 'webp', 'heic', 'gif', 'svg'];

// Validate uploaded file
    if (!isset($_FILES['image']) || $_FILES['image']['error'] !== UPLOAD_ERR_OK) {
        echo json_encode(['error' => 'File upload failed.']);
        exit;
    }

$imageInfo = getimagesize($_FILES['image']['tmp_name']);
    if (!$imageInfo) {
        echo json_encode(['error' => 'Invalid image file.']);
        exit;
    }

$originalExtension = strtolower(pathinfo($_FILES['image']['name'], PATHINFO_EXTENSION));
    if (!in_array($originalExtension, $allowedExtensions)) {
        echo json_encode(['error' => 'Unsupported file format.']);
        exit;
    }

// Generate unique filenames
    $originalFilename = uniqid('original_', true) . '.' . $originalExtension;
    $convertedFilename = uniqid('converted_', true) . '.' . $originalExtension;

// Save original file
    if (!move_uploaded_file($_FILES['image']['tmp_name'], $uploadDir . $originalFilename)) {
        echo json_encode(['error' => 'Failed to save the uploaded file.']);
        exit;
    }

// Get dimensions or social media size
    $width = $_POST['width'] ?? null;
    $height = $_POST['height'] ?? null;
    $socialMediaSize = $_POST['socialMediaSize'] ?? null;

// Predefined social media sizes
    $sizes = [
        'facebook_story' => [1080, 1920],
        'facebook_vertical_post' => [1080, 1350],
        'facebook_shared_image' => [1200, 630],
        'facebook_page_cover' => [820, 312],
        'facebook_event_cover' => [1920, 1080],
        'facebook_group_cover' => [1640, 859],
        'facebook_profile_image' => [180, 180],
        'instagram_story' => [1080, 1920],
        'instagram_vertical_post' => [1080, 1350],
        'instagram_square_post' => [1080, 1080],
        'instagram_horizontal_post' => [1080, 566],
        'twitter_share_image' => [1200, 675],
        'twitter_link_with_image' => [800, 418],
        'twitter_header' => [1500, 500],
        'youtube_channel_icon' => [800, 800],
        'youtube_channel_art' => [2560, 1440],
    ];

if ($socialMediaSize) {
        if (!isset($sizes[$socialMediaSize])) {
            echo json_encode(['error' => 'Invalid social media size.']);
            unlink($uploadDir . $originalFilename);
            exit;
        }
        list($width, $height) = $sizes[$socialMediaSize];
    }

// Validate dimensions
    if (!$width || !$height) {
        echo json_encode(['error' => 'Invalid dimensions.']);
        unlink($uploadDir . $originalFilename);
        exit;
    }

// Resize image using GD Library
    try {
        $sourcePath = $uploadDir . $originalFilename;
        $image = imagecreatefromstring(file_get_contents($sourcePath));
        if (!$image) {
            throw new Exception('Failed to read the image.');
        }

$originalWidth = imagesx($image);
        $originalHeight = imagesy($image);
        $newImage = imagecreatetruecolor($width, $height);
        imagecopyresampled(
            $newImage,
            $image,
            0, 0,
            0, 0,
            $width,
            $height,
            $originalWidth,
            $originalHeight
        );

// Save resized image
        $targetPath = $uploadDir . $convertedFilename;
        switch ($originalExtension) {
            case 'jpg':
            case 'jpeg':
                imagejpeg($newImage, $targetPath, 90);
                break;
            case 'png':
                imagepng($newImage, $targetPath);
                break;
            case 'webp':
                imagewebp($newImage, $targetPath);
                break;
            case 'gif':
                imagegif($newImage, $targetPath);
                break;
            default:
                echo json_encode(['error' => 'Unsupported format for resizing.']);
                unlink($uploadDir . $originalFilename);
                exit;
        }

// Cleanup
        imagedestroy($image);
        imagedestroy($newImage);
        unlink($uploadDir . $originalFilename);

echo json_encode(['success' => true, 'file' => $convertedFilename]);
    } catch (Exception $e) {
        echo json_encode(['error' => $e->getMessage()]);
        unlink($uploadDir . $originalFilename);
    }
} else {
    echo json_encode(['error' => 'Invalid request method.']);
}
?>

By Order of Mr.0UT1S