<?php
require_once __DIR__ . '/vendor/autoload.php';

use Imagine\Gd\Font;
use Imagine\Gd\Imagine;
use Imagine\Image\Palette\RGB;
use Imagine\Image\Point;

$dotenv = Dotenv\Dotenv::createImmutable(__DIR__);
$dotenv->safeLoad();

$templatesDirectory = __DIR__ . '/templates';
$validFiles = [
    'diplom-1.png' => [
        'positions' => [
            'top' => ['x' => 125, 'y' => 270, 'maxWidth' => 262],
            'bottom' => ['x' => 150, 'y' => 350, 'maxWidth' => 216],
            'bottomSecond' => ['x' => 150, 'y' => 400, 'maxWidth' => 216],
        ],
    ],
];

$template = $_GET['template'] ?? '';
$topText = $_GET['top'] ?? '';
$bottomText = $_GET['bottom'] ?? '';
$bottomSecondText = $_GET['bottomSecond'] ?? '';

if (!isset($validFiles[$template]) || !file_exists(sprintf('%s/%s', $templatesDirectory, $template))) {
    die('Invalid template');
}

if (empty($topText) || empty($bottomText)) {
    die('Invalid text');
}

/**
 * Get centered X coordinate
 *
 * @param int $originalX
 * @param int $maxWidth
 * @param Imagine\Image\BoxInterface $textBox
 *
 * @return int
 */
function getXCoord($originalX, $maxWidth, $textBox)
{
    $result = $originalX + ($maxWidth - $textBox->getWidth()) / 2;

    if ($result < 1) {
        return 1;
    }

    return (int) $result;
}

$templateFile = sprintf('%s/%s', $templatesDirectory, $template);
$positions = $validFiles[$template]['positions'];
$imagine = new Imagine();

$palette = new RGB();
$colorBlack = $palette->color('#000000', 100);
$transparent = $palette->color('#FFFFFF', 0);

$image = $imagine->open($templateFile);

$font = new Font($_ENV['FONT_LOCATION'], 12, $colorBlack);
$transparentFont = new Font($_ENV['FONT_LOCATION'], 0, $transparent);

$top = $positions['top'];
$bottom = $positions['bottom'];
$bottomSecond = $positions['bottomSecond'];

$topBox = $font->box($topText);
$topX = getXCoord($top['x'], $top['maxWidth'], $topBox);
$topY = $top['y'];

$bottomBox = $font->box($bottomText);
$bottomX = getXCoord($bottom['x'], $bottom['maxWidth'], $bottomBox);
$bottomY = $bottom['y'];

$bottomSecondBox = $transparentFont->box('placeholder');
if (!empty($bottomSecondText)) {
    $bottomSecondBox = $font->box($bottomSecondText);
}

$bottomSecondX = getXCoord($bottomSecond['x'], $bottomSecond['maxWidth'], $bottomSecondBox);
$bottomSecondY = $bottomSecond['y'];

$topPosition = new Point($topX, $topY);
$bottomPosition = new Point($bottomX, $bottomY);
$bottomSecondPosition = new Point($bottomSecondX, $bottomSecondY);

$image->draw()->text($topText, $font, $topPosition, 0, $top['maxWidth'] ?? null);
$image->draw()->text($bottomText, $font, $bottomPosition, 0, $bottom['maxWidth'] ?? null);
$image->draw()->text($bottomSecondText, $font, $bottomSecondPosition, 0, $bottomSecond['maxWidth'] ?? null);

$image->show('png');