MokoSuiteCross/source/packages/com_mokosuitecross/src/Helper/SocialImageHelper.php

<?php

/**
 * @package     MokoSuiteCross
 * @subpackage  com_mokosuitecross
 * @author      Moko Consulting <hello@mokoconsulting.tech>
 * @copyright   Copyright (C) 2026 Moko Consulting. All rights reserved.
 * @license     GNU General Public License version 3 or later; see LICENSE
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

namespace Joomla\Component\MokoSuiteCross\Administrator\Helper;

defined('_JEXEC') or die;

class SocialImageHelper
{
    private const WIDTH  = 1200;
    private const HEIGHT = 630;

    /**
     * Generate a branded social/OG image with text overlay.
     *
     * @param   string  $title     Article title to render on the image
     * @param   string  $siteName  Site name for branding watermark
     * @param   array   $config    Rendering config: bg_color, text_color, font_size, show_site_name
     *
     * @return  array  ['success' => bool, 'image_url' => string, 'error' => string]
     */
    public static function generate(string $title, string $siteName, array $config): array
    {
        if (!\function_exists('imagecreatetruecolor')) {
            return ['success' => false, 'error' => 'PHP GD extension is not available'];
        }

        $bgColor      = $config['bg_color'] ?? '#1a1a2e';
        $textColor    = $config['text_color'] ?? '#ffffff';
        $fontSize     = (int) ($config['font_size'] ?? 48);
        $showSiteName = (bool) ($config['show_site_name'] ?? true);

        $fontSize = max(24, min(96, $fontSize));

        $image = imagecreatetruecolor(self::WIDTH, self::HEIGHT);

        if ($image === false) {
            return ['success' => false, 'error' => 'Failed to create image canvas'];
        }

        $bgRgb   = self::hexToRgb($bgColor);
        $textRgb = self::hexToRgb($textColor);

        $bg   = imagecolorallocate($image, $bgRgb[0], $bgRgb[1], $bgRgb[2]);
        $text = imagecolorallocate($image, $textRgb[0], $textRgb[1], $textRgb[2]);

        imagefilledrectangle($image, 0, 0, self::WIDTH - 1, self::HEIGHT - 1, $bg);

        $fontFile = self::findFont();

        if ($fontFile !== null) {
            self::renderTtfText($image, $title, $text, $fontSize, $fontFile);

            if ($showSiteName && $siteName !== '') {
                $siteSize = (int) round($fontSize * 0.45);
                $siteBox  = imagettfbbox($siteSize, 0, $fontFile, $siteName);
                $siteX    = self::WIDTH - ($siteBox[2] - $siteBox[0]) - 40;
                $siteY    = self::HEIGHT - 30;
                imagettftext($image, $siteSize, 0, $siteX, $siteY, $text, $fontFile, $siteName);
            }
        } else {
            self::renderFallbackText($image, $title, $text);

            if ($showSiteName && $siteName !== '') {
                $siteX = self::WIDTH - (\strlen($siteName) * imagefontwidth(3)) - 40;
                $siteY = self::HEIGHT - 30;
                imagestring($image, 3, $siteX, $siteY, $siteName, $text);
            }
        }

        $outputDir = JPATH_ROOT . '/media/com_mokosuitecross/social';

        if (!is_dir($outputDir)) {
            mkdir($outputDir, 0755, true);
        }

        $hash     = hash('sha256', $title . $bgColor . $textColor . $fontSize);
        $filename = $hash . '.png';
        $filePath = $outputDir . '/' . $filename;

        if (!imagepng($image, $filePath, 6)) {
            imagedestroy($image);

            return ['success' => false, 'error' => 'Failed to save image file'];
        }

        imagedestroy($image);

        $imageUrl = 'media/com_mokosuitecross/social/' . $filename;

        return ['success' => true, 'image_url' => $imageUrl];
    }

    private static function renderTtfText(\GdImage $image, string $title, int $color, int $fontSize, string $fontFile): void
    {
        $maxWidth = self::WIDTH - 120;
        $lines    = self::wordWrapTtf($title, $fontFile, $fontSize, $maxWidth);
        $lineHeight = (int) round($fontSize * 1.4);
        $totalHeight = \count($lines) * $lineHeight;

        $startY = (int) round((self::HEIGHT - $totalHeight) / 2) + $fontSize;

        foreach ($lines as $i => $line) {
            $y = $startY + ($i * $lineHeight);
            imagettftext($image, $fontSize, 0, 60, $y, $color, $fontFile, $line);
        }
    }

    private static function renderFallbackText(\GdImage $image, string $title, int $color): void
    {
        $font        = 5;
        $charWidth   = imagefontwidth($font);
        $charHeight  = imagefontheight($font);
        $maxChars    = (int) floor((self::WIDTH - 120) / $charWidth);
        $lines       = wordwrap($title, $maxChars, "\n", true);
        $lineArray   = explode("\n", $lines);
        $lineHeight  = $charHeight + 8;
        $totalHeight = \count($lineArray) * $lineHeight;
        $startY      = (int) round((self::HEIGHT - $totalHeight) / 2);

        foreach ($lineArray as $i => $line) {
            $y = $startY + ($i * $lineHeight);
            imagestring($image, $font, 60, $y, $line, $color);
        }
    }

    /**
     * Word-wrap text for TTF rendering at a given pixel width.
     *
     * @return  string[]
     */
    private static function wordWrapTtf(string $text, string $fontFile, int $fontSize, int $maxWidth): array
    {
        $words = explode(' ', $text);
        $lines = [];
        $currentLine = '';

        foreach ($words as $word) {
            $testLine = $currentLine === '' ? $word : $currentLine . ' ' . $word;
            $box      = imagettfbbox($fontSize, 0, $fontFile, $testLine);
            $width    = abs($box[2] - $box[0]);

            if ($width > $maxWidth && $currentLine !== '') {
                $lines[]     = $currentLine;
                $currentLine = $word;
            } else {
                $currentLine = $testLine;
            }
        }

        if ($currentLine !== '') {
            $lines[] = $currentLine;
        }

        return $lines ?: [$text];
    }

    /**
     * Locate a usable TTF font file -- check common system locations.
     */
    private static function findFont(): ?string
    {
        $candidates = [
            JPATH_ROOT . '/media/com_mokosuitecross/fonts/OpenSans-Bold.ttf',
            JPATH_ROOT . '/media/com_mokosuitecross/fonts/Roboto-Bold.ttf',
            '/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf',
            '/usr/share/fonts/truetype/liberation/LiberationSans-Bold.ttf',
            '/usr/share/fonts/TTF/DejaVuSans-Bold.ttf',
            'C:/Windows/Fonts/arial.ttf',
            'C:/Windows/Fonts/segoeui.ttf',
        ];

        foreach ($candidates as $path) {
            if (is_file($path)) {
                return $path;
            }
        }

        return null;
    }

    /**
     * @return  int[]  [r, g, b]
     */
    private static function hexToRgb(string $hex): array
    {
        $hex = ltrim($hex, '#');

        if (\strlen($hex) === 3) {
            $hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
        }

        return [
            (int) hexdec(substr($hex, 0, 2)),
            (int) hexdec(substr($hex, 2, 2)),
            (int) hexdec(substr($hex, 4, 2)),
        ];
    }
}