From 551c366e6c06265591c1ee3e654a7587271f3beb Mon Sep 17 00:00:00 2001
From: Zankaria <zankaria.auxa@mailu.io>
Date: Tue, 18 Mar 2025 00:41:04 +0100
Subject: [PATCH] GdThumbGenerator.php: add GdThumbGenerator

---
 inc/Service/Media/GdThumbGenerator.php | 132 +++++++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 inc/Service/Media/GdThumbGenerator.php

diff --git a/inc/Service/Media/GdThumbGenerator.php b/inc/Service/Media/GdThumbGenerator.php
new file mode 100644
index 00000000..51278a34
--- /dev/null
+++ b/inc/Service/Media/GdThumbGenerator.php
@@ -0,0 +1,132 @@
+<?php
+namespace Vichan\Service\Media;
+
+use Vichan\Data\ThumbGenerationResult;
+
+use function Vichan\Functions\Fs\link_or_copy;
+
+class GdThumbGenerator implements ThumbGenerator {
+	private const PHP81 = PHP_MAJOR_VERSION >= 8 && PHP_MINOR_VERSION >= 1;
+
+	private const MIME_TO_EXT = [
+		'image/jpeg' => 'jpg',
+		'image/png' => 'png',
+		'image/gif' => 'gif',
+		'image/webp' => 'webp',
+		'image/bmp' => 'bmp',
+		'image/avif' => 'avif'
+	];
+
+
+	private static function imageCreateFrom(string $file, string $mime): mixed {
+		switch ($mime) {
+			case 'image/jpeg':
+				return imagecreatefromjpeg($file);
+			case 'image/png':
+				return imagecreatefrompng($file);
+			case 'image/gif':
+				return imagecreatefromgif($file);
+			case 'image/webp':
+				return imagecreatefromwbmp($file);
+			case 'image/bmp':
+				return imagecreatefrombmp($file);
+			case 'image/avif':
+				return self::PHP81 ? imagecreatefromavif($file) : false;
+		}
+		return false;
+	}
+
+	public static function imageSaveTo(mixed $gd, string $file, string $mime) {
+		// Somebody should tune the quality and speed values...
+		switch ($mime) {
+			case 'image/jpeg':
+				return imagejpeg($gd, $file, 50);
+			case 'image/png':
+				return imagepng($gd, $file, 7);
+			case 'image/gif':
+				return imagegif($gd, $file);
+			case 'image/webp':
+				return imagewbmp($gd, $file, 50);
+			case 'image/bmp':
+				return imagebmp($gd, $file, true);
+			case 'image/avif':
+				return self::PHP81 ? imageavif($gd, $file, 30, 6) : false;
+		}
+		return false;
+	}
+
+	private static function createCanvas(string $mime, int $width, int $height) {
+		$gd = \imagecreatetruecolor($width, $height);
+		switch ($mime) {
+			case 'image/png':
+				imagecolortransparent($gd, imagecolorallocatealpha($gd, 0, 0, 0, 0));
+				imagesavealpha($gd, true);
+				imagealphablending($gd, false);
+				break;
+			case 'image/gif':
+				\imagecolortransparent($gd, \imagecolorallocatealpha($gd, 0, 0, 0, 0));
+				\imagesavealpha($gd, true);
+				break;
+		}
+		return $gd;
+	}
+
+	public function supportsMime(string $mime): bool {
+		$info = \gd_info();
+		return ($mime === 'image/jpeg' && $info['JPEG Support'])
+			|| ($mime === 'image/png' && $info['PNG Support'])
+			|| ($mime === 'image/gif' && $info['GIF Read Support'] && $info['GIF Create Support'])
+			|| ($mime === 'image/webp' && $info['WebP Support'])
+			|| $mime === 'image/bmp'
+			|| ($mime === 'image/avif' && self::PHP81 && $info['AVIF Support']);
+	}
+
+	public function generateThumb(
+		string $source_file_path,
+		string $source_file_mime,
+		string $preferred_out_file_path,
+		string $preferred_out_mime,
+		int $max_width,
+		int $max_height
+	): ThumbGenerationResult {
+		$gd = self::imageCreateFrom($source_file_path, $source_file_mime);
+		if ($gd === false) {
+			throw new \RuntimeException("Could not open '$source_file_path'");
+		}
+
+		$width = \imagesx($gd);
+		$height = \imagesy($gd);
+
+		if ($width <= $max_width && $height <= $max_height) {
+			$out_path = $preferred_out_file_path . '.' . self::MIME_TO_EXT[$source_file_mime];
+
+			if (!link_or_copy($source_file_path, $out_path)) {
+				throw new \RuntimeException("Could not link or copy '$source_file_path' to '$out_path'");
+			}
+			$res = new ThumbGenerationResult();
+			$res->thumb_file_path = $out_path;
+			$res->thumb_mime = $source_file_mime;
+			$res->is_thumb_file_temporary = false;
+			$res->width = $width;
+			$res->height = $height;
+			return $res;
+		} else {
+			$out_path = $preferred_out_file_path . '.' . self::MIME_TO_EXT[$preferred_out_mime];
+
+			$gd_other = self::createCanvas($preferred_out_mime, $max_width, $max_height);
+			\imagecopyresampled($gd_other, $gd, 0, 0, 0, 0, $max_width, $max_height, $width, $height);
+
+			if (!self::imageSaveTo($gd_other, $out_path, $preferred_out_mime)) {
+				throw new \RuntimeException("Could not create thumbnail file at '$out_path'");
+			}
+
+			$res = new ThumbGenerationResult();
+			$res->thumb_file_path = $out_path;
+			$res->thumb_mime = $preferred_out_mime;
+			$res->is_thumb_file_temporary = false;
+			$res->width = $max_width;
+			$res->height = $max_height;
+			return $res;
+		}
+	}
+}