From a0fbf3931f22b677a5045fb2392f6fa9714ca478 Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Thu, 5 Oct 2017 22:03:55 +0200
Subject: [PATCH] thumb: dynamic image relay with resize option

Generate image with requested height from data source, which should be
bypassed by the server if target file exists.

Copied from Lijtweg at commit v2.5-58-gac5434f0af (2017-12-12).
---
 thumb/.gitignore |  1 +
 thumb/.htaccess  |  3 +++
 thumb/index.php  | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 38 insertions(+)
 create mode 100644 thumb/.gitignore
 create mode 100644 thumb/.htaccess
 create mode 100644 thumb/index.php

diff --git a/thumb/.gitignore b/thumb/.gitignore
new file mode 100644
index 0000000..34bbc9f
--- /dev/null
+++ b/thumb/.gitignore
@@ -0,0 +1 @@
+/[1-9]*/
diff --git a/thumb/.htaccess b/thumb/.htaccess
new file mode 100644
index 0000000..c63c79e
--- /dev/null
+++ b/thumb/.htaccess
@@ -0,0 +1,3 @@
+<IfModule mod_headers.c>
+	Header set Cache-Control "max-age=2628000, immutable"
+</IfModule>
diff --git a/thumb/index.php b/thumb/index.php
new file mode 100644
index 0000000..b49ca6e
--- /dev/null
+++ b/thumb/index.php
@@ -0,0 +1,34 @@
+<?php
+ob_clean();
+
+list ($height, $imgarg) = explode('/', ltrim($Args, '/'), 2);
+$width= 1000;
+$imgpath = "data/$imgarg";
+
+if (!file_exists($imgpath)) {
+	http_response_code(404);
+	exit;
+}
+
+$target = preg_replace("{^data/}", "thumb/$height/", $imgpath, 1);
+if (!file_exists($target)) {
+	@mkdir(dirname($target), 0777, TRUE);
+
+	$cmd = implode(' ', array_map('escapeshellarg', [
+		'convert',
+		'-trim',
+		'-resize', "${width}x${height}",
+		'-quality', '90%',
+		$imgpath, $target
+	]));
+	$return = shell_exec("$cmd 2>&1");
+	if ($return) {
+		http_response_code(500);
+		trigger_error("thumbnail creation failed: $return", E_USER_WARNING);
+		exit;
+	}
+}
+
+header('Content-type: '.mime_content_type($target));
+readfile($target);
+exit;
-- 
2.30.0