From 06d62d4304e2c41a96f8adda49a0cef315b1c744 Mon Sep 17 00:00:00 2001
From: MatMasIt <mattia.mascarello@outlook.it>
Date: Mon, 8 Nov 2021 18:29:45 +0100
Subject: [PATCH] Added isbn image fetcher

---
 isbnImage.php | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 isbnImage.php

diff --git a/isbnImage.php b/isbnImage.php
new file mode 100644
index 0000000..f27d8c1
--- /dev/null
+++ b/isbnImage.php
@@ -0,0 +1,39 @@
+<?php
+function cache_get($isbn){
+	if(!file_exists("2/isbnCacheImg.json")) return false;
+	$data = json_decode(file_get_contents("2/isbnCacheImg.json"),true);
+    if(!$data) return false;
+    $res = $data[$isbn];
+    if(!$res) return false;
+    if($res["time"] + $GLOBALS["imageISBNCache"] < time()) return false;
+    return $res["url"];
+}
+function cache_set($isbn,$url){
+	if(file_exists("2/isbnCacheImg.json")){
+    	$data = json_decode(file_get_contents("2/isbnCacheImg.json"),true)?:[];
+    }
+    else{
+    	$data = [];
+    }
+    $data[$isbn] = ["time"=>time(),"url"=>$url];
+    file_put_contents("2/isbnCacheImg.json", json_encode($data));
+}
+function isbnImage($isbn){
+	$url = cache_get($isbn);
+    if($url) return $url;
+	$curlSES=curl_init(); 
+	curl_setopt($curlSES,CURLOPT_URL,"https://www.googleapis.com/books/v1/volumes?q=isbn:".urlencode($isbn));
+	curl_setopt($curlSES,CURLOPT_RETURNTRANSFER,true);
+	curl_setopt($curlSES,CURLOPT_HEADER, false); 
+	$result=curl_exec($curlSES);
+	curl_close($curlSES);
+	$data=json_decode($result,true);
+    if(!$data) return "books.png";
+    $images=$data["items"][0]["volumeInfo"]["imageLinks"];
+    $lak = array_keys($images);
+    $le = $lak[count($lak)-1];
+    $url = $images[$le]?: "books.png";
+    cache_set($isbn,$url);
+    return $url;
+}
+?>