Implemented API Caching

Fix #3

index.php

@@ -36,36 +36,73 @@
 
 
 ###### Fetch Video Views ######
-// Process videos in batches of 50
-$all_ids = array_chunk(
-			array_keys($GLOBALS["data"]),
-			50);
+// Check last time videos were checked
+$last_query_file = "last_query.txt";
+$views_cache_file = "views_cache.txt";
 
-$curl = curl_init();
-curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
-foreach($all_ids as $id_list) {
+if(!file_exists($last_query_file)) {
+	// Time of Last Query Doesn't Exist
+	file_put_contents($last_query_file, serialize(new DateTime()));
+}
+
+if(!file_exists($views_cache_file)) {
+	// Views Cache Doesn't Exist
+	file_put_contents($views_cache_file, serialize([]));
+}
+
+
+$date_last_query = unserialize(file_get_contents($last_query_file));
+
+//Check time since last query
+$time_difference_minutes = $date_last_query->diff(new DateTime)->i;
+
+if($time_difference_minutes >= 1) {
+	// If it's been more than 1 minute, cache video data
+
+	// Process videos in batches of 50
+	$all_ids = array_chunk(
+				array_keys($GLOBALS["data"]),
+				50);
 
-	curl_setopt_array($curl, [
-		CURLOPT_URL => "https://youtube.googleapis.com/youtube/v3/videos?part=statistics&id=" . implode(",", $id_list) . "&key=" . $GLOBALS["API_KEY"],
-		CURLOPT_RETURNTRANSFER => true,
-		CURLOPT_ENCODING => "",
-		CURLOPT_MAXREDIRS => 10,
-		CURLOPT_TIMEOUT => 30,
-		CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
-		CURLOPT_CUSTOMREQUEST => "GET",
-		CURLOPT_HTTPHEADER => [],
-	]);
-	$response = json_decode(curl_exec($curl), true);
-	if (array_key_exists("items", $response)){
-		foreach($response["items"] as $vid) {
-			$GLOBALS["data"][$vid["id"]]->set_views($vid["statistics"]["viewCount"]);
+	$curl = curl_init();
+	curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
+	$all_responses = [];
+	foreach($all_ids as $id_list) {
+
+		curl_setopt_array($curl, [
+			CURLOPT_URL => "https://youtube.googleapis.com/youtube/v3/videos?part=statistics&id=" . implode(",", $id_list) . "&key=" . $GLOBALS["API_KEY"],
+			CURLOPT_RETURNTRANSFER => true,
+			CURLOPT_ENCODING => "",
+			CURLOPT_MAXREDIRS => 10,
+			CURLOPT_TIMEOUT => 30,
+			CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
+			CURLOPT_CUSTOMREQUEST => "GET",
+			CURLOPT_HTTPHEADER => [],
+		]);
+		$response = json_decode(curl_exec($curl), true);
+		if (array_key_exists("items", $response)){
+			$all_responses = array_merge($all_responses,$response["items"]);
 		}
-	} else {
-		echo("API ERROR");
-		echo("Num of Videos:" . sizeof($id_list));
-		var_dump($response);
 	}
+	// Cache Video Data
+	file_put_contents($views_cache_file, serialize($all_responses));
+	// Update Time file
+	file_put_contents($last_query_file, serialize(new DateTime()));
+} else {
+	// Get Data from file
+	$all_responses = unserialize(file_get_contents($views_cache_file));
+}
+
+//var_dump($all_responses);
+//exit();
+
+// Save video views to tree
+foreach($all_responses as $vid) {
+	$GLOBALS["data"][$vid["id"]]->set_views($vid["statistics"]["viewCount"]);
 }
+
+
+
 //var_dump($GLOBALS["data"]);
 //exit();
 
@@ -95,6 +132,7 @@ function gtag(){dataLayer.push(arguments);}
 			<!-- Title -->
 			<h1 id="title">CGP Grey: Rock Paper Scissors</h1>
 			<h2>A Visual and Statistical Overview</h2>
+			<p><i>Last Updated: <?=$date_last_query->format("y/m/d - H:i")?> UTC</i></p>
 			<br/><br/>
 
 			<!-- Visual Controls -->