Replace Logger static class with Log class

lib/Log.php

@@ -0,0 +1,39 @@
+<?
+use function Safe\fopen;
+use function Safe\fwrite;
+use function Safe\fclose;
+use function Safe\error_log;
+use function Safe\gmdate;
+
+class Log{
+	private $RequestId = null;
+	private $LogFilePath = null;
+
+	public function __construct(?string $logFilePath){
+		// Get a semi-random ID to identify this request within the log.
+		$this->RequestId = substr(sha1(time() . rand()), 0, 8);
+		$this->LogFilePath = $logFilePath;
+	}
+
+	public function Write(string $text): void{
+		if($this->LogFilePath === null){
+			self::WriteErrorLogEntry($text);
+		}
+		else{
+			try{
+				$fp = fopen($this->LogFilePath, 'a+');
+			}
+			catch(\Exception $ex){
+				self::WriteErrorLogEntry('Couldn\'t open log file: ' . $this->LogFilePath . '. Exception: ' . vds($ex));
+				return;
+			}
+
+			fwrite($fp, gmdate('Y-m-d H:i:s') . "\t" . $this->RequestId . "\t" . $text . "\n");
+			fclose($fp);
+		}
+	}
+
+	public static function WriteErrorLogEntry(string $text): void{
+		error_log($text);
+	}
+}