Improve the code, and add extention method

src/get-mime-type.php

@@ -1,12 +1,32 @@
 	/**
-	 * Get the mime type based on file extension
+	 * Get the file extension from a full path OR file name.
 	 * 
-	 * @param   string   $file The file name or path
+	 * @param   string   $file  The full file path or file name.
 	 *
-	 * @return  string the mime type on success
-	 * 
+	 * @return  string  The file extension in lowercase or an empty string if none found.
+	 * @since   5.0.3
 	 */
-	public static function mimeType($file)
+	public static function extension(string $file): string
+	{
+		// Ensure the input is a valid string and contains a file extension
+		if (strpos($file, '.') === false)
+		{
+			return '';
+		}
+
+		// Extract and return the extension from the path
+		return strtolower(pathinfo($file, PATHINFO_EXTENSION));
+	}
+
+	/**
+	 * Get the mime type based on the full file path.
+	 * 
+	 * @param   string   $file The full file path.
+	 *
+	 * @return  string  The mime type or 'application/octet-stream' if none found.
+	 * @since   5.0.3
+	 */
+	public static function mimeType(string $file): string
 	{
 		/**
 		 *                  **DISCLAIMER**
@@ -14,25 +34,60 @@
 		 * array. It does not guarantee that the file is TRULY that
 		 * of the extension that this function returns.
 		 * https://gist.github.com/Llewellynvdm/74be373357e131b8775a7582c3de508b
-		 */		
+		 */
 
-		// get the extension form file
-		$extension = strtolower(pathinfo($file, PATHINFO_EXTENSION));
-		// check if we have the extension listed
-		if (isset(self::$fileExtensionToMimeType[$extension]))
+		// Ensure the file exists to avoid unnecessary processing
+		if (!is_file($file) || !is_readable($file))
+		{
+			return  self::mimeTypeFilename($file);
+		}
+
+		// Use finfo to get MIME type based on file content if available
+		if (function_exists('finfo_open'))
+		{
+			$finfo = finfo_open(FILEINFO_MIME_TYPE);
+			$mimetype = finfo_file($finfo, $file);
+			finfo_close($finfo);
+
+			if ($mimetype)
+			{
+				return $mimetype;
+			}
+		}
+
+		// Fallback to mime_content_type() if available
+		if (function_exists('mime_content_type'))
+		{
+			$mimetype = mime_content_type($file);
+			if ($mimetype)
+			{
+				return $mimetype;
+			}
+		}
+
+		// Fallback to application/octet-stream as a generic binary stream type
+		return 'application/octet-stream';
+	}
+
+	/**
+	 * Get the mime type based on the file extension from a file name.
+	 * 
+	 * @param   string   $file The file name (without path).
+	 *
+	 * @return  string The mime type or 'application/octet-stream' if none found.
+	 * @since   5.0.3
+	 */
+	protected static function mimeTypeFilename(string $file): string
+	{
+		// Get the extension
+		$extension = self::extension($file);
+
+		// Predefined MIME types by extension for quick lookup
+		if (!empty($extension) && isset(self::$fileExtensionToMimeType[$extension]))
 		{
 			return self::$fileExtensionToMimeType[$extension];
 		}
-		elseif (function_exists('mime_content_type'))
-		{
-			return mime_content_type($file);
-		}
-		elseif (function_exists('finfo_open'))
-		{
-			$finfo	= finfo_open(FILEINFO_MIME);
-			$mimetype = finfo_file($finfo, $file);
-			finfo_close($finfo);
-			return $mimetype;
-		}
+
+		// Fallback to application/octet-stream if extension is unknown
 		return 'application/octet-stream';
 	}