import os
import mimetypes

class ServeStatic:
    def __init__(self, static_dir, wrapped_app):
        self.static_dir = os.path.abspath(static_dir) + os.sep
        self.wrapped_app = wrapped_app

    def __call__(self, env, resp):
        filepath = os.path.join(self.static_dir, env["PATH_INFO"][1:])

        if os.path.normpath(filepath).startswith(self.static_dir) and os.path.isfile(filepath):
            mime, _ = mimetypes.guess_type(filepath)
            resp('200 OK', [('Content-type', mime or 'application/octet-stream')])
            with open(filepath, 'rb') as file:
                return [file.read()]
        else:
            return self.wrapped_app(env, resp)