import os
from urllib.parse import urlparse

class JPEGRequestHandler:
    def __init__(self, app):
        self.app = app

    def __call__(self, environ, start_response):
        url = urlparse(environ['REQUEST_URI'])
        path = url.path

        if path.endswith('.jpg'):
            file_path = path[1:]

            if os.path.isfile(file_path):
                with open(file_path, 'rb') as file:
                    response_body = file.read()
                    status = '200 OK'
                    headers = [('Content-type', 'image/jpeg'),
                               ('Content-Length', str(len(response_body)))]

                    start_response(status, headers)
                    return [response_body]
            else:
                status = '404 Not Found'
                headers = [('Content-type', 'text/plain'),
                           ('Content-Length', '0')]

                start_response(status, headers)
                return []
        else:
            status = '403 Forbidden'
            headers = [('Content-type', 'text/plain'),
                       ('Content-Length', '0')]

            start_response(status, headers)
            return []

if __name__ == '__main__':
    from werkzeug.serving import run_simple
    from werkzeug.middleware.dispatcher import DispatcherMiddleware

    app = DispatcherMiddleware(JPEGRequestHandler(app), {'/': app})
    run_simple('0.0.0.0', 8000, app, use_reloader=True)