const CACHE_NAME = "emergency-gesture-v1";

const FILES = [
    "./",
    "./index.html",
    "./manifest.json"
];

self.addEventListener(
    "install",
    event => {

        event.waitUntil(

            caches.open(
                CACHE_NAME
            ).then(
                cache =>
                    cache.addAll(FILES)
            )

        );

    }
);


self.addEventListener(
    "activate",
    event => {

        event.waitUntil(

            caches.keys().then(
                keys =>

                    Promise.all(

                        keys.map(
                            key => {

                                if (
                                    key !==
                                    CACHE_NAME
                                ) {

                                    return caches.delete(
                                        key
                                    );

                                }

                            }
                        )

                    )

            )

        );

    }
);


self.addEventListener(
    "fetch",
    event => {

        event.respondWith(

            caches.match(
                event.request
            ).then(
                cached =>

                    cached ||
                    fetch(
                        event.request
                    )

            )

        );

    }
);