/*
  Copyright 2018 Google LLC

  Use of this source code is governed by an MIT-style
  license that can be found in the LICENSE file or at
  https://opensource.org/licenses/MIT.
*/
import { assert } from 'workbox-core/_private/assert.js';
import { timeout } from 'workbox-core/_private/timeout.js';
import { resultingClientExists } from 'workbox-core/_private/resultingClientExists.js';
import { logger } from 'workbox-core/_private/logger.js';
import { responsesAreSame } from './responsesAreSame.js';
import { CACHE_UPDATED_MESSAGE_TYPE, CACHE_UPDATED_MESSAGE_META, DEFAULT_HEADERS_TO_CHECK } from './utils/constants.js';
import './_version.js';
// UA-sniff Safari: https://stackoverflow.com/questions/7944460/detect-safari-browser
// TODO(philipwalton): remove once this Safari bug fix has been released.
// https://bugs.webkit.org/show_bug.cgi?id=201169
const isSafari = /^((?!chrome|android).)*safari/i.test(navigator.userAgent);
/**
 * Generates the default payload used in update messages. By default the
 * payload includes the `cacheName` and `updatedURL` fields.
 *
 * @return Object
 * @private
 */
function defaultPayloadGenerator(data) {
    return {
        cacheName: data.cacheName,
        updatedURL: data.request.url,
    };
}
/**
 * Uses the `postMessage()` API to inform any open windows/tabs when a cached
 * response has been updated.
 *
 * For efficiency's sake, the underlying response bodies are not compared;
 * only specific response headers are checked.
 *
 * @memberof module:workbox-broadcast-update
 */
class BroadcastCacheUpdate {
    /**
     * Construct a BroadcastCacheUpdate instance with a specific `channelName` to
     * broadcast messages on
     *
     * @param {Object} options
     * @param {Array<string>} [options.headersToCheck=['content-length', 'etag', 'last-modified']]
     *     A list of headers that will be used to determine whether the responses
     *     differ.
     * @param {string} [options.generatePayload] A function whose return value
     *     will be used as the `payload` field in any cache update messages sent
     *     to the window clients.
     */
    constructor({ headersToCheck, generatePayload, } = {}) {
        this._headersToCheck = headersToCheck || DEFAULT_HEADERS_TO_CHECK;
        this._generatePayload = generatePayload || defaultPayloadGenerator;
    }
    /**
     * Compares two [Responses](https://developer.mozilla.org/en-US/docs/Web/API/Response)
     * and sends a message (via `postMessage()`) to all window clients if the
     * responses differ (note: neither of the Responses can be
     * {@link http://stackoverflow.com/questions/39109789|opaque}).
     *
     * The message that's posted has the following format (where `payload` can
     * be customized via the `generatePayload` option the instance is created
     * with):
     *
     * ```
     * {
     *   type: 'CACHE_UPDATED',
     *   meta: 'workbox-broadcast-update',
     *   payload: {
     *     cacheName: 'the-cache-name',
     *     updatedURL: 'https://example.com/'
     *   }
     * }
     * ```
     *
     * @param {Object} options
     * @param {Response} [options.oldResponse] Cached response to compare.
     * @param {Response} options.newResponse Possibly updated response to compare.
     * @param {Request} options.request The request.
     * @param {string} options.cacheName Name of the cache the responses belong
     *     to. This is included in the broadcast message.
     * @param {Event} [options.event] event An optional event that triggered
     *     this possible cache update.
     * @return {Promise} Resolves once the update is sent.
     */
    async notifyIfUpdated(options) {
        if (process.env.NODE_ENV !== 'production') {
            assert.isType(options.cacheName, 'string', {
                moduleName: 'workbox-broadcast-update',
                className: 'BroadcastCacheUpdate',
                funcName: 'notifyIfUpdated',
                paramName: 'cacheName',
            });
            assert.isInstance(options.newResponse, Response, {
                moduleName: 'workbox-broadcast-update',
                className: 'BroadcastCacheUpdate',
                funcName: 'notifyIfUpdated',
                paramName: 'newResponse',
            });
            assert.isInstance(options.request, Request, {
                moduleName: 'workbox-broadcast-update',
                className: 'BroadcastCacheUpdate',
                funcName: 'notifyIfUpdated',
                paramName: 'request',
            });
        }
        // Without two responses there is nothing to compare.
        if (!options.oldResponse) {
            return;
        }
        if (!responsesAreSame(options.oldResponse, options.newResponse, this._headersToCheck)) {
            if (process.env.NODE_ENV !== 'production') {
                logger.log(`Newer response found (and cached) for:`, options.request.url);
            }
            const messageData = {
                type: CACHE_UPDATED_MESSAGE_TYPE,
                meta: CACHE_UPDATED_MESSAGE_META,
                payload: this._generatePayload(options),
            };
            // For navigation requests, wait until the new window client exists
            // before sending the message
            if (options.request.mode === 'navigate') {
                let resultingClientId;
                if (options.event instanceof FetchEvent) {
                    resultingClientId = options.event.resultingClientId;
                }
                const resultingWin = await resultingClientExists(resultingClientId);
                // Safari does not currently implement postMessage buffering and
                // there's no good way to feature detect that, so to increase the
                // chances of the message being delivered in Safari, we add a timeout.
                // We also do this if `resultingClientExists()` didn't return a client,
                // which means it timed out, so it's worth waiting a bit longer.
                if (!resultingWin || isSafari) {
                    // 3500 is chosen because (according to CrUX data) 80% of mobile
                    // websites hit the DOMContentLoaded event in less than 3.5 seconds.
                    // And presumably sites implementing service worker are on the
                    // higher end of the performance spectrum.
                    await timeout(3500);
                }
            }
            const windows = await self.clients.matchAll({ type: 'window' });
            for (const win of windows) {
                win.postMessage(messageData);
            }
        }
    }
}
export { BroadcastCacheUpdate };