Application refactor (#591)

* Rename Yomitan class to Application, change initialization style

* Rename file

* Update init

* Update config

* Remove dead code

1 files changed, 255 insertions, 0 deletions

diff --git a/ext/js/application.js b/ext/js/application.js
new file mode 100644
index 00000000..87bd0e86
--- /dev/null
+++ b/ext/js/application.js
@@ -0,0 +1,255 @@
+/*
+ * Copyright (C) 2023-2024  Yomitan Authors
+ * Copyright (C) 2020-2022  Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import {API} from './comm/api.js';
+import {CrossFrameAPI} from './comm/cross-frame-api.js';
+import {createApiMap, invokeApiMapHandler} from './core/api-map.js';
+import {EventDispatcher} from './core/event-dispatcher.js';
+import {ExtensionError} from './core/extension-error.js';
+import {log} from './core/logger.js';
+import {deferPromise} from './core/utilities.js';
+import {WebExtension} from './extension/web-extension.js';
+
+/**
+ * @returns {boolean}
+ */
+function checkChromeNotAvailable() {
+    let hasChrome = false;
+    let hasBrowser = false;
+    try {
+        hasChrome = (typeof chrome === 'object' && chrome !== null && typeof chrome.runtime !== 'undefined');
+    } catch (e) {
+        // NOP
+    }
+    try {
+        hasBrowser = (typeof browser === 'object' && browser !== null && typeof browser.runtime !== 'undefined');
+    } catch (e) {
+        // NOP
+    }
+    return (hasBrowser && !hasChrome);
+}
+
+// Set up chrome alias if it's not available (Edge Legacy)
+if (checkChromeNotAvailable()) {
+    // @ts-expect-error - objects should have roughly the same interface
+    // eslint-disable-next-line no-global-assign
+    chrome = browser;
+}
+
+/**
+ * The Yomitan class is a core component through which various APIs are handled and invoked.
+ * @augments EventDispatcher<import('application').Events>
+ */
+export class Application extends EventDispatcher {
+    /**
+     * Creates a new instance. The instance should not be used until it has been fully prepare()'d.
+     */
+    constructor() {
+        super();
+
+        /** @type {WebExtension} */
+        this._webExtension = new WebExtension();
+
+        /** @type {string} */
+        this._extensionName = 'Yomitan';
+        try {
+            const manifest = chrome.runtime.getManifest();
+            this._extensionName = `${manifest.name} v${manifest.version}`;
+        } catch (e) {
+            // NOP
+        }
+
+        /** @type {?string} */
+        this._extensionUrlBase = null;
+        try {
+            this._extensionUrlBase = this._webExtension.getUrl('/');
+        } catch (e) {
+            // NOP
+        }
+
+        /** @type {?boolean} */
+        this._isBackground = null;
+        /** @type {?API} */
+        this._api = null;
+        /** @type {?CrossFrameAPI} */
+        this._crossFrame = null;
+        /** @type {boolean} */
+        this._isReady = false;
+
+        const {promise, resolve} = /** @type {import('core').DeferredPromiseDetails<void>} */ (deferPromise());
+        /** @type {Promise<void>} */
+        this._isBackendReadyPromise = promise;
+        /** @type {?(() => void)} */
+        this._isBackendReadyPromiseResolve = resolve;
+
+        /* eslint-disable no-multi-spaces */
+        /** @type {import('application').ApiMap} */
+        this._apiMap = createApiMap([
+            ['applicationIsReady',         this._onMessageIsReady.bind(this)],
+            ['applicationBackendReady',    this._onMessageBackendReady.bind(this)],
+            ['applicationGetUrl',          this._onMessageGetUrl.bind(this)],
+            ['applicationOptionsUpdated',  this._onMessageOptionsUpdated.bind(this)],
+            ['applicationDatabaseUpdated', this._onMessageDatabaseUpdated.bind(this)],
+            ['applicationZoomChanged',     this._onMessageZoomChanged.bind(this)]
+        ]);
+        /* eslint-enable no-multi-spaces */
+    }
+
+    /** @type {WebExtension} */
+    get webExtension() {
+        return this._webExtension;
+    }
+
+    /**
+     * Whether the current frame is the background page/service worker or not.
+     * @type {boolean}
+     */
+    get isBackground() {
+        if (this._isBackground === null) { throw new Error('Not prepared'); }
+        return /** @type {boolean} */ (this._isBackground);
+    }
+
+    /**
+     * Gets the API instance for communicating with the backend.
+     * This value will be null on the background page/service worker.
+     * @type {API}
+     */
+    get api() {
+        if (this._api === null) { throw new Error('Not prepared'); }
+        return this._api;
+    }
+
+    /**
+     * Gets the CrossFrameAPI instance for communicating with different frames.
+     * This value will be null on the background page/service worker.
+     * @type {CrossFrameAPI}
+     */
+    get crossFrame() {
+        if (this._crossFrame === null) { throw new Error('Not prepared'); }
+        return this._crossFrame;
+    }
+
+    /**
+     * Prepares the instance for use.
+     * @param {boolean} [isBackground=false] Assigns whether this instance is being used from the background page/service worker.
+     */
+    async prepare(isBackground = false) {
+        this._isBackground = isBackground;
+        chrome.runtime.onMessage.addListener(this._onMessage.bind(this));
+
+        if (!isBackground) {
+            this._api = new API(this._webExtension);
+
+            await this._webExtension.sendMessagePromise({action: 'requestBackendReadySignal'});
+            await this._isBackendReadyPromise;
+
+            this._crossFrame = new CrossFrameAPI(this._api);
+            await this._crossFrame.prepare();
+
+            log.on('log', this._onForwardLog.bind(this));
+        }
+    }
+
+    /**
+     * Sends a message to the backend indicating that the frame is ready and all script
+     * setup has completed.
+     */
+    ready() {
+        this._isReady = true;
+        this._webExtension.sendMessagePromise({action: 'applicationReady'});
+    }
+
+    /**
+     * Checks whether or not a URL is an extension URL.
+     * @param {string} url The URL to check.
+     * @returns {boolean} `true` if the URL is an extension URL, `false` otherwise.
+     */
+    isExtensionUrl(url) {
+        return this._extensionUrlBase !== null && url.startsWith(this._extensionUrlBase);
+    }
+
+    /** */
+    triggerStorageChanged() {
+        this.trigger('storageChanged', {});
+    }
+
+    /** */
+    triggerClosePopups() {
+        this.trigger('closePopups', {});
+    }
+
+    // Private
+
+    /**
+     * @returns {string}
+     */
+    _getUrl() {
+        return location.href;
+    }
+
+    /** @type {import('extension').ChromeRuntimeOnMessageCallback<import('application').ApiMessageAny>} */
+    _onMessage({action, params}, _sender, callback) {
+        return invokeApiMapHandler(this._apiMap, action, params, [], callback);
+    }
+
+    /** @type {import('application').ApiHandler<'applicationIsReady'>} */
+    _onMessageIsReady() {
+        return this._isReady;
+    }
+
+    /** @type {import('application').ApiHandler<'applicationBackendReady'>} */
+    _onMessageBackendReady() {
+        if (this._isBackendReadyPromiseResolve === null) { return; }
+        this._isBackendReadyPromiseResolve();
+        this._isBackendReadyPromiseResolve = null;
+    }
+
+    /** @type {import('application').ApiHandler<'applicationGetUrl'>} */
+    _onMessageGetUrl() {
+        return {url: this._getUrl()};
+    }
+
+    /** @type {import('application').ApiHandler<'applicationOptionsUpdated'>} */
+    _onMessageOptionsUpdated({source}) {
+        if (source !== 'background') {
+            this.trigger('optionsUpdated', {source});
+        }
+    }
+
+    /** @type {import('application').ApiHandler<'applicationDatabaseUpdated'>} */
+    _onMessageDatabaseUpdated({type, cause}) {
+        this.trigger('databaseUpdated', {type, cause});
+    }
+
+    /** @type {import('application').ApiHandler<'applicationZoomChanged'>} */
+    _onMessageZoomChanged({oldZoomFactor, newZoomFactor}) {
+        this.trigger('zoomChanged', {oldZoomFactor, newZoomFactor});
+    }
+
+    /**
+     * @param {{error: unknown, level: import('log').LogLevel, context?: import('log').LogContext}} params
+     */
+    async _onForwardLog({error, level, context}) {
+        try {
+            const api = /** @type {API} */ (this._api);
+            await api.log(ExtensionError.serialize(error), level, context);
+        } catch (e) {
+            // NOP
+        }
+    }
+}