var __classPrivateFieldSet = (this && this.__classPrivateFieldSet) || function (receiver, state, value, kind, f) {
    if (kind === "m") throw new TypeError("Private method is not writable");
    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a setter");
    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot write private member to an object whose class did not declare it");
    return (kind === "a" ? f.call(receiver, value) : f ? f.value = value : state.set(receiver, value)), value;
};
var __classPrivateFieldGet = (this && this.__classPrivateFieldGet) || function (receiver, state, kind, f) {
    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
    return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
};
var _MutationObserver_callback, _MutationObserver_listeners, _MutationObserver_window;
import DOMException from '../exception/DOMException.js';
import * as PropertySymbol from '../PropertySymbol.js';
import MutationListener from './MutationListener.js';
/**
 * The MutationObserver interface provides the ability to watch for changes being made to the DOM tree.
 *
 * @see https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver
 */
class MutationObserver {
    /**
     * Constructor.
     *
     * @param callback Callback.
     */
    constructor(callback) {
        _MutationObserver_callback.set(this, void 0);
        _MutationObserver_listeners.set(this, []);
        _MutationObserver_window.set(this, null);
        __classPrivateFieldSet(this, _MutationObserver_callback, callback, "f");
    }
    /**
     * Starts observing.
     *
     * @param target Target.
     * @param options Options.
     */
    observe(target, options) {
        if (!target) {
            throw new DOMException(`Failed to execute 'observe' on 'MutationObserver': The first parameter "target" should be of type "Node".`);
        }
        if (!options || (!options.childList && !options.attributes && !options.characterData)) {
            throw new DOMException(`Failed to execute 'observe' on 'MutationObserver': The options object must set at least one of 'attributes', 'characterData', or 'childList' to true.`);
        }
        if (!__classPrivateFieldGet(this, _MutationObserver_window, "f")) {
            __classPrivateFieldSet(this, _MutationObserver_window, target[PropertySymbol.ownerDocument]
                ? target[PropertySymbol.ownerDocument][PropertySymbol.ownerWindow]
                : target[PropertySymbol.ownerWindow], "f");
        }
        // Makes sure that attribute names are lower case.
        // TODO: Is this correct?
        options = Object.assign({}, options, {
            attributeFilter: options.attributeFilter
                ? options.attributeFilter.map((name) => name.toLowerCase())
                : null
        });
        /**
         * @see https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver/observe#reusing_mutationobservers
         */
        for (const listener of __classPrivateFieldGet(this, _MutationObserver_listeners, "f")) {
            if (listener.target === target) {
                listener.options = options;
                return;
            }
        }
        const listener = new MutationListener({
            window: __classPrivateFieldGet(this, _MutationObserver_window, "f"),
            options,
            callback: __classPrivateFieldGet(this, _MutationObserver_callback, "f").bind(this),
            observer: this,
            target
        });
        __classPrivateFieldGet(this, _MutationObserver_listeners, "f").push(listener);
        // Stores all observers on the window object, so that they can be disconnected when the window is closed.
        __classPrivateFieldGet(this, _MutationObserver_window, "f")[PropertySymbol.mutationObservers].push(this);
        // Starts observing target node.
        target[PropertySymbol.observe](listener);
    }
    /**
     * Disconnects.
     */
    disconnect() {
        if (__classPrivateFieldGet(this, _MutationObserver_listeners, "f").length === 0) {
            return;
        }
        const mutationObservers = __classPrivateFieldGet(this, _MutationObserver_window, "f")[PropertySymbol.mutationObservers];
        const index = mutationObservers.indexOf(this);
        if (index !== -1) {
            mutationObservers.splice(index, 1);
        }
        for (const listener of __classPrivateFieldGet(this, _MutationObserver_listeners, "f")) {
            listener.target[PropertySymbol.unobserve](listener);
            listener.destroy();
        }
        __classPrivateFieldSet(this, _MutationObserver_listeners, [], "f");
    }
    /**
     * Returns a list of all matching DOM changes that have been detected but not yet processed by the observer's callback function, leaving the mutation queue empty.
     *
     * @returns Records.
     */
    takeRecords() {
        let records = [];
        for (const listener of __classPrivateFieldGet(this, _MutationObserver_listeners, "f")) {
            records = records.concat(listener.takeRecords());
        }
        return records;
    }
}
_MutationObserver_callback = new WeakMap(), _MutationObserver_listeners = new WeakMap(), _MutationObserver_window = new WeakMap();
export default MutationObserver;
//# sourceMappingURL=MutationObserver.js.map