/**
 * @author Toru Nagashima <https://github.com/mysticatea>
 * See LICENSE file in root directory for full license.
 */
import { EventTarget, defineEventAttribute } from 'event-target-shim';

/**
 * The signal class.
 * @see https://dom.spec.whatwg.org/#abortsignal
 */
class AbortSignal extends EventTarget {
    /**
     * AbortSignal cannot be constructed directly.
     */
    constructor() {
        super();
        throw new TypeError("AbortSignal cannot be constructed directly");
    }
    /**
     * Returns `true` if this `AbortSignal`'s `AbortController` has signaled to abort, and `false` otherwise.
     */
    get aborted() {
        const aborted = abortedFlags.get(this);
        if (typeof aborted !== "boolean") {
            throw new TypeError(`Expected 'this' to be an 'AbortSignal' object, but got ${this === null ? "null" : typeof this}`);
        }
        return aborted;
    }
}
defineEventAttribute(AbortSignal.prototype, "abort");
/**
 * Create an AbortSignal object.
 */
function createAbortSignal() {
    const signal = Object.create(AbortSignal.prototype);
    EventTarget.call(signal);
    abortedFlags.set(signal, false);
    return signal;
}
/**
 * Abort a given signal.
 */
function abortSignal(signal) {
    if (abortedFlags.get(signal) !== false) {
        return;
    }
    abortedFlags.set(signal, true);
    signal.dispatchEvent({ type: "abort" });
}
/**
 * Aborted flag for each instances.
 */
const abortedFlags = new WeakMap();
// Properties should be enumerable.
Object.defineProperties(AbortSignal.prototype, {
    aborted: { enumerable: true },
});
// `toString()` should return `"[object AbortSignal]"`
if (typeof Symbol === "function" && typeof Symbol.toStringTag === "symbol") {
    Object.defineProperty(AbortSignal.prototype, Symbol.toStringTag, {
        configurable: true,
        value: "AbortSignal",
    });
}

/**
 * The AbortController.
 * @see https://dom.spec.whatwg.org/#abortcontroller
 */
class AbortController {
    /**
     * Initialize this controller.
     */
    constructor() {
        signals.set(this, createAbortSignal());
    }
    /**
     * Returns the `AbortSignal` object associated with this object.
     */
    get signal() {
        return getSignal(this);
    }
    /**
     * Abort and signal to any observers that the associated activity is to be aborted.
     */
    abort() {
        abortSignal(getSignal(this));
    }
}
/**
 * Associated signals.
 */
const signals = new WeakMap();
/**
 * Get the associated signal of a given controller.
 */
function getSignal(controller) {
    const signal = signals.get(controller);
    if (signal == null) {
        throw new TypeError(`Expected 'this' to be an 'AbortController' object, but got ${controller === null ? "null" : typeof controller}`);
    }
    return signal;
}
// Properties should be enumerable.
Object.defineProperties(AbortController.prototype, {
    signal: { enumerable: true },
    abort: { enumerable: true },
});
if (typeof Symbol === "function" && typeof Symbol.toStringTag === "symbol") {
    Object.defineProperty(AbortController.prototype, Symbol.toStringTag, {
        configurable: true,
        value: "AbortController",
    });
}

export default AbortController;
export { AbortController, AbortSignal };
//# sourceMappingURL=abort-controller.mjs.map