(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('@lumino/coreutils'), require('@lumino/signaling')) :
    typeof define === 'function' && define.amd ? define(['exports', '@lumino/coreutils', '@lumino/signaling'], factory) :
    (global = global || self, factory(global.lumino_polling = {}, global.lumino_coreutils, global.lumino_signaling));
}(this, (function (exports, coreutils, signaling) { 'use strict';

    /*! *****************************************************************************
    Copyright (c) Microsoft Corporation. All rights reserved.
    Licensed under the Apache License, Version 2.0 (the "License"); you may not use
    this file except in compliance with the License. You may obtain a copy of the
    License at http://www.apache.org/licenses/LICENSE-2.0

    THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
    WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
    MERCHANTABLITY OR NON-INFRINGEMENT.

    See the Apache Version 2.0 License for specific language governing permissions
    and limitations under the License.
    ***************************************************************************** */
    /* global Reflect, Promise */

    var extendStatics = function(d, b) {
        extendStatics = Object.setPrototypeOf ||
            ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
            function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
        return extendStatics(d, b);
    };

    function __extends(d, b) {
        extendStatics(d, b);
        function __() { this.constructor = d; }
        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
    }

    var __assign = function() {
        __assign = Object.assign || function __assign(t) {
            for (var s, i = 1, n = arguments.length; i < n; i++) {
                s = arguments[i];
                for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p)) t[p] = s[p];
            }
            return t;
        };
        return __assign.apply(this, arguments);
    };

    function __awaiter(thisArg, _arguments, P, generator) {
        return new (P || (P = Promise))(function (resolve, reject) {
            function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
            function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
            function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
            step((generator = generator.apply(thisArg, _arguments || [])).next());
        });
    }

    function __generator(thisArg, body) {
        var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
        return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
        function verb(n) { return function (v) { return step([n, v]); }; }
        function step(op) {
            if (f) throw new TypeError("Generator is already executing.");
            while (_) try {
                if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
                if (y = 0, t) op = [op[0] & 2, t.value];
                switch (op[0]) {
                    case 0: case 1: t = op; break;
                    case 4: _.label++; return { value: op[1], done: false };
                    case 5: _.label++; y = op[1]; op = [0]; continue;
                    case 7: op = _.ops.pop(); _.trys.pop(); continue;
                    default:
                        if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
                        if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
                        if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
                        if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
                        if (t[2]) _.ops.pop();
                        _.trys.pop(); continue;
                }
                op = body.call(thisArg, _);
            } catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
            if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
        }
    }

    // Copyright (c) Jupyter Development Team.
    /**
     * A function to defer an action immediately.
     */
    var defer = typeof requestAnimationFrame === 'function'
        ? requestAnimationFrame
        : setImmediate;
    /**
     * A function to cancel a deferred action.
     */
    var cancel = typeof cancelAnimationFrame === 'function'
        ? cancelAnimationFrame
        : clearImmediate;
    /**
     * A class that wraps an asynchronous function to poll at a regular interval
     * with exponential increases to the interval length if the poll fails.
     *
     * @typeparam T - The resolved type of the factory's promises.
     * Defaults to `any`.
     *
     * @typeparam U - The rejected type of the factory's promises.
     * Defaults to `any`.
     *
     * @typeparam V - An optional type to extend the phases supported by a poll.
     * Defaults to `standby`, which already exists in the `Phase` type.
     */
    exports.Poll = /** @class */ (function () {
        /**
         * Instantiate a new poll with exponential backoff in case of failure.
         *
         * @param options - The poll instantiation options.
         */
        function Poll(options) {
            var _this = this;
            this._disposed = new signaling.Signal(this);
            this._tick = new coreutils.PromiseDelegate();
            this._ticked = new signaling.Signal(this);
            this._timeout = -1;
            this._factory = options.factory;
            this._standby = options.standby || Private.DEFAULT_STANDBY;
            this._state = __assign(__assign({}, Private.DEFAULT_STATE), { timestamp: new Date().getTime() });
            // Normalize poll frequency `max` to be the greater of
            // default `max`, `options.frequency.max`, or `options.frequency.interval`.
            var frequency = options.frequency || {};
            var max = Math.max(frequency.interval || 0, frequency.max || 0, Private.DEFAULT_FREQUENCY.max);
            this.frequency = __assign(__assign(__assign({}, Private.DEFAULT_FREQUENCY), frequency), { max: max });
            this.name = options.name || Private.DEFAULT_NAME;
            if ('auto' in options ? options.auto : true) {
                defer(function () { return void _this.start(); });
            }
        }
        Object.defineProperty(Poll.prototype, "disposed", {
            /**
             * A signal emitted when the poll is disposed.
             */
            get: function () {
                return this._disposed;
            },
            enumerable: true,
            configurable: true
        });
        Object.defineProperty(Poll.prototype, "frequency", {
            /**
             * The polling frequency parameters.
             */
            get: function () {
                return this._frequency;
            },
            set: function (frequency) {
                if (this.isDisposed || coreutils.JSONExt.deepEqual(frequency, this.frequency || {})) {
                    return;
                }
                var backoff = frequency.backoff, interval = frequency.interval, max = frequency.max;
                interval = Math.round(interval);
                max = Math.round(max);
                if (typeof backoff === 'number' && backoff < 1) {
                    throw new Error('Poll backoff growth factor must be at least 1');
                }
                if ((interval < 0 || interval > max) && interval !== Poll.NEVER) {
                    throw new Error('Poll interval must be between 0 and max');
                }
                if (max > Poll.MAX_INTERVAL && max !== Poll.NEVER) {
                    throw new Error("Max interval must be less than " + Poll.MAX_INTERVAL);
                }
                this._frequency = { backoff: backoff, interval: interval, max: max };
            },
            enumerable: true,
            configurable: true
        });
        Object.defineProperty(Poll.prototype, "isDisposed", {
            /**
             * Whether the poll is disposed.
             */
            get: function () {
                return this.state.phase === 'disposed';
            },
            enumerable: true,
            configurable: true
        });
        Object.defineProperty(Poll.prototype, "standby", {
            /**
             * Indicates when the poll switches to standby.
             */
            get: function () {
                return this._standby;
            },
            set: function (standby) {
                if (this.isDisposed || this.standby === standby) {
                    return;
                }
                this._standby = standby;
            },
            enumerable: true,
            configurable: true
        });
        Object.defineProperty(Poll.prototype, "state", {
            /**
             * The poll state, which is the content of the current poll tick.
             */
            get: function () {
                return this._state;
            },
            enumerable: true,
            configurable: true
        });
        Object.defineProperty(Poll.prototype, "tick", {
            /**
             * A promise that resolves when the poll next ticks.
             */
            get: function () {
                return this._tick.promise;
            },
            enumerable: true,
            configurable: true
        });
        Object.defineProperty(Poll.prototype, "ticked", {
            /**
             * A signal emitted when the poll ticks and fires off a new request.
             */
            get: function () {
                return this._ticked;
            },
            enumerable: true,
            configurable: true
        });
        /**
         * Dispose the poll.
         */
        Poll.prototype.dispose = function () {
            if (this.isDisposed) {
                return;
            }
            this._state = __assign(__assign({}, Private.DISPOSED_STATE), { timestamp: new Date().getTime() });
            this._tick.promise.catch(function (_) { return undefined; });
            this._tick.reject(new Error("Poll (" + this.name + ") is disposed."));
            this._disposed.emit(undefined);
            signaling.Signal.clearData(this);
        };
        /**
         * Refreshes the poll. Schedules `refreshed` tick if necessary.
         *
         * @returns A promise that resolves after tick is scheduled and never rejects.
         *
         * #### Notes
         * The returned promise resolves after the tick is scheduled, but before
         * the polling action is run. To wait until after the poll action executes,
         * await the `poll.tick` promise: `await poll.refresh(); await poll.tick;`
         */
        Poll.prototype.refresh = function () {
            return this.schedule({
                cancel: function (_a) {
                    var phase = _a.phase;
                    return phase === 'refreshed';
                },
                interval: Poll.IMMEDIATE,
                phase: 'refreshed'
            });
        };
        /**
         * Schedule the next poll tick.
         *
         * @param next - The next poll state data to schedule. Defaults to standby.
         *
         * @param next.cancel - Cancels state transition if function returns `true`.
         *
         * @returns A promise that resolves when the next poll state is active.
         *
         * #### Notes
         * This method is not meant to be invoked by user code typically. It is public
         * to allow poll instances to be composed into classes that schedule ticks.
         */
        Poll.prototype.schedule = function (next) {
            if (next === void 0) { next = {}; }
            return __awaiter(this, void 0, void 0, function () {
                var last, pending, scheduled, state, execute;
                var _this = this;
                return __generator(this, function (_a) {
                    switch (_a.label) {
                        case 0:
                            if (this.isDisposed) {
                                return [2 /*return*/];
                            }
                            // Check if the phase transition should be canceled.
                            if (next.cancel && next.cancel(this.state)) {
                                return [2 /*return*/];
                            }
                            last = this.state;
                            pending = this._tick;
                            scheduled = new coreutils.PromiseDelegate();
                            state = __assign({ interval: this.frequency.interval, payload: null, phase: 'standby', timestamp: new Date().getTime() }, next);
                            this._state = state;
                            this._tick = scheduled;
                            // Clear the schedule if possible.
                            if (last.interval === Poll.IMMEDIATE) {
                                cancel(this._timeout);
                            }
                            else {
                                clearTimeout(this._timeout);
                            }
                            // Emit ticked signal, resolve pending promise, and await its settlement.
                            this._ticked.emit(this.state);
                            pending.resolve(this);
                            return [4 /*yield*/, pending.promise];
                        case 1:
                            _a.sent();
                            execute = function () {
                                if (_this.isDisposed || _this.tick !== scheduled.promise) {
                                    return;
                                }
                                _this._execute();
                            };
                            this._timeout =
                                state.interval === Poll.IMMEDIATE
                                    ? defer(execute)
                                    : state.interval === Poll.NEVER
                                        ? -1
                                        : setTimeout(execute, state.interval);
                            return [2 /*return*/];
                    }
                });
            });
        };
        /**
         * Starts the poll. Schedules `started` tick if necessary.
         *
         * @returns A promise that resolves after tick is scheduled and never rejects.
         */
        Poll.prototype.start = function () {
            return this.schedule({
                cancel: function (_a) {
                    var phase = _a.phase;
                    return phase !== 'constructed' && phase !== 'standby' && phase !== 'stopped';
                },
                interval: Poll.IMMEDIATE,
                phase: 'started'
            });
        };
        /**
         * Stops the poll. Schedules `stopped` tick if necessary.
         *
         * @returns A promise that resolves after tick is scheduled and never rejects.
         */
        Poll.prototype.stop = function () {
            return this.schedule({
                cancel: function (_a) {
                    var phase = _a.phase;
                    return phase === 'stopped';
                },
                interval: Poll.NEVER,
                phase: 'stopped'
            });
        };
        /**
         * Execute a new poll factory promise or stand by if necessary.
         */
        Poll.prototype._execute = function () {
            var _this = this;
            var standby = typeof this.standby === 'function' ? this.standby() : this.standby;
            standby =
                standby === 'never'
                    ? false
                    : standby === 'when-hidden'
                        ? !!(typeof document !== 'undefined' && document && document.hidden)
                        : standby;
            // If in standby mode schedule next tick without calling the factory.
            if (standby) {
                void this.schedule();
                return;
            }
            var pending = this.tick;
            this._factory(this.state)
                .then(function (resolved) {
                if (_this.isDisposed || _this.tick !== pending) {
                    return;
                }
                void _this.schedule({
                    payload: resolved,
                    phase: _this.state.phase === 'rejected' ? 'reconnected' : 'resolved'
                });
            })
                .catch(function (rejected) {
                if (_this.isDisposed || _this.tick !== pending) {
                    return;
                }
                void _this.schedule({
                    interval: Private.sleep(_this.frequency, _this.state),
                    payload: rejected,
                    phase: 'rejected'
                });
            });
        };
        return Poll;
    }());
    /**
     * A namespace for `Poll` types, interfaces, and statics.
     */
    (function (Poll) {
        /**
         * An interval value that indicates the poll should tick immediately.
         */
        Poll.IMMEDIATE = 0;
        /**
         * Delays are 32-bit integers in many browsers so intervals need to be capped.
         *
         * #### Notes
         * https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/setTimeout#Maximum_delay_value
         */
        Poll.MAX_INTERVAL = 2147483647;
        /**
         * An interval value that indicates the poll should never tick.
         */
        Poll.NEVER = Infinity;
    })(exports.Poll || (exports.Poll = {}));
    /**
     * A namespace for private module data.
     */
    var Private;
    (function (Private) {
        /**
         * The default backoff growth rate if `backoff` is `true`.
         */
        Private.DEFAULT_BACKOFF = 3;
        /**
         * The default polling frequency.
         */
        Private.DEFAULT_FREQUENCY = {
            backoff: true,
            interval: 1000,
            max: 30 * 1000
        };
        /**
         * The default poll name.
         */
        Private.DEFAULT_NAME = 'unknown';
        /**
         * The default poll standby behavior.
         */
        Private.DEFAULT_STANDBY = 'when-hidden';
        /**
         * The first poll tick state's default values superseded in constructor.
         */
        Private.DEFAULT_STATE = {
            interval: exports.Poll.NEVER,
            payload: null,
            phase: 'constructed',
            timestamp: new Date(0).getTime()
        };
        /**
         * The disposed tick state values.
         */
        Private.DISPOSED_STATE = {
            interval: exports.Poll.NEVER,
            payload: null,
            phase: 'disposed',
            timestamp: new Date(0).getTime()
        };
        /**
         * Get a random integer between min and max, inclusive of both.
         *
         * #### Notes
         * From
         * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random#Getting_a_random_integer_between_two_values_inclusive
         *
         * From the MDN page: It might be tempting to use Math.round() to accomplish
         * that, but doing so would cause your random numbers to follow a non-uniform
         * distribution, which may not be acceptable for your needs.
         */
        function getRandomIntInclusive(min, max) {
            min = Math.ceil(min);
            max = Math.floor(max);
            return Math.floor(Math.random() * (max - min + 1)) + min;
        }
        /**
         * Returns the number of milliseconds to sleep before the next tick.
         *
         * @param frequency - The poll's base frequency.
         * @param last - The poll's last tick.
         */
        function sleep(frequency, last) {
            var backoff = frequency.backoff, interval = frequency.interval, max = frequency.max;
            if (interval === exports.Poll.NEVER) {
                return interval;
            }
            var growth = backoff === true ? Private.DEFAULT_BACKOFF : backoff === false ? 1 : backoff;
            var random = getRandomIntInclusive(interval, last.interval * growth);
            return Math.min(max, random);
        }
        Private.sleep = sleep;
    })(Private || (Private = {}));

    // Copyright (c) Jupyter Development Team.
    /**
     * A base class to implement rate limiters with different invocation strategies.
     *
     * @typeparam T - The resolved type of the underlying function.
     *
     * @typeparam U - The rejected type of the underlying function.
     */
    var RateLimiter = /** @class */ (function () {
        /**
         * Instantiate a rate limiter.
         *
         * @param fn - The function to rate limit.
         *
         * @param limit - The rate limit; defaults to 500ms.
         */
        function RateLimiter(fn, limit) {
            var _this = this;
            if (limit === void 0) { limit = 500; }
            /**
             * A promise that resolves on each successful invocation.
             */
            this.payload = null;
            this.limit = limit;
            this.poll = new exports.Poll({
                auto: false,
                factory: function () { return __awaiter(_this, void 0, void 0, function () { return __generator(this, function (_a) {
                    switch (_a.label) {
                        case 0: return [4 /*yield*/, fn()];
                        case 1: return [2 /*return*/, _a.sent()];
                    }
                }); }); },
                frequency: { backoff: false, interval: exports.Poll.NEVER, max: exports.Poll.NEVER },
                standby: 'never'
            });
            this.payload = new coreutils.PromiseDelegate();
            this.poll.ticked.connect(function (_, state) {
                var payload = _this.payload;
                if (state.phase === 'resolved') {
                    _this.payload = new coreutils.PromiseDelegate();
                    payload.resolve(state.payload);
                    return;
                }
                if (state.phase === 'rejected' || state.phase === 'stopped') {
                    _this.payload = new coreutils.PromiseDelegate();
                    payload.promise.catch(function (_) { return undefined; });
                    payload.reject(state.payload);
                    return;
                }
            }, this);
        }
        Object.defineProperty(RateLimiter.prototype, "isDisposed", {
            /**
             * Whether the rate limiter is disposed.
             */
            get: function () {
                return this.payload === null;
            },
            enumerable: true,
            configurable: true
        });
        /**
         * Disposes the rate limiter.
         */
        RateLimiter.prototype.dispose = function () {
            if (this.isDisposed) {
                return;
            }
            this.payload = null;
            this.poll.dispose();
        };
        /**
         * Stop the function if it is mid-flight.
         */
        RateLimiter.prototype.stop = function () {
            return __awaiter(this, void 0, void 0, function () {
                return __generator(this, function (_a) {
                    return [2 /*return*/, this.poll.stop()];
                });
            });
        };
        return RateLimiter;
    }());
    /**
     * Wraps and debounces a function that can be called multiple times and only
     * executes the underlying function one `interval` after the last invocation.
     *
     * @typeparam T - The resolved type of the underlying function. Defaults to any.
     *
     * @typeparam U - The rejected type of the underlying function. Defaults to any.
     */
    var Debouncer = /** @class */ (function (_super) {
        __extends(Debouncer, _super);
        function Debouncer() {
            return _super !== null && _super.apply(this, arguments) || this;
        }
        /**
         * Invokes the function and only executes after rate limit has elapsed.
         * Each invocation resets the timer.
         */
        Debouncer.prototype.invoke = function () {
            void this.poll.schedule({ interval: this.limit, phase: 'invoked' });
            return this.payload.promise;
        };
        return Debouncer;
    }(RateLimiter));
    /**
     * Wraps and throttles a function that can be called multiple times and only
     * executes the underlying function once per `interval`.
     *
     * @typeparam T - The resolved type of the underlying function. Defaults to any.
     *
     * @typeparam U - The rejected type of the underlying function. Defaults to any.
     */
    exports.Throttler = /** @class */ (function (_super) {
        __extends(Throttler, _super);
        /**
         * Instantiate a throttler.
         *
         * @param fn - The function being throttled.
         *
         * @param options - Throttling configuration or throttling limit in ms.
         *
         * #### Notes
         * The `edge` defaults to `leading`; the `limit` defaults to `500`.
         */
        function Throttler(fn, options) {
            var _this = _super.call(this, fn, typeof options === 'number' ? options : options && options.limit) || this;
            var edge = 'leading';
            if (typeof options !== 'number') {
                options = options || {};
                edge = 'edge' in options ? options.edge : edge;
            }
            _this._interval = edge === 'trailing' ? _this.limit : exports.Poll.IMMEDIATE;
            return _this;
        }
        /**
         * Throttles function invocations if one is currently in flight.
         */
        Throttler.prototype.invoke = function () {
            if (this.poll.state.phase !== 'invoked') {
                void this.poll.schedule({ interval: this._interval, phase: 'invoked' });
            }
            return this.payload.promise;
        };
        return Throttler;
    }(RateLimiter));
    /**
     * A namespace for `Throttler` interfaces.
     */
    (function (Throttler) {
    })(exports.Throttler || (exports.Throttler = {}));

    exports.Debouncer = Debouncer;
    exports.RateLimiter = RateLimiter;

    Object.defineProperty(exports, '__esModule', { value: true });

})));
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