
/** 
based on framer-motion@4.0.3,
Copyright (c) 2018 Framer B.V.
*/
import { fixed } from '../utils/fix-process-env';
import sync, { getFrameData } from 'framesync';
import { velocityPerSecond } from 'popmotion';
import { SubscriptionManager } from '../utils/subscription-manager.js';

var isFloat = function (value) {
    return !isNaN(parseFloat(value));
};
/**
 * `MotionValue` is used to track the state and velocity of motion values.
 *
 * @public
 */
var MotionValue = /** @class */ (function () {
    /**
     * @param init - The initiating value
     * @param config - Optional configuration options
     *
     * -  `transformer`: A function to transform incoming values with.
     *
     * @internal
     */
    function MotionValue(init, startStopNotifier) {
        var _this = this;
        /**
         * Duration, in milliseconds, since last updating frame.
         *
         * @internal
         */
        this.timeDelta = 0;
        /**
         * Timestamp of the last time this `MotionValue` was updated.
         *
         * @internal
         */
        this.lastUpdated = 0;
        /**
         * Functions to notify when the `MotionValue` updates.
         *
         * @internal
         */
        this.updateSubscribers = new SubscriptionManager();
        /**
         * Functions to notify when the velocity updates.
         *
         * @internal
         */
        this.velocityUpdateSubscribers = new SubscriptionManager();
        /**
         * Functions to notify when the `MotionValue` updates and `render` is set to `true`.
         *
         * @internal
         */
        this.renderSubscribers = new SubscriptionManager();
        /**
         * Tracks whether this value can output a velocity. Currently this is only true
         * if the value is numerical, but we might be able to widen the scope here and support
         * other value types.
         *
         * @internal
         */
        this.canTrackVelocity = false;
        this.updateAndNotify = function (v, render) {
            if (render === void 0) { render = true; }
            _this.prev = _this.current;
            _this.current = v;
            // Update timestamp
            var _a = getFrameData(), delta = _a.delta, timestamp = _a.timestamp;
            if (_this.lastUpdated !== timestamp) {
                _this.timeDelta = delta;
                _this.lastUpdated = timestamp;
                sync.postRender(_this.scheduleVelocityCheck);
            }
            // Update update subscribers
            if (_this.prev !== _this.current) {
                _this.updateSubscribers.notify(_this.current);
            }
            // Update velocity subscribers
            if (_this.velocityUpdateSubscribers.getSize()) {
                _this.velocityUpdateSubscribers.notify(_this.getVelocity());
            }
            // Update render subscribers
            if (render) {
                _this.renderSubscribers.notify(_this.current);
            }
        };
        /**
         * Schedule a velocity check for the next frame.
         *
         * This is an instanced and bound function to prevent generating a new
         * function once per frame.
         *
         * @internal
         */
        this.scheduleVelocityCheck = function () { return sync.postRender(_this.velocityCheck); };
        /**
         * Updates `prev` with `current` if the value hasn't been updated this frame.
         * This ensures velocity calculations return `0`.
         *
         * This is an instanced and bound function to prevent generating a new
         * function once per frame.
         *
         * @internal
         */
        this.velocityCheck = function (_a) {
            var timestamp = _a.timestamp;
            if (timestamp !== _this.lastUpdated) {
                _this.prev = _this.current;
                _this.velocityUpdateSubscribers.notify(_this.getVelocity());
            }
        };
        this.hasAnimated = false;
        this.prev = this.current = init;
        this.canTrackVelocity = isFloat(this.current);
        this.onSubscription = () => { }
        this.onUnsubscription = () => { }
        if (startStopNotifier) {
            this.onSubscription = () => {
                if (this.updateSubscribers.getSize() + this.velocityUpdateSubscribers.getSize() + this.renderSubscribers.getSize() === 0) {

                    const unsub = startStopNotifier()
                    this.onUnsubscription = () => { }
                    if (unsub) {
                        this.onUnsubscription = () => {
                            if (this.updateSubscribers.getSize() + this.velocityUpdateSubscribers.getSize() + this.renderSubscribers.getSize() === 0) {
                                unsub()
                            }
                        }
                    }

                }
            }
        }
    }
    /**
     * Adds a function that will be notified when the `MotionValue` is updated.
     *
     * It returns a function that, when called, will cancel the subscription.
     *
     * When calling `onChange` inside a React component, it should be wrapped with the
     * `useEffect` hook. As it returns an unsubscribe function, this should be returned
     * from the `useEffect` function to ensure you don't add duplicate subscribers..
     *
     * @motion
     *
     * ```jsx
     * export const MyComponent = () => {
     *   const x = useMotionValue(0)
     *   const y = useMotionValue(0)
     *   const opacity = useMotionValue(1)
     *
     *   useEffect(() => {
     *     function updateOpacity() {
     *       const maxXY = Math.max(x.get(), y.get())
     *       const newOpacity = transform(maxXY, [0, 100], [1, 0])
     *       opacity.set(newOpacity)
     *     }
     *
     *     const unsubscribeX = x.onChange(updateOpacity)
     *     const unsubscribeY = y.onChange(updateOpacity)
     *
     *     return () => {
     *       unsubscribeX()
     *       unsubscribeY()
     *     }
     *   }, [])
     *
     *   return <MotionDiv style={{ x }} />
     * }
     * ```
     *
     * @internalremarks
     *
     * We could look into a `useOnChange` hook if the above lifecycle management proves confusing.
     *
     * ```jsx
     * useOnChange(x, () => {})
     * ```
     *
     * @param subscriber - A function that receives the latest value.
     * @returns A function that, when called, will cancel this subscription.
     *
     * @public
     */
    MotionValue.prototype.onChange = function (subscription) {
        this.onSubscription();
        const unsub = this.updateSubscribers.add(subscription);
        return () => {
            unsub()
            this.onUnsubscription()

        }
    };
    /** Add subscribe method for Svelte store interface */
    MotionValue.prototype.subscribe = function (subscription) {
        return this.onChange(subscription);
    };

    MotionValue.prototype.clearListeners = function () {
        this.updateSubscribers.clear();
        this.onUnsubscription()
    };
    /**
     * Adds a function that will be notified when the `MotionValue` requests a render.
     *
     * @param subscriber - A function that's provided the latest value.
     * @returns A function that, when called, will cancel this subscription.
     *
     * @internal
     */
    MotionValue.prototype.onRenderRequest = function (subscription) {
        this.onSubscription()
        // Render immediately
        subscription(this.get());
        const unsub = this.renderSubscribers.add(subscription);
        return () => {
            unsub()
            this.onUnsubscription()
        }
    };
    /**
     * Attaches a passive effect to the `MotionValue`.
     *
     * @internal
     */
    MotionValue.prototype.attach = function (passiveEffect) {
        this.passiveEffect = passiveEffect;
    };
    /**
     * Sets the state of the `MotionValue`.
     *
     * @remarks
     *
     * ```jsx
     * const x = useMotionValue(0)
     * x.set(10)
     * ```
     *
     * @param latest - Latest value to set.
     * @param render - Whether to notify render subscribers. Defaults to `true`
     *
     * @public
     */
    MotionValue.prototype.set = function (v, render) {
        if (render === void 0) { render = true; }
        if (!render || !this.passiveEffect) {
            this.updateAndNotify(v, render);
        }
        else {
            this.passiveEffect(v, this.updateAndNotify);
        }
    };
    /** Add update method for Svelte Store behavior */
    MotionValue.prototype.update = function (v) {
        this.set(v(this.get()));
    }
    /**
     * Returns the latest state of `MotionValue`
     *
     * @returns - The latest state of `MotionValue`
     *
     * @public
     */
    MotionValue.prototype.get = function () {
        this.onSubscription()
        const curr = this.current;
        this.onUnsubscription()
        return curr
    };
    /**
     * @public
     */
    MotionValue.prototype.getPrevious = function () {
        return this.prev;
    };
    /**
     * Returns the latest velocity of `MotionValue`
     *
     * @returns - The latest velocity of `MotionValue`. Returns `0` if the state is non-numerical.
     *
     * @public
     */
    MotionValue.prototype.getVelocity = function () {
        // This could be isFloat(this.prev) && isFloat(this.current), but that would be wasteful
        this.onSubscription()
        const vel = this.canTrackVelocity
            ? // These casts could be avoided if parseFloat would be typed better
            velocityPerSecond(parseFloat(this.current) -
                parseFloat(this.prev), this.timeDelta)
            : 0;
        this.onUnsubscription()
        return vel;
    };
    /**
     * Registers a new animation to control this `MotionValue`. Only one
     * animation can drive a `MotionValue` at one time.
     *
     * ```jsx
     * value.start()
     * ```
     *
     * @param animation - A function that starts the provided animation
     *
     * @internal
     */
    MotionValue.prototype.start = function (animation) {
        var _this = this;
        this.stop();
        return new Promise(function (resolve) {
            _this.hasAnimated = true;
            _this.stopAnimation = animation(resolve);
        }).then(function () { return _this.clearAnimation(); });
    };
    /**
     * Stop the currently active animation.
     *
     * @public
     */
    MotionValue.prototype.stop = function () {
        if (this.stopAnimation)
            this.stopAnimation();
        this.clearAnimation();
    };
    /**
     * Returns `true` if this value is currently animating.
     *
     * @public
     */
    MotionValue.prototype.isAnimating = function () {
        return !!this.stopAnimation;
    };
    MotionValue.prototype.clearAnimation = function () {
        this.stopAnimation = null;
    };
    /**
     * Destroy and clean up subscribers to this `MotionValue`.
     *
     * The `MotionValue` hooks like `useMotionValue` and `useTransform` automatically
     * handle the lifecycle of the returned `MotionValue`, so this method is only necessary if you've manually
     * created a `MotionValue` via the `motionValue` function.
     *
     * @public
     */
    MotionValue.prototype.destroy = function () {
        this.updateSubscribers.clear();
        this.renderSubscribers.clear();
        this.stop();
        this.onUnsubscription()
    };
    return MotionValue;
}());
/**
 * @internal
 */
function motionValue(init, startStopNotifier) {
    return new MotionValue(init, startStopNotifier);
}

export { MotionValue, motionValue };

