import { millisecondsToSeconds, clamp, secondsToMilliseconds, warning } from 'motion-utils';
import { generateLinearEasing } from '../waapi/utils/linear.mjs';
import { calcGeneratorDuration, maxGeneratorDuration } from './utils/calc-duration.mjs';
import { createGeneratorEasing } from './utils/create-generator-easing.mjs';

const springDefaults = {
    // Default spring physics
    stiffness: 100,
    damping: 10,
    mass: 1.0,
    velocity: 0.0,
    // Default duration/bounce-based options
    duration: 800, // in ms
    bounce: 0.3,
    visualDuration: 0.3, // in seconds
    // Rest thresholds
    restSpeed: {
        granular: 0.01,
        default: 2,
    },
    restDelta: {
        granular: 0.005,
        default: 0.5,
    },
    // Limits
    minDuration: 0.01, // in seconds
    maxDuration: 10.0, // in seconds
    minDamping: 0.05,
    maxDamping: 1,
};
function calcAngularFreq(undampedFreq, dampingRatio) {
    return undampedFreq * Math.sqrt(1 - dampingRatio * dampingRatio);
}
const rootIterations = 12;
function approximateRoot(envelope, derivative, initialGuess) {
    let result = initialGuess;
    for (let i = 1; i < rootIterations; i++) {
        result = result - envelope(result) / derivative(result);
    }
    return result;
}
/**
 * This is ported from the Framer implementation of duration-based spring resolution.
 */
const safeMin = 0.001;
function findSpring({ duration = springDefaults.duration, bounce = springDefaults.bounce, velocity = springDefaults.velocity, mass = springDefaults.mass, }) {
    let envelope;
    let derivative;
    warning(duration <= secondsToMilliseconds(springDefaults.maxDuration), "Spring duration must be 10 seconds or less", "spring-duration-limit");
    let dampingRatio = 1 - bounce;
    /**
     * Restrict dampingRatio and duration to within acceptable ranges.
     */
    dampingRatio = clamp(springDefaults.minDamping, springDefaults.maxDamping, dampingRatio);
    duration = clamp(springDefaults.minDuration, springDefaults.maxDuration, millisecondsToSeconds(duration));
    if (dampingRatio < 1) {
        /**
         * Underdamped spring
         */
        envelope = (undampedFreq) => {
            const exponentialDecay = undampedFreq * dampingRatio;
            const delta = exponentialDecay * duration;
            const a = exponentialDecay - velocity;
            const b = calcAngularFreq(undampedFreq, dampingRatio);
            const c = Math.exp(-delta);
            return safeMin - (a / b) * c;
        };
        derivative = (undampedFreq) => {
            const exponentialDecay = undampedFreq * dampingRatio;
            const delta = exponentialDecay * duration;
            const d = delta * velocity + velocity;
            const e = Math.pow(dampingRatio, 2) * Math.pow(undampedFreq, 2) * duration;
            const f = Math.exp(-delta);
            const g = calcAngularFreq(Math.pow(undampedFreq, 2), dampingRatio);
            const factor = -envelope(undampedFreq) + safeMin > 0 ? -1 : 1;
            return (factor * ((d - e) * f)) / g;
        };
    }
    else {
        /**
         * Critically-damped spring
         */
        envelope = (undampedFreq) => {
            const a = Math.exp(-undampedFreq * duration);
            const b = (undampedFreq - velocity) * duration + 1;
            return -safeMin + a * b;
        };
        derivative = (undampedFreq) => {
            const a = Math.exp(-undampedFreq * duration);
            const b = (velocity - undampedFreq) * (duration * duration);
            return a * b;
        };
    }
    const initialGuess = 5 / duration;
    const undampedFreq = approximateRoot(envelope, derivative, initialGuess);
    duration = secondsToMilliseconds(duration);
    if (isNaN(undampedFreq)) {
        return {
            stiffness: springDefaults.stiffness,
            damping: springDefaults.damping,
            duration,
        };
    }
    else {
        const stiffness = Math.pow(undampedFreq, 2) * mass;
        return {
            stiffness,
            damping: dampingRatio * 2 * Math.sqrt(mass * stiffness),
            duration,
        };
    }
}
const durationKeys = ["duration", "bounce"];
const physicsKeys = ["stiffness", "damping", "mass"];
function isSpringType(options, keys) {
    return keys.some((key) => options[key] !== undefined);
}
function getSpringOptions(options) {
    let springOptions = {
        velocity: springDefaults.velocity,
        stiffness: springDefaults.stiffness,
        damping: springDefaults.damping,
        mass: springDefaults.mass,
        isResolvedFromDuration: false,
        ...options,
    };
    // stiffness/damping/mass overrides duration/bounce
    if (!isSpringType(options, physicsKeys) &&
        isSpringType(options, durationKeys)) {
        // Time-defined springs should ignore inherited velocity.
        // Velocity from interrupted animations can cause findSpring()
        // to compute wildly different spring parameters, leading to
        // massive oscillation on small-range animations.
        springOptions.velocity = 0;
        if (options.visualDuration) {
            const visualDuration = options.visualDuration;
            const root = (2 * Math.PI) / (visualDuration * 1.2);
            const stiffness = root * root;
            const damping = 2 *
                clamp(0.05, 1, 1 - (options.bounce || 0)) *
                Math.sqrt(stiffness);
            springOptions = {
                ...springOptions,
                mass: springDefaults.mass,
                stiffness,
                damping,
            };
        }
        else {
            const derived = findSpring({ ...options, velocity: 0 });
            springOptions = {
                ...springOptions,
                ...derived,
                mass: springDefaults.mass,
            };
            springOptions.isResolvedFromDuration = true;
        }
    }
    return springOptions;
}
function spring(optionsOrVisualDuration = springDefaults.visualDuration, bounce = springDefaults.bounce) {
    const options = typeof optionsOrVisualDuration !== "object"
        ? {
            visualDuration: optionsOrVisualDuration,
            keyframes: [0, 1],
            bounce,
        }
        : optionsOrVisualDuration;
    let { restSpeed, restDelta } = options;
    const origin = options.keyframes[0];
    const target = options.keyframes[options.keyframes.length - 1];
    /**
     * This is the Iterator-spec return value. We ensure it's mutable rather than using a generator
     * to reduce GC during animation.
     */
    const state = { done: false, value: origin };
    const { stiffness, damping, mass, duration, velocity, isResolvedFromDuration, } = getSpringOptions({
        ...options,
        velocity: -millisecondsToSeconds(options.velocity || 0),
    });
    const initialVelocity = velocity || 0.0;
    const dampingRatio = damping / (2 * Math.sqrt(stiffness * mass));
    const initialDelta = target - origin;
    const undampedAngularFreq = millisecondsToSeconds(Math.sqrt(stiffness / mass));
    /**
     * If we're working on a granular scale, use smaller defaults for determining
     * when the spring is finished.
     *
     * These defaults have been selected emprically based on what strikes a good
     * ratio between feeling good and finishing as soon as changes are imperceptible.
     */
    const isGranularScale = Math.abs(initialDelta) < 5;
    restSpeed || (restSpeed = isGranularScale
        ? springDefaults.restSpeed.granular
        : springDefaults.restSpeed.default);
    restDelta || (restDelta = isGranularScale
        ? springDefaults.restDelta.granular
        : springDefaults.restDelta.default);
    let resolveSpring;
    let resolveVelocity;
    // Underdamped coefficients, hoisted for use in the inlined next() hot path
    let angularFreq;
    let A;
    let sinCoeff;
    let cosCoeff;
    if (dampingRatio < 1) {
        angularFreq = calcAngularFreq(undampedAngularFreq, dampingRatio);
        A =
            (initialVelocity +
                dampingRatio * undampedAngularFreq * initialDelta) /
                angularFreq;
        // Underdamped spring
        resolveSpring = (t) => {
            const envelope = Math.exp(-dampingRatio * undampedAngularFreq * t);
            return (target -
                envelope *
                    (A * Math.sin(angularFreq * t) +
                        initialDelta * Math.cos(angularFreq * t)));
        };
        // Analytical derivative of underdamped spring (px/ms)
        sinCoeff =
            dampingRatio * undampedAngularFreq * A + initialDelta * angularFreq;
        cosCoeff =
            dampingRatio * undampedAngularFreq * initialDelta - A * angularFreq;
        resolveVelocity = (t) => {
            const envelope = Math.exp(-dampingRatio * undampedAngularFreq * t);
            return envelope *
                (sinCoeff * Math.sin(angularFreq * t) +
                    cosCoeff * Math.cos(angularFreq * t));
        };
    }
    else if (dampingRatio === 1) {
        // Critically damped spring
        resolveSpring = (t) => target -
            Math.exp(-undampedAngularFreq * t) *
                (initialDelta +
                    (initialVelocity + undampedAngularFreq * initialDelta) * t);
        // Analytical derivative of critically damped spring (px/ms)
        const C = initialVelocity + undampedAngularFreq * initialDelta;
        resolveVelocity = (t) => Math.exp(-undampedAngularFreq * t) *
            (undampedAngularFreq * C * t - initialVelocity);
    }
    else {
        // Overdamped spring
        const dampedAngularFreq = undampedAngularFreq * Math.sqrt(dampingRatio * dampingRatio - 1);
        resolveSpring = (t) => {
            const envelope = Math.exp(-dampingRatio * undampedAngularFreq * t);
            // When performing sinh or cosh values can hit Infinity so we cap them here
            const freqForT = Math.min(dampedAngularFreq * t, 300);
            return (target -
                (envelope *
                    ((initialVelocity +
                        dampingRatio * undampedAngularFreq * initialDelta) *
                        Math.sinh(freqForT) +
                        dampedAngularFreq *
                            initialDelta *
                            Math.cosh(freqForT))) /
                    dampedAngularFreq);
        };
        // Analytical derivative of overdamped spring (px/ms)
        const P = (initialVelocity +
            dampingRatio * undampedAngularFreq * initialDelta) /
            dampedAngularFreq;
        const sinhCoeff = dampingRatio * undampedAngularFreq * P - initialDelta * dampedAngularFreq;
        const coshCoeff = dampingRatio * undampedAngularFreq * initialDelta - P * dampedAngularFreq;
        resolveVelocity = (t) => {
            const envelope = Math.exp(-dampingRatio * undampedAngularFreq * t);
            const freqForT = Math.min(dampedAngularFreq * t, 300);
            return envelope *
                (sinhCoeff * Math.sinh(freqForT) +
                    coshCoeff * Math.cosh(freqForT));
        };
    }
    const generator = {
        calculatedDuration: isResolvedFromDuration ? duration || null : null,
        velocity: (t) => secondsToMilliseconds(resolveVelocity(t)),
        next: (t) => {
            /**
             * For underdamped physics springs we need both position and
             * velocity each tick. Compute shared trig values once to avoid
             * duplicate Math.exp/sin/cos calls on the hot path.
             */
            if (!isResolvedFromDuration && dampingRatio < 1) {
                const envelope = Math.exp(-dampingRatio * undampedAngularFreq * t);
                const sin = Math.sin(angularFreq * t);
                const cos = Math.cos(angularFreq * t);
                const current = target -
                    envelope *
                        (A * sin + initialDelta * cos);
                const currentVelocity = secondsToMilliseconds(envelope *
                    (sinCoeff * sin + cosCoeff * cos));
                state.done =
                    Math.abs(currentVelocity) <= restSpeed &&
                        Math.abs(target - current) <= restDelta;
                state.value = state.done ? target : current;
                return state;
            }
            const current = resolveSpring(t);
            if (!isResolvedFromDuration) {
                const currentVelocity = secondsToMilliseconds(resolveVelocity(t));
                state.done =
                    Math.abs(currentVelocity) <= restSpeed &&
                        Math.abs(target - current) <= restDelta;
            }
            else {
                state.done = t >= duration;
            }
            state.value = state.done ? target : current;
            return state;
        },
        toString: () => {
            const calculatedDuration = Math.min(calcGeneratorDuration(generator), maxGeneratorDuration);
            const easing = generateLinearEasing((progress) => generator.next(calculatedDuration * progress).value, calculatedDuration, 30);
            return calculatedDuration + "ms " + easing;
        },
        toTransition: () => { },
    };
    return generator;
}
spring.applyToOptions = (options) => {
    const generatorOptions = createGeneratorEasing(options, 100, spring);
    options.ease = generatorOptions.ease;
    options.duration = secondsToMilliseconds(generatorOptions.duration);
    options.type = "keyframes";
    return options;
};

export { spring };
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