import React__default, { useContext, createContext, useEffect, useLayoutEffect, useState, useRef, useCallback } from 'react';

// Global state used to deduplicate requests and store listeners
const SWRGlobalState = new WeakMap();

const EMPTY_CACHE = {};
const INITIAL_CACHE = {};
const noop = ()=>{};
// Using noop() as the undefined value as undefined can be replaced
// by something else. Prettier ignore and extra parentheses are necessary here
// to ensure that tsc doesn't remove the __NOINLINE__ comment.
// prettier-ignore
const UNDEFINED = /*#__NOINLINE__*/ noop();
const OBJECT = Object;
const isUndefined = (v)=>v === UNDEFINED;
const isFunction = (v)=>typeof v == 'function';
const mergeObjects = (a, b)=>({
        ...a,
        ...b
    });
const STR_UNDEFINED = 'undefined';
// NOTE: Use the function to guarantee it's re-evaluated between jsdom and node runtime for tests.
const isWindowDefined = typeof window != STR_UNDEFINED;
const isDocumentDefined = typeof document != STR_UNDEFINED;
const hasRequestAnimationFrame = ()=>isWindowDefined && typeof window['requestAnimationFrame'] != STR_UNDEFINED;
const createCacheHelper = (cache, key)=>{
    const state = SWRGlobalState.get(cache);
    return [
        // Getter
        ()=>cache.get(key) || EMPTY_CACHE,
        // Setter
        (info)=>{
            if (!isUndefined(key)) {
                const prev = cache.get(key);
                // Before writing to the store, we keep the value in the initial cache
                // if it's not there yet.
                if (!(key in INITIAL_CACHE)) {
                    INITIAL_CACHE[key] = prev;
                }
                state[5](key, mergeObjects(prev, info), prev || EMPTY_CACHE);
            }
        },
        // Subscriber
        state[6],
        // Get server cache snapshot
        ()=>{
            if (!isUndefined(key)) {
                // If the cache was updated on the client, we return the stored initial value.
                if (key in INITIAL_CACHE) return INITIAL_CACHE[key];
            }
            // If we haven't done any client-side updates, we return the current value.
            return cache.get(key) || EMPTY_CACHE;
        }
    ];
};

// use WeakMap to store the object->key mapping
// so the objects can be garbage collected.
// WeakMap uses a hashtable under the hood, so the lookup
// complexity is almost O(1).
const table = new WeakMap();
// counter of the key
let counter = 0;
// A stable hash implementation that supports:
// - Fast and ensures unique hash properties
// - Handles unserializable values
// - Handles object key ordering
// - Generates short results
//
// This is not a serialization function, and the result is not guaranteed to be
// parsable.
const stableHash = (arg)=>{
    const type = typeof arg;
    const constructor = arg && arg.constructor;
    const isDate = constructor == Date;
    let result;
    let index;
    if (OBJECT(arg) === arg && !isDate && constructor != RegExp) {
        // Object/function, not null/date/regexp. Use WeakMap to store the id first.
        // If it's already hashed, directly return the result.
        result = table.get(arg);
        if (result) return result;
        // Store the hash first for circular reference detection before entering the
        // recursive `stableHash` calls.
        // For other objects like set and map, we use this id directly as the hash.
        result = ++counter + '~';
        table.set(arg, result);
        if (constructor == Array) {
            // Array.
            result = '@';
            for(index = 0; index < arg.length; index++){
                result += stableHash(arg[index]) + ',';
            }
            table.set(arg, result);
        }
        if (constructor == OBJECT) {
            // Object, sort keys.
            result = '#';
            const keys = OBJECT.keys(arg).sort();
            while(!isUndefined(index = keys.pop())){
                if (!isUndefined(arg[index])) {
                    result += index + ':' + stableHash(arg[index]) + ',';
                }
            }
            table.set(arg, result);
        }
    } else {
        result = isDate ? arg.toJSON() : type == 'symbol' ? arg.toString() : type == 'string' ? JSON.stringify(arg) : '' + arg;
    }
    return result;
};

/**
 * Due to the bug https://bugs.chromium.org/p/chromium/issues/detail?id=678075,
 * it's not reliable to detect if the browser is currently online or offline
 * based on `navigator.onLine`.
 * As a workaround, we always assume it's online on the first load, and change
 * the status upon `online` or `offline` events.
 */ let online = true;
const isOnline = ()=>online;
// For node and React Native, `add/removeEventListener` doesn't exist on window.
const [onWindowEvent, offWindowEvent] = isWindowDefined && window.addEventListener ? [
    window.addEventListener.bind(window),
    window.removeEventListener.bind(window)
] : [
    noop,
    noop
];
const isVisible = ()=>{
    const visibilityState = isDocumentDefined && document.visibilityState;
    return isUndefined(visibilityState) || visibilityState !== 'hidden';
};
const initFocus = (callback)=>{
    // focus revalidate
    if (isDocumentDefined) {
        document.addEventListener('visibilitychange', callback);
    }
    onWindowEvent('focus', callback);
    return ()=>{
        if (isDocumentDefined) {
            document.removeEventListener('visibilitychange', callback);
        }
        offWindowEvent('focus', callback);
    };
};
const initReconnect = (callback)=>{
    // revalidate on reconnected
    const onOnline = ()=>{
        online = true;
        callback();
    };
    // nothing to revalidate, just update the status
    const onOffline = ()=>{
        online = false;
    };
    onWindowEvent('online', onOnline);
    onWindowEvent('offline', onOffline);
    return ()=>{
        offWindowEvent('online', onOnline);
        offWindowEvent('offline', onOffline);
    };
};
const preset = {
    isOnline,
    isVisible
};
const defaultConfigOptions = {
    initFocus,
    initReconnect
};

const IS_REACT_LEGACY = !React__default.useId;
const IS_SERVER = !isWindowDefined || 'Deno' in window;
// Polyfill requestAnimationFrame
const rAF = (f)=>hasRequestAnimationFrame() ? window['requestAnimationFrame'](f) : setTimeout(f, 1);
// React currently throws a warning when using useLayoutEffect on the server.
// To get around it, we can conditionally useEffect on the server (no-op) and
// useLayoutEffect in the browser.
const useIsomorphicLayoutEffect = IS_SERVER ? useEffect : useLayoutEffect;
// This assignment is to extend the Navigator type to use effectiveType.
const navigatorConnection = typeof navigator !== 'undefined' && navigator.connection;
// Adjust the config based on slow connection status (<= 70Kbps).
const slowConnection = !IS_SERVER && navigatorConnection && ([
    'slow-2g',
    '2g'
].includes(navigatorConnection.effectiveType) || navigatorConnection.saveData);

const serialize = (key)=>{
    if (isFunction(key)) {
        try {
            key = key();
        } catch (err) {
            // dependencies not ready
            key = '';
        }
    }
    // Use the original key as the argument of fetcher. This can be a string or an
    // array of values.
    const args = key;
    // If key is not falsy, or not an empty array, hash it.
    key = typeof key == 'string' ? key : (Array.isArray(key) ? key.length : key) ? stableHash(key) : '';
    return [
        key,
        args
    ];
};

// Global timestamp.
let __timestamp = 0;
const getTimestamp = ()=>++__timestamp;

const FOCUS_EVENT = 0;
const RECONNECT_EVENT = 1;
const MUTATE_EVENT = 2;
const ERROR_REVALIDATE_EVENT = 3;

var constants = {
  __proto__: null,
  FOCUS_EVENT: FOCUS_EVENT,
  RECONNECT_EVENT: RECONNECT_EVENT,
  MUTATE_EVENT: MUTATE_EVENT,
  ERROR_REVALIDATE_EVENT: ERROR_REVALIDATE_EVENT
};

async function internalMutate(...args) {
    const [cache, _key, _data, _opts] = args;
    // When passing as a boolean, it's explicitly used to disable/enable
    // revalidation.
    const options = mergeObjects({
        populateCache: true,
        throwOnError: true
    }, typeof _opts === 'boolean' ? {
        revalidate: _opts
    } : _opts || {});
    let populateCache = options.populateCache;
    const rollbackOnErrorOption = options.rollbackOnError;
    let optimisticData = options.optimisticData;
    const revalidate = options.revalidate !== false;
    const rollbackOnError = (error)=>{
        return typeof rollbackOnErrorOption === 'function' ? rollbackOnErrorOption(error) : rollbackOnErrorOption !== false;
    };
    const throwOnError = options.throwOnError;
    // If the second argument is a key filter, return the mutation results for all
    // filtered keys.
    if (isFunction(_key)) {
        const keyFilter = _key;
        const matchedKeys = [];
        const it = cache.keys();
        for(let keyIt = it.next(); !keyIt.done; keyIt = it.next()){
            const key = keyIt.value;
            if (// Skip the special useSWRInfinite and useSWRSubscription keys.
            !/^\$(inf|sub)\$/.test(key) && keyFilter(cache.get(key)._k)) {
                matchedKeys.push(key);
            }
        }
        return Promise.all(matchedKeys.map(mutateByKey));
    }
    return mutateByKey(_key);
    async function mutateByKey(_k) {
        // Serialize key
        const [key] = serialize(_k);
        if (!key) return;
        const [get, set] = createCacheHelper(cache, key);
        const [EVENT_REVALIDATORS, MUTATION, FETCH] = SWRGlobalState.get(cache);
        const revalidators = EVENT_REVALIDATORS[key];
        const startRevalidate = ()=>{
            if (revalidate) {
                // Invalidate the key by deleting the concurrent request markers so new
                // requests will not be deduped.
                delete FETCH[key];
                if (revalidators && revalidators[0]) {
                    return revalidators[0](MUTATE_EVENT).then(()=>get().data);
                }
            }
            return get().data;
        };
        // If there is no new data provided, revalidate the key with current state.
        if (args.length < 3) {
            // Revalidate and broadcast state.
            return startRevalidate();
        }
        let data = _data;
        let error;
        // Update global timestamps.
        const beforeMutationTs = getTimestamp();
        MUTATION[key] = [
            beforeMutationTs,
            0
        ];
        const hasOptimisticData = !isUndefined(optimisticData);
        const state = get();
        // `displayedData` is the current value on screen. It could be the optimistic value
        // that is going to be overridden by a `committedData`, or get reverted back.
        // `committedData` is the validated value that comes from a fetch or mutation.
        const displayedData = state.data;
        const currentData = state._c;
        const committedData = isUndefined(currentData) ? displayedData : currentData;
        // Do optimistic data update.
        if (hasOptimisticData) {
            optimisticData = isFunction(optimisticData) ? optimisticData(committedData) : optimisticData;
            // When we set optimistic data, backup the current committedData data in `_c`.
            set({
                data: optimisticData,
                _c: committedData
            });
        }
        if (isFunction(data)) {
            // `data` is a function, call it passing current cache value.
            try {
                data = data(committedData);
            } catch (err) {
                // If it throws an error synchronously, we shouldn't update the cache.
                error = err;
            }
        }
        // `data` is a promise/thenable, resolve the final data first.
        if (data && isFunction(data.then)) {
            // This means that the mutation is async, we need to check timestamps to
            // avoid race conditions.
            data = await data.catch((err)=>{
                error = err;
            });
            // Check if other mutations have occurred since we've started this mutation.
            // If there's a race we don't update cache or broadcast the change,
            // just return the data.
            if (beforeMutationTs !== MUTATION[key][0]) {
                if (error) throw error;
                return data;
            } else if (error && hasOptimisticData && rollbackOnError(error)) {
                // Rollback. Always populate the cache in this case but without
                // transforming the data.
                populateCache = true;
                data = committedData;
                // Reset data to be the latest committed data, and clear the `_c` value.
                set({
                    data,
                    _c: UNDEFINED
                });
            }
        }
        // If we should write back the cache after request.
        if (populateCache) {
            if (!error) {
                // Transform the result into data.
                if (isFunction(populateCache)) {
                    data = populateCache(data, committedData);
                }
                // Only update cached data if there's no error. Data can be `undefined` here.
                set({
                    data,
                    _c: UNDEFINED
                });
            }
        }
        // Reset the timestamp to mark the mutation has ended.
        MUTATION[key][1] = getTimestamp();
        // Update existing SWR Hooks' internal states:
        const res = await startRevalidate();
        // The mutation and revalidation are ended, we can clear it since the data is
        // not an optimistic value anymore.
        set({
            _c: UNDEFINED
        });
        // Throw error or return data
        if (error) {
            if (throwOnError) throw error;
            return;
        }
        return populateCache ? res : data;
    }
}

const revalidateAllKeys = (revalidators, type)=>{
    for(const key in revalidators){
        if (revalidators[key][0]) revalidators[key][0](type);
    }
};
const initCache = (provider, options)=>{
    // The global state for a specific provider will be used to deduplicate
    // requests and store listeners. As well as a mutate function that is bound to
    // the cache.
    // The provider's global state might be already initialized. Let's try to get the
    // global state associated with the provider first.
    if (!SWRGlobalState.has(provider)) {
        const opts = mergeObjects(defaultConfigOptions, options);
        // If there's no global state bound to the provider, create a new one with the
        // new mutate function.
        const EVENT_REVALIDATORS = {};
        const mutate = internalMutate.bind(UNDEFINED, provider);
        let unmount = noop;
        const subscriptions = {};
        const subscribe = (key, callback)=>{
            const subs = subscriptions[key] || [];
            subscriptions[key] = subs;
            subs.push(callback);
            return ()=>subs.splice(subs.indexOf(callback), 1);
        };
        const setter = (key, value, prev)=>{
            provider.set(key, value);
            const subs = subscriptions[key];
            if (subs) {
                for (const fn of subs){
                    fn(value, prev);
                }
            }
        };
        const initProvider = ()=>{
            if (!SWRGlobalState.has(provider)) {
                // Update the state if it's new, or if the provider has been extended.
                SWRGlobalState.set(provider, [
                    EVENT_REVALIDATORS,
                    {},
                    {},
                    {},
                    mutate,
                    setter,
                    subscribe
                ]);
                if (!IS_SERVER) {
                    // When listening to the native events for auto revalidations,
                    // we intentionally put a delay (setTimeout) here to make sure they are
                    // fired after immediate JavaScript executions, which can be
                    // React's state updates.
                    // This avoids some unnecessary revalidations such as
                    // https://github.com/vercel/swr/issues/1680.
                    const releaseFocus = opts.initFocus(setTimeout.bind(UNDEFINED, revalidateAllKeys.bind(UNDEFINED, EVENT_REVALIDATORS, FOCUS_EVENT)));
                    const releaseReconnect = opts.initReconnect(setTimeout.bind(UNDEFINED, revalidateAllKeys.bind(UNDEFINED, EVENT_REVALIDATORS, RECONNECT_EVENT)));
                    unmount = ()=>{
                        releaseFocus && releaseFocus();
                        releaseReconnect && releaseReconnect();
                        // When un-mounting, we need to remove the cache provider from the state
                        // storage too because it's a side-effect. Otherwise, when re-mounting we
                        // will not re-register those event listeners.
                        SWRGlobalState.delete(provider);
                    };
                }
            }
        };
        initProvider();
        // This is a new provider, we need to initialize it and setup DOM events
        // listeners for `focus` and `reconnect` actions.
        // We might want to inject an extra layer on top of `provider` in the future,
        // such as key serialization, auto GC, etc.
        // For now, it's just a `Map` interface without any modifications.
        return [
            provider,
            mutate,
            initProvider,
            unmount
        ];
    }
    return [
        provider,
        SWRGlobalState.get(provider)[4]
    ];
};

// error retry
const onErrorRetry = (_, __, config, revalidate, opts)=>{
    const maxRetryCount = config.errorRetryCount;
    const currentRetryCount = opts.retryCount;
    // Exponential backoff
    const timeout = ~~((Math.random() + 0.5) * (1 << (currentRetryCount < 8 ? currentRetryCount : 8))) * config.errorRetryInterval;
    if (!isUndefined(maxRetryCount) && currentRetryCount > maxRetryCount) {
        return;
    }
    setTimeout(revalidate, timeout, opts);
};
const compare = (currentData, newData)=>stableHash(currentData) == stableHash(newData);
// Default cache provider
const [cache, mutate] = initCache(new Map());
// Default config
const defaultConfig = mergeObjects({
    // events
    onLoadingSlow: noop,
    onSuccess: noop,
    onError: noop,
    onErrorRetry,
    onDiscarded: noop,
    // switches
    revalidateOnFocus: true,
    revalidateOnReconnect: true,
    revalidateIfStale: true,
    shouldRetryOnError: true,
    // timeouts
    errorRetryInterval: slowConnection ? 10000 : 5000,
    focusThrottleInterval: 5 * 1000,
    dedupingInterval: 2 * 1000,
    loadingTimeout: slowConnection ? 5000 : 3000,
    // providers
    compare,
    isPaused: ()=>false,
    cache,
    mutate,
    fallback: {}
}, // use web preset by default
preset);

const mergeConfigs = (a, b)=>{
    // Need to create a new object to avoid mutating the original here.
    const v = mergeObjects(a, b);
    // If two configs are provided, merge their `use` and `fallback` options.
    if (b) {
        const { use: u1 , fallback: f1  } = a;
        const { use: u2 , fallback: f2  } = b;
        if (u1 && u2) {
            v.use = u1.concat(u2);
        }
        if (f1 && f2) {
            v.fallback = mergeObjects(f1, f2);
        }
    }
    return v;
};

const SWRConfigContext = createContext({});

// @ts-expect-error
const enableDevtools = isWindowDefined && window.__SWR_DEVTOOLS_USE__;
const use = enableDevtools ? window.__SWR_DEVTOOLS_USE__ : [];
const setupDevTools = ()=>{
    if (enableDevtools) {
        // @ts-expect-error
        window.__SWR_DEVTOOLS_REACT__ = React__default;
    }
};

const normalize = (args)=>{
    return isFunction(args[1]) ? [
        args[0],
        args[1],
        args[2] || {}
    ] : [
        args[0],
        null,
        (args[1] === null ? args[2] : args[1]) || {}
    ];
};

const useSWRConfig = ()=>{
    return mergeObjects(defaultConfig, useContext(SWRConfigContext));
};
const middleware = (useSWRNext)=>(key_, fetcher_, config)=>{
        // fetcher might be a sync function, so this should not be an async function
        const fetcher = fetcher_ && ((...args)=>{
            const key = serialize(key_)[0];
            const [, , , PRELOAD] = SWRGlobalState.get(cache);
            const req = PRELOAD[key];
            if (req) {
                delete PRELOAD[key];
                return req;
            }
            return fetcher_(...args);
        });
        return useSWRNext(key_, fetcher, config);
    };

const BUILT_IN_MIDDLEWARE = use.concat(middleware);

// It's tricky to pass generic types as parameters, so we just directly override
// the types here.
const withArgs = (hook)=>{
    return function useSWRArgs(...args) {
        // Get the default and inherited configuration.
        const fallbackConfig = useSWRConfig();
        // Normalize arguments.
        const [key, fn, _config] = normalize(args);
        // Merge configurations.
        const config = mergeConfigs(fallbackConfig, _config);
        // Apply middleware
        let next = hook;
        const { use  } = config;
        const middleware = (use || []).concat(BUILT_IN_MIDDLEWARE);
        for(let i = middleware.length; i--;){
            next = middleware[i](next);
        }
        return next(key, fn || config.fetcher || null, config);
    };
};

/**
 * An implementation of state with dependency-tracking.
 */ const useStateWithDeps = (state)=>{
    const rerender = useState({})[1];
    const unmountedRef = useRef(false);
    const stateRef = useRef(state);
    // If a state property (data, error, or isValidating) is accessed by the render
    // function, we mark the property as a dependency so if it is updated again
    // in the future, we trigger a rerender.
    // This is also known as dependency-tracking.
    const stateDependenciesRef = useRef({
        data: false,
        error: false,
        isValidating: false
    });
    /**
   * @param payload To change stateRef, pass the values explicitly to setState:
   * @example
   * ```js
   * setState({
   *   isValidating: false
   *   data: newData // set data to newData
   *   error: undefined // set error to undefined
   * })
   *
   * setState({
   *   isValidating: false
   *   data: undefined // set data to undefined
   *   error: err // set error to err
   * })
   * ```
   */ const setState = useCallback((payload)=>{
        let shouldRerender = false;
        const currentState = stateRef.current;
        for(const _ in payload){
            const k = _;
            // If the property has changed, update the state and mark rerender as
            // needed.
            if (currentState[k] !== payload[k]) {
                currentState[k] = payload[k];
                // If the property is accessed by the component, a rerender should be
                // triggered.
                if (stateDependenciesRef.current[k]) {
                    shouldRerender = true;
                }
            }
        }
        if (shouldRerender && !unmountedRef.current) {
            if (IS_REACT_LEGACY) {
                rerender({});
            } else {
                React__default.startTransition(()=>rerender({}));
            }
        }
    }, // config.suspense isn't allowed to change during the lifecycle
    // eslint-disable-next-line react-hooks/exhaustive-deps
    []);
    useIsomorphicLayoutEffect(()=>{
        unmountedRef.current = false;
        return ()=>{
            unmountedRef.current = true;
        };
    });
    return [
        stateRef,
        stateDependenciesRef.current,
        setState
    ];
};

// Add a callback function to a list of keyed callback functions and return
// the unsubscribe function.
const subscribeCallback = (key, callbacks, callback)=>{
    const keyedRevalidators = callbacks[key] || (callbacks[key] = []);
    keyedRevalidators.push(callback);
    return ()=>{
        const index = keyedRevalidators.indexOf(callback);
        if (index >= 0) {
            // O(1): faster than splice
            keyedRevalidators[index] = keyedRevalidators[keyedRevalidators.length - 1];
            keyedRevalidators.pop();
        }
    };
};

// Create a custom hook with a middleware
const withMiddleware = (useSWR, middleware)=>{
    return (...args)=>{
        const [key, fn, config] = normalize(args);
        const uses = (config.use || []).concat(middleware);
        return useSWR(key, fn, {
            ...config,
            use: uses
        });
    };
};

setupDevTools();

export { IS_REACT_LEGACY, IS_SERVER, OBJECT, SWRGlobalState, UNDEFINED, cache, compare, createCacheHelper, defaultConfig, defaultConfigOptions, getTimestamp, hasRequestAnimationFrame, initCache, internalMutate, isDocumentDefined, isFunction, isUndefined, isWindowDefined, mergeConfigs, mergeObjects, mutate, noop, normalize, preset, rAF, constants as revalidateEvents, serialize, slowConnection, stableHash, subscribeCallback, useIsomorphicLayoutEffect, useSWRConfig, useStateWithDeps, withArgs, withMiddleware };
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