import { shallowEqualObjects, noop, isServer, isValidTimeout, timeUntilStale, replaceData } from './utils.esm.js';
import { notifyManager } from './notifyManager.esm.js';
import { focusManager } from './focusManager.esm.js';
import { Subscribable } from './subscribable.esm.js';
import { canFetch, isCancelledError } from './retryer.esm.js';

class QueryObserver extends Subscribable {
  constructor(client, options) {
    super();
    this.client = client;
    this.options = options;
    this.trackedProps = new Set();
    this.selectError = null;
    this.bindMethods();
    this.setOptions(options);
  }

  bindMethods() {
    this.remove = this.remove.bind(this);
    this.refetch = this.refetch.bind(this);
  }

  onSubscribe() {
    if (this.listeners.size === 1) {
      this.currentQuery.addObserver(this);

      if (shouldFetchOnMount(this.currentQuery, this.options)) {
        this.executeFetch();
      }

      this.updateTimers();
    }
  }

  onUnsubscribe() {
    if (!this.hasListeners()) {
      this.destroy();
    }
  }

  shouldFetchOnReconnect() {
    return shouldFetchOn(this.currentQuery, this.options, this.options.refetchOnReconnect);
  }

  shouldFetchOnWindowFocus() {
    return shouldFetchOn(this.currentQuery, this.options, this.options.refetchOnWindowFocus);
  }

  destroy() {
    this.listeners = new Set();
    this.clearStaleTimeout();
    this.clearRefetchInterval();
    this.currentQuery.removeObserver(this);
  }

  setOptions(options, notifyOptions) {
    const prevOptions = this.options;
    const prevQuery = this.currentQuery;
    this.options = this.client.defaultQueryOptions(options);

    if (process.env.NODE_ENV !== 'production' && typeof (options == null ? void 0 : options.isDataEqual) !== 'undefined') {
      this.client.getLogger().error("The isDataEqual option has been deprecated and will be removed in the next major version. You can achieve the same functionality by passing a function as the structuralSharing option");
    }

    if (!shallowEqualObjects(prevOptions, this.options)) {
      this.client.getQueryCache().notify({
        type: 'observerOptionsUpdated',
        query: this.currentQuery,
        observer: this
      });
    }

    if (typeof this.options.enabled !== 'undefined' && typeof this.options.enabled !== 'boolean') {
      throw new Error('Expected enabled to be a boolean');
    } // Keep previous query key if the user does not supply one


    if (!this.options.queryKey) {
      this.options.queryKey = prevOptions.queryKey;
    }

    this.updateQuery();
    const mounted = this.hasListeners(); // Fetch if there are subscribers

    if (mounted && shouldFetchOptionally(this.currentQuery, prevQuery, this.options, prevOptions)) {
      this.executeFetch();
    } // Update result


    this.updateResult(notifyOptions); // Update stale interval if needed

    if (mounted && (this.currentQuery !== prevQuery || this.options.enabled !== prevOptions.enabled || this.options.staleTime !== prevOptions.staleTime)) {
      this.updateStaleTimeout();
    }

    const nextRefetchInterval = this.computeRefetchInterval(); // Update refetch interval if needed

    if (mounted && (this.currentQuery !== prevQuery || this.options.enabled !== prevOptions.enabled || nextRefetchInterval !== this.currentRefetchInterval)) {
      this.updateRefetchInterval(nextRefetchInterval);
    }
  }

  getOptimisticResult(options) {
    const query = this.client.getQueryCache().build(this.client, options);
    const result = this.createResult(query, options);

    if (shouldAssignObserverCurrentProperties(this, result, options)) {
      // this assigns the optimistic result to the current Observer
      // because if the query function changes, useQuery will be performing
      // an effect where it would fetch again.
      // When the fetch finishes, we perform a deep data cloning in order
      // to reuse objects references. This deep data clone is performed against
      // the `observer.currentResult.data` property
      // When QueryKey changes, we refresh the query and get new `optimistic`
      // result, while we leave the `observer.currentResult`, so when new data
      // arrives, it finds the old `observer.currentResult` which is related
      // to the old QueryKey. Which means that currentResult and selectData are
      // out of sync already.
      // To solve this, we move the cursor of the currentResult everytime
      // an observer reads an optimistic value.
      // When keeping the previous data, the result doesn't change until new
      // data arrives.
      this.currentResult = result;
      this.currentResultOptions = this.options;
      this.currentResultState = this.currentQuery.state;
    }

    return result;
  }

  getCurrentResult() {
    return this.currentResult;
  }

  trackResult(result) {
    const trackedResult = {};
    Object.keys(result).forEach(key => {
      Object.defineProperty(trackedResult, key, {
        configurable: false,
        enumerable: true,
        get: () => {
          this.trackedProps.add(key);
          return result[key];
        }
      });
    });
    return trackedResult;
  }

  getCurrentQuery() {
    return this.currentQuery;
  }

  remove() {
    this.client.getQueryCache().remove(this.currentQuery);
  }

  refetch({
    refetchPage,
    ...options
  } = {}) {
    return this.fetch({ ...options,
      meta: {
        refetchPage
      }
    });
  }

  fetchOptimistic(options) {
    const defaultedOptions = this.client.defaultQueryOptions(options);
    const query = this.client.getQueryCache().build(this.client, defaultedOptions);
    query.isFetchingOptimistic = true;
    return query.fetch().then(() => this.createResult(query, defaultedOptions));
  }

  fetch(fetchOptions) {
    var _fetchOptions$cancelR;

    return this.executeFetch({ ...fetchOptions,
      cancelRefetch: (_fetchOptions$cancelR = fetchOptions.cancelRefetch) != null ? _fetchOptions$cancelR : true
    }).then(() => {
      this.updateResult();
      return this.currentResult;
    });
  }

  executeFetch(fetchOptions) {
    // Make sure we reference the latest query as the current one might have been removed
    this.updateQuery(); // Fetch

    let promise = this.currentQuery.fetch(this.options, fetchOptions);

    if (!(fetchOptions != null && fetchOptions.throwOnError)) {
      promise = promise.catch(noop);
    }

    return promise;
  }

  updateStaleTimeout() {
    this.clearStaleTimeout();

    if (isServer || this.currentResult.isStale || !isValidTimeout(this.options.staleTime)) {
      return;
    }

    const time = timeUntilStale(this.currentResult.dataUpdatedAt, this.options.staleTime); // The timeout is sometimes triggered 1 ms before the stale time expiration.
    // To mitigate this issue we always add 1 ms to the timeout.

    const timeout = time + 1;
    this.staleTimeoutId = setTimeout(() => {
      if (!this.currentResult.isStale) {
        this.updateResult();
      }
    }, timeout);
  }

  computeRefetchInterval() {
    var _this$options$refetch;

    return typeof this.options.refetchInterval === 'function' ? this.options.refetchInterval(this.currentResult.data, this.currentQuery) : (_this$options$refetch = this.options.refetchInterval) != null ? _this$options$refetch : false;
  }

  updateRefetchInterval(nextInterval) {
    this.clearRefetchInterval();
    this.currentRefetchInterval = nextInterval;

    if (isServer || this.options.enabled === false || !isValidTimeout(this.currentRefetchInterval) || this.currentRefetchInterval === 0) {
      return;
    }

    this.refetchIntervalId = setInterval(() => {
      if (this.options.refetchIntervalInBackground || focusManager.isFocused()) {
        this.executeFetch();
      }
    }, this.currentRefetchInterval);
  }

  updateTimers() {
    this.updateStaleTimeout();
    this.updateRefetchInterval(this.computeRefetchInterval());
  }

  clearStaleTimeout() {
    if (this.staleTimeoutId) {
      clearTimeout(this.staleTimeoutId);
      this.staleTimeoutId = undefined;
    }
  }

  clearRefetchInterval() {
    if (this.refetchIntervalId) {
      clearInterval(this.refetchIntervalId);
      this.refetchIntervalId = undefined;
    }
  }

  createResult(query, options) {
    const prevQuery = this.currentQuery;
    const prevOptions = this.options;
    const prevResult = this.currentResult;
    const prevResultState = this.currentResultState;
    const prevResultOptions = this.currentResultOptions;
    const queryChange = query !== prevQuery;
    const queryInitialState = queryChange ? query.state : this.currentQueryInitialState;
    const prevQueryResult = queryChange ? this.currentResult : this.previousQueryResult;
    const {
      state
    } = query;
    let {
      dataUpdatedAt,
      error,
      errorUpdatedAt,
      fetchStatus,
      status
    } = state;
    let isPreviousData = false;
    let isPlaceholderData = false;
    let data; // Optimistically set result in fetching state if needed

    if (options._optimisticResults) {
      const mounted = this.hasListeners();
      const fetchOnMount = !mounted && shouldFetchOnMount(query, options);
      const fetchOptionally = mounted && shouldFetchOptionally(query, prevQuery, options, prevOptions);

      if (fetchOnMount || fetchOptionally) {
        fetchStatus = canFetch(query.options.networkMode) ? 'fetching' : 'paused';

        if (!dataUpdatedAt) {
          status = 'loading';
        }
      }

      if (options._optimisticResults === 'isRestoring') {
        fetchStatus = 'idle';
      }
    } // Keep previous data if needed


    if (options.keepPreviousData && !state.dataUpdatedAt && prevQueryResult != null && prevQueryResult.isSuccess && status !== 'error') {
      data = prevQueryResult.data;
      dataUpdatedAt = prevQueryResult.dataUpdatedAt;
      status = prevQueryResult.status;
      isPreviousData = true;
    } // Select data if needed
    else if (options.select && typeof state.data !== 'undefined') {
      // Memoize select result
      if (prevResult && state.data === (prevResultState == null ? void 0 : prevResultState.data) && options.select === this.selectFn) {
        data = this.selectResult;
      } else {
        try {
          this.selectFn = options.select;
          data = options.select(state.data);
          data = replaceData(prevResult == null ? void 0 : prevResult.data, data, options);
          this.selectResult = data;
          this.selectError = null;
        } catch (selectError) {
          if (process.env.NODE_ENV !== 'production') {
            this.client.getLogger().error(selectError);
          }

          this.selectError = selectError;
        }
      }
    } // Use query data
    else {
      data = state.data;
    } // Show placeholder data if needed


    if (typeof options.placeholderData !== 'undefined' && typeof data === 'undefined' && status === 'loading') {
      let placeholderData; // Memoize placeholder data

      if (prevResult != null && prevResult.isPlaceholderData && options.placeholderData === (prevResultOptions == null ? void 0 : prevResultOptions.placeholderData)) {
        placeholderData = prevResult.data;
      } else {
        placeholderData = typeof options.placeholderData === 'function' ? options.placeholderData() : options.placeholderData;

        if (options.select && typeof placeholderData !== 'undefined') {
          try {
            placeholderData = options.select(placeholderData);
            this.selectError = null;
          } catch (selectError) {
            if (process.env.NODE_ENV !== 'production') {
              this.client.getLogger().error(selectError);
            }

            this.selectError = selectError;
          }
        }
      }

      if (typeof placeholderData !== 'undefined') {
        status = 'success';
        data = replaceData(prevResult == null ? void 0 : prevResult.data, placeholderData, options);
        isPlaceholderData = true;
      }
    }

    if (this.selectError) {
      error = this.selectError;
      data = this.selectResult;
      errorUpdatedAt = Date.now();
      status = 'error';
    }

    const isFetching = fetchStatus === 'fetching';
    const isLoading = status === 'loading';
    const isError = status === 'error';
    const result = {
      status,
      fetchStatus,
      isLoading,
      isSuccess: status === 'success',
      isError,
      isInitialLoading: isLoading && isFetching,
      data,
      dataUpdatedAt,
      error,
      errorUpdatedAt,
      failureCount: state.fetchFailureCount,
      failureReason: state.fetchFailureReason,
      errorUpdateCount: state.errorUpdateCount,
      isFetched: state.dataUpdateCount > 0 || state.errorUpdateCount > 0,
      isFetchedAfterMount: state.dataUpdateCount > queryInitialState.dataUpdateCount || state.errorUpdateCount > queryInitialState.errorUpdateCount,
      isFetching,
      isRefetching: isFetching && !isLoading,
      isLoadingError: isError && state.dataUpdatedAt === 0,
      isPaused: fetchStatus === 'paused',
      isPlaceholderData,
      isPreviousData,
      isRefetchError: isError && state.dataUpdatedAt !== 0,
      isStale: isStale(query, options),
      refetch: this.refetch,
      remove: this.remove
    };
    return result;
  }

  updateResult(notifyOptions) {
    const prevResult = this.currentResult;
    const nextResult = this.createResult(this.currentQuery, this.options);
    this.currentResultState = this.currentQuery.state;
    this.currentResultOptions = this.options; // Only notify and update result if something has changed

    if (shallowEqualObjects(nextResult, prevResult)) {
      return;
    }

    this.currentResult = nextResult; // Determine which callbacks to trigger

    const defaultNotifyOptions = {
      cache: true
    };

    const shouldNotifyListeners = () => {
      if (!prevResult) {
        return true;
      }

      const {
        notifyOnChangeProps
      } = this.options;
      const notifyOnChangePropsValue = typeof notifyOnChangeProps === 'function' ? notifyOnChangeProps() : notifyOnChangeProps;

      if (notifyOnChangePropsValue === 'all' || !notifyOnChangePropsValue && !this.trackedProps.size) {
        return true;
      }

      const includedProps = new Set(notifyOnChangePropsValue != null ? notifyOnChangePropsValue : this.trackedProps);

      if (this.options.useErrorBoundary) {
        includedProps.add('error');
      }

      return Object.keys(this.currentResult).some(key => {
        const typedKey = key;
        const changed = this.currentResult[typedKey] !== prevResult[typedKey];
        return changed && includedProps.has(typedKey);
      });
    };

    if ((notifyOptions == null ? void 0 : notifyOptions.listeners) !== false && shouldNotifyListeners()) {
      defaultNotifyOptions.listeners = true;
    }

    this.notify({ ...defaultNotifyOptions,
      ...notifyOptions
    });
  }

  updateQuery() {
    const query = this.client.getQueryCache().build(this.client, this.options);

    if (query === this.currentQuery) {
      return;
    }

    const prevQuery = this.currentQuery;
    this.currentQuery = query;
    this.currentQueryInitialState = query.state;
    this.previousQueryResult = this.currentResult;

    if (this.hasListeners()) {
      prevQuery == null ? void 0 : prevQuery.removeObserver(this);
      query.addObserver(this);
    }
  }

  onQueryUpdate(action) {
    const notifyOptions = {};

    if (action.type === 'success') {
      notifyOptions.onSuccess = !action.manual;
    } else if (action.type === 'error' && !isCancelledError(action.error)) {
      notifyOptions.onError = true;
    }

    this.updateResult(notifyOptions);

    if (this.hasListeners()) {
      this.updateTimers();
    }
  }

  notify(notifyOptions) {
    notifyManager.batch(() => {
      // First trigger the configuration callbacks
      if (notifyOptions.onSuccess) {
        var _this$options$onSucce, _this$options, _this$options$onSettl, _this$options2;

        (_this$options$onSucce = (_this$options = this.options).onSuccess) == null ? void 0 : _this$options$onSucce.call(_this$options, this.currentResult.data);
        (_this$options$onSettl = (_this$options2 = this.options).onSettled) == null ? void 0 : _this$options$onSettl.call(_this$options2, this.currentResult.data, null);
      } else if (notifyOptions.onError) {
        var _this$options$onError, _this$options3, _this$options$onSettl2, _this$options4;

        (_this$options$onError = (_this$options3 = this.options).onError) == null ? void 0 : _this$options$onError.call(_this$options3, this.currentResult.error);
        (_this$options$onSettl2 = (_this$options4 = this.options).onSettled) == null ? void 0 : _this$options$onSettl2.call(_this$options4, undefined, this.currentResult.error);
      } // Then trigger the listeners


      if (notifyOptions.listeners) {
        this.listeners.forEach(({
          listener
        }) => {
          listener(this.currentResult);
        });
      } // Then the cache listeners


      if (notifyOptions.cache) {
        this.client.getQueryCache().notify({
          query: this.currentQuery,
          type: 'observerResultsUpdated'
        });
      }
    });
  }

}

function shouldLoadOnMount(query, options) {
  return options.enabled !== false && !query.state.dataUpdatedAt && !(query.state.status === 'error' && options.retryOnMount === false);
}

function shouldFetchOnMount(query, options) {
  return shouldLoadOnMount(query, options) || query.state.dataUpdatedAt > 0 && shouldFetchOn(query, options, options.refetchOnMount);
}

function shouldFetchOn(query, options, field) {
  if (options.enabled !== false) {
    const value = typeof field === 'function' ? field(query) : field;
    return value === 'always' || value !== false && isStale(query, options);
  }

  return false;
}

function shouldFetchOptionally(query, prevQuery, options, prevOptions) {
  return options.enabled !== false && (query !== prevQuery || prevOptions.enabled === false) && (!options.suspense || query.state.status !== 'error') && isStale(query, options);
}

function isStale(query, options) {
  return query.isStaleByTime(options.staleTime);
} // this function would decide if we will update the observer's 'current'
// properties after an optimistic reading via getOptimisticResult


function shouldAssignObserverCurrentProperties(observer, optimisticResult, options) {
  // it is important to keep this condition like this for three reasons:
  // 1. It will get removed in the v5
  // 2. it reads: don't update the properties if we want to keep the previous
  // data.
  // 3. The opposite condition (!options.keepPreviousData) would fallthrough
  // and will result in a bad decision
  if (options.keepPreviousData) {
    return false;
  } // this means we want to put some placeholder data when pending and queryKey
  // changed.


  if (options.placeholderData !== undefined) {
    // re-assign properties only if current data is placeholder data
    // which means that data did not arrive yet, so, if there is some cached data
    // we need to "prepare" to receive it
    return optimisticResult.isPlaceholderData;
  } // if the newly created result isn't what the observer is holding as current,
  // then we'll need to update the properties as well


  if (!shallowEqualObjects(observer.getCurrentResult(), optimisticResult)) {
    return true;
  } // basically, just keep previous properties if nothing changed


  return false;
}

export { QueryObserver };
//# sourceMappingURL=queryObserver.esm.js.map