import {
  TileState_default
} from "./chunk-5D2XPBR2.js";
import {
  assert
} from "./chunk-QFCIXVZ3.js";
import {
  EventType_default
} from "./chunk-KJXIHBKT.js";
import {
  clear
} from "./chunk-5RHQVMYD.js";

// node_modules/ol/structs/PriorityQueue.js
var DROP = Infinity;
var PriorityQueue = class {
  /**
   * @param {function(T): number} priorityFunction Priority function.
   * @param {function(T): string} keyFunction Key function.
   */
  constructor(priorityFunction, keyFunction) {
    this.priorityFunction_ = priorityFunction;
    this.keyFunction_ = keyFunction;
    this.elements_ = [];
    this.priorities_ = [];
    this.queuedElements_ = {};
  }
  /**
   * FIXME empty description for jsdoc
   */
  clear() {
    this.elements_.length = 0;
    this.priorities_.length = 0;
    clear(this.queuedElements_);
  }
  /**
   * Remove and return the highest-priority element. O(log N).
   * @return {T} Element.
   */
  dequeue() {
    const elements = this.elements_;
    const priorities = this.priorities_;
    const element = elements[0];
    if (elements.length == 1) {
      elements.length = 0;
      priorities.length = 0;
    } else {
      elements[0] = /** @type {T} */
      elements.pop();
      priorities[0] = /** @type {number} */
      priorities.pop();
      this.siftUp_(0);
    }
    const elementKey = this.keyFunction_(element);
    delete this.queuedElements_[elementKey];
    return element;
  }
  /**
   * Enqueue an element. O(log N).
   * @param {T} element Element.
   * @return {boolean} The element was added to the queue.
   */
  enqueue(element) {
    assert(
      !(this.keyFunction_(element) in this.queuedElements_),
      "Tried to enqueue an `element` that was already added to the queue"
    );
    const priority = this.priorityFunction_(element);
    if (priority != DROP) {
      this.elements_.push(element);
      this.priorities_.push(priority);
      this.queuedElements_[this.keyFunction_(element)] = true;
      this.siftDown_(0, this.elements_.length - 1);
      return true;
    }
    return false;
  }
  /**
   * @return {number} Count.
   */
  getCount() {
    return this.elements_.length;
  }
  /**
   * Gets the index of the left child of the node at the given index.
   * @param {number} index The index of the node to get the left child for.
   * @return {number} The index of the left child.
   * @private
   */
  getLeftChildIndex_(index) {
    return index * 2 + 1;
  }
  /**
   * Gets the index of the right child of the node at the given index.
   * @param {number} index The index of the node to get the right child for.
   * @return {number} The index of the right child.
   * @private
   */
  getRightChildIndex_(index) {
    return index * 2 + 2;
  }
  /**
   * Gets the index of the parent of the node at the given index.
   * @param {number} index The index of the node to get the parent for.
   * @return {number} The index of the parent.
   * @private
   */
  getParentIndex_(index) {
    return index - 1 >> 1;
  }
  /**
   * Make this a heap. O(N).
   * @private
   */
  heapify_() {
    let i;
    for (i = (this.elements_.length >> 1) - 1; i >= 0; i--) {
      this.siftUp_(i);
    }
  }
  /**
   * @return {boolean} Is empty.
   */
  isEmpty() {
    return this.elements_.length === 0;
  }
  /**
   * @param {string} key Key.
   * @return {boolean} Is key queued.
   */
  isKeyQueued(key) {
    return key in this.queuedElements_;
  }
  /**
   * @param {T} element Element.
   * @return {boolean} Is queued.
   */
  isQueued(element) {
    return this.isKeyQueued(this.keyFunction_(element));
  }
  /**
   * @param {number} index The index of the node to move down.
   * @private
   */
  siftUp_(index) {
    const elements = this.elements_;
    const priorities = this.priorities_;
    const count = elements.length;
    const element = elements[index];
    const priority = priorities[index];
    const startIndex = index;
    while (index < count >> 1) {
      const lIndex = this.getLeftChildIndex_(index);
      const rIndex = this.getRightChildIndex_(index);
      const smallerChildIndex = rIndex < count && priorities[rIndex] < priorities[lIndex] ? rIndex : lIndex;
      elements[index] = elements[smallerChildIndex];
      priorities[index] = priorities[smallerChildIndex];
      index = smallerChildIndex;
    }
    elements[index] = element;
    priorities[index] = priority;
    this.siftDown_(startIndex, index);
  }
  /**
   * @param {number} startIndex The index of the root.
   * @param {number} index The index of the node to move up.
   * @private
   */
  siftDown_(startIndex, index) {
    const elements = this.elements_;
    const priorities = this.priorities_;
    const element = elements[index];
    const priority = priorities[index];
    while (index > startIndex) {
      const parentIndex = this.getParentIndex_(index);
      if (priorities[parentIndex] > priority) {
        elements[index] = elements[parentIndex];
        priorities[index] = priorities[parentIndex];
        index = parentIndex;
      } else {
        break;
      }
    }
    elements[index] = element;
    priorities[index] = priority;
  }
  /**
   * FIXME empty description for jsdoc
   */
  reprioritize() {
    const priorityFunction = this.priorityFunction_;
    const elements = this.elements_;
    const priorities = this.priorities_;
    let index = 0;
    const n = elements.length;
    let element, i, priority;
    for (i = 0; i < n; ++i) {
      element = elements[i];
      priority = priorityFunction(element);
      if (priority == DROP) {
        delete this.queuedElements_[this.keyFunction_(element)];
      } else {
        priorities[index] = priority;
        elements[index++] = element;
      }
    }
    elements.length = index;
    priorities.length = index;
    this.heapify_();
  }
};
var PriorityQueue_default = PriorityQueue;

// node_modules/ol/TileQueue.js
var TileQueue = class extends PriorityQueue_default {
  /**
   * @param {PriorityFunction} tilePriorityFunction Tile priority function.
   * @param {function(): ?} tileChangeCallback Function called on each tile change event.
   */
  constructor(tilePriorityFunction, tileChangeCallback) {
    super(
      (element) => tilePriorityFunction.apply(null, element),
      (element) => element[0].getKey()
    );
    this.boundHandleTileChange_ = this.handleTileChange.bind(this);
    this.tileChangeCallback_ = tileChangeCallback;
    this.tilesLoading_ = 0;
    this.tilesLoadingKeys_ = {};
  }
  /**
   * @param {TileQueueElement} element Element.
   * @return {boolean} The element was added to the queue.
   * @override
   */
  enqueue(element) {
    const added = super.enqueue(element);
    if (added) {
      const tile = element[0];
      tile.addEventListener(EventType_default.CHANGE, this.boundHandleTileChange_);
    }
    return added;
  }
  /**
   * @return {number} Number of tiles loading.
   */
  getTilesLoading() {
    return this.tilesLoading_;
  }
  /**
   * @param {import("./events/Event.js").default} event Event.
   * @protected
   */
  handleTileChange(event) {
    const tile = (
      /** @type {import("./Tile.js").default} */
      event.target
    );
    const state = tile.getState();
    if (state === TileState_default.LOADED || state === TileState_default.ERROR || state === TileState_default.EMPTY) {
      if (state !== TileState_default.ERROR) {
        tile.removeEventListener(EventType_default.CHANGE, this.boundHandleTileChange_);
      }
      const tileKey = tile.getKey();
      if (tileKey in this.tilesLoadingKeys_) {
        delete this.tilesLoadingKeys_[tileKey];
        --this.tilesLoading_;
      }
      this.tileChangeCallback_();
    }
  }
  /**
   * @param {number} maxTotalLoading Maximum number tiles to load simultaneously.
   * @param {number} maxNewLoads Maximum number of new tiles to load.
   */
  loadMoreTiles(maxTotalLoading, maxNewLoads) {
    let newLoads = 0;
    while (this.tilesLoading_ < maxTotalLoading && newLoads < maxNewLoads && this.getCount() > 0) {
      const tile = this.dequeue()[0];
      const tileKey = tile.getKey();
      const state = tile.getState();
      if (state === TileState_default.IDLE && !(tileKey in this.tilesLoadingKeys_)) {
        this.tilesLoadingKeys_[tileKey] = true;
        ++this.tilesLoading_;
        ++newLoads;
        tile.load();
      }
    }
  }
};
var TileQueue_default = TileQueue;
function getTilePriority(frameState, tile, tileSourceKey, tileCenter, tileResolution) {
  if (!frameState || !(tileSourceKey in frameState.wantedTiles)) {
    return DROP;
  }
  if (!frameState.wantedTiles[tileSourceKey][tile.getKey()]) {
    return DROP;
  }
  const center = frameState.viewState.center;
  const deltaX = tileCenter[0] - center[0];
  const deltaY = tileCenter[1] - center[1];
  return 65536 * Math.log(tileResolution) + Math.sqrt(deltaX * deltaX + deltaY * deltaY) / tileResolution;
}

export {
  TileQueue_default,
  getTilePriority
};
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