export declare const bounded: <A>(requestedCapacity: number) => Effect.Effect<Queue<A>, never, never>

export declare const dropping: <A>(requestedCapacity: number) => Effect.Effect<Queue<A>, never, never>

export declare const make: <A>(queue: BackingQueue<A>, strategy: Strategy<A>) => Effect.Effect<Queue<A>, never, never>

export declare const sliding: <A>(requestedCapacity: number) => Effect.Effect<Queue<A>, never, never>

export declare const unbounded: <A>() => Effect.Effect<Queue<A>, never, never>

export declare const capacity: <A>(self: Dequeue<A> | Enqueue<A>) => number

export declare const isEmpty: <A>(self: Dequeue<A> | Enqueue<A>) => Effect.Effect<boolean>

export declare const isFull: <A>(self: Dequeue<A> | Enqueue<A>) => Effect.Effect<boolean>

export declare const isShutdown: <A>(self: Dequeue<A> | Enqueue<A>) => Effect.Effect<boolean>

export declare const size: <A>(self: Dequeue<A> | Enqueue<A>) => Effect.Effect<number>

export interface BackingQueue<in out A> extends Queue.BackingQueueVariance<A> {
  /**
   * Dequeues an element from the queue.
   * Returns either an element from the queue, or the `def` param.
   */
  poll<Def>(def: Def): A | Def
  /**
   * Dequeues up to `limit` elements from the queue.
   */
  pollUpTo(limit: number): Chunk.Chunk<A>
  /**
   * Enqueues a collection of values into the queue.
   *
   * Returns a `Chunk` of the values that were **not** able to be enqueued.
   */
  offerAll(elements: Iterable<A>): Chunk.Chunk<A>
  /**
   * Offers an element to the queue.
   *
   * Returns whether the enqueue was successful or not.
   */
  offer(element: A): boolean
  /**
   * The **maximum** number of elements that a queue can hold.
   *
   * **Note**: unbounded queues can still implement this interface with
   * `capacity = Infinity`.
   */
  capacity(): number
  /**
   * Returns the number of elements currently in the queue
   */
  length(): number
}

export interface BaseQueue {
  /**
   * Returns the number of elements the queue can hold.
   */
  capacity(): number

  /**
   * Returns false if shutdown has been called.
   */
  isActive(): boolean

  /**
   * Retrieves the size of the queue, which is equal to the number of elements
   * in the queue. This may be negative if fibers are suspended waiting for
   * elements to be added to the queue.
   */
  readonly size: Effect.Effect<number>

  /**
   * Retrieves the size of the queue, which is equal to the number of elements
   * in the queue. This may be negative if fibers are suspended waiting for
   * elements to be added to the queue. Returns None if shutdown has been called
   */
  unsafeSize(): Option.Option<number>

  /**
   * Returns `true` if the `Queue` contains at least one element, `false`
   * otherwise.
   */
  readonly isFull: Effect.Effect<boolean>

  /**
   * Returns `true` if the `Queue` contains zero elements, `false` otherwise.
   */
  readonly isEmpty: Effect.Effect<boolean>

  /**
   * Interrupts any fibers that are suspended on `offer` or `take`. Future calls
   * to `offer*` and `take*` will be interrupted immediately.
   */
  readonly shutdown: Effect.Effect<void>

  /**
   * Returns `true` if `shutdown` has been called, otherwise returns `false`.
   */
  readonly isShutdown: Effect.Effect<boolean>

  /**
   * Waits until the queue is shutdown. The `Effect` returned by this method will
   * not resume until the queue has been shutdown. If the queue is already
   * shutdown, the `Effect` will resume right away.
   */
  readonly awaitShutdown: Effect.Effect<void>
}

export interface Dequeue<out A> extends Queue.DequeueVariance<A>, BaseQueue, Pipeable {
  /**
   * Takes the oldest value in the queue. If the queue is empty, this will return
   * a computation that resumes when an item has been added to the queue.
   */
  readonly take: Effect.Effect<A>

  /**
   * Takes all the values in the queue and returns the values. If the queue is
   * empty returns an empty collection.
   */
  readonly takeAll: Effect.Effect<Chunk.Chunk<A>>

  /**
   * Takes up to max number of values from the queue.
   */
  takeUpTo(max: number): Effect.Effect<Chunk.Chunk<A>>

  /**
   * Takes a number of elements from the queue between the specified minimum and
   * maximum. If there are fewer than the minimum number of elements available,
   * suspends until at least the minimum number of elements have been collected.
   */
  takeBetween(min: number, max: number): Effect.Effect<Chunk.Chunk<A>>
}

export interface Enqueue<in A> extends Queue.EnqueueVariance<A>, BaseQueue, Pipeable {
  /**
   * Places one value in the queue.
   */
  offer(value: A): Effect.Effect<boolean>

  /**
   * Places one value in the queue when possible without needing the fiber runtime.
   */
  unsafeOffer(value: A): boolean

  /**
   * For Bounded Queue: uses the `BackPressure` Strategy, places the values in
   * the queue and always returns true. If the queue has reached capacity, then
   * the fiber performing the `offerAll` will be suspended until there is room
   * in the queue.
   *
   * For Unbounded Queue: Places all values in the queue and returns true.
   *
   * For Sliding Queue: uses `Sliding` Strategy If there is room in the queue,
   * it places the values otherwise it removes the old elements and enqueues the
   * new ones. Always returns true.
   *
   * For Dropping Queue: uses `Dropping` Strategy, It places the values in the
   * queue but if there is no room it will not enqueue them and return false.
   */
  offerAll(iterable: Iterable<A>): Effect.Effect<boolean>
}

export interface Queue<in out A> extends Enqueue<A>, Dequeue<A>, Pipeable {
  /** @internal */
  readonly queue: BackingQueue<A>
  /** @internal */
  readonly takers: MutableQueue.MutableQueue<Deferred.Deferred<A>>
  /** @internal */
  readonly shutdownHook: Deferred.Deferred<void>
  /** @internal */
  readonly shutdownFlag: MutableRef.MutableRef<boolean>
  /** @internal */
  readonly strategy: Strategy<A>
}

export interface Strategy<in out A> extends Queue.StrategyVariance<A> {
  /**
   * Returns the number of surplus values that were unable to be added to the
   * `Queue`
   */
  surplusSize(): number

  /**
   * Determines how the `Queue.Strategy` should shut down when the `Queue` is
   * shut down.
   */
  readonly shutdown: Effect.Effect<void>

  /**
   * Determines the behavior of the `Queue.Strategy` when there are surplus
   * values that could not be added to the `Queue` following an `offer`
   * operation.
   */
  handleSurplus(
    iterable: Iterable<A>,
    queue: BackingQueue<A>,
    takers: MutableQueue.MutableQueue<Deferred.Deferred<A>>,
    isShutdown: MutableRef.MutableRef<boolean>
  ): Effect.Effect<boolean>

  /**
   * It is called when the backing queue is empty but there are some
   * takers that can be completed
   */
  onCompleteTakersWithEmptyQueue(takers: MutableQueue.MutableQueue<Deferred.Deferred<A>>): void

  /**
   * Determines the behavior of the `Queue.Strategy` when the `Queue` has empty
   * slots following a `take` operation.
   */
  unsafeOnQueueEmptySpace(queue: BackingQueue<A>, takers: MutableQueue.MutableQueue<Deferred.Deferred<A>>): void
}

export declare const isDequeue: (u: unknown) => u is Dequeue<unknown>

export declare const isEnqueue: (u: unknown) => u is Enqueue<unknown>

export declare const isQueue: (u: unknown) => u is Queue<unknown>

export declare const backPressureStrategy: <A>() => Strategy<A>

export declare const droppingStrategy: <A>() => Strategy<A>

export declare const slidingStrategy: <A>() => Strategy<A>

export declare const BackingQueueTypeId: typeof BackingQueueTypeId

export type BackingQueueTypeId = typeof BackingQueueTypeId

export declare const DequeueTypeId: typeof DequeueTypeId

export type DequeueTypeId = typeof DequeueTypeId

export declare const EnqueueTypeId: typeof EnqueueTypeId

export type EnqueueTypeId = typeof EnqueueTypeId

export declare const QueueStrategyTypeId: typeof QueueStrategyTypeId

export type QueueStrategyTypeId = typeof QueueStrategyTypeId

export interface BackingQueueVariance<in out A> {
  readonly [BackingQueueTypeId]: {
    readonly _A: Types.Invariant<A>
  }
}

export interface DequeueVariance<out A> {
  readonly [DequeueTypeId]: {
    readonly _Out: Types.Covariant<A>
  }
}

export interface EnqueueVariance<in A> {
  readonly [EnqueueTypeId]: {
    readonly _In: Types.Contravariant<A>
  }
}

export interface StrategyVariance<in out A> {
  readonly [QueueStrategyTypeId]: {
    readonly _A: Types.Invariant<A>
  }
}

export declare const awaitShutdown: <A>(self: Dequeue<A> | Enqueue<A>) => Effect.Effect<void>

export declare const offer: {
  <A>(value: A): (self: Enqueue<A>) => Effect.Effect<boolean>
  <A>(self: Enqueue<A>, value: A): Effect.Effect<boolean>
}

export declare const offerAll: {
  <A>(iterable: Iterable<A>): (self: Enqueue<A>) => Effect.Effect<boolean>
  <A>(self: Enqueue<A>, iterable: Iterable<A>): Effect.Effect<boolean>
}

export declare const poll: <A>(self: Dequeue<A>) => Effect.Effect<Option.Option<A>, never, never>

export declare const shutdown: <A>(self: Dequeue<A> | Enqueue<A>) => Effect.Effect<void>

export declare const take: <A>(self: Dequeue<A>) => Effect.Effect<A, never, never>

export declare const takeAll: <A>(self: Dequeue<A>) => Effect.Effect<Chunk.Chunk<A>, never, never>

export declare const takeBetween: {
  (min: number, max: number): <A>(self: Dequeue<A>) => Effect.Effect<Chunk.Chunk<A>, never, never>
  <A>(self: Dequeue<A>, min: number, max: number): Effect.Effect<Chunk.Chunk<A>, never, never>
}

export declare const takeN: {
  (n: number): <A>(self: Dequeue<A>) => Effect.Effect<Chunk.Chunk<A>, never, never>
  <A>(self: Dequeue<A>, n: number): Effect.Effect<Chunk.Chunk<A>, never, never>
}

export declare const takeUpTo: {
  (max: number): <A>(self: Dequeue<A>) => Effect.Effect<Chunk.Chunk<A>, never, never>
  <A>(self: Dequeue<A>, max: number): Effect.Effect<Chunk.Chunk<A>, never, never>
}

export declare const unsafeOffer: {
  <A>(value: A): (self: Enqueue<A>) => boolean
  <A>(self: Enqueue<A>, value: A): boolean
}