/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
import { Observable, Observer } from 'rxjs';
import { JsonObject, JsonValue, schema } from '../../json/index';
import { DeepReadonly } from '../../utils/index';
/**
 * A job name is just a string (needs to be serializable).
 */
export declare type JobName = string;
/**
 * The job handler function, which is a method that's executed for the job.
 */
export interface JobHandler<ArgT extends JsonValue, InputT extends JsonValue, OutputT extends JsonValue> {
    (argument: ArgT, context: JobHandlerContext<ArgT, InputT, OutputT>): Observable<JobOutboundMessage<OutputT>>;
    jobDescription: Partial<JobDescription>;
}
/**
 * The context in which the job is run.
 */
export interface JobHandlerContext<MinimumArgumentValueT extends JsonValue = JsonValue, MinimumInputValueT extends JsonValue = JsonValue, MinimumOutputValueT extends JsonValue = JsonValue> {
    readonly description: JobDescription;
    readonly scheduler: Scheduler<JsonValue, JsonValue, JsonValue>;
    readonly dependencies: Job<JsonValue, JsonValue, JsonValue>[];
    readonly inboundBus: Observable<JobInboundMessage<MinimumInputValueT>>;
}
/**
 * Metadata associated with a job.
 */
export interface JobDescription extends JsonObject {
    readonly name: JobName;
    readonly argument: DeepReadonly<schema.JsonSchema>;
    readonly input: DeepReadonly<schema.JsonSchema>;
    readonly output: DeepReadonly<schema.JsonSchema>;
}
/**
 * Messages that can be sent TO a job. The job needs to listen to those.
 */
export declare enum JobInboundMessageKind {
    Ping = "ip",
    Stop = "is",
    Input = "in"
}
/** Base interface for the all job inbound messages. */
export interface JobInboundMessageBase extends JsonObject {
    /**
     * The kind of message this is.
     */
    readonly kind: JobInboundMessageKind;
}
/**
 * A ping to the job. The job should reply with a pong as soon as possible.
 */
export interface JobInboundMessagePing extends JobInboundMessageBase {
    readonly kind: JobInboundMessageKind.Ping;
    /**
     * An ID that should be returned in the corresponding Pong.
     */
    readonly id: number;
}
/**
 * Stop the job. This is handled by the job itself and jobs might not handle it. It will also
 * unsubscribe from the Observable<>.
 * This is equivalent to SIGTERM.
 */
export interface JobInboundMessageStop extends JobInboundMessageBase {
    readonly kind: JobInboundMessageKind.Stop;
}
/**
 * A Job wants to send a message to a channel. This can be marshaled, and the Job object
 * has helpers to transform this into an observable. The context also can create RxJS subjects that
 * marshall messages through a channel.
 */
export interface JobInboundMessageInput<InputT extends JsonValue> extends JobInboundMessageBase {
    readonly kind: JobInboundMessageKind.Input;
    /**
     * The input being sent to the job.
     */
    readonly value: InputT;
}
export declare type JobInboundMessage<InputT extends JsonValue> = JobInboundMessagePing | JobInboundMessageStop | JobInboundMessageInput<InputT>;
/**
 * Kind of messages that can be outputted from a job.
 */
export declare enum JobOutboundMessageKind {
    OnReady = "c",
    Start = "s",
    End = "e",
    Pong = "p",
    Output = "o",
    ChannelCreate = "cn",
    ChannelMessage = "cm",
    ChannelError = "ce",
    ChannelComplete = "cc"
}
/** Base interface for the all job messages. */
export interface JobOutboundMessageBase {
    /**
     * The job description.
     */
    readonly description: JobDescription;
    /**
     * The kind of message this is.
     */
    readonly kind: JobOutboundMessageKind;
}
/**
 * The job has been created and will validate its input.
 */
export interface JobOutboundMessageOnReady extends JobOutboundMessageBase {
    readonly kind: JobOutboundMessageKind.OnReady;
}
/**
 * The job started. This is done by the job itself.
 */
export interface JobOutboundMessageStart extends JobOutboundMessageBase {
    readonly kind: JobOutboundMessageKind.Start;
}
/**
 * An output value is available.
 */
export interface JobOutboundMessageOutput<OutputT extends JsonValue> extends JobOutboundMessageBase {
    readonly kind: JobOutboundMessageKind.Output;
    /**
     * The message being outputted from the job.
     */
    readonly value: OutputT;
}
/**
 * Base interface for all job message related to channels.
 */
export interface JobOutboundMessageChannelBase extends JobOutboundMessageBase {
    /**
     * The name of the channel.
     */
    readonly name: string;
}
/**
 * A job wants to send a message to a channel. This can be marshaled, and the Job object
 * has helpers to transform this into an observable. The context also can create RxJS subjects that
 * marshall messages through a channel.
 */
export interface JobOutboundMessageChannelMessage extends JobOutboundMessageChannelBase {
    readonly kind: JobOutboundMessageKind.ChannelMessage;
    /**
     * The message being sent to the channel.
     */
    readonly message: JsonValue;
}
/**
 * A job wants to send an error to one of its channel. This is the equivalent of throwing through
 * an Observable. The side channel will not receive any more messages after this, and will not
 * complete.
 */
export interface JobOutboundMessageChannelError extends JobOutboundMessageChannelBase {
    readonly kind: JobOutboundMessageKind.ChannelError;
    /**
     * The error message being sent to the channel.
     */
    readonly error: JsonValue;
}
/**
 * A job wants to create a new channel.
 */
export interface JobOutboundMessageChannelCreate extends JobOutboundMessageChannelBase {
    readonly kind: JobOutboundMessageKind.ChannelCreate;
}
/**
 * A job wants to close the channel, as completed. This is done automatically when the job ends,
 * or can be done from the job to close it. A closed channel might be reopened, but the user
 * need to recall getChannel().
 */
export interface JobOutboundMessageChannelComplete extends JobOutboundMessageChannelBase {
    readonly kind: JobOutboundMessageKind.ChannelComplete;
}
/**
 * OnEnd of the job run.
 */
export interface JobOutboundMessageEnd extends JobOutboundMessageBase {
    readonly kind: JobOutboundMessageKind.End;
}
/**
 * A pong response from a ping input. The id is the same as the one passed in.
 */
export interface JobOutboundMessagePong extends JobOutboundMessageBase {
    readonly kind: JobOutboundMessageKind.Pong;
    /**
     * The ID that was passed in the `Ping` messages.
     */
    readonly id: number;
}
/**
 * Generic message type.
 */
export declare type JobOutboundMessage<OutputT extends JsonValue> = JobOutboundMessageOnReady | JobOutboundMessageStart | JobOutboundMessageOutput<OutputT> | JobOutboundMessageChannelCreate | JobOutboundMessageChannelMessage | JobOutboundMessageChannelError | JobOutboundMessageChannelComplete | JobOutboundMessageEnd | JobOutboundMessagePong;
/**
 * The state of a job. These are changed as the job reports a new state through its messages.
 */
export declare enum JobState {
    /**
     * The job was queued and is waiting to start.
     */
    Queued = "queued",
    /**
     * The job description was found, its dependencies (see "Synchronizing and Dependencies")
     * are done running, and the job's argument is validated and the job's code will be executed.
     */
    Ready = "ready",
    /**
     * The job has been started. The job implementation is expected to send this as soon as its
     * work is starting.
     */
    Started = "started",
    /**
     * The job has ended and is done running.
     */
    Ended = "ended",
    /**
     * An error occured and the job stopped because of internal state.
     */
    Errored = "errored"
}
/**
 * A Job instance, returned from scheduling a job. A Job instance is _not_ serializable.
 */
export interface Job<ArgumentT extends JsonValue = JsonValue, InputT extends JsonValue = JsonValue, OutputT extends JsonValue = JsonValue> {
    /**
     * Description of the job. Resolving the job's description can be done asynchronously, so this
     * is an observable that will resolve when it's ready.
     */
    readonly description: Observable<JobDescription>;
    /**
     * Argument sent when scheduling the job. This is a copy of the argument.
     */
    readonly argument: ArgumentT;
    /**
     * The input to the job. This goes through the input channel as messages.
     */
    readonly input: Observer<InputT>;
    /**
     * Outputs of this job.
     */
    readonly output: Observable<OutputT>;
    /**
     * The current state of the job.
     */
    readonly state: JobState;
    /**
     * Get a channel that validates against the schema. Messages will be filtered by the schema.
     * @param name The name of the channel.
     * @param schema A schema to use to validate messages.
     */
    getChannel<T extends JsonValue>(name: string, schema?: schema.JsonSchema): Observable<T>;
    /**
     * Pings the job and wait for the resulting Pong before completing.
     */
    ping(): Observable<never>;
    /**
     * Stops the job from running. This is different than unsubscribing from the output as in it
     * sends the JobInboundMessageKind.Stop raw input to the job.
     */
    stop(): void;
    /**
     * The JobInboundMessage messages TO the job.
     */
    readonly inboundBus: Observer<JobInboundMessage<InputT>>;
    /**
     * The JobOutboundMessage FROM the job.
     */
    readonly outboundBus: Observable<JobOutboundMessage<OutputT>>;
}
/**
 * Options for scheduling jobs.
 */
export interface ScheduleJobOptions {
    /**
     * Jobs that need to finish before scheduling this job. These dependencies will be passed
     * to the job itself in its context.
     */
    dependencies?: Job | Job[];
}
export interface Registry<MinimumArgumentValueT extends JsonValue = JsonValue, MinimumInputValueT extends JsonValue = JsonValue, MinimumOutputValueT extends JsonValue = JsonValue> {
    /**
     * Get a job handler.
     * @param name The name of the job to get a handler from.
     */
    get<A extends MinimumArgumentValueT, I extends MinimumInputValueT, O extends MinimumOutputValueT>(name: JobName): Observable<JobHandler<A, I, O> | null>;
}
/**
 * An interface that can schedule jobs.
 */
export interface Scheduler<MinimumArgumentValueT extends JsonValue = JsonValue, MinimumInputValueT extends JsonValue = JsonValue, MinimumOutputValueT extends JsonValue = JsonValue> {
    /**
     * Get a job description for a named job.
     *
     * @param name The name of the job.
     * @returns A description, or null if no description is available for this job.
     */
    getDescription(name: JobName): Observable<JobDescription | null>;
    /**
     * Returns true if the job name has been registered.
     * @param name The name of the job.
     * @returns True if the job exists, false otherwise.
     */
    has(name: JobName): Observable<boolean>;
    /**
     * Pause the scheduler, temporary queueing _new_ jobs. Returns a resume function that should be
     * used to resume execution. If multiple `pause()` were called, all their resume functions must
     * be called before the Scheduler actually starts new jobs. Additional calls to the same resume
     * function will have no effect.
     *
     * Jobs already running are NOT paused. This is pausing the scheduler only.
     *
     * @returns A function that can be run to resume the scheduler. If multiple `pause()` calls
     *          were made, all their return function must be called (in any order) before the
     *          scheduler can resume.
     */
    pause(): () => void;
    /**
     * Schedule a job to be run, using its name.
     * @param name The name of job to be run.
     * @param argument The argument to send to the job when starting it.
     * @param options Scheduling options.
     * @returns The job being run.
     */
    schedule<A extends MinimumArgumentValueT, I extends MinimumInputValueT, O extends MinimumOutputValueT>(name: JobName, argument: A, options?: ScheduleJobOptions): Job<A, I, O>;
}
export declare function isJobHandler<A extends JsonValue, I extends JsonValue, O extends JsonValue>(value: unknown): value is JobHandler<A, I, O>;
