import type * as Effect from "effect/Effect";
import type * as Stream from "effect/Stream";
import {
  consumeBusEvents,
  type EventRecord,
  type EventRouteProps,
} from "../EventBridge/EventSource.ts";

/**
 * The `detail` payload Amazon Translate delivers to EventBridge when a
 * batch translation job changes state
 * (`Translate TextTranslationJob State Change`).
 */
export interface TranslationJobEventDetail {
  /** Id of the batch translation job. */
  jobId?: string;
  /** The job's new status, e.g. `COMPLETED`, `FAILED`, `STOPPED`. */
  jobStatus?: string;
  /** Additional event fields (the schema grows over time). */
  [key: string]: unknown;
}

/** A Translate batch-translation-job EventBridge event delivered to the handler. */
export type TranslationJobEvent = EventRecord<TranslationJobEventDetail>;

export interface TranslationJobEventSourceProps extends EventRouteProps {
  /**
   * Logical id for the backing EventBridge rule.
   * @default "TranslateTranslationJobEvents"
   */
  id?: string;
  /**
   * Only deliver events with these `detail.jobStatus` values (e.g.
   * `["COMPLETED", "FAILED"]`).
   * @default all statuses
   */
  statuses?: readonly string[];
}

/**
 * Event source connecting Amazon Translate batch translation job state
 * changes to the hosting compute. Translate publishes every job state
 * transition (`Translate TextTranslationJob State Change`, source
 * `aws.translate`) to the account's default EventBridge bus; this
 * subscribes the host Function to those events so it can chain
 * post-translation automation or alert on `FAILED` jobs.
 *
 * Translate publishes to EventBridge automatically — no additional resource
 * is created besides the EventBridge rule targeting the host. Provide the
 * host-specific implementation layer (e.g. `AWS.Lambda.EventSource`) on the
 * Function effect.
 *
 * ### Consuming Job Events
 * **Example:** React to finished batch translation jobs
 * ```typescript
 * import * as AWS from "alchemy/AWS";
 *
 * export default TranslationReactor.make(
 *   { main: import.meta.url },
 *   Effect.gen(function* () {
 *     yield* AWS.Translate.consumeTranslationJobEvents(
 *       { statuses: ["COMPLETED", "FAILED"] },
 *       (events) =>
 *         Stream.runForEach(events, (event) =>
 *           Effect.log(`job ${event.detail.jobId}: ${event.detail.jobStatus}`),
 *         ),
 *     );
 *     return {};
 *   }).pipe(Effect.provide(AWS.Lambda.EventSource)),
 * );
 * ```
 */
export const consumeTranslationJobEvents = <StreamReq = never, Req = never>(
  props: TranslationJobEventSourceProps,
  process: (
    events: Stream.Stream<TranslationJobEvent, never, StreamReq>,
  ) => Effect.Effect<void, never, Req>,
) =>
  consumeBusEvents(
    props.id ?? "TranslateTranslationJobEvents",
    {
      source: ["aws.translate"],
      "detail-type": ["Translate TextTranslationJob State Change"],
      ...(props.statuses ? { detail: { jobStatus: [...props.statuses] } } : {}),
    },
    { description: props.description, state: props.state },
    process,
  );