import {
  SEQUENCER_MEDIA_REVISION_SCHEMA,
  gateSequencerMediaRevision,
  parseSequencerMediaRevisionRequest,
  parseSequencerMediaRevisionState,
  SequencerMediaRevisionValidationError,
  type SequencerMediaOperation,
  type SequencerMediaRevisionDecisionIR,
  type SequencerMediaRevisionRequestIR,
  type SequencerMediaRevisionResultIR,
  type SequencerMediaRevisionStateIR,
} from "../../../protocol/sequencer-media-revision";

export class SequencerMediaRevisionGate {
  private stateValue: SequencerMediaRevisionStateIR;

  constructor(timelineId: string, timelineRevision: number) {
    this.stateValue = parseSequencerMediaRevisionState({
      schemaVersion: SEQUENCER_MEDIA_REVISION_SCHEMA,
      timelineId,
      timelineRevision,
      latestRequestRevision: 0,
    });
  }

  state(): SequencerMediaRevisionStateIR {
    return { ...this.stateValue };
  }

  begin(operation: SequencerMediaOperation, frame: number): SequencerMediaRevisionRequestIR {
    this.stateValue = {
      ...this.stateValue,
      latestRequestRevision: this.stateValue.latestRequestRevision + 1,
    };
    return parseSequencerMediaRevisionRequest({
      schemaVersion: SEQUENCER_MEDIA_REVISION_SCHEMA,
      requestId: `media:${this.stateValue.latestRequestRevision}`,
      timelineId: this.stateValue.timelineId,
      timelineRevision: this.stateValue.timelineRevision,
      requestRevision: this.stateValue.latestRequestRevision,
      operation,
      frame,
    });
  }

  replaceTimeline(timelineId: string, timelineRevision: number): SequencerMediaRevisionStateIR {
    if (timelineId === this.stateValue.timelineId && timelineRevision <= this.stateValue.timelineRevision) {
      throw new SequencerMediaRevisionValidationError("REVISION_CONFLICT", "Sequencer timeline revision must advance monotonically");
    }
    this.stateValue = parseSequencerMediaRevisionState({
      schemaVersion: SEQUENCER_MEDIA_REVISION_SCHEMA,
      timelineId,
      timelineRevision,
      latestRequestRevision: this.stateValue.latestRequestRevision + 1,
    });
    return this.state();
  }

  resolve(
    request: SequencerMediaRevisionRequestIR,
    result: SequencerMediaRevisionResultIR,
    publish: (result: SequencerMediaRevisionResultIR) => void,
  ): SequencerMediaRevisionDecisionIR {
    const decision = gateSequencerMediaRevision(request, this.stateValue, result);
    if (decision.status === "PUBLISH") publish(result);
    return decision;
  }
}

export type {
  SequencerMediaOperation,
  SequencerMediaRevisionDecisionIR,
  SequencerMediaRevisionRequestIR,
  SequencerMediaRevisionResultIR,
  SequencerMediaRevisionStateIR,
};