import type { AssessorApiClient } from './assessor-api-client';
import type { AssessmentContextResponse } from './assessor-api-contract';

// The client-opening workflow and every mounted reader share the same request.
// Weak ownership prevents old datasets (and their context) from being retained.
let requests = new WeakMap<object, Map<string, Promise<AssessmentContextResponse>>>();

export function preparedAssessmentContext(
  api: Pick<AssessorApiClient, 'getAssessmentContext'>,
  dataset: object,
  projectId: string,
  assessmentIds: string[],
  scanRunIds: string[] = []
): Promise<AssessmentContextResponse> {
  const assessments = [...new Set(assessmentIds)].sort();
  const scans = [...new Set(scanRunIds)].sort();
  const key = JSON.stringify([projectId, assessments, scans]);
  let scopes = requests.get(dataset);
  if (!scopes) { scopes = new Map(); requests.set(dataset, scopes); }
  let request = scopes.get(key);
  if (!request) {
    request = api.getAssessmentContext(projectId, assessments, scans);
    scopes.set(key, request);
  }
  // Keep failures too: mounting another reader must not silently retry. Opening
  // the client again creates a fresh dataset and therefore a fresh attempt.
  return request;
}

export function resetPreparedAssessmentContextForTests(): void { requests = new WeakMap(); }