import type { CinemaGenerationLedgerArtifact } from './cinema-types.js';

export interface CinemaRetryPolicy {
  maximumAttemptsPerShot: number;
  maximumRepeatedFailureTag: number;
}

export interface CinemaRetryPolicyDecision {
  shotId: string;
  disposition: 'retry-eligible' | 'redesign-required';
  attemptCount: number;
  parentAttemptId: string | null;
  blockingFailureTags: string[];
  reason: string;
}

export function evaluateCinemaRetryPolicy(
  ledger: CinemaGenerationLedgerArtifact,
  shotId: string,
  policy: CinemaRetryPolicy,
): CinemaRetryPolicyDecision {
  if (!Number.isInteger(policy.maximumAttemptsPerShot) || policy.maximumAttemptsPerShot < 1) throw new Error('Cinema maximumAttemptsPerShot must be a positive integer');
  if (!Number.isInteger(policy.maximumRepeatedFailureTag) || policy.maximumRepeatedFailureTag < 1) throw new Error('Cinema maximumRepeatedFailureTag must be a positive integer');
  const attempts = ledger.attempts.filter((attempt) => attempt.shotId === shotId).sort((left, right) => left.preparedAt.localeCompare(right.preparedAt) || left.attemptId.localeCompare(right.attemptId));
  const counts = new Map<string, number>();
  for (const attempt of attempts) for (const tag of new Set(attempt.failureTags)) counts.set(tag, (counts.get(tag) ?? 0) + 1);
  const blockingFailureTags = [...counts].filter(([, count]) => count >= policy.maximumRepeatedFailureTag).map(([tag]) => tag).sort();
  const parentAttemptId = attempts.at(-1)?.attemptId ?? null;
  if (attempts.length >= policy.maximumAttemptsPerShot) {
    return { shotId, disposition: 'redesign-required', attemptCount: attempts.length, parentAttemptId, blockingFailureTags, reason: `Attempt ceiling ${policy.maximumAttemptsPerShot} reached; an authority-verified redesign decision must name one controlled variable before any new attempt.` };
  }
  if (blockingFailureTags.length > 0) {
    return { shotId, disposition: 'redesign-required', attemptCount: attempts.length, parentAttemptId, blockingFailureTags, reason: `Repeated failure tag ceiling reached (${blockingFailureTags.join(', ')}); blind retry is forbidden.` };
  }
  return { shotId, disposition: 'retry-eligible', attemptCount: attempts.length, parentAttemptId, blockingFailureTags: [], reason: 'A single-variable child attempt may be prepared under the existing lineage validator.' };
}