import type { PuzzleDraftLevel } from '../../../packages/shared/src/contracts/puzzleAgentDraft';
import type { PuzzleAgentSessionSnapshot } from '../../../packages/shared/src/contracts/puzzleAgentSession';

function normalizeRecoveryText(value: string | null | undefined) {
  return value?.trim() || null;
}

function hasPuzzleAssetReference(
  imageSrc: string | null | undefined,
  objectKey: string | null | undefined,
) {
  return Boolean(normalizeRecoveryText(imageSrc) || normalizeRecoveryText(objectKey));
}

function resolvePrimaryPuzzleLevel(session: PuzzleAgentSessionSnapshot) {
  return session.draft?.levels?.[0] ?? null;
}

function resolvePuzzleRecoveryCandidate(
  session: PuzzleAgentSessionSnapshot,
  primaryLevel: PuzzleDraftLevel | null,
) {
  const draft = session.draft;
  if (!draft) {
    return null;
  }

  return (
    primaryLevel?.candidates.find((candidate) => candidate.selected) ??
    primaryLevel?.candidates[0] ??
    draft.candidates.find((candidate) => candidate.selected) ??
    draft.candidates[0] ??
    null
  );
}

function resolvePuzzleRecoveryCoverFields(
  session: PuzzleAgentSessionSnapshot,
) {
  const draft = session.draft;
  const primaryLevel = resolvePrimaryPuzzleLevel(session);
  const selectedCandidate = resolvePuzzleRecoveryCandidate(
    session,
    primaryLevel,
  );

  return {
    coverImageSrc:
      normalizeRecoveryText(draft?.coverImageSrc) ??
      normalizeRecoveryText(primaryLevel?.coverImageSrc) ??
      normalizeRecoveryText(selectedCandidate?.imageSrc),
    coverAssetId:
      normalizeRecoveryText(draft?.coverAssetId) ??
      normalizeRecoveryText(primaryLevel?.coverAssetId) ??
      normalizeRecoveryText(selectedCandidate?.assetId),
    selectedCandidateId:
      draft?.selectedCandidateId ??
      primaryLevel?.selectedCandidateId ??
      selectedCandidate?.candidateId ??
      null,
  };
}

function hasCompleteGeneratedPuzzleLevelAssets(
  level: PuzzleDraftLevel | null,
  coverImageSrc: string | null,
) {
  return Boolean(
    normalizeRecoveryText(coverImageSrc) &&
      hasPuzzleAssetReference(
        level?.levelSceneImageSrc,
        level?.levelSceneImageObjectKey,
      ) &&
      hasPuzzleAssetReference(
        level?.uiSpritesheetImageSrc,
        level?.uiSpritesheetImageObjectKey,
      ) &&
      hasPuzzleAssetReference(
        level?.levelBackgroundImageSrc,
        level?.levelBackgroundImageObjectKey,
      ),
  );
}

export function hasRecoverableGeneratedPuzzleDraft(
  session: PuzzleAgentSessionSnapshot,
) {
  const draft = session.draft;
  if (!draft) {
    return false;
  }

  const primaryLevel = resolvePrimaryPuzzleLevel(session);
  const { coverImageSrc } = resolvePuzzleRecoveryCoverFields(session);
  return hasCompleteGeneratedPuzzleLevelAssets(primaryLevel, coverImageSrc);
}

export function normalizeRecoveredPuzzleDraftSession(
  session: PuzzleAgentSessionSnapshot,
): PuzzleAgentSessionSnapshot {
  const draft = session.draft;
  if (!draft) {
    return session;
  }

  const { coverImageSrc, coverAssetId, selectedCandidateId } =
    resolvePuzzleRecoveryCoverFields(session);
  const nextLevels = draft.levels?.map((level, index) =>
    index === 0
      ? {
          ...level,
          coverImageSrc: normalizeRecoveryText(level.coverImageSrc)
            ? level.coverImageSrc
            : coverImageSrc,
          coverAssetId: normalizeRecoveryText(level.coverAssetId)
            ? level.coverAssetId
            : coverAssetId,
          selectedCandidateId:
            level.selectedCandidateId ?? selectedCandidateId,
        }
      : level,
  );
  const nextSession = {
    ...session,
    draft: {
      ...draft,
      coverImageSrc,
      coverAssetId,
      selectedCandidateId,
      levels: nextLevels,
    },
  } satisfies PuzzleAgentSessionSnapshot;
  const isRecoverable = hasRecoverableGeneratedPuzzleDraft(nextSession);

  if (!isRecoverable) {
    return nextSession;
  }

  return {
    ...nextSession,
    draft: {
      ...nextSession.draft,
      generationStatus: 'ready',
      levels: nextSession.draft.levels?.map((level, index) =>
        index === 0
          ? {
              ...level,
              generationStatus: 'ready',
            }
          : level,
      ),
    },
  };
}