import type { FileDavDoDb } from "@/worker/db/file-dav-do/client";
import {
  deleteLocks,
  ensureRoot,
  expiredLocks,
  expiredPendingUploads,
  getBlob,
  markPendingUpload,
  pendingUploadByBlob,
  rootNode,
} from "@/worker/db/file-dav-do/repository";
import type {
  BlobGcCandidate,
  CleanupExpiredLocksInput,
  CleanupExpiredPendingUploadsInput,
  FileDavRepairInput,
  VerifyBlobUnreferencedInput,
} from "@/worker/objects/file-dav/types";

function storedSubjectId(db: FileDavDoDb): string | null {
  return db.query.fileMeta.findFirst({ where: (meta, { eq }) => eq(meta.key, "subject_id") }).sync()?.value ?? null;
}

export function verifyBlobUnreferenced(
  db: FileDavDoDb,
  input: VerifyBlobUnreferencedInput,
): { ok: true; unreferenced: boolean } {
  const existingSubjectId = storedSubjectId(db);
  if (existingSubjectId && existingSubjectId !== input.subjectId) return { ok: true, unreferenced: false };

  const pending = pendingUploadByBlob(db, input.blobId);
  if (pending?.state === "pending") return { ok: true, unreferenced: false };

  const blob = getBlob(db, input.blobId);
  if (!blob) return { ok: true, unreferenced: true };
  if (blob.blobKey !== input.blobKey) return { ok: true, unreferenced: false };
  return { ok: true, unreferenced: blob.refcount <= 0 };
}

export function cleanupExpiredPendingUploads(
  db: FileDavDoDb,
  input: CleanupExpiredPendingUploadsInput,
): { ok: true; cleaned: number; blobGc: BlobGcCandidate[] } {
  ensureRoot(db, input.subjectId, input.nowMs);
  const expired = expiredPendingUploads(db, input.nowMs, input.limit);
  for (const upload of expired) markPendingUpload(db, upload.uploadId, "aborted");
  return {
    ok: true,
    cleaned: expired.length,
    blobGc: expired.map((upload) => ({ blobId: upload.blobId, blobKey: upload.blobKey })),
  };
}

export function cleanupExpiredLocks(db: FileDavDoDb, input: CleanupExpiredLocksInput): { ok: true; cleaned: number } {
  ensureRoot(db, input.subjectId, input.nowMs);
  const expired = expiredLocks(db, input.nowMs, input.limit);
  deleteLocks(
    db,
    expired.map((lock) => lock.token),
  );
  return { ok: true, cleaned: expired.length };
}

export function repairFileDav(db: FileDavDoDb, input: FileDavRepairInput) {
  if (!rootNode(db)) ensureRoot(db, input.subjectId, input.nowMs);
  const pendingUploads = cleanupExpiredPendingUploads(db, {
    subjectId: input.subjectId,
    storageId: input.storageId,
    nowMs: input.nowMs,
    limit: input.limit,
  });
  const locks = cleanupExpiredLocks(db, {
    subjectId: input.subjectId,
    storageId: input.storageId,
    nowMs: input.nowMs,
    limit: input.limit,
  });
  return {
    ok: true as const,
    cleanedPendingUploads: pendingUploads.cleaned,
    cleanedLocks: locks.cleaned,
    blobGc: pendingUploads.blobGc,
  };
}