import { extractPropTextValue } from "@/worker/db/dav-collections";
import { DAV_NS } from "@/worker/xml/namespaces";
import type {
  CollectionDomainError,
  DomainCollection,
  DomainConditionalInput,
  DomainProppatchInput,
} from "@/worker/objects/common/collection-types";

export interface CollectionProppatchSpec<
  TDb,
  TTx,
  TCollection extends DomainCollection,
  TObject extends { id: string; etag: string },
  TError extends CollectionDomainError,
> {
  collectionKind: string;
  ensureDefaultCollection(db: TDb, subjectId: string, nowMs: number): TCollection;
  ensureCollection(db: TDb, subjectId: string, nowMs: number, collectionName: string): TCollection | null;
  objectByName(db: TDb, collectionId: string, objectName: string): TObject | undefined;
  targetHref(collection: TCollection, kind: string, objectName?: string): string;
  writePrecondition(
    db: TDb,
    input: DomainConditionalInput,
    targetHref: string,
    targetEtag: string | null,
  ): TError | null;
  transaction(db: TDb, callback: (tx: TTx) => void): void;
  updateCollectionDisplayName(tx: TTx, collectionId: string, displayName: string, nowMs: number): void;
  upsertDeadProp(
    tx: TTx,
    key: { resourceKind: string; resourceId: string; nsUri: string; localName: string },
    xmlValue: string,
  ): void;
  deleteDeadProp(tx: TTx, key: { resourceKind: string; resourceId: string; nsUri: string; localName: string }): void;
  collectionNotFound(): TError;
  resourceNotFound(): TError;
}

export function proppatchCollectionDomain<
  TDb,
  TTx,
  TCollection extends DomainCollection,
  TObject extends { id: string; etag: string },
  TError extends CollectionDomainError,
>(
  db: TDb,
  input: DomainProppatchInput,
  spec: CollectionProppatchSpec<TDb, TTx, TCollection, TObject, TError>,
): { ok: true } | TError {
  const collection =
    input.kind === "home"
      ? spec.ensureDefaultCollection(db, input.subjectId, input.nowMs)
      : spec.ensureCollection(db, input.subjectId, input.nowMs, input.collectionName ?? "");
  if (!collection) return spec.collectionNotFound();

  const resourceId = input.resourceId ?? resolveDomainResourceId(db, input, collection, spec);
  if (!resourceId) return spec.resourceNotFound();

  const object = input.kind === "object" ? spec.objectByName(db, collection.id, input.objectName ?? "") : undefined;
  const precondition = spec.writePrecondition(
    db,
    input,
    spec.targetHref(collection, input.kind, input.objectName),
    object?.etag ?? null,
  );
  if (precondition) return precondition;

  spec.transaction(db, (tx) => {
    for (const instruction of input.instructions) {
      if (instruction.kind === "set") {
        if (isMappedDisplayName(input.kind, spec.collectionKind, instruction)) {
          spec.updateCollectionDisplayName(tx, resourceId, extractPropTextValue(instruction.xmlValue), input.nowMs);
          continue;
        }
        spec.upsertDeadProp(
          tx,
          {
            resourceKind: input.kind,
            resourceId,
            nsUri: instruction.nsUri,
            localName: instruction.localName,
          },
          instruction.xmlValue,
        );
        continue;
      }
      if (isMappedDisplayName(input.kind, spec.collectionKind, instruction)) {
        spec.updateCollectionDisplayName(tx, resourceId, collection.name, input.nowMs);
        continue;
      }
      spec.deleteDeadProp(tx, {
        resourceKind: input.kind,
        resourceId,
        nsUri: instruction.nsUri,
        localName: instruction.localName,
      });
    }
  });

  return { ok: true };
}

function resolveDomainResourceId<
  TDb,
  TTx,
  TCollection extends DomainCollection,
  TObject extends { id: string; etag: string },
  TError extends CollectionDomainError,
>(
  db: TDb,
  input: DomainProppatchInput,
  collection: TCollection,
  spec: CollectionProppatchSpec<TDb, TTx, TCollection, TObject, TError>,
): string | null {
  if (input.kind === "home") return "home";
  if (input.kind === spec.collectionKind) return collection.id;
  return spec.objectByName(db, collection.id, input.objectName ?? "")?.id ?? null;
}

function isMappedDisplayName(
  kind: string,
  collectionKind: string,
  prop: { nsUri: string; localName: string },
): boolean {
  return kind === collectionKind && prop.nsUri === DAV_NS && prop.localName === "displayname";
}