import { Platform } from "react-native";
import { isDesktop } from "@/desktop/host";
import type { AttachmentStore } from "@/attachments/types";

let attachmentStorePromise: Promise<AttachmentStore> | null = null;

async function createAttachmentStore(): Promise<AttachmentStore> {
  if (Platform.OS === "web") {
    if (isDesktop()) {
      const { createDesktopAttachmentStore } = await import(
        "../desktop/attachments/desktop-attachment-store"
      );
      return createDesktopAttachmentStore();
    }

    const { createIndexedDbAttachmentStore } = await import(
      "./web/indexeddb-attachment-store"
    );
    return createIndexedDbAttachmentStore();
  }

  const { createNativeFileAttachmentStore } = await import(
    "./native/native-file-attachment-store"
  );
  return createNativeFileAttachmentStore();
}

export async function getAttachmentStore(): Promise<AttachmentStore> {
  if (!attachmentStorePromise) {
    attachmentStorePromise = createAttachmentStore();
  }
  return await attachmentStorePromise;
}

/** Test-only hook to inject a deterministic store implementation. */
export function __setAttachmentStoreForTests(store: AttachmentStore | null): void {
  attachmentStorePromise = store ? Promise.resolve(store) : null;
}