// db.ts
const DB_NAME = 'report-db';
const STORE_NAME = 'report-store';
const DB_VERSION = 1;

export async function openDB(): Promise<IDBDatabase> {
  return new Promise((resolve, reject) => {
    const request = indexedDB.open(DB_NAME, DB_VERSION);

    request.onupgradeneeded = (event) => {
      const db = (event.target as IDBOpenDBRequest).result;
      if (!db.objectStoreNames.contains(STORE_NAME)) {
        db.createObjectStore(STORE_NAME, { keyPath: 'month' });
      }
    };

    request.onsuccess = () => resolve(request.result);
    request.onerror = () => reject(request.error);
  });
}

export async function getMonthRecord(month: string): Promise<{ count: number } | undefined> {
  const db = await openDB();
  return new Promise((resolve, reject) => {
    const tx = db.transaction(STORE_NAME, 'readonly');
    const store = tx.objectStore(STORE_NAME);
    const request = store.get(month);
    request.onsuccess = () => resolve(request.result);
    request.onerror = () => reject(request.error);
  });
}

export async function setMonthRecord(month: string, count: number) {
  const db = await openDB();
  return new Promise<void>((resolve, reject) => {
    const tx = db.transaction(STORE_NAME, 'readwrite');
    const store = tx.objectStore(STORE_NAME);
    store.put({ month, count });
    tx.oncomplete = () => resolve();
    tx.onerror = () => reject(tx.error);
  });
}