import { SalesRecord } from '../types';

const DB_NAME = 'CrazeAnalytixDB';
const STORE_NAME = 'salesData';
const DB_VERSION = 1;

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

export const saveSalesData = async (data: SalesRecord[]): Promise<void> => {
  try {
    const db = await initDB();
    return new Promise((resolve, reject) => {
      const transaction = db.transaction(STORE_NAME, 'readwrite');
      const store = transaction.objectStore(STORE_NAME);
      
      // Store the data array
      store.put(data, 'currentData');
      // Store the timestamp
      store.put(new Date().toISOString(), 'lastUpdated');
      
      transaction.oncomplete = () => resolve();
      transaction.onerror = () => reject(transaction.error);
    });
  } catch (error) {
    console.error("Error saving to IndexedDB:", error);
    // Fallback or silence error (data just won't be cached)
  }
};

export const loadSalesData = async (): Promise<{ data: SalesRecord[]; lastUpdated: string | null }> => {
  try {
    const db = await initDB();
    return new Promise((resolve, reject) => {
      const transaction = db.transaction(STORE_NAME, 'readonly');
      const store = transaction.objectStore(STORE_NAME);
      
      const dataReq = store.get('currentData');
      const dateReq = store.get('lastUpdated');

      transaction.oncomplete = () => {
        resolve({
          data: dataReq.result || [],
          lastUpdated: dateReq.result || null
        });
      };
      
      transaction.onerror = () => reject(transaction.error);
    });
  } catch (error) {
    console.error("Error loading from IndexedDB:", error);
    return { data: [], lastUpdated: null };
  }
};

export const clearSalesData = async (): Promise<void> => {
    try {
        const db = await initDB();
        return new Promise((resolve, reject) => {
            const transaction = db.transaction(STORE_NAME, 'readwrite');
            const store = transaction.objectStore(STORE_NAME);
            store.clear();
            transaction.oncomplete = () => resolve();
            transaction.onerror = () => reject(transaction.error);
        });
    } catch (e) {
        console.error(e);
    }
}