// 使用示例：
// const db = new IndexedDB('myDatabase', 1, 'myStore');
// await db.open();
// await db.add({ id: 1, name: 'John' });
// const data = await db.get(1);
// console.log(data);
// await db.delete(1);

export default class IndexedDB {
    constructor(databaseName, databaseVersion, storeName) {
      this.databaseName = databaseName;
      this.databaseVersion = databaseVersion;
      this.storeName = storeName;
      this.db = null;
    }
  
    open() {
      return new Promise((resolve, reject) => {
        const request = indexedDB.open(this.databaseName, this.databaseVersion);
  
        request.onerror = (event) => {
          reject(event.target.error);
        };
  
        request.onsuccess = (event) => {
          this.db = event.target.result;
          resolve(this.db);
        };
  
        request.onupgradeneeded = (event) => {
          const db = event.target.result;
          if (!db.objectStoreNames.contains(this.storeName)) {
            db.createObjectStore(this.storeName, { keyPath: 'id' });
          }
        };
      });
    }
  
    add(data) {
      return new Promise((resolve, reject) => {
        const transaction = this.db.transaction([this.storeName], 'readwrite');
        const objectStore = transaction.objectStore(this.storeName);
        const request = objectStore.add(data);
  
        request.onerror = (event) => {
          reject(event.target.error);
        };
  
        request.onsuccess = (event) => {
          resolve(event.target.result);
        };
      });
    }
  
    get(id) {
      return new Promise((resolve, reject) => {
        const transaction = this.db.transaction([this.storeName], 'readonly');
        const objectStore = transaction.objectStore(this.storeName);
        const request = objectStore.get(id);
  
        request.onerror = (event) => {
          reject(event.target.error);
        };
  
        request.onsuccess = (event) => {
          resolve(event.target.result);
        };
      });
    }
  
    getAll() {
      return new Promise((resolve, reject) => {
        const transaction = this.db.transaction([this.storeName], 'readonly');
        const objectStore = transaction.objectStore(this.storeName);
        const request = objectStore.getAll();
  
        request.onerror = (event) => {
          reject(event.target.error);
        };
  
        request.onsuccess = (event) => {
          resolve(event.target.result);
        };
      });
    }
  
    delete(id) {
      return new Promise((resolve, reject) => {
        const transaction = this.db.transaction([this.storeName], 'readwrite');
        const objectStore = transaction.objectStore(this.storeName);
        const request = objectStore.delete(id);
  
        request.onerror = (event) => {
          reject(event.target.error);
        };
  
        request.onsuccess = (event) => {
          resolve(event.target.result);
        };
      });
    }
  }