Refactor storage architecture with modular IndexedDB services

Implements a more flexible, modular approach to IndexedDB storage:
- Introduces IStore interface for dynamic store creation
- Adds specialized services for each entity (BookingService, CustomerService, etc.)
- Moves serialization logic to entity-specific classes
- Improves dependency injection and extensibility

Enables easier addition of new entity types with minimal configuration

src/storage/customers/CustomerService.ts

@@ -0,0 +1,144 @@
+import { ICustomer } from '../../types/CustomerTypes';
+import { CustomerStore } from './CustomerStore';
+
+/**
+ * CustomerService - CRUD operations for customers in IndexedDB
+ *
+ * Handles all customer-related database operations.
+ * Part of modular storage architecture where each entity has its own service.
+ *
+ * Note: No serialization needed - ICustomer has no Date fields.
+ */
+export class CustomerService {
+  private db: IDBDatabase;
+
+  /**
+   * @param db - IDBDatabase instance (injected dependency)
+   */
+  constructor(db: IDBDatabase) {
+    this.db = db;
+  }
+
+  /**
+   * Get a single customer by ID
+   *
+   * @param id - Customer ID
+   * @returns ICustomer or null if not found
+   */
+  async get(id: string): Promise<ICustomer | null> {
+    return new Promise((resolve, reject) => {
+      const transaction = this.db.transaction([CustomerStore.STORE_NAME], 'readonly');
+      const store = transaction.objectStore(CustomerStore.STORE_NAME);
+      const request = store.get(id);
+
+      request.onsuccess = () => {
+        resolve(request.result || null);
+      };
+
+      request.onerror = () => {
+        reject(new Error(`Failed to get customer ${id}: ${request.error}`));
+      };
+    });
+  }
+
+  /**
+   * Get all customers
+   *
+   * @returns Array of all customers
+   */
+  async getAll(): Promise<ICustomer[]> {
+    return new Promise((resolve, reject) => {
+      const transaction = this.db.transaction([CustomerStore.STORE_NAME], 'readonly');
+      const store = transaction.objectStore(CustomerStore.STORE_NAME);
+      const request = store.getAll();
+
+      request.onsuccess = () => {
+        resolve(request.result as ICustomer[]);
+      };
+
+      request.onerror = () => {
+        reject(new Error(`Failed to get all customers: ${request.error}`));
+      };
+    });
+  }
+
+  /**
+   * Save a customer (create or update)
+   *
+   * @param customer - ICustomer to save
+   */
+  async save(customer: ICustomer): Promise<void> {
+    return new Promise((resolve, reject) => {
+      const transaction = this.db.transaction([CustomerStore.STORE_NAME], 'readwrite');
+      const store = transaction.objectStore(CustomerStore.STORE_NAME);
+      const request = store.put(customer);
+
+      request.onsuccess = () => {
+        resolve();
+      };
+
+      request.onerror = () => {
+        reject(new Error(`Failed to save customer ${customer.id}: ${request.error}`));
+      };
+    });
+  }
+
+  /**
+   * Delete a customer
+   *
+   * @param id - Customer ID to delete
+   */
+  async delete(id: string): Promise<void> {
+    return new Promise((resolve, reject) => {
+      const transaction = this.db.transaction([CustomerStore.STORE_NAME], 'readwrite');
+      const store = transaction.objectStore(CustomerStore.STORE_NAME);
+      const request = store.delete(id);
+
+      request.onsuccess = () => {
+        resolve();
+      };
+
+      request.onerror = () => {
+        reject(new Error(`Failed to delete customer ${id}: ${request.error}`));
+      };
+    });
+  }
+
+  /**
+   * Get customers by phone number
+   *
+   * @param phone - Phone number
+   * @returns Array of customers with this phone
+   */
+  async getByPhone(phone: string): Promise<ICustomer[]> {
+    return new Promise((resolve, reject) => {
+      const transaction = this.db.transaction([CustomerStore.STORE_NAME], 'readonly');
+      const store = transaction.objectStore(CustomerStore.STORE_NAME);
+      const index = store.index('phone');
+      const request = index.getAll(phone);
+
+      request.onsuccess = () => {
+        resolve(request.result as ICustomer[]);
+      };
+
+      request.onerror = () => {
+        reject(new Error(`Failed to get customers by phone ${phone}: ${request.error}`));
+      };
+    });
+  }
+
+  /**
+   * Search customers by name (partial match)
+   *
+   * @param searchTerm - Search term (case insensitive)
+   * @returns Array of customers matching search
+   */
+  async searchByName(searchTerm: string): Promise<ICustomer[]> {
+    const allCustomers = await this.getAll();
+    const lowerSearch = searchTerm.toLowerCase();
+
+    return allCustomers.filter(customer =>
+      customer.name.toLowerCase().includes(lowerSearch)
+    );
+  }
+}