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)
    );
  }
}