CREATE TABLE IF NOT EXISTS customers (
  id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  assigned_user_id BIGINT UNSIGNED NULL,
  name VARCHAR(150) NOT NULL,
  phone VARCHAR(30) NOT NULL,
  email VARCHAR(190) NULL,
  address TEXT NULL,
  source VARCHAR(100) NULL,
  status ENUM('active','passive','blacklist') NOT NULL DEFAULT 'active',
  created_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  deleted_at TIMESTAMP NULL,
  UNIQUE KEY uq_customers_phone (phone),
  INDEX idx_customers_email (email),
  INDEX idx_customers_assigned_user (assigned_user_id),
  INDEX idx_customers_status (status),
  CONSTRAINT fk_customers_assigned_user FOREIGN KEY (assigned_user_id) REFERENCES users(id) ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_turkish_ci;