import {Omit} from '../../utils';
import {StripeError} from '../stripe';
import {StripeElementBase} from './base';
import {StripeExpressCheckoutElementConfirmEvent} from './express-checkout';
import {TaxIdType, ExternalTaxIdType} from './tax-id';

/**
 * Address type used in CheckoutForm change events.
 */
export type CheckoutFormAddress = {
  line1?: string | null;
  line2?: string | null;
  city?: string | null;
  state?: string | null;
  postal_code?: string | null;
  country?: string | null;
};

/**
 * The change event payload for the CheckoutForm.
 */
export interface StripeCheckoutFormChangeEvent {
  /**
   * The type of element that emitted this event.
   */
  elementType: 'checkoutForm';

  /**
   * Whether all required fields in the CheckoutForm are complete.
   */
  complete: boolean;

  /**
   * Whether the CheckoutForm is currently empty.
   */
  empty: boolean;

  /**
   * An object containing the current form values.
   */
  value: {
    customerDetails: {
      email: string;
      name?: string;
      businessName?: string;
    };
    shippingOption?: {
      id: string;
      displayName: string;
      amount: string;
    };
    shippingAddress?: {
      name: string;
      address: CheckoutFormAddress;
    };
    billingAddress?: {
      name: string;
      address: CheckoutFormAddress;
    };
    tax?: {
      businessName?: string;
      taxId: string;
      taxIdType: TaxIdType;
      externalTaxIdType: ExternalTaxIdType;
    };
    customFields?: Record<string, string | number>;
    payment?: {
      collapsed: boolean;
      type: string;
      country?: string | null;
      billingDetails?: {
        address?: {
          country?: string;
          postal_code?: string;
        };
      } | null;
      payment_method?: {
        id: string;
        type: string;
        billing_details: {
          address: CheckoutFormAddress;
          name: string | null;
          email: string | null;
          phone: string | null;
        };
      } | null;
      savePaymentMethod?: boolean;
    };
    adaptivePricing?: {
      /**
       * The currently selected local currency code (e.g. 'eur', 'gbp').
       */
      currency: string;
    };
  };

  /**
   * Array of views in compact layout. Only defined for compact layout.
   */
  views?: {
    /**
     * Localized view name: "Express" | "Payment" | etc
     * */
    label: string;

    /**
     * Whether the user can currently navigate to this view
     * */
    canNavigate: boolean;

    /**
     * Whether this is the current view
     * */
    active: boolean;
  }[];
}

/**
 * Confirm event when user completes via Express Checkout (Apple Pay, Google Pay, etc.)
 */
interface StripeCheckoutFormExpressCheckoutConfirmEvent
  extends StripeExpressCheckoutElementConfirmEvent {
  source: 'checkout-form-ece';
}

/**
 * Confirm event when user clicks the Pay button.
 * paymentMethodType is the selected payment method (e.g., 'card', 'sepa_debit')
 * or null if payment collection is not needed.
 */
interface StripeCheckoutFormPayButtonConfirmEvent {
  source: 'checkout-form-pay-button';
  paymentMethodType: string | null;
}

/**
 * The value returned by `checkoutForm.getValue()`.
 * Same shape as the change event payload, but without `elementType`.
 */
export type StripeCheckoutFormValue = Omit<
  StripeCheckoutFormChangeEvent,
  'elementType'
>;

/**
 * The confirm event payload for the CheckoutForm.
 */
export type StripeCheckoutFormConfirmEvent =
  | StripeCheckoutFormExpressCheckoutConfirmEvent
  | StripeCheckoutFormPayButtonConfirmEvent;

export type StripeCheckoutForm = StripeElementBase & {
  /**
   * Triggered when the element is fully rendered and can accept `element.focus` calls.
   */
  on(
    eventType: 'ready',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  once(
    eventType: 'ready',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  off(
    eventType: 'ready',
    handler?: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;

  /**
   * Triggered when the element gains focus.
   */
  on(
    eventType: 'focus',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  once(
    eventType: 'focus',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  off(
    eventType: 'focus',
    handler?: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;

  /**
   * Triggered when the element loses focus.
   */
  on(
    eventType: 'blur',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  once(
    eventType: 'blur',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  off(
    eventType: 'blur',
    handler?: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;

  /**
   * Triggered when the escape key is pressed within the element.
   */
  on(
    eventType: 'escape',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  once(
    eventType: 'escape',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  off(
    eventType: 'escape',
    handler?: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;

  /**
   * Triggered when the element fails to load.
   */
  on(
    eventType: 'loaderror',
    handler: (event: {elementType: 'checkoutForm'; error: StripeError}) => any
  ): StripeCheckoutForm;
  once(
    eventType: 'loaderror',
    handler: (event: {elementType: 'checkoutForm'; error: StripeError}) => any
  ): StripeCheckoutForm;
  off(
    eventType: 'loaderror',
    handler?: (event: {elementType: 'checkoutForm'; error: StripeError}) => any
  ): StripeCheckoutForm;

  /**
   * Triggered when the loader UI is mounted to the DOM and ready to be displayed.
   */
  on(
    eventType: 'loaderstart',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  once(
    eventType: 'loaderstart',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  off(
    eventType: 'loaderstart',
    handler?: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;

  /**
   * Triggered when the element's value changes.
   */
  on(
    eventType: 'change',
    handler: (event: StripeCheckoutFormChangeEvent) => any
  ): StripeCheckoutForm;
  once(
    eventType: 'change',
    handler: (event: StripeCheckoutFormChangeEvent) => any
  ): StripeCheckoutForm;
  off(
    eventType: 'change',
    handler?: (event: StripeCheckoutFormChangeEvent) => any
  ): StripeCheckoutForm;

  /**
   * Triggered when a buyer authorizes a payment within a supported payment method.
   */
  on(
    eventType: 'confirm',
    handler: (event: StripeCheckoutFormConfirmEvent) => any
  ): StripeCheckoutForm;
  once(
    eventType: 'confirm',
    handler: (event: StripeCheckoutFormConfirmEvent) => any
  ): StripeCheckoutForm;
  off(
    eventType: 'confirm',
    handler?: (event: StripeCheckoutFormConfirmEvent) => any
  ): StripeCheckoutForm;

  /**
   * Triggered when the payment interface is dismissed (e.g., a buyer closes the payment interface).
   */
  on(
    eventType: 'cancel',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  once(
    eventType: 'cancel',
    handler: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;
  off(
    eventType: 'cancel',
    handler?: (event: {elementType: 'checkoutForm'}) => any
  ): StripeCheckoutForm;

  /**
   * Retrieves the current form values from the CheckoutForm.
   */
  getValue(): Promise<StripeCheckoutFormValue>;

  /**
   * Navigates to the view at the given index (from the change event's views array).
   */
  setView(viewIndex: number): Promise<void>;
};