/**
 * Hook: checkout validation API call.
 * Payload-agnostic: the caller is responsible for building the
 * CheckoutValidateRequest payload and passing it to validate().
 *
 * Supports cancellation: when resetValidation() is called (e.g. on modal close),
 * in-flight requests are ignored and validation state is cleared so Book buttons
 * are not left disabled.
 */
import { useState, useCallback, useRef } from '@wordpress/element';
import { __ } from '@wordpress/i18n';
import apiFetch from '@wordpress/api-fetch';
import type {
	ValidationResponse,
	CheckoutValidateRequest,
} from '../../types';
import { getApiErrorMessage } from '../utils';
import {
	captureException,
	addBreadcrumb,
	withSpan,
	captureMessage,
} from '../sentry';

export interface UseCheckoutValidationReturn {
	validate: (
		payload: CheckoutValidateRequest
	) => Promise<ValidationResponse | null>;
	validationResult: ValidationResponse | null;
	isValidating: boolean;
	resetValidation: () => void;
}

export function useCheckoutValidation(): UseCheckoutValidationReturn {
	const [isValidating, setIsValidating] = useState(false);
	const [validationResult, setValidationResult] =
		useState<ValidationResponse | null>(null);
	const requestIdRef = useRef(0);

	const validate = useCallback(
		async (
			payload: CheckoutValidateRequest
		): Promise<ValidationResponse | null> => {
			requestIdRef.current += 1;
			const currentId = requestIdRef.current;
			setIsValidating(true);
			setValidationResult(null);

			try {
				const response = (await withSpan(
					'Checkout validation',
					'http.client',
					async () =>
						apiFetch({
							path: '/parcel2go-shipping/v1/checkout/validate',
							method: 'POST',
							data: payload,
						}) as Promise<ValidationResponse>,
					{ payload: payload }
				)) as ValidationResponse;

				if (currentId !== requestIdRef.current) return response;

				if (!response.success && !!response.error) {
					setValidationResult(response);
					captureMessage('checkout_validation_failed', 'warning', {
						payload: payload,
						response: response,
					});
					setIsValidating(false);
					return response;
				}

				setValidationResult(response);
				setIsValidating(false);
				return response;
			} catch (err: unknown) {
				if (currentId !== requestIdRef.current) return null;
				captureException(
					err instanceof Error ? err : new Error(String(err))
				);
				addBreadcrumb(
					'Checkout validation failed',
					{ payload: payload },
					'api'
				);
				const message = getApiErrorMessage(
					err,
					__(
						'Validation failed. Please try again.',
						'parcel2go-shipping'
					)
				);
			} finally {
				if (currentId === requestIdRef.current) {
					setIsValidating(false);
				}
			}
			return null;
		},
		[] // no external deps — pure API state machine
	);

	const resetValidation = useCallback(() => {
		requestIdRef.current += 1;
		setValidationResult(null);
		setIsValidating(false);
	}, []);

	return {
		validate,
		validationResult,
		isValidating,
		resetValidation,
	};
}