import { FormData, StepValidation } from './types';
import { EMAIL_REGEX, PHONE_REGEX } from './constants';
import { getAppContentLocation } from '../../utils';

export const trackEnquiryEvent = (
  name: string,
  method: string,
  errorMessage?: string
): void => {
  if (typeof window === 'undefined' || !window.utag) {
    return;
  }
  const payload: Record<string, string> = {
    event_navigation_action: 'navigation',
    event_navigation_name: name,
    event_navigation_browsing_method: method,
    app_content_location: getAppContentLocation('nuk_preferred_edition')
  };
  if (errorMessage) {
    payload.article_parent_name = errorMessage;
  }
  window.utag.link(payload);
};

export const formatCurrency = (value: number) =>
  `£${value.toLocaleString('en-GB')}`;

type FieldRule = {
  field: keyof FormData;
  message: string;
  pattern?: RegExp;
  patternMessage?: string;
};

const STEP_RULES: Record<number, FieldRule[]> = {
  1: [
    { field: 'firstName', message: 'Please enter your first name' },
    { field: 'lastName', message: 'Please enter your last name' },
    {
      field: 'telephone',
      message: 'Please enter your telephone number',
      pattern: PHONE_REGEX,
      patternMessage: 'Please enter a valid telephone number'
    },
    {
      field: 'email',
      message: 'Please enter your email address',
      pattern: EMAIL_REGEX,
      patternMessage: 'Please enter a valid email address'
    }
  ],
  2: [
    { field: 'departurePort', message: 'Please enter your departure' },
    { field: 'destination', message: 'Please enter your destination' },
    { field: 'month', message: 'Please select the month' },
    { field: 'year', message: 'Please select the year' },
    { field: 'duration', message: 'Please select the duration' },
    { field: 'adults', message: 'Please select the number of adults' },
    { field: 'children', message: 'Please select the number of children' }
  ]
};

export const validateStep = (
  step: number,
  formData: FormData
): StepValidation => {
  const stepErrors: Record<string, string> = {};
  const rules = STEP_RULES[step] || [];

  for (const rule of rules) {
    const value = String(formData[rule.field]).trim();
    if (!value) {
      stepErrors[rule.field] = rule.message;
    } else if (rule.pattern && !rule.pattern.test(value)) {
      stepErrors[rule.field] = rule.patternMessage!;
    }
  }

  return {
    isValid: Object.keys(stepErrors).length === 0,
    errors: stepErrors
  };
};