import { FormData } from './types';

export class ApiError extends Error {
  constructor(message: string) {
    super(message);
    this.name = 'ApiError';
  }
}

const FORM_PATH = '/holidays/wp-admin/admin-ajax.php';

const getSubmissionUrl = (): string => {
  if (typeof window !== 'undefined') {
    if (window.location.hostname.includes('thetimes')) {
      return `${window.location.origin}${FORM_PATH}`;
    }
    return `https://www.staging-thetimes.com${FORM_PATH}`;
  }
  return `https://www.thetimes.com${FORM_PATH}`;
};

const buildComments = (comments: string): string => {
  const pageUrl = typeof window !== 'undefined' ? window.location.href : '';
  const pageTitle = typeof document !== 'undefined' ? document.title : '';

  return [comments, `\nSubmitted from: ${pageUrl}`, `Page title: ${pageTitle}`]
    .filter(Boolean)
    .join('\n');
};

const buildRequestBody = (formData: FormData): string => {
  const body = new URLSearchParams();

  const requiredFields: Record<string, string> = {
    action: 'tt_ContactUsHook',
    first_name: formData.firstName,
    last_name: formData.lastName,
    telephone_number: formData.telephone,
    email_address: formData.email,
    depart_from: formData.departurePort,
    destination: formData.destination,
    month: formData.month,
    year: formData.year,
    duration: formData.duration,
    adults: formData.adults,
    children: formData.children,
    budget: `${formData.budgetMin},${formData.budgetMax}`
  };

  Object.keys(requiredFields).forEach((key: string) => {
    body.append(key, requiredFields[key]);
  });

  // Contact type (optional)
  const contactMethods: string[] = [];
  if (formData.contactByTelephone) {
    contactMethods.push('Telephone');
  }
  if (formData.contactByEmail) {
    contactMethods.push('Email');
  }
  if (contactMethods.length > 0) {
    body.append('contact_type', contactMethods.join(', '));
  }

  // Appointment type (optional)
  const appointmentTypes: string[] = [];
  if (formData.appointmentVideoCall) {
    appointmentTypes.push('Video call');
  }
  if (formData.appointmentTelephoneCall) {
    appointmentTypes.push('Telephone call');
  }
  if (appointmentTypes.length > 0) {
    body.append('appointment_type', appointmentTypes.join(', '));
  }

  // Appointment date & time (optional)
  if (formData.preferredDate) {
    body.append('appointment_date', formData.preferredDate);
  }
  if (formData.preferredTime) {
    body.append('appointment_time', formData.preferredTime);
  }

  // Discount code (optional)
  if (formData.subscriberCode) {
    body.append('discount_code', formData.subscriberCode);
  }

  // Comments (optional)
  const comments = buildComments(formData.comments);
  if (comments) {
    body.append('comments', comments);
  }

  // Newsletter opt-in (optional)
  if (formData.newsletterOptIn) {
    body.append('newsletter', '1');
  }

  return body.toString();
};

export const submitEnquiry = async (formData: FormData): Promise<void> => {
  const response = await fetch(getSubmissionUrl(), {
    method: 'POST',
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
      'X-Requested-With': 'XMLHttpRequest'
    },
    body: buildRequestBody(formData),
    mode: 'cors',
    credentials: 'omit'
  });

  const data = await response.json().catch(() => ({}));

  if (!response.ok || !data.success) {
    if (data && data.data) {
      throw new ApiError(data.data);
    }
    throw new Error(`HTTP error ${response.status}`);
  }
};