import { NextFetchEvent, NextMiddleware, NextResponse } from 'next/server';
import settings from 'settings';
import { PzNextRequest } from '.';
import { LocaleUrlStrategy } from '../localization';
import { urlLocaleMatcherRegex } from '../utils';
import logger from '../utils/log';
import { getUrlPathWithLocale } from '../utils/localization';

const getMatchedLocale = (pathname: string, req: PzNextRequest) => {
  let matchedLocale = pathname.match(urlLocaleMatcherRegex)?.[0] ?? '';
  matchedLocale = matchedLocale.replace('/', '');

  const { localeUrlStrategy, defaultLocaleValue } = settings.localization;

  if (localeUrlStrategy === LocaleUrlStrategy.Subdomain) {
    const host =
      req.headers.get('x-forwarded-host') || req.headers.get('host') || '';

    if (host) {
      const subDomain = host.split('.')[0] || '';
      const subDomainLocaleMatched = `/${subDomain}`.match(
        urlLocaleMatcherRegex
      );

      if (subDomainLocaleMatched && subDomainLocaleMatched[0]) {
        matchedLocale = subDomainLocaleMatched[0].slice(1);
      }
    }
  }

  if (!matchedLocale.length) {
    if (localeUrlStrategy !== LocaleUrlStrategy.ShowAllLocales) {
      matchedLocale = defaultLocaleValue;
    }
  }

  return matchedLocale;
};

const withLocale =
  (middleware: NextMiddleware) =>
  async (req: PzNextRequest, event: NextFetchEvent) => {
    const ip = req.headers.get('x-forwarded-for') ?? '';

    try {
      const url = req.nextUrl.clone();
      const matchedLocale = getMatchedLocale(url.pathname, req);
      let { localeUrlStrategy } = settings.localization;

      const { defaultLocaleValue, redirectToDefaultLocale } =
        settings.localization;

      localeUrlStrategy =
        localeUrlStrategy ?? LocaleUrlStrategy.HideDefaultLocale;

      if (!defaultLocaleValue) {
        logger.error('Default locale value is not defined in settings.', {
          ip
        });
        throw new Error(
          'Default locale value is not defined. Use `defaultLocaleValue` property in `localization` object in `settings.js` file.'
        );
      }

      if (
        !matchedLocale?.length &&
        localeUrlStrategy === LocaleUrlStrategy.ShowAllLocales &&
        redirectToDefaultLocale &&
        req.method === 'GET'
      ) {
        // Redirect to existing or default locale
        url.pathname = getUrlPathWithLocale(
          url.pathname,
          req.cookies.get('pz-locale')?.value
        );

        // Use 303 for POST requests
        return NextResponse.redirect(url, 303);
      }

      req.middlewareParams.rewrites.locale = matchedLocale;
    } catch (error) {
      logger.error('withLocale error', {
        error,
        ip
      });
    }
    return middleware(req, event);
  };

export default withLocale;