import { useSelector } from 'react-redux';

import { StoreState } from '../../../../types';

const SUFFIX_REGEX = /\/api\/v[1|2]\/alerts/i;
type AlertmanagerConfig = { url: string; status: string; actualUrl: string };

export function useExternalAmSelector(): AlertmanagerConfig[] | [] {
  const discoveredAlertmanagers = useSelector(
    (state: StoreState) => state.unifiedAlerting.externalAlertmanagers.discoveredAlertmanagers.result?.data
  );
  const alertmanagerConfig = useSelector(
    (state: StoreState) => state.unifiedAlerting.externalAlertmanagers.alertmanagerConfig.result?.alertmanagers
  );

  if (!discoveredAlertmanagers || !alertmanagerConfig) {
    return [];
  }

  const enabledAlertmanagers: AlertmanagerConfig[] = [];
  const droppedAlertmanagers: AlertmanagerConfig[] = discoveredAlertmanagers.droppedAlertManagers.map((am) => ({
    url: am.url.replace(SUFFIX_REGEX, ''),
    status: 'dropped',
    actualUrl: am.url,
  }));

  for (const url of alertmanagerConfig) {
    if (discoveredAlertmanagers.activeAlertManagers.length === 0) {
      enabledAlertmanagers.push({
        url: url,
        status: 'pending',
        actualUrl: '',
      });
    } else {
      const matchingActiveAM = discoveredAlertmanagers.activeAlertManagers.find(
        (am) => am.url === `${url}/api/v2/alerts`
      );
      matchingActiveAM
        ? enabledAlertmanagers.push({
            url: matchingActiveAM.url.replace(SUFFIX_REGEX, ''),
            status: 'active',
            actualUrl: matchingActiveAM.url,
          })
        : enabledAlertmanagers.push({
            url: url,
            status: 'pending',
            actualUrl: '',
          });
    }
  }

  return [...enabledAlertmanagers, ...droppedAlertmanagers];
}