import { v4 as uuid } from 'uuid';
import once from 'lodash.once';
import { getDateString, getDifInMins } from './date.helper';
import { SESSION_CACHE_KEY, LAST_ACTIVITY_CACHE_KEY } from '../constants/constants';

type CachedSessionObj = {
  sessionId: string;
  sessionCreated: string;
};

export const supportsSessionStorage = once(() => {
  const value = '_OMBORI_GRID_SIGNALS_SESSION_STORAGE_TEST';

  try {
    sessionStorage.setItem(value, value);
    sessionStorage.removeItem(value);
    return true;
  } catch (e) {
    return false;
  }
});

const getCachedSession = () => {
  try {
    const sessionStringCache = sessionStorage.getItem(SESSION_CACHE_KEY);
    if (!sessionStringCache) return null;

    return JSON.parse(sessionStringCache) as CachedSessionObj;
  } catch (e) {
    return null;
  }
};

export const cacheSession = (sessionId: string, sessionCreated: string) => {
  sessionStorage.setItem(SESSION_CACHE_KEY, JSON.stringify({ sessionId, sessionCreated }));
};

export const generateSession = ({
  forceCreateNewSession = false,
  maxSessionLastActivityMins,
}: {
  forceCreateNewSession?: boolean;
  maxSessionLastActivityMins: number;
}) => {
  const sessionId = uuid();
  const sessionCreated = getDateString();

  if (supportsSessionStorage()) {
    const cachedSession = getCachedSession();
    if (
      !forceCreateNewSession &&
      cachedSession &&
      cachedSession.sessionId &&
      cachedSession.sessionCreated
    ) {
      const lastActivity = getLastActivityCache();
      if (lastActivity) {
        const isAfterMins =
          getDifInMins(getDateString(), lastActivity) >= maxSessionLastActivityMins;
        if (!isAfterMins) {
          return {
            sessionId: cachedSession.sessionId,
            sessionCreated: cachedSession.sessionCreated,
            isFromCache: true,
          };
        }
      }
    }

    cacheSession(sessionId, sessionCreated);
    setLastActivityCache(sessionCreated);
  }

  return { sessionId, sessionCreated, isFromCache: false };
};

export const getLastActivityCache = () => {
  try {
    if (!supportsSessionStorage()) return null;

    const lastActivityCache = sessionStorage.getItem(LAST_ACTIVITY_CACHE_KEY);
    return lastActivityCache;
  } catch (e) {
    return null;
  }
};

export const setLastActivityCache = (dateString: string) => {
  try {
    if (!supportsSessionStorage()) return false;
    sessionStorage.setItem(LAST_ACTIVITY_CACHE_KEY, dateString);
    return dateString;
  } catch (e) {
    return false;
  }
};