import { push } from 'connected-react-router';
import queryString from 'query-string';
import users from '../users';
import { selectUser, selectWeek, selectCurrentWeek } from './selectors';
import purifyWeek from '../lib/purifyWeek';
import withinRange from '../lib/withinRange';

function updatePathname(pathname = '') {
  return (dispatch, getState) => {
    const query = getState().router.location.search;
    dispatch(push(`/${pathname}${query}`));
  };
}

function updateQuery(newQuery) {
  return (dispatch, getState) => {
    const { location } = getState().router;
    const query = queryString.stringify({
      ...queryString.parse(location.search),
      ...newQuery,
    });

    dispatch(push(`${location.pathname}?${query}`));
  };
}

export function setUser(newUser) {
  return (dispatch) => {
    dispatch({ type: 'SEARCH/RESET' });
    dispatch(updatePathname(newUser));
  };
}

export function shiftRoom(shift) {
  return (dispatch, getState) => {
    const state = getState();
    const user = selectUser(state);
    const { allRoomIds } = users;

    if (users.byId[user].type !== 'r') throw new Error('User must be a room');

    const currentRoom = user;
    const currentRoomIndex = allRoomIds.indexOf(currentRoom);
    const nextRoomIndex = withinRange(
      currentRoomIndex + shift,
      allRoomIds.length - 1,
    );
    const nextRoom = allRoomIds[nextRoomIndex];

    dispatch(setUser(nextRoom));
  };
}

export function setWeek(newWeek) {
  return (dispatch, getState) => {
    const state = getState();
    const isCurrentWeek = selectCurrentWeek(state) === newWeek;

    dispatch(updateQuery({
      week: isCurrentWeek ? undefined : newWeek,
    }));
  };
}

export function shiftWeek(shift) {
  return (dispatch, getState) => {
    const state = getState();
    const week = selectWeek(state);
    dispatch(setWeek(purifyWeek(week + shift)));
  };
}

export function showRoomFinder() {
  return (dispatch, getState) => {
    const state = getState();
    const user = selectUser(state);

    if (user == null || users.byId[user].type !== 'r') {
      // We are not currently viewing a room, correct the situation.
      dispatch(setUser(users.allRoomIds[0]));
    }

    dispatch({ type: 'ROOM_FINDER/SHOW' });
  };
}