import { omit } from '../../utils/helpers';
import { ACTIONS } from './constants';
import type { PortalType } from './contexts';
import type {
  ActionTypes,
  AddUpdatePortalAction,
  RemovePortalAction,
} from './types';

type State = Record<string, Array<PortalType>>;

const registerHostIfNotExist = (state: State, hostName: string): State => {
  if (!(hostName in state)) {
    return {
      ...state,
      [hostName]: [],
    };
  }
  return { ...state };
};

const deregisterHost = (state: State, hostName: string): State => {
  return { ...omit([hostName], state) };
};

const addUpdatePortal = (
  state: Record<string, Array<PortalType>>,
  hostName: string,
  portalName: string,
  node: React.ReactNode
) => {
  const newState = registerHostIfNotExist(state, hostName);

  const index = newState[hostName].findIndex(
    (item) => item.name === portalName
  );

  if (index !== -1) {
    return {
      ...newState,
      [hostName]: newState[hostName].map((item, i) => {
        if (index === i) {
          return {
            ...item,
            node,
          };
        }
        return item;
      }),
    };
  }

  return {
    ...newState,
    [hostName]: [
      ...newState[hostName],
      {
        name: portalName,
        node,
      },
    ],
  };
};

const removePortal = (
  state: Record<string, Array<PortalType>>,
  hostName: string,
  portalName: string
) => {
  if (!(hostName in state)) {
    return { ...state };
  }

  return {
    ...state,
    [hostName]: state[hostName].filter((item) => item.name !== portalName),
  };
};

export const reducer = (
  state: Record<string, Array<PortalType>>,
  action: ActionTypes
) => {
  const { type } = action;
  switch (type) {
    case ACTIONS.REGISTER_HOST:
      return registerHostIfNotExist(state, action.hostName);
    case ACTIONS.DEREGISTER_HOST:
      return deregisterHost(state, action.hostName);
    case ACTIONS.ADD_UPDATE_PORTAL:
      return addUpdatePortal(
        state,
        action.hostName,
        (action as AddUpdatePortalAction).portalName,
        (action as AddUpdatePortalAction).node
      );
    case ACTIONS.REMOVE_PORTAL:
      return removePortal(
        state,
        action.hostName,
        (action as RemovePortalAction).portalName
      );
    default:
      return { ...state };
  }
};