import { SessionData, SessionOptions } from './sessionData';
import { LOCALSTORAGE_SESSION_KEY } from './constants';
import { NoSessionDataError } from '@stacks/common';

/**
 * An abstract class representing the SessionDataStore interface.

 */
export class SessionDataStore {
  constructor(sessionOptions?: SessionOptions) {
    if (sessionOptions) {
      const newSessionData = new SessionData(sessionOptions);
      this.setSessionData(newSessionData);
    }
  }

  getSessionData(): SessionData {
    throw new Error('Abstract class');
  }

  // TODO: fix, not used?
  setSessionData(_session: SessionData): boolean {
    throw new Error('Abstract class');
  }

  deleteSessionData(): boolean {
    throw new Error('Abstract class');
  }
}

/**
 * Stores session data in the instance of this class.
 * @ignore
 */
export class InstanceDataStore extends SessionDataStore {
  sessionData?: SessionData;

  constructor(sessionOptions?: SessionOptions) {
    super(sessionOptions);
    if (!this.sessionData) {
      this.setSessionData(new SessionData({}));
    }
  }

  getSessionData(): SessionData {
    if (!this.sessionData) {
      throw new NoSessionDataError('No session data was found.');
    }
    return this.sessionData;
  }

  setSessionData(session: SessionData): boolean {
    this.sessionData = session;
    return true;
  }

  deleteSessionData(): boolean {
    this.setSessionData(new SessionData({}));
    return true;
  }
}

/**
 * Stores session data in browser a localStorage entry.
 * @ignore
 */
export class LocalStorageStore extends SessionDataStore {
  key: string;

  constructor(sessionOptions?: SessionOptions) {
    super(sessionOptions);
    if (
      sessionOptions &&
      sessionOptions.storeOptions &&
      sessionOptions.storeOptions.localStorageKey &&
      typeof sessionOptions.storeOptions.localStorageKey === 'string'
    ) {
      this.key = sessionOptions.storeOptions.localStorageKey;
    } else {
      this.key = LOCALSTORAGE_SESSION_KEY;
    }

    const data = localStorage.getItem(this.key);
    if (!data) {
      const sessionData = new SessionData({});
      this.setSessionData(sessionData);
    }
  }

  getSessionData(): SessionData {
    const data = localStorage.getItem(this.key);
    if (!data) {
      throw new NoSessionDataError('No session data was found in localStorage');
    }
    const dataJSON = JSON.parse(data);
    return SessionData.fromJSON(dataJSON);
  }

  setSessionData(session: SessionData): boolean {
    localStorage.setItem(this.key, session.toString());
    return true;
  }

  deleteSessionData(): boolean {
    localStorage.removeItem(this.key);
    this.setSessionData(new SessionData({}));
    return true;
  }
}