willin/svelte-session

import type { Cookies, RequestEvent } from '@sveltejs/kit';
import type { SessionData, SessionStorageOptions, SessionStorageStrategy } from './types.js';
import { Session } from './session.js';
import { decodeCookieValue, encodeCookieValue } from './utils.js';
import { sign, unsign } from './crypto.js';
import { MemoryStrategy } from '$lib/index.js';
import { CloudflareKVStrategy } from './implements/cloudflare-kv.js';
import { CookieStrategy } from './implements/cookie.js';

export class SessionStorage<Data = SessionData, FlashData = Data, CustomStrategyOptions = any> {
  #options: Pick<
    SessionStorageOptions<Data, FlashData, CustomStrategyOptions>,
    'cookie' | 'session'
  >;
  #cookies: Cookies;
  #session: Session<Data, FlashData> | null = null;
  #adapter: SessionStorageStrategy<Data, FlashData>;
  #needSync: boolean = false;

  constructor(
    event: RequestEvent,
    opts: SessionStorageOptions<
      Data,
      FlashData,
      CustomStrategyOptions
    > = {} as SessionStorageOptions<Data, FlashData, CustomStrategyOptions>
  ) {
    const { adapter, ...rest } = opts;
    this.#options = rest;
    this.#cookies = event.cookies;
    const { strategy: S, name = 'cookie', options = {} } = adapter ?? {};
    if (S) {
      this.#adapter = new S(event, { ...rest, ...options }) as SessionStorageStrategy<
        Data,
        FlashData
      >;
    } else {
      switch (name) {
        case 'memory': {
          this.#adapter = new MemoryStrategy();
          break;
        }
        case 'cloudflare-kv': {
          this.#adapter = new CloudflareKVStrategy(event, options);
          break;
        }
        case 'cookie':
        default: {
          this.#adapter = new CookieStrategy(event, { ...rest, ...options } as any);
        }
      }
    }
  }

  /**
   * You must init Storage from handler first
   */
  async init() {
    const key = this.#options?.session?.key ?? '__sid';
    const secrets = this.#options?.session?.secrets ?? [];
    const signedId = this.#cookies.get(key);
    if (signedId) {
      const { id } = await decodeCookieValue<{ id?: string }>(unsign, signedId, secrets);
      if (id) {
        const data = await this.#adapter.readData(id);
        this.#session = new Session((data ?? {}) as any, id);
        return;
      }
    }
    const id = await this.#adapter.createData({}, this.#expires);
    this.#session = new Session({}, id);
    this.#cookies.set(key, await encodeCookieValue(sign, { id }, secrets), this.#options.cookie);
  }

  get sid() {
    if (!this.#session) throw new Error('Not Initialized');
    return this.#session.id;
  }
  /**
   * Change the session id
   */
  async updateSid(id: string, initData?: Data) {
    if (initData) {
      await this.#adapter.updateData(id, initData);
      this.#session = new Session(initData as any, id);
      return;
    }
    const data = await this.#adapter.readData(id);
    this.#session = new Session((data ?? {}) as any, id);
  }

  get data() {
    if (!this.#session) throw new Error('Not Initialized');
    return this.#session?.data;
  }

  get<Key extends keyof Data & string>(key: Key) {
    if (!this.#session) throw new Error('Not Initialized');
    return this.#session.get(key);
  }

  async set<Key extends keyof Data & string>(key: Key, value: Data[Key]) {
    if (!this.#session) throw new Error('Not Initialized');
    this.#session.set(key, value);
    await this.#adapter.updateData(this.#session.id, this.#session.data, this.#expires);
  }

  async flash<Key extends keyof FlashData & string>(key: Key, value: FlashData[Key]) {
    if (!this.#session) throw new Error('Not Initialized');
    this.#session?.flash(key, value);
    await this.#adapter.updateData(this.#session.id, this.#session.data, this.#expires);
  }

  async unset<Key extends keyof Data & string>(key: Key) {
    if (!this.#session) throw new Error('Not Initialized');
    this.#session?.unset(key);
    await this.#adapter.updateData(this.#session.id, this.#session.data, this.#expires);
  }

  async destory() {
    if (!this.#session) throw new Error('Not Initialized');
    await this.#adapter.deleteData(this.#session.id);
    this.#session = new Session({} as any, this.#session.id);
  }

  get #expires() {
    const options = this.#options.cookie ?? {};
    const expires =
      options?.maxAge != null
        ? new Date(Date.now() + options.maxAge * 1000)
        : options?.expires != null
          ? options.expires
          : undefined;

    return expires;
  }
}