src/session.ts
import * as Crypto from "./components/crypto/implementation.js"
import * as Storage from "./components/storage/implementation.js"
import * as Events from "./events.js"
import * as TypeChecks from "./common/type-checks.js"
import { Maybe } from "./common/types.js"
import FileSystem from "./fs/index.js"
// ✨
export class Session {
#crypto: Crypto.Implementation
#storage: Storage.Implementation
#eventEmitter: Events.Emitter<Events.Session<Session>>
fs?: FileSystem
type: string
username: string
constructor(props: {
crypto: Crypto.Implementation
storage: Storage.Implementation
eventEmitter: Events.Emitter<Events.Session<Session>>
fs?: FileSystem
type: string
username: string
}) {
this.#crypto = props.crypto
this.#storage = props.storage
this.#eventEmitter = props.eventEmitter
this.fs = props.fs
this.type = props.type
this.username = props.username
this.#eventEmitter.emit("session:create", { session: this })
}
async destroy() {
this.#eventEmitter.emit("session:destroy", { username: this.username })
await this.#storage.removeItem(this.#storage.KEYS.ACCOUNT_UCAN)
await this.#storage.removeItem(this.#storage.KEYS.CID_LOG)
await this.#storage.removeItem(this.#storage.KEYS.SESSION)
await this.#storage.removeItem(this.#storage.KEYS.UCANS)
await this.#crypto.keystore.clearStore()
if (this.fs) this.fs.deactivate()
}
}
// INFO
type SessionInfo = {
type: string
username: string
}
export function isSessionInfo(a: unknown): a is SessionInfo {
return TypeChecks.isObject(a)
&& TypeChecks.hasProp(a, "username")
&& TypeChecks.hasProp(a, "type")
}
/**
* Begin to restore a `Session` by looking up the `SessionInfo` in the storage.
*/
export async function restore(storage: Storage.Implementation): Promise<Maybe<SessionInfo>> {
return storage
.getItem(storage.KEYS.SESSION)
.then((a: unknown) => a ? a as string : null)
.then(a => a ? JSON.parse(a) : null)
.then(a => isSessionInfo(a) ? a : null)
}
/**
* Prepare the system for the creation of a `Session`
* by adding the necessary info to the storage.
*/
export function provide(storage: Storage.Implementation, info: SessionInfo): Promise<string> {
return storage.setItem(
storage.KEYS.SESSION,
JSON.stringify({ type: info.type, username: info.username })
)
}