import { AsyncLocalStorage } from 'async_hooks'
import {Request} from './lifecycle/Request'
import {Singleton} from '../di'
import {ErrorWithContext} from '../util'

export class InvalidOutOfRequestAccessError extends ErrorWithContext {
    constructor() {
        super(`Attempted to access request via local storage outside of async lifecycle!`)
    }
}

@Singleton()
export class RequestLocalStorage {
    protected readonly store: AsyncLocalStorage<Request> = new AsyncLocalStorage<Request>()

    get(): Request {
        const req = this.store.getStore()
        if ( !req ) {
            throw new InvalidOutOfRequestAccessError()
        }

        return req
    }

    has(): boolean {
        return Boolean(this.store.getStore())
    }

    run<T>(req: Request, closure: () => T): T {
        return this.store.run(req, closure)
    }
}