123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112
import { Envelope } from './types-envelope.ts';import { Fn, FnsBag } from './types-bag.ts';import { Watchable, WatchableSet } from './watchable.ts';
export type Thunk = () => void;
/** * Typical options for the Transport constructor. * * But note that each flavor of Transport will have a slightly different constructor */export interface ITransportOpts<BagType extends FnsBag> {    deviceId: string; // id of this device    methods: BagType;    //streams: { [method: string]: Fn },}
export type TransportStatus = 'OPEN' | 'CLOSED';
/** * Manages a specific kind of connection (an HTTP server, etc). * * Creates Connections. */export interface ITransport<BagType extends FnsBag> {    status: Watchable<TransportStatus>;    isClosed: boolean;
    methods: BagType;    deviceId: string;    connections: WatchableSet<IConnection<BagType>>;
    onClose(cb: Thunk): Thunk;    close(): void;
    // constructor(opts: ITransportOpts)}
export interface ConnectionOpts<BagType extends FnsBag> {    description: string;    transport: ITransport<BagType>;    deviceId: string;    methods: BagType;
    // conn will be "this"    sendEnvelope: (conn: IConnection<BagType>, env: Envelope<BagType>) => Promise<void>;}
/** * Status always starts as CONNECTING, then * can switch back and forth between OPEN and ERROR, * (or skips OPEN and ERROR completely) * and finally ends at CLOSED. * * ERROR means something failed but it's ok to try again. * CLOSED means it's never coming back. */export type ConnectionStatus =    | 'CONNECTING'    | 'OPEN'    | 'ERROR'    | 'CLOSED';
/** * Converts method calls to Envelopes and passes them to a Transport. * * Represents a one-to-one network connection. */export interface IConnection<    MethodsType extends FnsBag,> {    // TODO: actually connections need to track their incoming and outgoing    // statuses separately, and then exposed a combined status somehow?    // What if only one direction has an error?
    status: Watchable<ConnectionStatus>;    _closeCbs: Set<Thunk>;
    description: string;    _transport: ITransport<MethodsType>;    _deviceId: string;    _otherDeviceId: string | null; // null until we discover it    _methods: { [methodName: string]: Fn };    _lastSeen: number;
    get isClosed(): boolean;    onClose(cb: Thunk): Thunk;    close(): void;
    _sendEnvelope: (conn: IConnection<MethodsType>, env: Envelope<MethodsType>) => Promise<void>; // the transport provides this function for us
    // constructor(transport: ITransport);
    handleIncomingEnvelope(env: Envelope<MethodsType>): Promise<void>;
    // TODO: maybe this can be synchronous since    // we don't care about the result --    // does it wait until sent over the network, or just queued in a batch?    notify<MethodKey extends keyof MethodsType>(        method: MethodKey,        ...args: Parameters<MethodsType[MethodKey]>    ): Promise<void>;
    // Wait for the return value to come back    request<MethodKey extends keyof MethodsType>(        method: MethodKey,        ...args: Parameters<MethodsType[MethodKey]>    ): Promise<ReturnType<MethodsType[MethodKey]>>;
    // TODO: stream}