// WSTS protocol layer — sits between the raw WebSocket and the event pool.
// Routes incoming frames to either a correlated reply handler (numeric id) or
// a named signal handler (string id). Outbound frames are encoded by the codec.

import { WSTSCodec } from './codec.js';

export default class WSTSProtocol {
    constructor(mwse) {
        this.mwse  = mwse;
        this.codec = new WSTSCodec();
        this._listen();
    }

    _listen() {
        this.mwse.server.onRecaivePack(raw => this.PackAnalyze(raw));
    }

    // ---- Outbound -------------------------------------------------------

    // SendOnly: fire-and-forget WOM frame — no id, no pending waiter.
    SendOnly(pack) {
        this.mwse.server.tranferToServer(this.codec.encode([pack, 'R']));
    }

    // SendRequest: request expecting exactly one reply (action 'R' → server replies 'E').
    SendRequest(pack, id) {
        this.mwse.server.tranferToServer(this.codec.encode([pack, id, 'R']));
    }

    // StartStream: request expecting multiple replies (server replies 'C' until done).
    StartStream(pack, id) {
        this.mwse.server.tranferToServer(this.codec.encode([pack, id, 'S']));
    }

    // SendRaw: bypass codec (used by internal tooling only).
    SendRaw(pack) {
        this.mwse.server.tranferToServer(JSON.stringify(pack));
    }

    // ---- Inbound --------------------------------------------------------

    // PackAnalyze routes one decoded frame to the right listener.
    // raw may be a string (JSON) or an ArrayBuffer (binary, when #42 lands).
    PackAnalyze(raw) {
        const data = this.codec.decode(raw);
        const [payload, id, action] = data;

        if (typeof id === 'number') {
            // Correlated reply: numeric id maps to a pending request.
            const entry = this.mwse.EventPooling.events.get(id);
            if (entry) {
                entry[0](payload, action);
                if (action === 'E') {
                    // 'E'nd — one-shot request fulfilled; remove the waiter.
                    this.mwse.EventPooling.events.delete(id);
                }
                // 'C'ontinue — stream replies stay in the map until the server closes.
            } else {
                console.warn('MWSE: reply for unknown request id', id);
            }
        } else {
            // Signal: string id (signal name) fans out to all registered listeners.
            const listeners = this.mwse.EventPooling.signals.get(id);
            if (listeners) {
                for (const cb of listeners) cb(payload);
            } else {
                console.warn('MWSE: unhandled signal', id);
            }
        }
    }
}