}

    this.timeoutId = (setTimeout(this._pingLoop.bind(this), 10000) as unknown) as number;

  }

}

export class RdfDbChannel {

  // lower level reconnecting websocket -- knows about message types, but not what's inside a patch body

  private ws?: WebSocket = undefined;

  private pinger?: ChannelPinger;

  private connectionId: string = "none"; // server's name for us

  private reconnectTimer?: NodeJS.Timeout = undefined;

  private messagesReceived = 0; // (non-ping messages)

  private messagesSent = 0;

  newConnection: SubEvent<void> = new SubEvent();

  serverMessage: SubEvent<{ evType: string; body: SyncgraphPatchMessage }> = new SubEvent();

  statusDisplay: SubEvent<string> = new SubEvent();

  constructor(public patchSenderUrl: string) {

    this.openConnection();

  }

  sendMessage(body: string): boolean {

    // one try, best effort, true if we think it worked

    if (!this.ws || this.ws.readyState !== this.ws.OPEN) {

      return false;

    }

    log("send patch to server, " + body.length + " bytes");

    this.ws.send(body);

    this.messagesSent++;

    this.updateStatus();

    return true;

  }

  disconnect(why:string) {

    // will be followed by an autoconnect

    log("disconnect requested:", why);

    if (this.ws !== undefined) {

      const closeHandler = this.ws.onclose?.bind(this.ws);

      if (!closeHandler) {

        throw new Error();

      }

      closeHandler(new CloseEvent("forced"));

    }

  }

  private openConnection() {

    const wsOrWss = window.location.protocol.replace("http", "ws");

    const fullUrl = wsOrWss + "//" + window.location.host + this.patchSenderUrl;

    const adds: Quad[] = [];

    const parser = new N3.Parser();

    parser.parse(trig, (error: any, quad: any, prefixes: any) => {

      if (error) {

        throw new Error(error);

      }

      if (quad) {

        adds.push(quad);

      } else {

        this._applyPatch(new Patch([], adds));

        // todo: here, add those prefixes to our known set

        if (cb) {

          cb();

        }

      }

    });

  }

  quads(): any {

    // for debugging

    return Array.from(this.graph.getQuads(null, null, null, null)).map((q: Quad) => [q.subject, q.predicate, q.object, q.graph]);

  }

  applyAndSendPatch(patch: Patch) {

    if (!this.client) {

      return;

    }

      this._applyPatch(patch);

      // // chaos delay

      //       setTimeout(()=>{

        log("sending patch:\n", patch.dump());

        this.client.sendPatch(patch);

      // },300*Math.random())

    }

  _applyPatch(patch: Patch) {

    // In most cases you want applyAndSendPatch.

    //

    // This is the only method that writes to this.graph!

    if (patch.isEmpty()) throw "dont send empty patches here";

    log("_applyPatch [1] \n", patch.dump());

    this.cachedFloatValues.clear();

    this.cachedUriValues.clear();

    patch.applyToGraph(this.graph);

    if (false) {

      log("applied patch locally", patch.summary());

    } else {

      log("applied patch locally:\n" + patch.dump());

    }

    this.autoDeps.graphChanged(patch);

  }

  getObjectPatch(s: N3.NamedNode, p: N3.NamedNode, newObject: N3.Quad_Object | null, g: N3.NamedNode): Patch {

    // make a patch which removes existing values for (s,p,*,c) and

    // adds (s,p,newObject,c). Values in other graphs are not affected.

    const existing = this.graph.getQuads(s, p, null, g);

    return new Patch(existing, newObject !== null ? [this.Quad(s, p, newObject, g)] : []);

  }

import debug from "debug";

import { parseJsonPatch, Patch } from "./patch";

import { RdfDbChannel } from "./RdfDbChannel";

const log = debug("rdfdbclient");

export class RdfDbClient {

  private channel: RdfDbChannel;

  // Send and receive patches from rdfdb. Primarily used in SyncedGraph.

  //

  // What this should do, and does not yet, is keep the graph

  // 'coasting' over a reconnect, applying only the diffs from the old

  // contents to the new ones once they're in. Then, remove all the

  // clearGraph stuff in graph.coffee that doesn't even work right.

  //

  constructor(

    patchSenderUrl: string,

    private clearGraphOnNewConnection: () => void,

    private applyPatch: (p: Patch) => void,

    setStatus: (status: string) => void

  ) {

    this.channel = new RdfDbChannel(patchSenderUrl);

    this.channel.statusDisplay.subscribe((st: string) => {

    });

    this.channel.newConnection.subscribe(() => {

      this.clearGraphOnNewConnection();

    });

    this.channel.serverMessage.subscribe((m) => {

      parseJsonPatch(m.body, (p: Patch) => {

        log('patch from server:', p.dump())

        if (p.isEmpty()) {

          return;

        }

        this.applyPatch(p);

      });

    });

  }

  sendPatch(patch: Patch) {

    log("queue patch to server ", patch.summary());

    this._continueSending();

  }

  disconnect(why:string) {

    this.channel.disconnect(why);

  }

  async _continueSending() {

    // we could call this less often and coalesce patches together to optimize

    // the dragging cases. See rdfdb 'compactPatches' and 'processInbox'.

      const json = await patch.toJsonPatch();

      const ret = this.channel.sendMessage(json);

      if (!ret) {

        setTimeout(this._continueSending.bind(this), 500);

        // this.disconnect()

        return;

      }

    }

  }

}