import debug from "debug";

import { SubEvent } from "sub-events";

import { SyncgraphPatchMessage } from "./patch";

const log = debug("rdfdbclient");

class ChannelPinger {

  private timeoutId?: number;

  private lastMs: number = 0;

  constructor(private ws: WebSocket) {

    this._pingLoop();

  }

  lastPingMs(): number {

    return this.lastMs;

  }

  pong() {

    this.lastMs = Date.now() + this.lastMs;

  }

  _pingLoop() {

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

      return;

    }

    this.ws.send("PING");

    this.lastMs = -Date.now();

    if (this.timeoutId != null) {

      clearTimeout(this.timeoutId);

    }

    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;

    if (this.ws !== undefined) {

      this.ws.close();

    }

    this.ws = new WebSocket(fullUrl);

    this.ws.onopen = this.onWsOpen.bind(this, this.ws);

    this.ws.onerror = this.onWsError.bind(this);

    this.ws.onclose = this.onWsClose.bind(this);

    this.ws.onmessage = this.onWsMessage.bind(this);

  }

  private onWsOpen(ws: WebSocket) {

    log("new connection to", this.patchSenderUrl);

    this.updateStatus();

    this.newConnection.emit();

    this.pinger = new ChannelPinger(ws);

  }

  private onWsMessage(evt: { data: string }) {

    const msg = evt.data;

    if (msg === "PONG") {

      this.onPong();

      return;

    }

    this.onJson(msg);

  }

  private onPong() {

    if (this.pinger) {

      this.pinger.pong();

      this.updateStatus();

    }

  }

  private onJson(msg: string) {

    const input = JSON.parse(msg);

    if (input.connectedAs) {

      this.connectionId = input.connectedAs;

    } else {

      this.onPatch(input as SyncgraphPatchMessage);

    }

  }

  private onPatch(input: SyncgraphPatchMessage) {

    log(`patch msg from server`);

    this.serverMessage.emit({ evType: "patch", body: input });

    this.messagesReceived++;

    this.updateStatus();

  }

  private onWsError(e: Event) {

    log("ws error", e);

    this.disconnect("ws error");

    this.updateStatus();

  }

  private onWsClose(ev: CloseEvent) {

    log("ws close");

    this.updateStatus();

    if (this.reconnectTimer !== undefined) {

      clearTimeout(this.reconnectTimer);

    }

    this.reconnectTimer = setTimeout(this.openConnection.bind(this), 1000);

  }

  private updateStatus() {

    const conn = (() => {

      if (this.ws === undefined) {

        return "no";

      } else {

        switch (this.ws.readyState) {

          case this.ws.CONNECTING:

            return "connecting";

    // if we had a Store already, this lets N3.Store free all its indices/etc

    this.graph = new N3.Store();

    this.rebuildPrefixFuncs(this.prefixes);

  }

  _clearGraphOnNewConnection() {

    // must not try send a patch to the server

    log("clearGraphOnNewConnection");

    this.clearGraph();

    log("clearGraphOnNewConnection done");

  }

  private rebuildPrefixFuncs(prefixes: Map<string, string>) {

    const p = Object.create(null);

    prefixes.forEach((v: string, k: string) => (p[k] = v));

    this.prefixFuncs = N3.Util.prefixes(p);

    return this.prefixFuncs;

  }

  U() {

    // just a shorthand

    return this.Uri.bind(this);

  }

  Uri(curie: string) {

    if (curie == null) {

      throw new Error("no uri");

    }

    if (curie.match(/^http/)) {

      return N3.DataFactory.namedNode(curie);

    }

    const part = curie.split(":");

    return this.prefixFuncs(part[0])(part[1]);

  }

  // Uri(shorten(u)).value==u

  shorten(uri: N3.NamedNode): string {

    for (let row of [

      { sh: "dev", lo: "http://light9.bigasterisk.com/theater/vet/device/" },

      { sh: "effect", lo: "http://light9.bigasterisk.com/effect/" },

      { sh: "", lo: "http://light9.bigasterisk.com/" },

      { sh: "rdfs", lo: "http://www.w3.org/2000/01/rdf-schema#" },

      { sh: "xsd", lo: "http://www.w3.org/2001/XMLSchema#" },

    ]) {

      if (uri.value.startsWith(row.lo)) {

        return row.sh + ":" + uri.value.substring(row.lo.length);

      }

    }

    return uri.value;

  }

  Literal(jsValue: string | number) {

    return N3.DataFactory.literal(jsValue);

  }

  LiteralRoundedFloat(f: number) {

    return N3.DataFactory.literal(f.toPrecision(3), this.Uri("http://www.w3.org/2001/XMLSchema#decimal"));

  }

  Quad(s: any, p: any, o: any, g: any) {

    return N3.DataFactory.quad(s, p, o, g);

  }

  toJs(literal: { value: any }) {

    // incomplete

    return parseFloat(literal.value);

  }

  loadTrig(trig: any, cb: () => any) {

    // for debugging

    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;

    }

  }

  _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)] : []);

  }

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

    this.applyAndSendPatch(this.getObjectPatch(s, p, newObject, g));

  }

  clearObjects(s: N3.NamedNode, p: N3.NamedNode, g: N3.NamedNode) {

    this.applyAndSendPatch(new Patch(this.graph.getQuads(s, p, null, g), []));

  }

  public runHandler(func: HandlerFunc, label: string) {

    // runs your func once, tracking graph calls. if a future patch

    // matches what you queried, we runHandler your func again (and

    // forget your queries from the first time).

    // helps with memleak? not sure yet. The point was if two matching

    // labels get puushed on, we should run only one. So maybe

    // appending a serial number is backwards.

    if (!this.serial) {

      this.serial = 1;

    }

    this.serial += 1;

    //label = label + @serial

    this.autoDeps.runHandler(func, label);

  }

  _singleValue(s: Quad_Subject, p: Quad_Predicate) {

    this.autoDeps.askedFor(s, p, null, null);

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

    const objs = new Set(Array.from(quads).map((q: Quad) => q.object));

    switch (objs.size) {

      case 0:

        throw new Error("no value for " + s.value + " " + p.value);

      case 1:

        var obj = objs.values().next().value;

        return obj;

      default:

        throw new Error("too many different values: " + JSON.stringify(quads));

    }

  }

  floatValue(s: Quad_Subject, p: Quad_Predicate) {

    const key = s.value + "|" + p.value;

    const hit = this.cachedFloatValues.get(key);

    if (hit !== undefined) {

      return hit;

    }

    //log('float miss', s, p)

    const v = this._singleValue(s, p).value;

    const ret = parseFloat(v);

    if (isNaN(ret)) {

      throw new Error(`${s.value} ${p.value} -> ${v} not a float`);

    }

    this.cachedFloatValues.set(key, ret);

    return ret;

  }

  stringValue(s: any, p: any) {

    return this._singleValue(s, p).value;

  }

  uriValue(s: Quad_Subject, p: Quad_Predicate) {

    const key = s.value + "|" + p.value;

    const hit = this.cachedUriValues.get(key);

    if (hit !== undefined) {

      return hit;

    }

    const ret = this._singleValue(s, p);

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;

      }

    }

  }

}