import debug from "debug";

import * as N3 from "n3";

import { Quad, Quad_Object, Quad_Predicate, Quad_Subject } from "n3";

import { sortBy, unique } from "underscore";

import { AutoDependencies, HandlerFunc } from "./AutoDependencies";

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

import { RdfDbClient } from "./rdfdbclient";

const log = debug("graph");

const RDF = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";

export class SyncedGraph {

  private autoDeps: AutoDependencies;

  private client: RdfDbClient;

  private graph: N3.Store;

  private cachedFloatValues: Map<string, number> = new Map();

  private cachedUriValues: Map<string, N3.NamedNode> = new Map();

  private prefixFuncs: (prefix: string) => N3.PrefixedToIri;

  private serial: any;

  private nextNumber: any;

  // Main graph object for a browser to use. Consider using RdfdbSyncedGraph element to create & own

  // one of these. Syncs both ways with rdfdb. Meant to hide the choice of RDF lib, so we can change it

  // later.

  //

  // Note that _applyPatch is the only method to write to the graph, so

  // it can fire subscriptions.

  constructor(

    // The /syncedGraph path of an rdfdb server.

    patchSenderUrl: string,

    // prefixes can be used in Uri(curie) calls. This mapping may grow during loadTrig calls.

    public prefixes: Map<string, string>,

    private setStatus: (status: string) => void

  ) {

    this.prefixFuncs = this.rebuildPrefixFuncs(prefixes);

    this.graph = new N3.Store();

    this.autoDeps = new AutoDependencies(this);

    this.autoDeps.graphError.subscribe((e) => {

      log("graph learned of error - reconnecting", e);

      this.client.disconnect();

    });

    this.clearGraph();

    this.client = new RdfDbClient(patchSenderUrl, this._clearGraphOnNewConnection.bind(this), this._applyPatch.bind(this), this.setStatus);

  }

  clearGraph() {

    // must not try send a patch to the server!

    // just deletes the statements; watchers are unaffected.

    this.cachedFloatValues = new Map(); // s + '|' + p -> number

    this.cachedUriValues = new Map(); // s + '|' + p -> Uri

    // 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) {