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import type { LibraryContext } from "./context.ts";import {  toRdf,  Quad,  Iri,  Literal,  NamedNode,  BlankNode,  DataFactory,  literal,  Variable,} from "./rdf.ts";import type { Schema, Property } from "./schema/mod.ts";import { rdf, xsd } from "./namespaces/mod.ts";
type DecodedNode = Record<string, unknown>;
type NodeId = NamedNode | BlankNode;
export const encode = (  node: DecodedNode,  schema: Schema,  context: LibraryContext,  variableInitCounter = 0) => {  return Encoder.encode(node, schema, context, variableInitCounter);};
class Encoder {  private context: LibraryContext;
  private df: DataFactory = new DataFactory({    blankNodePrefix: "b",  });
  private variableCounter: number;
  private output: Quad[] = [];
  private constructor(context: LibraryContext, variableInitCounter: number) {    this.context = context;    this.variableCounter = variableInitCounter;  }
  static encode(    node: DecodedNode,    schema: Schema,    context: LibraryContext,    variableInitCounter: number  ) {    return new Encoder(context, variableInitCounter).encode(node, schema);  }
  encode(node: DecodedNode, schema: Schema) {    const nodeId = this.getNodeId(node);    this.encodeNode(node, schema, nodeId);
    return this.output;  }
  push(    s: NamedNode | BlankNode,    p: NamedNode,    o: NamedNode | BlankNode | Literal | Variable  ) {    this.output.push(this.df.quad(s, p, o));  }
  getNodeId(node: DecodedNode) {    return node.$id      ? this.df.namedNode(node.$id as string)      : this.df.blankNode();  }
  getNodeTypes(node: DecodedNode) {    if (Array.isArray(node.$type)) {      return node.$type;    }
    return node.$type ? [node.$type] : [];  }
  encodeNode(node: DecodedNode, schema: Schema, nodeId: NodeId) {    this.encodeNodeType(node, schema["@type"], nodeId);
    Object.keys(schema).forEach((key) => {      if (key === "@type") {        return;      }      this.encodeNodeProperty(node[key], schema[key] as Property, nodeId);    });  }
  encodeNodeType(node: DecodedNode, requiredTypes: Iri[], nodeId: NodeId) {    const finalTypes = new Set([...this.getNodeTypes(node), ...requiredTypes]);
    finalTypes.forEach((type) => {      this.push(nodeId, this.df.namedNode(rdf.type), this.df.namedNode(type));    });  }
  encodeNodeProperty(value: any, property: Property, nodeId: NodeId) {    if (value === undefined) {      return;    }
    const propertyId = this.df.namedNode(property["@id"]);
    if (value === null) {      // TODO      this.push(        nodeId,        propertyId,        this.df.variable(`v${this.variableCounter++}`)      );      return;    }
    if (property["@multilang"]) {      Object.keys(value).forEach((language) => {        const languageValue: string[] = Array.isArray(value[language])          ? value[language]          : [value[language]];        languageValue.forEach((singleValue) => {          this.push(            nodeId,            propertyId,            literal(singleValue, language.length > 0 ? language : undefined)          );        });      });      return;    }
    const values = Array.isArray(value) ? value : [value];
    values.forEach((val) => {      if (property["@context"]) {        const subNodeId = this.getNodeId(val);        this.encodeNode(val, property["@context"], subNodeId);        this.push(nodeId, propertyId, subNodeId);        return;      }
      const propertyType = property["@type"] ?? xsd.string;
      if (typeof val === "string" && this.context.language) {        if (propertyType === xsd.string || propertyType === rdf.langString) {          this.push(nodeId, propertyId, literal(val, this.context.language));          return;        }      }
      const rdfValue = toRdf(val, {        datatype: this.df.namedNode(property["@type"] ?? xsd.string),      });      this.push(nodeId, propertyId, rdfValue);    });  }}