src/ContentInfo.js

import * as asn1js from "asn1js";
import { getParametersValue, clearProps } from "pvutils";
//**************************************************************************************
/**
 * Class from RFC5652
 */
export default class ContentInfo
{
	//**********************************************************************************
	/**
	 * Constructor for ContentInfo class
	 * @param {Object} [parameters={}]
	 * @property {Object} [schema] asn1js parsed value
	 */
	constructor(parameters = {})
	{
		//region Internal properties of the object
		/**
		 * @type {string}
		 * @description contentType
		 */
		this.contentType = getParametersValue(parameters, "contentType", ContentInfo.defaultValues("contentType"));
		/**
		 * @type {Any}
		 * @description content
		 */
		this.content = getParametersValue(parameters, "content", ContentInfo.defaultValues("content"));
		//endregion

		//region If input argument array contains "schema" for this object
		if("schema" in parameters)
			this.fromSchema(parameters.schema);
		//endregion
	}
	//**********************************************************************************
	/**
	 * Return default values for all class members
	 * @param {string} memberName String name for a class member
	 */
	static defaultValues(memberName)
	{
		switch(memberName)
		{
			case "contentType":
				return "";
			case "content":
				return new asn1js.Any();
			default:
				throw new Error(`Invalid member name for ContentInfo class: ${memberName}`);
		}
	}
	//**********************************************************************************
	/**
	 * Compare values with default values for all class members
	 * @param {string} memberName String name for a class member
	 * @param {*} memberValue Value to compare with default value
	 */
	static compareWithDefault(memberName, memberValue)
	{
		switch(memberName)
		{
			case "contentType":
				return (memberValue === "");
			case "content":
				return (memberValue instanceof asn1js.Any);
			default:
				throw new Error(`Invalid member name for ContentInfo class: ${memberName}`);
		}
	}
	//**********************************************************************************
	/**
	 * Return value of asn1js schema for current class
	 * @param {Object} parameters Input parameters for the schema
	 * @returns {Object} asn1js schema object
	 */
	static schema(parameters = {})
	{
		//ContentInfo ::= SEQUENCE {
		//    contentType ContentType,
		//    content [0] EXPLICIT ANY DEFINED BY contentType }

		/**
		 * @type {Object}
		 * @property {string} [blockName]
		 * @property {string} [contentType]
		 * @property {string} [content]
		 */
		const names = getParametersValue(parameters, "names", {});

		if(("optional" in names) === false)
			names.optional = false;

		return (new asn1js.Sequence({
			name: (names.blockName || "ContentInfo"),
			optional: names.optional,
			value: [
				new asn1js.ObjectIdentifier({ name: (names.contentType || "contentType") }),
				new asn1js.Constructed({
					idBlock: {
						tagClass: 3, // CONTEXT-SPECIFIC
						tagNumber: 0 // [0]
					},
					value: [new asn1js.Any({ name: (names.content || "content") })] // EXPLICIT ANY value
				})
			]
		}));
	}
	//**********************************************************************************
	/**
	 * Convert parsed asn1js object into current class
	 * @param {!Object} schema
	 */
	fromSchema(schema)
	{
		//region Clear input data first
		clearProps(schema, [
			"contentType",
			"content"
		]);
		//endregion
		
		//region Check the schema is valid
		const asn1 = asn1js.compareSchema(schema,
			schema,
			ContentInfo.schema()
		);

		if(asn1.verified === false)
			throw new Error("Object's schema was not verified against input data for ContentInfo");
		//endregion

		//region Get internal properties from parsed schema
		this.contentType = asn1.result.contentType.valueBlock.toString();
		this.content = asn1.result.content;
		//endregion
	}
	//**********************************************************************************
	/**
	 * Convert current object to asn1js object and set correct values
	 * @returns {Object} asn1js object
	 */
	toSchema()
	{
		//region Construct and return new ASN.1 schema for this object
		return (new asn1js.Sequence({
			value: [
				new asn1js.ObjectIdentifier({ value: this.contentType }),
				new asn1js.Constructed({
					idBlock: {
						tagClass: 3, // CONTEXT-SPECIFIC
						tagNumber: 0 // [0]
					},
					value: [this.content] // EXPLICIT ANY value
				})
			]
		}));
		//endregion
	}
	//**********************************************************************************
	/**
	 * Convertion for the class to JSON object
	 * @returns {Object}
	 */
	toJSON()
	{
		const object = {
			contentType: this.contentType
		};

		if(!(this.content instanceof asn1js.Any))
			object.content = this.content.toJSON();

		return object;
	}
	//**********************************************************************************
}
//**************************************************************************************