import { ParserResult } from "./parserResult";
import { Scanner } from "./scanner";

// Deprecated but useful function for easy UTF-8 handling
/**
 * @hidden
 */
declare function escape(s: string): string;

/**
 * A data string parser.
 *
 * Parsers are capable of parsing one particular data format, which is passed to them during construction.
 *
 * The parser is created through [[BarcodePicker.createParserForFormat]] or [[Scanner.createParserForFormat]].
 * Note that you need to have a valid license with the parsing feature enabled to use the parser functionalities.
 *
 * For documentation on the available formats, check the official parser library documentation here:
 * https://docs.scandit.com/parser/formats.html.
 */
export class Parser {
  private options?: object;

  /**
   * @hidden
   *
   * @param scanner The [[Scanner]] object used to interact with the external Scandit library.
   * @param dataFormat The data format for this parser.
   */
  constructor(private readonly scanner: Scanner, private readonly dataFormat: Parser.DataFormat) {}

  /**
   * Apply the option map to the parser, allowing the user to fine-tune the behaviour of the parser.
   * Available options depend on the data format and are specified in the respective documentation.
   *
   * @param options The new options to be applied (replacing previous ones, if any).
   */
  public setOptions(options?: object): void {
    this.options = options;
  }

  /**
   * Process the given raw data with the parser, retrieving the result as a [[ParserResult]] object.
   *
   * Multiple requests done without waiting for previous results will be queued and handled in order.
   *
   * If parsing of the data fails the returned promise is rejected with a `ScanditEngineError` error.
   *
   * @param dataRaw The raw data to be parsed.
   * @returns A promise resolving to the [[ParserResult]] object.
   */
  public parseRawData(dataRaw: Uint8Array): Promise<ParserResult> {
    let dataString: string = "";
    try {
      dataRaw.forEach((byte: number) => {
        dataString += String.fromCharCode(byte);
      });
      dataString = decodeURIComponent(escape(dataString));
    } catch {
      dataString = "";
    }

    return this.scanner.parseString(this.dataFormat, dataString, this.options);
  }

  /**
   * Process the given string data with the parser, retrieving the result as a [[ParserResult]] object.
   *
   * Multiple requests done without waiting for previous results will be queued and handled in order.
   *
   * If parsing of the data fails the returned promise is rejected with a `ScanditEngineError` error.
   *
   * @param dataString The string to be parsed.
   * @returns A promise resolving to the [[ParserResult]] object.
   */
  public parseString(dataString: string): Promise<ParserResult> {
    return this.scanner.parseString(this.dataFormat, dataString, this.options);
  }
}

// istanbul ignore next
export namespace Parser {
  /**
   * Data format of a string to be parsed into a set of key-value mappings by the Scandit Parser Library.
   *
   * See https://docs.scandit.com/parser/formats.html for more details.
   */
  export enum DataFormat {
    /**
     * GS1 Application Identifier (AI).
     *
     * See: http://www.gs1.org/docs/barcodes/GS1_General_Specifications.pdf.
     */
    GS1_AI = 1,
    /**
     * Health Industry Bar Code (HIBC).
     *
     * See: http://www.hibcc.org.
     */
    HIBC = 2,
    /**
     * AAMVA Driver License/Identification (DL/ID).
     *
     * See: http://www.aamva.org.
     */
    DLID = 3,
    /**
     * ICAO Machine Readable Travel Document (MRTD).
     *
     * See: https://www.icao.int.
     */
    MRTD = 4,
    /**
     * Swiss QR ISO 20022.
     *
     * See: https://www.paymentstandards.ch.
     */
    SWISSQR = 5
  }
}