/**
 * Created by Samuel Gratzl on 29.09.2016.
 */



import {BaseUtils} from 'phovea_core';
import * as papaparse from 'papaparse';

export interface IParseResult {
  data: any;
  meta: any;
}

export interface ICSVParsingOptions {
  header?: boolean;
  delimiter?: string;
  newline?: string;
}

const defaultOptions = {
  skipEmptyLines: true
};

export class ParserUtils {

  /**
   * parses the given csv file/blob using PapaParse
   * @param data
   * @param options additional options
   * @return {Promise<R>|Promise}
   */
  static parseCSV(data: any, options: ICSVParsingOptions = {}): Promise<IParseResult> {

    return new Promise((resolve, reject) => {
      papaparse.parse(data, BaseUtils.mixin({
        complete: (result) => resolve({data: result.data, meta: result.meta}),
        error: (error) => reject(error)
      }, defaultOptions, options));
    });
  }

  static streamCSV(data: any, chunk: (chunk: IParseResult)=>any, options: ICSVParsingOptions = {}): Promise<IParseResult> {

    return new Promise((resolve, reject) => {
      papaparse.parse(data, BaseUtils.mixin({
        complete: (result) => resolve(null),
        chunk: (result) => chunk({data: result.data, meta: result.meta}),
        error: (error) => reject(error)
      }, defaultOptions, options));
    });
  }
}