import { Injectable } from '@angular/core';

import { ToCsvType } from './to-csv-type';

@Injectable({
  providedIn: 'root',
})
export class ToCsvService {
  // eslint-disable-next-line class-methods-use-this
  toCsv(headers: { [display: string]: string }, data: unknown[]): string {
    const header = Object.keys(headers);
    const replacer = (key: string, value: string | number | null) => (value === null ? '' : value);
    const csv = data.map((row) =>
      header
        .map((fieldName) => JSON.stringify((row as ToCsvType)[headers[fieldName]], replacer))
        .join(','),
    );
    csv.unshift(header.join(','));
    return csv.join('\r\n');
  }
}