import type { DocumentField, FillDataResponse, FillFieldValue } from './types';

export interface DraftField extends DocumentField {
  documentValue: FillFieldValue;
  draftValue: FillFieldValue;
}

function isEmpty(value: FillFieldValue): boolean {
  return typeof value === 'string' && value.trim() === '';
}

export function buildDraftFields(documentFields: DocumentField[], data: FillDataResponse): DraftField[] {
  return documentFields.map((field) => {
    const source = data.fields[field.tag];
    let draftValue = field.currentValue;
    if (source?.type === field.type) {
      if (field.type === 'checkbox') draftValue = Boolean(source.value);
      else if (isEmpty(field.currentValue) && typeof source.value === 'string' && source.value !== '') draftValue = source.value;
    }
    return { ...field, documentValue: field.currentValue, draftValue };
  });
}