import DataUnit from "../dataunit/DataUnit.js";
import { FieldDescriptor, Sort, SortMode } from "../dataunit/metadata/UnitMetadata.js";
import { FieldComparator } from "../dataunit/sorting/FieldComparator.js";
import { Record } from '../dataunit/interfaces/dataUnit.js';

/**
 * `SortingUtils`: Utilizado para auxiliar na ordenacao de registros.
 */
export default class SortingUtils {    

    public static getSortingFunction(dataUnit: DataUnit, sorting?: Array<Sort>): ((recordA: Record, recordB: Record) => number) | undefined {

        if (sorting == undefined || sorting.length == 0) {
            return undefined;
        }

        return (recordA, recordB) => {
            for (const sort of sorting) {
                if (sort.field){
                    let field = dataUnit.getField(sort.field) as FieldDescriptor;
                    let onlyLabel = false;
                    if(!field){
                        const sourceFieldName = dataUnit.getSourceFieldValue(sort.field) ?? "";

                        field = dataUnit.getField(sourceFieldName) as FieldDescriptor;
                        onlyLabel = true;
                    }

                    const result = FieldComparator.compare(field, recordA, recordB, sort.mode === SortMode.ASC, onlyLabel);
                    if (result != 0) {
                        return result;
                    }
                }
            }
            return 0;
        };
    }
    
}