import { TIME_UNITS_PATTERN, parseDuration, REGEX_PARTS } from "../constants";
import { ParsingContext } from "../../../chrono";
import { ParsingComponents } from "../../../results";
import { AbstractParserWithLeftRightBoundaryChecking } from "./AbstractParserWithWordBoundaryChecking";
import { reverseDuration } from "../../../calculation/duration";

export default class RUTimeUnitCasualRelativeFormatParser extends AbstractParserWithLeftRightBoundaryChecking {
    innerPatternString(context: ParsingContext): string {
        return `(эти|последние|прошлые|следующие|после|спустя|через|\\+|-)\\s*(${TIME_UNITS_PATTERN})`;
    }

    innerExtract(context: ParsingContext, match: RegExpMatchArray): ParsingComponents {
        const prefix = match[1].toLowerCase();
        let timeUnits = parseDuration(match[2]);
        switch (prefix) {
            case "последние":
            case "прошлые":
            case "-":
                timeUnits = reverseDuration(timeUnits);
                break;
        }

        return ParsingComponents.createRelativeFromReference(context.reference, timeUnits);
    }
}