import type { ExcelValue, FunctionResult } from "./types";
import FormulaError from '../error';
import {FormulaHelpers as H, Types} from '../helpers';
import DateFunctions from './date';

const FinancialFunctions = {
    /**
     * https://support.microsoft.com/en-us/office/accrint-function-fe45d089-6722-4fb3-9379-e1f911d8dc74
     */
    ACCRINT: (issue, firstInterest, settlement, rate, par, frequency, basis, calcMethod) => {
        issue = H.accept(issue);
        firstInterest = H.accept(firstInterest);
        settlement = H.accept(settlement);

        // Parse date string to serial
        if (typeof issue === "string") {
            issue = DateFunctions.DATEVALUE(issue);
        }
        if (typeof firstInterest === "string") {
            firstInterest = DateFunctions.DATEVALUE(firstInterest);
        }
        if (typeof settlement === "string") {
            settlement = DateFunctions.DATEVALUE(settlement);
        }

        rate = H.accept(rate, Types.NUMBER);
        par = H.accept(par, Types.NUMBER);
        frequency = H.accept(frequency, Types.NUMBER);
        basis = H.accept(basis, Types.NUMBER, 0);
        calcMethod = H.accept(calcMethod, Types.BOOLEAN, true);

        // Issue, first_interest, settlement, frequency, and basis are truncated to integers
        issue = Math.trunc(issue);
        firstInterest = Math.trunc(firstInterest);
        settlement = Math.trunc(settlement);
        frequency = Math.trunc(frequency);
        basis = Math.trunc(basis);

        // If rate ≤ 0 or if par ≤ 0, ACCRINT returns the #NUM! error value.
        if (rate <= 0 || par <= 0 )
            return FormulaError.NUM;

        // If frequency is any number other than 1, 2, or 4, ACCRINT returns the #NUM! error value.
        if (frequency !== 1 && frequency !== 2 && frequency !== 4)
            return FormulaError.NUM;

        // If basis < 0 or if basis > 4, ACCRINT returns the #NUM! error value.
        if (basis < 0 || basis > 4)
            return FormulaError.NUM;

        // If issue ≥ settlement, ACCRINT returns the #NUM! error value.
        if (issue >= settlement)
            return FormulaError.NUM;

        // Calculate accrued interest
        // If calc_method is TRUE or omitted, the accrued interest from issue date to settlement date
        // If calc_method is FALSE, the accrued interest from first_interest date to settlement date
        let startDate = calcMethod ? issue : firstInterest;
        
        // Calculate the fraction of year
        let yearFraction: any = DateFunctions.YEARFRAC(startDate, settlement, basis);
        if (yearFraction instanceof FormulaError) {
            return yearFraction;
        }
        
        // ACCRINT = par × rate × year_fraction
        return par * rate * yearFraction;
    }
};

export default FinancialFunctions;