import { BadRequestException } from "@nestjs/common";
import { DayExpenseResponse } from "../types and interfaces/expenses.types.interfaces";

//uppercase and trim for validation
export function normalizeType(type: string): string {
    return (type ?? '').trim().toUpperCase();
};

//required comment after trim
export function assertAndTrimComment(comment: string): string {
    const cmt = (comment ?? '').trim();
    if(cmt.length === 0) {
        throw new BadRequestException('A comment is required');
    }
    return cmt;
};

//rounding $ to 2 decimals
export function roundMoney2(num: number): number {
    return Math.round((num + Number.EPSILON) * 100)/ 100;
};

export function computeMileageAmount(km: number, modifier: number): number {
    if(km < 0)       throw new BadRequestException('mileage must be positive');
    if(modifier < 0) throw new BadRequestException('modifier must be positive');
    return roundMoney2(km * modifier);
};

//compat. types with Prisma.Decimal. work around Prisma import in utils.
export type DecimalLike = 
    | number
    | string
    | { toNumber?: () => number }
    | { toString?: () => string };


//safe conversion to number
export function toNumberSafe(value: DecimalLike): number {
    if(typeof value === 'number') return value;
    if(value && typeof (value as any).toNumber === 'function') return (value as any).toNumber();
    return Number(
        typeof (value as any)?.toString === 'function'
        ? (value as any).toString()
        : value,
    );
}


//map of a row for DayExpenseResponse
export function mapDbExpenseToDayResponse(row: {
    date: Date;
    amount: DecimalLike;
    comment: string;
    is_approved: boolean;
    bank_code?: { type?: string |  null } | null;
}): DayExpenseResponse {
    const yyyyMmDd = row.date.toISOString().slice(0,10);
    return {
        date: yyyyMmDd,
        type: normalizeType(row.bank_code?.type ?? 'UNKNOWN'),
        amount: toNumberSafe(row.amount),
        comment: row.comment,
        is_approved: row.is_approved,
    };
}