import {
    selectFx,
    fxSelectionKey,
    type FxSelection,
} from './iva-fx-selection.ts';
import { currencyEventBook, newCurrencyEvent } from './iva-currency-events.ts';
import { convertCents } from './business-financial-plan.ts';
import {
    decimalFraction,
    fraction,
    type FiscalFraction,
} from './fiscal-rational.ts';
import { closureFingerprint } from './iva-closure.ts';

export type IrpcFxLink = { id: string; fingerprint: string };
export type IrpcFxAmount = {
    currency: string;
    fxSelection?: FxSelection;
    fxLink?: IrpcFxLink;
};
export type IrpcFxEvidence = {
    originalAmount: string;
    originalCurrency: string;
    convertedCurrency: 'MZN';
    column: string;
    rate: string;
    date: string;
    direction: string;
    source: string;
    selectionKey: string;
    rounding: string;
};
export function irpcFxSources(d: Record<string, unknown>) {
    return currencyEventBook(d)
        .rows.filter((r) => r.fxSelection)
        .map((r) => ({
            id: r.id,
            label: `${r.description || r.id} — ${r.sourceCurrency} — ${r.fxSelection?.applied?.rate ?? 'por aplicar'}`,
            fingerprint: closureFingerprint(r),
            selection: structuredClone(r.fxSelection!),
        }));
}
export function irpcFxDependency(
    d: Record<string, unknown>,
    input: IrpcFxAmount,
): string {
    if (input.currency === 'MZN' || !input.fxLink) return '';
    const source = irpcFxSources(d).find((s) => s.id === input.fxLink!.id);
    return !source
        ? 'Selecção cambial de origem indisponível;vínculo e histórico conservados.'
        : source.fingerprint !== input.fxLink.fingerprint
          ? 'Selecção cambial de origem alterada;compare a nova selecção antes de a aplicar às retenções.'
          : '';
}
export function irpcFxRow(id: string, input: IrpcFxAmount) {
    const s = input.fxSelection,
        a = s?.applied;
    return {
        ...newCurrencyEvent(id, 'MZN'),
        sourceCurrency: input.currency,
        fxSelection: s,
        fxDirection: s?.direction ?? '',
        fxRate: a?.rate ?? '',
        fxDate: a?.date ?? '',
        fxSource: a?.source ?? '',
    };
}
export function convertIrpcAmount(
    d: Record<string, unknown>,
    amount: string,
    input: IrpcFxAmount,
): { value: FiscalFraction; evidence: IrpcFxEvidence | null } {
    const original = decimalFraction(amount);
    if (input.currency === 'MZN') return { value: original, evidence: null };
    const issue = irpcFxDependency(d, input);
    if (issue) throw Error(issue);
    const s = input.fxSelection;
    if (!s)
        throw Error(
            'Reutilize ou aplique a selecção cambial já entregue:moeda original,boletim,coluna,data e sentido;sem taxa actual por defeito.',
        );
    const selected = selectFx(s),
        a = s.applied;
    if (
        !a ||
        a.selectionKey !== fxSelectionKey(s) ||
        a.rate !== selected.rate ||
        a.date !== selected.date ||
        a.source !== selected.source ||
        a.column !== selected.column ||
        s.sourceCurrency !== input.currency
    )
        throw Error(
            'Selecção cambial alterada,não confirmada ou de outra moeda;use a conferência e confirmação existentes,sem recalcular históricos.',
        );
    const [whole, places = ''] = selected.rate.split('.'),
        rate = BigInt(whole + places.padEnd(8, '0')),
        scale = 100000000n;
    const micro =
        (BigInt(original.numerator) * 1000000n) / BigInt(original.denominator);
    const converted =
        s.direction === 'mzn_per_unit'
            ? convertCents(micro, rate, scale)
            : convertCents(micro, scale, rate);
    return {
        value: fraction(converted, 1000000n),
        evidence: {
            originalAmount: amount,
            originalCurrency: input.currency,
            convertedCurrency: 'MZN',
            column: selected.column,
            rate: selected.rate,
            date: selected.date,
            direction: s.direction,
            source: selected.source,
            selectionKey: a.selectionKey,
            rounding:
                'Mesmo convertCents entregue;conversão à unidade de0,000001MZN;apresentação separada,não regra nova de arredondamento do imposto.',
        },
    };
}

export function irpcFxEvidenceLabel(e: IrpcFxEvidence): string {
    const column =
        (
            {
                buy: 'Compra',
                sell: 'Venda',
                mean: 'Média de referência BM',
                exception: 'Excepção fiscal identificada',
            } as Record<string, string>
        )[e.column] ?? e.column;
    const direction =
        e.direction === 'mzn_per_unit'
            ? 'MZN por ' + e.originalCurrency
            : e.originalCurrency + ' por MZN';
    return `Original: ${e.originalAmount} ${e.originalCurrency}; coluna: ${column}; taxa: ${e.rate}; cotação: ${direction}; data cambial: ${e.date}; fonte: ${e.source.split(';perspectiva:')[0]}. Montante e selecção originais conservados.`;
}

export function updateIrpcFx(
    input: IrpcFxAmount,
    selection: FxSelection,
): Partial<IrpcFxAmount> {
    return {
        fxSelection: selection,
        fxLink:
            input.fxSelection &&
            fxSelectionKey(input.fxSelection) === fxSelectionKey(selection)
                ? input.fxLink
                : undefined,
    };
}