import { categorize, roundEur } from "../lib/categorize";
import { resolveAssignedAndEffective, type SalaryShiftSettings } from "../lib/month";
import type { NormalizedTransaction } from "./types";

export type FintsStatementTransaction = {
  valueDate: Date;
  entryDate: Date;
  amount: number;
  transactionType: string;
  bankReference: string;
  bookingText?: string;
  purpose?: string;
  remoteName?: string;
  customerReference?: string;
};

export function formatFinTsDate(date: Date): string {
  const y = date.getFullYear();
  const m = String(date.getMonth() + 1).padStart(2, "0");
  const d = String(date.getDate()).padStart(2, "0");
  return `${y}-${m}-${d}`;
}

export function mapFinTsTransaction(
  tx: FintsStatementTransaction,
  ownNames: string[],
  salaryShift: SalaryShiftSettings,
): Omit<NormalizedTransaction, "externalRef"> & {
  categoryName: string;
  assignedMonth?: string;
  effectiveMonth?: string;
  externalRef?: string;
} {
  const amount = roundEur(tx.amount);
  const rawText = [tx.purpose, tx.bookingText, tx.transactionType].filter(Boolean).join(" ");
  const counterparty = tx.remoteName || undefined;
  const description = counterparty ?? (rawText.slice(0, 80) || "Umsatz");
  const vorgang = tx.transactionType || tx.bookingText;
  const bookingDate = formatFinTsDate(tx.entryDate);
  const valueDate = formatFinTsDate(tx.valueDate);
  const categoryName = categorize(rawText, amount, vorgang ?? "", ownNames);
  const { assignedMonth, effectiveMonth } = resolveAssignedAndEffective(
    bookingDate,
    amount,
    categoryName,
    salaryShift,
  );

  return {
    bookingDate,
    valueDate,
    description,
    counterparty,
    amount,
    vorgang,
    isPending: false,
    rawText: rawText || undefined,
    externalRef: tx.bankReference || tx.customerReference || undefined,
    categoryName,
    assignedMonth,
    effectiveMonth,
  };
}