import { eq } from 'drizzle-orm';

import { db } from '@/lib/db';
import { ports } from '@/lib/db/schema/ports';
import { convert } from '@/lib/services/currency';

/**
 * Port's default currency for money normalisation. Falls back to USD
 * when the column is null (legacy ports). Shared across the report
 * services so every money figure lands in one reporting currency.
 */
export async function resolvePortCurrency(portId: string): Promise<string> {
  const [row] = await db
    .select({ defaultCurrency: ports.defaultCurrency })
    .from(ports)
    .where(eq(ports.id, portId));
  return row?.defaultCurrency ?? 'USD';
}

/**
 * Convert `amount` from `from` → `to`. Returns the amount unchanged when
 * the currencies match or a rate is unavailable (so a missing FX rate
 * degrades to "report in source units" rather than dropping the figure).
 */
export async function normalizeAmount(amount: number, from: string, to: string): Promise<number> {
  if (!amount) return amount;
  const f = from.toUpperCase();
  const t = to.toUpperCase();
  if (f === t) return amount;
  const converted = await convert(amount, f, t);
  return converted?.result ?? amount;
}