import { useTranslation } from "react-i18next";
import type { MonthlyTrendItem } from "../../shared/types";

const cadFormatter = (value: number) =>
  new Intl.NumberFormat("en-CA", { style: "currency", currency: "CAD", maximumFractionDigits: 0 }).format(value);

function formatMonth(month: string): string {
  const [year, m] = month.split("-");
  const date = new Date(Number(year), Number(m) - 1);
  return date.toLocaleDateString("default", { month: "short", year: "2-digit" });
}

interface MonthlyTrendsTableProps {
  data: MonthlyTrendItem[];
}

export default function MonthlyTrendsTable({ data }: MonthlyTrendsTableProps) {
  const { t } = useTranslation();

  if (data.length === 0) {
    return (
      <div className="bg-[var(--card)] border border-[var(--border)] rounded-xl p-8 text-center text-[var(--muted-foreground)]">
        {t("dashboard.noData")}
      </div>
    );
  }

  const totals = data.reduce(
    (acc, row) => ({ income: acc.income + row.income, expenses: acc.expenses + row.expenses }),
    { income: 0, expenses: 0 },
  );

  return (
    <div className="bg-[var(--card)] border border-[var(--border)] rounded-xl overflow-hidden">
      <div className="overflow-x-auto overflow-y-auto" style={{ maxHeight: "calc(100vh - 220px)" }}>
        <table className="w-full text-sm">
          <thead className="sticky top-0 z-20">
            <tr className="border-b border-[var(--border)] bg-[var(--card)]">
              <th className="text-left px-3 py-2 font-medium text-[var(--muted-foreground)] bg-[var(--card)]">
                {t("reports.pivot.month")}
              </th>
              <th className="text-right px-3 py-2 font-medium text-[var(--muted-foreground)] bg-[var(--card)]">
                {t("dashboard.income")}
              </th>
              <th className="text-right px-3 py-2 font-medium text-[var(--muted-foreground)] bg-[var(--card)]">
                {t("dashboard.expenses")}
              </th>
              <th className="text-right px-3 py-2 font-medium text-[var(--muted-foreground)] bg-[var(--card)]">
                {t("dashboard.net")}
              </th>
            </tr>
          </thead>
          <tbody>
            {data.map((row) => (
              <tr key={row.month} className="border-b border-[var(--border)]/50">
                <td className="px-3 py-1.5">{formatMonth(row.month)}</td>
                <td className="text-right px-3 py-1.5 text-[var(--positive)]">{cadFormatter(row.income)}</td>
                <td className="text-right px-3 py-1.5 text-[var(--negative)]">{cadFormatter(row.expenses)}</td>
                <td className={`text-right px-3 py-1.5 ${row.income - row.expenses >= 0 ? "text-[var(--positive)]" : "text-[var(--negative)]"}`}>
                  {cadFormatter(row.income - row.expenses)}
                </td>
              </tr>
            ))}
            <tr className="border-t-2 border-[var(--border)] font-bold text-sm bg-[var(--muted)]/20">
              <td className="px-3 py-3">{t("common.total")}</td>
              <td className="text-right px-3 py-3 text-[var(--positive)]">{cadFormatter(totals.income)}</td>
              <td className="text-right px-3 py-3 text-[var(--negative)]">{cadFormatter(totals.expenses)}</td>
              <td className={`text-right px-3 py-3 ${totals.income - totals.expenses >= 0 ? "text-[var(--positive)]" : "text-[var(--negative)]"}`}>
                {cadFormatter(totals.income - totals.expenses)}
              </td>
            </tr>
          </tbody>
        </table>
      </div>
    </div>
  );
}
