import { Banknote, FileSignature, FileText, Package } from "lucide-react";

import { KpiStrip, type KpiItem } from "@/components/page";
import type { IOverviewKpis, IOverviewPeriodTotals } from "@/types/overview";
import { CountUp } from "./CountUp";

function formatCurrency(amount: number, currency: "ETB" | "USD") {
  return new Intl.NumberFormat("en-US", {
    style: "currency",
    currency,
    maximumFractionDigits: 0,
  }).format(amount);
}

/** Compact form ("ETB 58.6M") — the hero cell is too narrow for nine digits. */
function formatCompactCurrency(amount: number, currency: "ETB" | "USD") {
  return new Intl.NumberFormat("en-US", {
    style: "currency",
    currency,
    notation: "compact",
    maximumFractionDigits: 1,
  }).format(amount);
}

/** Period-over-period % change, or undefined when there's no prior baseline to compare against. */
function pctDelta(current: number, previous: number): number | undefined {
  if (previous === 0) return undefined;
  return Math.round(((current - previous) / previous) * 100);
}

interface OverviewHeroKpisProps {
  kpis: IOverviewKpis;
  current: IOverviewPeriodTotals;
  previous: IOverviewPeriodTotals;
  rangeLabel: string;
}

/**
 * The four numbers an executive reads first: money and volume for the
 * selected range, plus what's currently in flight. Revenue and cargo carry a
 * real vs-prior-period delta; the two workflow snapshots don't, because
 * "active bookings/contracts" is a point-in-time gauge, not a period total —
 * showing a delta for it would mean inventing a comparison that isn't real.
 */
export function OverviewHeroKpis({ kpis, current, previous, rangeLabel }: OverviewHeroKpisProps) {
  const items: KpiItem[] = [
    // An API deployed before the overview revamp omits the period totals —
    // drop the two tiles that need them rather than crash (or hide the strip).
    ...(current
      ? [
          {
            label: `Revenue (${rangeLabel})`,
            value: <CountUp value={current.revenueEtb} format={(n) => formatCompactCurrency(n, "ETB")} />,
            hint: formatCurrency(current.revenueUsd, "USD"),
            icon: Banknote,
            color: "yellow",
            delta: pctDelta(current.revenueEtb, previous?.revenueEtb ?? 0),
          },
          {
            label: "Cargo moved",
            value: <CountUp value={current.tons} format={(n) => `${Math.round(n).toLocaleString()} t`} />,
            icon: Package,
            color: "edr-green",
            delta: pctDelta(current.tons, previous?.tons ?? 0),
          },
        ]
      : []),
    {
      label: "Active bookings",
      value: <CountUp value={kpis.bookings.totalActive} />,
      icon: FileText,
      color: "edr-green",
    },
    {
      label: "Active contracts",
      value: <CountUp value={kpis.contracts.totalActive} />,
      icon: FileSignature,
      color: "edr-green",
    },
  ];

  return <KpiStrip items={items} />;
}