import { Fragment } from "react";
import { Icon } from "./Icon";
import { useFetch } from "../hooks";
import { fmtCost, fmtPercent, useT } from "../i18n";

interface BudgetRow {
  provider: string;
  budget: number | null;
  spent: number;
  remaining: number | null;
  share: number | null;
  warning: boolean;
  exceeded: boolean;
  images?: boolean;
  plan?: Plan;
  remote?: { currency?: string; remaining?: number | null; limit?: number | null; used?: number | null; spent_month?: number; scope?: string; error?: string };
}

/** opencode Go: usage windows against the plan's limits (USD). */
export interface Plan {
  limit: number;
  windows: { window: "5h" | "week" | "month"; used: number; limit: number; ratio: number }[];
}

/** Three small meters (5 hours, week, month) for a subscription plan. */
export function PlanUsage({ plan }: { plan: Plan }) {
  const t = useT();
  return (
    <div className="plan-usage">
      {plan.windows.map((w) => (
        <div key={w.window} className="plan-window" title={`${fmtCost(w.used, "USD")} / ${fmtCost(w.limit, "USD")}`}>
          <span className="plan-label">{t(`budget.window.${w.window}`)}</span>
          <Bar share={w.ratio} warning={w.ratio >= 0.8} exceeded={w.ratio >= 1} />
          <span className="plan-pct">{fmtPercent(w.ratio)}</span>
        </div>
      ))}
    </div>
  );
}

interface BudgetData {
  currency: string;
  total: BudgetRow;
  providers: BudgetRow[];
}

export function Bar({ share, warning, exceeded }: { share: number; warning: boolean; exceeded: boolean }) {
  const color = exceeded ? "var(--red)" : warning ? "var(--accent2)" : "var(--green)";
  return (
    <div className="budget-bar" role="meter" aria-valuenow={Math.round(share * 100)} aria-valuemin={0} aria-valuemax={100}>
      <div style={{ width: `${Math.min(share, 1) * 100}%`, background: color }} />
    </div>
  );
}

function Remote({ r, t }: { r: BudgetRow["remote"]; t: ReturnType<typeof useT> }) {
  if (!r) return <span className="muted">–</span>;
  if (r.error) return <span className="muted" title={r.error}><Icon name="warning" /> {t("budget.remoteError")}</span>;
  const cur = r.currency ?? "USD";
  if (r.spent_month !== undefined) return <span title={t("budget.orgWide")}>{t("budget.providerSpent", { v: fmtCost(r.spent_month, cur) })}</span>;
  if (r.remaining !== null && r.remaining !== undefined) return <span>{t("budget.balance", { v: fmtCost(r.remaining, cur) })}</span>;
  if (r.used !== null && r.used !== undefined) return <span>{t("budget.providerSpent", { v: fmtCost(r.used, cur) })}</span>;
  return <span className="muted">–</span>;
}

/** Monthly budgets per provider (admins). */
export function BudgetPanel() {
  const t = useT();
  const { data, error } = useFetch<BudgetData>("/budget");
  if (error || !data) return null;
  const rows = [data.total, ...data.providers];
  return (
    <div className="panel">
      <h3>{t("budget.title")}</h3>
      <div style={{ overflowX: "auto" }}>
        <table className="grid">
          <thead>
            <tr>
              <th>{t("stats.provider")}</th>
              <th className="num">{t("budget.spent")}</th>
              <th className="num">{t("budget.budget")}</th>
              <th style={{ minWidth: 140 }} />
              <th className="num">{t("budget.remaining")}</th>
              <th>{t("budget.provider")}</th>
            </tr>
          </thead>
          <tbody>
            {rows.map((r) => (
              <Fragment key={r.provider}>
                <tr>
                  <td>
                    {r.provider === "total" ? <b>{t("stats.total")}</b> : r.provider}
                    {r.images && <span className="chip" style={{ marginLeft: 6 }}>{t("nav.images")}</span>}
                  </td>
                  <td className="num">{fmtCost(r.spent, data.currency)}</td>
                  <td className="num">{r.budget ? fmtCost(r.budget, data.currency) : "–"}</td>
                  <td>{r.share !== null && <Bar share={r.share} warning={r.warning} exceeded={r.exceeded} />}</td>
                  <td className="num" style={{ color: r.exceeded ? "var(--red)" : r.warning ? "var(--accent2)" : undefined }}>
                    {r.remaining !== null ? fmtCost(r.remaining, data.currency) : "–"}
                    {r.share !== null && <span className="muted"> ({fmtPercent(r.share)})</span>}
                  </td>
                  <td>{r.provider === "total" ? null : <Remote r={r.remote} t={t} />}</td>
                </tr>
                {r.plan && (
                  <tr className="plan-row">
                    <td className="muted">{t("budget.plan", { v: fmtCost(r.plan.limit, "USD") })}</td>
                    <td colSpan={5}>
                      <PlanUsage plan={r.plan} />
                    </td>
                  </tr>
                )}
              </Fragment>
            ))}
          </tbody>
        </table>
      </div>
      <div style={{ fontSize: 12, color: "var(--muted)", marginTop: 6 }}>{t("budget.hint")}</div>
    </div>
  );
}

/** Small header chip when the overall budget is nearly used up. */
export function BudgetChip() {
  const t = useT();
  const { data } = useFetch<BudgetData>("/budget");
  const worst = data ? [data.total, ...data.providers].filter((r) => r.warning).sort((a, b) => (b.share ?? 0) - (a.share ?? 0))[0] : undefined;
  if (!worst) return null;
  return (
    <span className="chip warn hide-mobile" title={t("budget.chipHint")}>
      {t("budget.chip", { name: worst.provider === "total" ? t("stats.total") : worst.provider, p: fmtPercent(worst.share ?? 0) })}
    </span>
  );
}