import { useEffect, useState } from "react";
import { useTranslation } from "react-i18next";
import { api } from "../api";
import { useSettings } from "../settings";
import IconChip from "../components/IconChip";
import Money from "../components/Money";
import { formatMoney, formatAmount } from "../format";
import { tokenFarbe } from "./palette";
import Donut from "./charts/Donut";
import Line from "./charts/Line";

function useData(loader) {
  const [data, setData] = useState(null);
  useEffect(() => {
    let ok = true;
    loader().then((d) => ok && setData(d)).catch(() => ok && setData({ __error: true }));
    return () => { ok = false; };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);
  return data;
}

function Loading() {
  const { t } = useTranslation();
  return <div className="dash-loading muted">{t("common.loading")}</div>;
}

function shortDate(iso) {
  const [, m, d] = iso.split("-");
  return `${d}.${m}.`;
}

function AccountBalances() {
  const { t } = useTranslation();
  const { baseCurrency } = useSettings();
  const data = useData(() => api.cardBalances());
  if (!data) return <Loading />;
  if (!data.accounts?.length) return <div className="dash-empty muted">{t("accounts.empty")}</div>;
  return (
    <div className="dash-list">
      {data.accounts.map((a) => (
        <div className="dash-line" key={a.id}>
          <IconChip name={a.icon} color={a.color} size={26} />
          <span className="grow ellipsis">{a.name}</span>
          <Money cents={a.balance_cents} currency={a.currency} baseCents={a.balance_base_cents} baseCurrency={baseCurrency} />
        </div>
      ))}
      <div className="dash-total">
        <span className="grow">{t("cards.total")}</span>
        <strong>{formatMoney(data.total, data.currency)}</strong>
      </div>
    </div>
  );
}

function BudgetDonut({ props }) {
  const { t } = useTranslation();
  const groupBy = props?.group_by || "group";
  const data = useData(() => api.cardBudgetDonut(groupBy));
  if (!data) return <Loading />;
  if (!data.segments?.length) return <div className="dash-empty muted">{t("cards.noBudget")}</div>;
  const label = data.mode === "planned" ? t("cards.planned") : t("cards.spent");
  return <Donut segmente={data.segments} gesamtLabel={label} fmt={(v) => formatMoney(v, data.currency)} />;
}

function NetWorth() {
  const { t } = useTranslation();
  const data = useData(() => api.cardNetWorth(90));
  if (!data) return <Loading />;
  const labels = (data.labels || []).map(shortDate);
  const serien = [{ name: t("cards.assets"), color: tokenFarbe("--accent", "#3f51b5"), werte: data.values || [] }];
  return (
    <Line labels={labels} serien={serien}
          fmt={(v) => formatMoney(v, data.currency)}
          achsenFmt={(v) => formatAmount(v, data.currency)} />
  );
}

function BudgetProgress({ props }) {
  const { t } = useTranslation();
  const groupBy = props?.group_by || "group";
  const data = useData(() => api.cardBudgetProgress(groupBy));
  if (!data) return <Loading />;
  if (!data.rows?.length) return <div className="dash-empty muted">{t("cards.noBudget")}</div>;
  return (
    <div className="dash-list">
      {data.rows.map((r) => {
        const pct = r.planned > 0 ? Math.min(r.actual / r.planned, 1) * 100 : r.actual > 0 ? 100 : 0;
        return (
          <div className="dash-progress" key={r.name}>
            <div className="dash-progress-top">
              <span className="ellipsis" style={{ color: r.color }}>●</span>
              <span className="grow ellipsis">{r.name}</span>
              <span className={`amount small ${r.over ? "neg" : "muted"}`}>{formatMoney(r.actual, data.currency)}</span>
              <span className="muted small"> / {formatMoney(r.planned, data.currency)}</span>
            </div>
            <div className="budget-bar">
              <div className={`budget-bar-fill${r.over ? " over" : ""}`} style={{ width: `${pct}%` }} />
            </div>
          </div>
        );
      })}
    </div>
  );
}

function IncomeExpense() {
  const { t } = useTranslation();
  const data = useData(() => api.cardIncomeExpense());
  if (!data) return <Loading />;
  return (
    <div className="dash-kpis">
      <div className="dash-kpi">
        <span className="muted small">{t("cards.income")}</span>
        <strong className="amount pos">{formatMoney(data.income, data.currency)}</strong>
      </div>
      <div className="dash-kpi">
        <span className="muted small">{t("cards.expense")}</span>
        <strong className="amount neg">{formatMoney(data.expense, data.currency)}</strong>
      </div>
      <div className="dash-kpi">
        <span className="muted small">{t("cards.net")}</span>
        <strong className={`amount ${data.net < 0 ? "neg" : "pos"}`}>{formatMoney(data.net, data.currency)}</strong>
      </div>
    </div>
  );
}

function RecentTransactions() {
  const { t } = useTranslation();
  const { formatDate } = useSettings();
  const data = useData(() => api.cardRecent(8));
  if (!data) return <Loading />;
  if (!data.transactions?.length) return <div className="dash-empty muted">{t("transactions.empty")}</div>;
  return (
    <div className="dash-list">
      {data.transactions.map((tx) => (
        <div className="dash-line" key={tx.id}>
          <IconChip name={tx.icon} color={tx.color} size={26} />
          <div className="grow ellipsis">
            <div className="ellipsis">{tx.title}</div>
            <div className="muted small">{formatDate(tx.date)}</div>
          </div>
          <Money cents={tx.amount_cents} currency={tx.currency} baseCents={tx.amount_base_cents}
                 baseCurrency={data.currency} sign={tx.sign} showConverted={false} />
        </div>
      ))}
    </div>
  );
}

function ExpenseShare({ props }) {
  const { t } = useTranslation();
  const groupBy = props?.group_by || "category";
  const data = useData(() => api.cardExpenseShare(groupBy));
  if (!data) return <Loading />;
  if (!data.rows?.length) return <div className="dash-empty muted">{t("cards.noExpenses")}</div>;
  return (
    <div className="dash-list">
      {data.rows.map((r) => {
        // Anteil aus den Rohwerten – gerundete Prozente ergäben in der Summe
        // sonst nicht 100 %.
        const pct = data.total > 0 ? (r.amount / data.total) * 100 : 0;
        return (
          <div className="dash-progress" key={r.name}>
            <div className="dash-progress-top share-row">
              <span style={{ color: r.color }}>●</span>
              <span className="grow ellipsis share-name">{r.name}</span>
              <strong className="share-pct">{pct.toFixed(1).replace(".", ",")} %</strong>
              <span className="muted small share-amount">{formatMoney(r.amount, data.currency)}</span>
            </div>
            <div className="budget-bar">
              <div className="budget-bar-fill" style={{ width: `${pct}%`, background: r.color }} />
            </div>
          </div>
        );
      })}
      <div className="dash-total">
        <span className="grow">{t("cards.total")}</span>
        <strong>{formatMoney(data.total, data.currency)}</strong>
      </div>
    </div>
  );
}

// Aufschlüsselungs-Option (Gruppen vs. Kategorien) – von Donut und Fortschritt geteilt.
const AUFSCHLUESSELUNG = {
  key: "group_by", labelKey: "cards.breakdown", def: "group",
  choices: [
    { v: "group", labelKey: "cards.byGroup" },
    { v: "category", labelKey: "cards.byCategory" },
  ],
};

// Registry: Kartentyp -> { Titel-Schlüssel, Komponente, Standardgröße/Mindestgröße,
// optional `options` (im Anordnen-Modus einstellbare Karten-Optionen) }.
export const KARTEN = {
  "account-balances": { titleKey: "cards.balances", Comp: AccountBalances, w: 4, h: 5, minW: 3, minH: 3 },
  "budget-donut": { titleKey: "cards.budgetDonut", Comp: BudgetDonut, w: 4, h: 5, minW: 3, minH: 4, options: [AUFSCHLUESSELUNG] },
  "net-worth": { titleKey: "cards.netWorth", Comp: NetWorth, w: 8, h: 4, minW: 4, minH: 3 },
  "budget-progress": { titleKey: "cards.budgetProgress", Comp: BudgetProgress, w: 4, h: 3, minW: 3, minH: 2, options: [AUFSCHLUESSELUNG] },
  "expense-share": { titleKey: "cards.expenseShare", Comp: ExpenseShare, w: 4, h: 5, minW: 3, minH: 3,
                     options: [{ ...AUFSCHLUESSELUNG, def: "category" }] },
  "income-expense": { titleKey: "cards.incomeExpense", Comp: IncomeExpense, w: 4, h: 2, minW: 2, minH: 2 },
  "recent-transactions": { titleKey: "cards.recent", Comp: RecentTransactions, w: 4, h: 4, minW: 3, minH: 3 },
};

export const KARTEN_TYPEN = Object.keys(KARTEN);