import { useEffect, useMemo, useRef, useState } from "react";
import { useTranslation } from "react-i18next";
import { api } from "../api";
import { useSettings } from "../settings";
import { useConfirm } from "../confirm";
import { useToast } from "../toast";
import Icon from "../components/Icon";
import AccountSelect from "../components/AccountSelect";
import CategorySelect from "../components/CategorySelect";
import DataTable from "../components/DataTable";
import { gruppenFuer } from "../kategorien";
import { formatMoney } from "../format";

// Eine Uhrzeit im Wert ist unkritisch – parse_date im Backend schneidet sie ab.
// Die Varianten mit Uhrzeit stehen trotzdem hier, damit die Bank-Vorlagen im
// Dropdown ihren echten Eintrag zeigen statt eines leeren Feldes.
const DATE_FORMATS = [
  { v: "%d.%m.%Y", l: "TT.MM.JJJJ" },
  { v: "%Y-%m-%d", l: "JJJJ-MM-TT" },
  { v: "%d/%m/%Y", l: "TT/MM/JJJJ" },
  { v: "%m/%d/%Y", l: "MM/TT/JJJJ" },
  { v: "%d.%m.%y", l: "TT.MM.JJ" },
  { v: "%Y-%m-%d %H:%M:%S", l: "JJJJ-MM-TT SS:MM:SS" },
  { v: "%Y-%m-%d %H:%M:%S.%f", l: "JJJJ-MM-TT SS:MM:SS.s" },
  { v: "%d.%m.%Y %H:%M:%S", l: "TT.MM.JJJJ SS:MM:SS" },
];

function defaultConfig() {
  return {
    delimiter: ";",
    decimal_sep: ",",
    date_format: "%d.%m.%Y",
    encoding: "utf-8",
    has_header: true,
    skip_rows: 0,
    amount_mode: "signed",
    column_map: {},
    filter_column: null,
    filter_value: "",
  };
}

export default function Import() {
  const { t } = useTranslation();
  const { formatDate } = useSettings();
  const confirm = useConfirm();
  const toast = useToast();
  const fileRef = useRef(null);

  const [accounts, setAccounts] = useState([]);
  const [groups, setGroups] = useState([]);
  const [templates, setTemplates] = useState([]);
  const [presets, setPresets] = useState([]);
  const [batches, setBatches] = useState([]);

  const [mode, setMode] = useState("csv"); // "csv" | "doc"
  const [accountId, setAccountId] = useState("");
  const [file, setFile] = useState(null);
  const [config, setConfig] = useState(defaultConfig());
  const [raw, setRaw] = useState(null);
  // Dateien, die per Kurzbefehl vom Telefon hereinkamen.
  const [uploads, setUploads] = useState([]);
  const [quelle, setQuelle] = useState(""); // "preset:i" | "tpl:id" | ""
  const [rows, setRows] = useState(null);
  const [recon, setRecon] = useState(null);
  const [docText, setDocText] = useState("");
  const [docPages, setDocPages] = useState([]);
  const [busy, setBusy] = useState(false);
  const [saveName, setSaveName] = useState("");

  const accountById = useMemo(() => Object.fromEntries(accounts.map((a) => [a.id, a])), [accounts]);

  async function loadStamm() {
    api.listUploads().then(setUploads).catch(() => {});
    try {
      const [a, g, tp, pr, b] = await Promise.all([
        api.listAccounts(), api.listCategories(), api.importTemplates(), api.importPresets(), api.importBatches(),
      ]);
      setAccounts(a); setGroups(g); setTemplates(tp); setPresets(pr); setBatches(b);
      if (a[0] && !accountId) setAccountId(String(a[0].id));
    } catch (e) { toast(e.message, "error"); }
  }
  useEffect(() => { loadStamm(); }, []);

  // CSV: Spaltenvorschau automatisch erzeugen, sobald Datei/Format bereitstehen –
  // kein separater „Datei einlesen"-Klick mehr nötig.
  useEffect(() => {
    if (mode === "csv" && file) loadRaw();
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [file, mode, config.delimiter, config.encoding, config.has_header, config.skip_rows]);

  function setCfg(patch) { setConfig((c) => ({ ...c, ...patch })); }
  function setCol(field, value) {
    setConfig((c) => ({ ...c, column_map: { ...c.column_map, [field]: value === "" ? null : Number(value) } }));
  }

  function applyConfig(src) {
    setConfig({
      delimiter: src.delimiter, decimal_sep: src.decimal_sep, date_format: src.date_format,
      encoding: src.encoding, has_header: src.has_header, skip_rows: src.skip_rows,
      amount_mode: src.amount_mode, column_map: src.column_map || {},
      filter_column: src.filter_column ?? null, filter_value: src.filter_value || "",
    });
  }
  // Ein zusammengeführtes Vorlagen-Dropdown: Werte typ-getaggt "preset:i" / "tpl:id".
  function applySource(value) {
    setQuelle(value || "");
    if (!value) return;
    const [kind, id] = value.split(":");
    if (kind === "preset") {
      const p = presets[Number(id)];
      if (p) { applyConfig(p); setSaveName(p.name); }
    } else if (kind === "tpl") {
      const tpl = templates.find((x) => String(x.id) === String(id));
      if (tpl) { applyConfig(tpl); setSaveName(tpl.name); } // Name vorbelegen -> Speichern überschreibt
    }
  }

  // Beim Kontowechsel die Einstellung vorschlagen, mit der zuletzt in DIESES
  // Konto importiert wurde. Ohne das waehlt man jedes Mal neu – und liest im
  // schlimmsten Fall den Revolut-Auszug mit der Raiffeisen-Vorlage ein.
  useEffect(() => {
    if (!accountId || !batches.length) return;
    const letzter = batches.find(
      (b) => String(b.account_id) === String(accountId) && (b.template_id || b.preset));
    if (!letzter) return;
    if (letzter.template_id && templates.some((x) => x.id === letzter.template_id)) {
      applySource(`tpl:${letzter.template_id}`);
      return;
    }
    const i = presets.findIndex((p) => p.name === letzter.preset);
    if (i >= 0) applySource(`preset:${i}`);
  }, [accountId, batches, templates, presets]);

  function baseForm() {
    const fd = new FormData();
    fd.append("file", file);
    fd.append("delimiter", config.delimiter);
    fd.append("encoding", config.encoding);
    fd.append("has_header", config.has_header ? "true" : "false");
    fd.append("skip_rows", String(config.skip_rows || 0));
    return fd;
  }

  async function loadRaw() {
    if (!file) { toast(t("import.needFile"), "error"); return; }
    setBusy(true);
    try {
      setRaw(await api.importRaw(baseForm()));
      setRows(null); setRecon(null);
    } catch (e) { toast(e.message, "error"); } finally { setBusy(false); }
  }

  async function loadPreview() {
    if (!file || !accountId) { toast(t("import.needFileAccount"), "error"); return; }
    setBusy(true);
    try {
      const fd = baseForm();
      fd.append("account_id", accountId);
      fd.append("decimal_sep", config.decimal_sep);
      fd.append("date_format", config.date_format);
      fd.append("amount_mode", config.amount_mode);
      fd.append("column_map", JSON.stringify(config.column_map));
      if (config.filter_column != null && config.filter_value) {
        fd.append("filter_column", String(config.filter_column));
        fd.append("filter_value", config.filter_value);
      }
      const res = await api.importPreview(fd);
      setRows(res.rows.map((r) => ({ ...r })));
      setRecon(res.reconciliation || null);
    } catch (e) { toast(e.message, "error"); } finally { setBusy(false); }
  }

  async function loadDoc() {
    if (!file || !accountId) { toast(t("import.needFileAccount"), "error"); return; }
    setBusy(true);
    try {
      const fd = new FormData();
      fd.append("file", file);
      fd.append("account_id", accountId);
      const res = await api.documentPreview(fd);
      setRows(res.rows.map((r) => ({ ...r })));
      setRecon(null);
      setDocText(res.text || "");
      setDocPages(res.pages || []);
    } catch (e) { toast(e.message, "error"); } finally { setBusy(false); }
  }

  async function commit() {
    setBusy(true);
    try {
      const [art, id] = quelle.split(":");
      const batch = await api.importCommit({
        account_id: Number(accountId),
        template_id: art === "tpl" ? Number(id) : null,
        preset: art === "preset" ? presets[Number(id)]?.name || null : null,
        filename: file?.name || "",
        rows,
      });
      toast(t("import.imported", { n: batch.imported_count }));
      setRows(null); setRecon(null); setRaw(null); setFile(null); setDocText(""); setDocPages([]);
      if (fileRef.current) fileRef.current.value = "";
      loadStamm();
    } catch (e) { toast(e.message, "error"); } finally { setBusy(false); }
  }

  async function saveTemplate() {
    const name = saveName.trim();
    if (!name) { toast(t("import.templateName"), "error"); return; }
    const existing = templates.find((tp) => tp.name.toLowerCase() === name.toLowerCase());
    if (existing && !(await confirm({
      title: t("import.saveTemplate"),
      message: t("import.overwriteConfirm", { name: existing.name }),
      confirmLabel: t("common.save"),
    }))) return;
    try {
      if (existing) await api.updateImportTemplate(existing.id, { name, ...config });
      else await api.createImportTemplate({ name, ...config });
      setTemplates(await api.importTemplates());
      toast(t("settings.saved"));
    } catch (e) { toast(e.message, "error"); }
  }

  async function entfernen(b) {
    if (!(await confirm({
      title: t("import.removeEntry"),
      message: t("import.removeEntryConfirm", { file: b.filename || "—" }),
      danger: true, confirmLabel: t("common.delete"),
    }))) return;
    try { await api.removeImportBatch(b.id); loadStamm(); } catch (e) { toast(e.message, "error"); }
  }

  // Nach einer Reihe von Versuchen stehen schnell zwanzig rueckgaengig gemachte
  // Importe im Verlauf. Die einzeln wegzuklicken ist Fleissarbeit ohne Nutzen.
  async function alleErledigtenEntfernen() {
    const weg = batches.filter((b) => b.status === "undone");
    if (!weg.length) return;
    if (!(await confirm({
      title: t("import.removeAllUndone"),
      message: t("import.removeAllUndoneConfirm", { n: weg.length }),
      danger: true, confirmLabel: t("common.delete"),
    }))) return;
    try {
      for (const b of weg) await api.removeImportBatch(b.id);
      loadStamm();
    } catch (e) { toast(e.message, "error"); }
  }

  // Die abgelieferte Datei so behandeln, als haette man sie hier ausgewaehlt –
  // damit gilt der ganze normale Weg samt Vorschau und Saldo-Abgleich.
  async function uploadUebernehmen(u) {
    try {
      const antwort = await fetch(`/api/imports/uploads/${u.id}/content`, { credentials: "include" });
      if (!antwort.ok) throw new Error(await antwort.text());
      const blob = await antwort.blob();
      setAccountId(String(u.account_id));
      setFile(new File([blob], u.filename, { type: "text/csv" }));
      setRaw(null);
      setRows(null);
      setMode("csv");
      toast(t("import.phoneFileLoaded", { name: u.filename }));
    } catch (e) {
      toast(e.message, "error");
    }
  }

  async function uploadVerwerfen(u) {
    if (!(await confirm({
      title: t("import.discardPhoneFile"),
      message: t("import.discardPhoneFileConfirm", { name: u.filename }),
      danger: true, confirmLabel: t("common.delete"),
    }))) return;
    try { await api.deleteUpload(u.id); loadStamm(); } catch (e) { toast(e.message, "error"); }
  }

  async function undo(b) {
    if (!(await confirm({ title: t("import.undo"), message: t("import.undoConfirm", { file: b.filename }), danger: true, confirmLabel: t("import.undo") }))) return;
    try { await api.undoImportBatch(b.id); loadStamm(); } catch (e) { toast(e.message, "error"); }
  }

  const colOptions = useMemo(() => {
    const n = raw ? Math.max(raw.header?.length || 0, ...(raw.rows || []).map((r) => r.length), 0) : 0;
    return Array.from({ length: n }, (_, i) => ({
      i, label: `${i}${raw?.header?.[i] ? ` · ${raw.header[i]}` : ""}`,
    }));
  }, [raw]);

  // Spalten, die die Datei in wenige Gruppen teilen (Revolut: „Produkt").
  const filterSpalten = useMemo(
    () => colOptions.filter((c) => raw?.filter_values?.[String(c.i)]),
    [colOptions, raw],
  );

  const expenseGroups = useMemo(() => gruppenFuer(groups, "expense"), [groups]);
  const incomeGroups = useMemo(() => gruppenFuer(groups, "income"), [groups]);

  const includeCount = rows ? rows.filter((r) => r.include).length : 0;

  // Aktualisiert eine Zeile über ihren stabilen Erkennungs-Index (die Anzeige in
  // der Tabelle kann sortiert/gefiltert sein, der Index bleibt gleich).
  function updateRow(rowIndex, patch) {
    setRows((rs) => rs.map((r) => (r.index === rowIndex ? { ...r, ...patch } : r)));
  }

  const acc = accountById[Number(accountId)];

  const reviewColumns = useMemo(() => [
    {
      key: "include", header: "", width: 42, fixed: true,
      render: (r) => (
        <input type="checkbox" checked={!!r.include} disabled={!r.valid}
               onChange={(e) => updateRow(r.index, { include: e.target.checked })} />
      ),
    },
    {
      key: "date", header: t("transactions.date"), width: 112,
      sortValue: (r) => r.date || "",
      render: (r) => (r.date
        ? <span className="nowrap">{formatDate(r.date)}</span>
        : <span className="amount neg">{t("import.badDate")}</span>),
    },
    {
      key: "amount", header: t("transactions.amount"), align: "num", width: 120,
      sortValue: (r) => r.amount_cents || 0,
      render: (r) => (
        <span className={`amount ${(r.amount_cents || 0) < 0 ? "neg" : "pos"}`}>
          {formatMoney(Math.abs(r.amount_cents || 0), acc?.currency || "EUR")}
        </span>
      ),
    },
    {
      key: "type", header: t("import.typeCol"), width: 128,
      filterText: (r) => t(`transactions.${r.type}`),
      render: (r) => (
        <select value={r.type} onChange={(e) => updateRow(r.index, { type: e.target.value })}>
          <option value="expense">{t("transactions.expense")}</option>
          <option value="income">{t("transactions.income")}</option>
          <option value="transfer">{t("transactions.transfer")}</option>
        </select>
      ),
    },
    {
      key: "payee", header: t("import.payeeCol"), grow: true, min: 200,
      filterText: (r) => r.payee || r.purpose || "",
      render: (r) => (
        <span className="ellipsis" style={{ display: "block" }}>
          {r.payee || r.purpose || ""}
          {r.is_duplicate && (
            <span className="badge" style={{ marginLeft: 6 }}
                  title={r.duplicate_reason === "inbox" ? t("import.dupInboxHint") : undefined}>
              {r.duplicate_reason === "inbox" ? t("import.dupInbox") : t("import.duplicate")}
            </span>
          )}
          {r.is_counterpart && <span className="badge" style={{ marginLeft: 6 }}>{t("import.counterpart")}</span>}
          {r.needs_target && <span className="badge" style={{ marginLeft: 6 }}>{t("import.needsTarget")}</span>}
          {r.skip_reason === "state" && (
            <span className="badge" style={{ marginLeft: 6 }}>{r.state || t("import.skipState")}</span>
          )}
          {r.skip_reason === "currency" && (
            <span className="badge" style={{ marginLeft: 6 }}>{r.row_currency || t("import.skipCurrency")}</span>
          )}
        </span>
      ),
    },
    {
      key: "category", header: t("transactions.category"), width: 210, min: 160,
      render: (r) => (r.type === "transfer" ? (
        <select value={r.to_account_id || ""}
                onChange={(e) => updateRow(r.index, { to_account_id: e.target.value ? Number(e.target.value) : null })}>
          <option value="">{t("import.chooseAccount")}</option>
          {accounts.filter((a) => a.id !== Number(accountId)).map((a) => (
            <option key={a.id} value={a.id}>{a.name}</option>
          ))}
        </select>
      ) : (
        <CategorySelect
          groups={r.type === "income" ? incomeGroups : expenseGroups}
          value={r.category_id || ""}
          onChange={(id) => updateRow(r.index, { category_id: id != null ? Number(id) : null })}
          allowNone
          noneLabel={t("transactions.uncategorized")}
          placeholder={t("transactions.uncategorized")}
        />
      )),
    },
    // eslint-disable-next-line react-hooks/exhaustive-deps
  ], [t, formatDate, acc, accounts, accountId, incomeGroups, expenseGroups]);

  const historyColumns = useMemo(() => [
    {
      key: "file", header: t("import.file"), grow: true, min: 180,
      filterText: (b) => b.filename || "",
      render: (b) => (
        <span className="ellipsis" style={{ display: "block" }}>
          <strong>{b.filename || "—"}</strong>{" "}
          <span className="muted small">{accountById[b.account_id]?.name}</span>
        </span>
      ),
    },
    {
      key: "date", header: t("transactions.date"), width: 150,
      sortValue: (b) => b.created_at,
      render: (b) => <span className="nowrap">{formatDate(b.created_at)}</span>,
    },
    {
      key: "count", header: t("import.importedCount", { n: "" }).trim(), width: 110, align: "num",
      sortValue: (b) => b.imported_count,
      render: (b) => <span className="nowrap">{t("import.importedCount", { n: b.imported_count })}</span>,
    },
    {
      key: "action", header: "", width: 196, fixed: true,
      render: (b) => (b.status === "committed" ? (
        <button className="btn sm danger" onClick={() => undo(b)}>
          <Icon name="refresh-ccw" size={14} /> {t("import.undo")}
        </button>
      ) : (
        <span className="nowrap">
          <button className="btn sm ghost" title={t("import.removeEntry")}
                  onClick={() => entfernen(b)}>
            <Icon name="trash" size={14} /> {t("import.removeEntry")}
          </button>
        </span>
      )),
    },
    // eslint-disable-next-line react-hooks/exhaustive-deps
  ], [t, formatDate, accountById]);

  return (
    <div>
      <div className="page-head">
        <h1>{t("import.title")}</h1>
        <div className="seg" style={{ width: 240, marginBottom: 0 }}>
          <button type="button" className={`seg-btn${mode === "csv" ? " active" : ""}`}
                  onClick={() => { setMode("csv"); setRows(null); setRaw(null); setDocText(""); setDocPages([]); }}>{t("import.modeCsv")}</button>
          <button type="button" className={`seg-btn${mode === "doc" ? " active" : ""}`}
                  onClick={() => { setMode("doc"); setRows(null); setRaw(null); setDocText(""); setDocPages([]); }}>{t("import.modeDoc")}</button>
        </div>
      </div>

      {/* Schritt 1: Konto + Datei */}
      <div className="card">
        <h2>{t("import.step1")}</h2>
        <div className="row">
          <label className="grow">
            <span>{t("import.account")}</span>
            <AccountSelect accounts={accounts} value={accountId}
                           onChange={(id) => setAccountId(id != null ? String(id) : "")} />
          </label>
          <label className="grow">
            <span>{t("import.file")}</span>
            <input ref={fileRef} type="file"
                   accept={mode === "doc" ? ".pdf,application/pdf,image/*" : ".csv,text/csv,text/plain"}
                   onChange={(e) => { setFile(e.target.files?.[0] || null); setRaw(null); setRows(null); setDocText(""); setDocPages([]); }} />
          </label>
        </div>
        {mode === "doc" && (
          <>
            <button className="btn primary" onClick={loadDoc} disabled={busy || !file}>
              <Icon name="search" size={15} /> {t("import.readDoc")}
            </button>
            <p className="muted small" style={{ marginTop: "var(--sp-2)" }}>{t("import.docHint")}</p>
          </>
        )}
        <div className="row" style={{ display: mode === "csv" ? undefined : "none" }}>
          <label className="grow">
            <span>{t("import.templateAny")}</span>
            <select value={quelle} onChange={(e) => applySource(e.target.value)}>
              <option value="">{t("import.templateManual")}</option>
              {presets.length > 0 && (
                <optgroup label={t("import.presetGroup")}>
                  {presets.map((p, i) => <option key={`p${i}`} value={`preset:${i}`}>{p.name}</option>)}
                </optgroup>
              )}
              {templates.length > 0 && (
                <optgroup label={t("import.ownGroup")}>
                  {templates.map((tp) => <option key={`t${tp.id}`} value={`tpl:${tp.id}`}>{tp.name}</option>)}
                </optgroup>
              )}
            </select>
          </label>
        </div>
      </div>

      {/* Schritt 2: Format (nur CSV) */}
      {mode === "csv" && (
      <div className="card">
        <h2>{t("import.step2")}</h2>
        <div className="row">
          <label>
            <span>{t("import.delimiter")}</span>
            <select value={config.delimiter} onChange={(e) => setCfg({ delimiter: e.target.value })}>
              <option value=";">Semikolon ;</option>
              <option value=",">Komma ,</option>
              <option value={"\t"}>Tab</option>
            </select>
          </label>
          <label>
            <span>{t("import.decimal")}</span>
            <select value={config.decimal_sep} onChange={(e) => setCfg({ decimal_sep: e.target.value })}>
              <option value=",">Komma (1.234,56)</option>
              <option value=".">Punkt (1,234.56)</option>
            </select>
          </label>
          <label>
            <span>{t("import.dateFormat")}</span>
            <select value={config.date_format} onChange={(e) => setCfg({ date_format: e.target.value })}>
              {DATE_FORMATS.map((f) => <option key={f.v} value={f.v}>{f.l}</option>)}
            </select>
          </label>
        </div>
        <div className="row">
          <label>
            <span>{t("import.encoding")}</span>
            <select value={config.encoding} onChange={(e) => setCfg({ encoding: e.target.value })}>
              <option value="utf-8">UTF-8</option>
              <option value="latin-1">ISO-8859-1 / Latin-1</option>
              <option value="cp1252">Windows-1252</option>
            </select>
          </label>
          <label>
            <span>{t("import.amountMode")}</span>
            <select value={config.amount_mode} onChange={(e) => setCfg({ amount_mode: e.target.value })}>
              <option value="signed">{t("import.modeSigned")}</option>
              <option value="debit_credit">{t("import.modeDebitCredit")}</option>
              <option value="abs_expense">{t("import.modeAbsExpense")}</option>
            </select>
          </label>
          <label style={{ maxWidth: 160 }}>
            <span>{t("import.skipRows")}</span>
            <input type="number" min="0" value={config.skip_rows}
                   onChange={(e) => setCfg({ skip_rows: Math.max(0, Number(e.target.value) || 0) })} />
          </label>
          <label className="checkline" style={{ alignSelf: "flex-end", marginBottom: 14 }}>
            <input type="checkbox" checked={config.has_header}
                   onChange={(e) => setCfg({ has_header: e.target.checked })} />
            <span>{t("import.hasHeader")}</span>
          </label>
        </div>
        <p className="muted small">{t("import.autoPreviewNote")}</p>
      </div>
      )}

      {/* Beleg-Vorschau: Seiten als Bild + extrahierter Text (PDF/Bild) */}
      {mode === "doc" && (docPages.length > 0 || docText) && (
        <div className="card">
          <h2>{t("import.belegPreview")}</h2>
          {docPages.length > 0 && (
            <div className="doc-pages">
              {docPages.map((src, i) => (
                <img key={i} src={src} alt={`Seite ${i + 1}`} className="doc-page" loading="lazy" />
              ))}
            </div>
          )}
          {docText && (
            <details style={{ marginTop: "var(--sp-3)" }}>
              <summary className="muted">{t("import.extractedText")}</summary>
              <pre className="doc-text">{docText}</pre>
            </details>
          )}
        </div>
      )}

      {/* Schritt 3: Spaltenzuordnung */}
      {raw && (
        <div className="card">
          <h2>{t("import.step3")}</h2>
          <p className="muted small">{t("import.rawHint")}</p>
          <div className="table-scroll">
            <table className="table raw-table">
              <thead>
                <tr>{colOptions.map((c) => <th key={c.i}>{c.label}</th>)}</tr>
              </thead>
              <tbody>
                {raw.rows.map((r, ri) => (
                  <tr key={ri}>{colOptions.map((c) => <td key={c.i}>{r[c.i] ?? ""}</td>)}</tr>
                ))}
              </tbody>
            </table>
          </div>

          <div className="map-grid">
            {[
              ["date", t("import.colDate")],
              ...(config.amount_mode === "debit_credit"
                ? [["debit", t("import.colDebit")], ["credit", t("import.colCredit")]]
                : [["amount", t("import.colAmount")]]),
              ["payee", t("import.colPayee")],
              ["purpose", t("import.colPurpose")],
            ].map(([field, label]) => (
              <label key={field}>
                <span>{label}</span>
                <select value={config.column_map[field] ?? ""} onChange={(e) => setCol(field, e.target.value)}>
                  <option value="">—</option>
                  {colOptions.map((c) => <option key={c.i} value={c.i}>{c.label}</option>)}
                </select>
              </label>
            ))}
          </div>

          {/* Revolut legt alle Produkte in EINE Datei. Ohne Filter zaehlen die
              Bewegungen doppelt – deshalb steht der Filter offen, sobald die
              Datei eine Spalte mit wenigen wiederkehrenden Werten hat. */}
          {filterSpalten.length > 0 && (
            <div className="alert" style={{ marginTop: "var(--sp-3)", display: "block" }}>
              <strong>{t("import.filterTitle")}</strong>
              <p className="muted small">{t("import.filterHint")}</p>
              <div className="map-grid">
                <label>
                  <span>{t("import.filterColumn")}</span>
                  <select value={config.filter_column ?? ""}
                          onChange={(e) => setCfg({
                            filter_column: e.target.value === "" ? null : Number(e.target.value),
                            filter_value: "",
                          })}>
                    <option value="">{t("import.filterNone")}</option>
                    {filterSpalten.map((c) => <option key={c.i} value={c.i}>{c.label}</option>)}
                  </select>
                </label>
                <label>
                  <span>{t("import.filterValue")}</span>
                  <select value={config.filter_value}
                          disabled={config.filter_column == null}
                          onChange={(e) => setCfg({ filter_value: e.target.value })}>
                    <option value="">{t("import.filterNone")}</option>
                    {(raw?.filter_values?.[String(config.filter_column)] || []).map((w) => (
                      <option key={w.value} value={w.value}>
                        {t("import.filterValueOption", { value: w.value, count: w.count })}
                      </option>
                    ))}
                  </select>
                </label>
              </div>
            </div>
          )}

          <details className="import-more">
            <summary className="muted small">{t("import.moreColumns")}</summary>
            <p className="muted small">{t("import.ibanHint")}</p>
            <div className="map-grid">
              {[
                ["counterparty_iban", t("import.colIban")],
                ["fee", t("import.colFee")],
                ["currency", t("import.colCurrency")],
                ["state", t("import.colState")],
                ["balance", t("import.colBalance")],
              ].map(([field, label]) => (
                <label key={field}>
                  <span>{label}</span>
                  <select value={config.column_map[field] ?? ""} onChange={(e) => setCol(field, e.target.value)}>
                    <option value="">—</option>
                    {colOptions.map((c) => <option key={c.i} value={c.i}>{c.label}</option>)}
                  </select>
                </label>
              ))}
            </div>
            <p className="muted small">{t("import.extraColsHint")}</p>
          </details>

          <div className="field-inline" style={{ marginTop: "var(--sp-3)" }}>
            <button className="btn primary" onClick={loadPreview} disabled={busy}>
              <Icon name="chevron-right" size={15} /> {t("import.makePreview")}
            </button>
            <div className="input-with-button" style={{ maxWidth: 320 }}>
              <input placeholder={t("import.templateName")} value={saveName} onChange={(e) => setSaveName(e.target.value)} />
              <button className="btn sm" onClick={saveTemplate}>{t("import.saveTemplate")}</button>
            </div>
          </div>
          <p className="muted small" style={{ marginTop: "var(--sp-2)" }}>{t("import.makePreviewNote")}</p>
        </div>
      )}

      {/* Schritt 4: Prüfansicht */}
      {rows && (
        <div className="card">
          <div className="page-head">
            <h2 style={{ margin: 0 }}>{t("import.step4")}</h2>
            <button className="btn primary" onClick={commit} disabled={busy || includeCount === 0}>
              <Icon name="download" size={15} /> {t("import.commit", { n: includeCount })}
            </button>
          </div>
          <p className="muted small">{t("import.summary", { total: rows.length, n: includeCount })}</p>
          {rows.length > 0 && includeCount === 0 && (
            <div className="alert error" style={{ marginBottom: "var(--sp-3)" }}>
              <Icon name="alert" size={16} />
              <span>{t("import.noneValid")}</span>
            </div>
          )}
          {recon?.available && (
            <div className={`alert ${recon.ok ? "ok" : "error"}`} style={{ marginBottom: "var(--sp-3)" }}>
              <Icon name={recon.ok ? "check" : "alert"} size={16} />
              <div>
                {recon.ok ? (
                  <span>{t("import.reconOk", { n: recon.checked })}</span>
                ) : (
                  <>
                    <div>
                      {t("import.reconDiff", {
                        file: formatMoney(recon.final_balance_cents, acc?.currency || "EUR"),
                        app: formatMoney(recon.computed_final_cents, acc?.currency || "EUR"),
                        diff: formatMoney(recon.difference_cents, acc?.currency || "EUR"),
                      })}
                    </div>
                    {recon.first_mismatch && (
                      <div className="muted small">
                        {t("import.reconFirst", {
                          date: recon.first_mismatch.date ? formatDate(recon.first_mismatch.date) : "?",
                          payee: recon.first_mismatch.payee || "—",
                          expected: formatMoney(recon.first_mismatch.expected_cents, acc?.currency || "EUR"),
                          actual: formatMoney(recon.first_mismatch.actual_cents, acc?.currency || "EUR"),
                        })}
                      </div>
                    )}
                    {/* Häufigste Ursache: mehrere Konten in einer Datei, kein Zeilenfilter. */}
                    {config.filter_column == null && (
                      <div className="muted small">{t("import.reconMixedHint")}</div>
                    )}
                  </>
                )}
                <div className="muted small">
                  {t("import.reconOpening", {
                    value: formatMoney(recon.opening_balance_cents, acc?.currency || "EUR"),
                  })}
                </div>
              </div>
            </div>
          )}
          <DataTable
            id="import-review"
            rows={rows}
            getRowKey={(r) => r.index}
            rowClassName={(r) => (!r.valid ? "row-invalid" : r.is_duplicate || r.is_counterpart ? "row-dup" : "")}
            columns={reviewColumns}
          />
          {/* Zweiter Knopf unter der Liste: bei vielen Zeilen muss man zum Buchen
              sonst wieder ganz nach oben scrollen. */}
          <div className="commit-footer">
            <button className="btn primary" onClick={commit} disabled={busy || includeCount === 0}>
              <Icon name="download" size={15} /> {t("import.commit", { n: includeCount })}
            </button>
          </div>
        </div>
      )}

      {uploads.length > 0 && (
        <div className="card">
          <div className="card-head">
            <Icon name="smartphone" size={18} />
            <h2>{t("import.fromPhone")}</h2>
          </div>
          <p className="muted small">{t("import.fromPhoneHint")}</p>
          {uploads.map((u) => (
            <div className="mail-source" key={u.id}>
              <div><strong>{u.filename}</strong></div>
              <div className="muted small">
                {accountById[u.account_id]?.name || "—"} · {Math.round(u.size_bytes / 1024)} KB
                {u.created_at ? ` · ${formatDate(u.created_at.slice(0, 10))}` : ""}
              </div>
              <div className="mail-actions">
                <button className="btn sm primary" onClick={() => uploadUebernehmen(u)}>
                  <Icon name="download" size={14} /> {t("import.usePhoneFile")}
                </button>
                <button className="btn sm danger" onClick={() => uploadVerwerfen(u)}>
                  <Icon name="trash" size={14} />
                </button>
              </div>
            </div>
          ))}
        </div>
      )}

      {/* Verlauf */}
      {batches.length > 0 && (
        <div className="card">
          <div className="card-head">
            <h2>{t("import.history")}</h2>
            {batches.some((b) => b.status === "undone") && (
              <button className="btn sm ghost" style={{ marginLeft: "auto" }} onClick={alleErledigtenEntfernen}>
                <Icon name="trash" size={14} />{" "}
                {t("import.removeAllUndone")} ({batches.filter((b) => b.status === "undone").length})
              </button>
            )}
          </div>
          <DataTable
            id="import-history"
            rows={batches}
            getRowKey={(b) => b.id}
            rowClassName={(b) => (b.status === "undone" ? "row-dup" : "")}
            columns={historyColumns}
          />
        </div>
      )}
    </div>
  );
}