import { useCallback, useEffect, useState } from "react";
import { ApiError, api, type ApprovalTask } from "../api";

export default function ApprovalsTab() {
  const [tasks, setTasks] = useState<ApprovalTask[]>([]);
  const [approver, setApprover] = useState("");
  const [note, setNote] = useState("");
  const [error, setError] = useState("");
  const [busyId, setBusyId] = useState("");

  const load = useCallback(async () => {
    try {
      setTasks(await api.listApprovals());
    } catch (e) {
      setError(e instanceof ApiError ? `${e.status}: ${e.message}` : String(e));
    }
  }, []);

  useEffect(() => {
    void load();
  }, [load]);

  async function decide(taskId: string, decision: "approve" | "reject") {
    setBusyId(taskId);
    setError("");
    try {
      const result = await api.decide(taskId, decision, approver, note);
      setTasks((prev) =>
        prev.map((t) => (t.id === taskId ? result.task : t)),
      );
    } catch (e) {
      setError(e instanceof ApiError ? `${e.status}: ${e.message}` : String(e));
    } finally {
      setBusyId("");
    }
  }

  const open = tasks.filter((t) => t.status === "open");
  const done = tasks.filter((t) => t.status !== "open");

  return (
    <div>
      <h2>Freigaben</h2>
      {error && <p style={{ color: "crimson" }}>{error}</p>}
      <div style={{ display: "flex", gap: 8, marginBottom: 12 }}>
        <input
          value={approver}
          onChange={(e) => setApprover(e.target.value)}
          placeholder="Name (Bearbeiter)"
        />
        <input
          value={note}
          onChange={(e) => setNote(e.target.value)}
          placeholder="Notiz"
          style={{ flex: 1 }}
        />
        <button onClick={() => void load()}>Aktualisieren</button>
      </div>
      <h3>Offen ({open.length})</h3>
      {open.length === 0 && <p>Keine offenen Freigaben.</p>}
      <ul>
        {open.map((t) => (
          <li key={t.id} style={{ marginBottom: 8 }}>
            <strong>{t.title || t.id}</strong> · {t.tenant_id}
            <br />
            <code>{JSON.stringify(t.payload)}</code>
            <br />
            <button
              onClick={() => void decide(t.id, "approve")}
              disabled={busyId === t.id}
            >
              Freigeben
            </button>{" "}
            <button
              onClick={() => void decide(t.id, "reject")}
              disabled={busyId === t.id}
            >
              Ablehnen
            </button>
          </li>
        ))}
      </ul>
      <h3>Entschieden ({done.length})</h3>
      <ul>
        {done.map((t) => (
          <li key={t.id}>
            <strong>{t.status}</strong> · {t.title || t.id} ·{" "}
            {t.approver ?? "–"}
            {t.decision_note ? ` · „${t.decision_note}“` : ""}
          </li>
        ))}
      </ul>
    </div>
  );
}