import { useEffect, useState } from "react";
import { useParams } from "react-router-dom";
import { api, canEditRound, type Entity, type Partner } from "../api";
import { useAuth } from "../context/AuthContext";
import { formatDate, formatMoneyExact } from "../format";
import EntityHeader from "../components/EntityHeader";

export default function EntityPartners() {
  const { id } = useParams<{ id: string }>();
  const { user } = useAuth();
  const [entity, setEntity] = useState<Entity | null>(null);
  const [partners, setPartners] = useState<Partner[]>([]);
  const [error, setError] = useState("");
  const [notice, setNotice] = useState("");
  const [clearing, setClearing] = useState(false);
  const [loading, setLoading] = useState(true);
  // Row currently getting an exit date (inline date picker), and the chosen date.
  const [exitingId, setExitingId] = useState<number | null>(null);
  const [exitDate, setExitDate] = useState(() => new Date().toISOString().slice(0, 10));

  const isWriter = !!user && canEditRound(user.role);

  useEffect(() => {
    if (!id) return;
    const eid = parseInt(id);
    Promise.all([api.getEntity(eid), api.listPartners(eid)])
      .then(([e, p]) => {
        setEntity(e);
        setPartners(p);
      })
      .catch((err) => setError(err.message))
      .finally(() => setLoading(false));
  }, [id]);

  async function clearAllPartners() {
    if (!entity) return;
    if (
      !confirm(
        `Remove ALL ${partners.length} partner(s) from ${entity.name}?\n\n` +
          "This deletes this fund's capital-account statements and the investors' access to " +
          "it. The investor accounts themselves are kept (they may belong to other funds), " +
          "and holdings/NAV are not affected. Re-import the correct roster afterward.",
      )
    )
      return;
    setClearing(true);
    setError("");
    setNotice("");
    try {
      const res = await api.clearPartners(entity.id);
      const fresh = await api.listPartners(entity.id);
      setPartners(fresh);
      setNotice(
        `Cleared: removed ${res.statements} capital statement(s) and ${res.access_grants} access grant(s).`,
      );
    } catch (err: any) {
      setError(err.message || "Failed to clear partners");
    } finally {
      setClearing(false);
    }
  }

  async function saveExit(userId: number, exitedOn: string | null) {
    if (!entity) return;
    setError("");
    try {
      const updated = await api.setPartnerExited(entity.id, userId, exitedOn);
      setPartners((prev) => prev.map((p) => (p.user_id === userId ? updated : p)));
      setExitingId(null);
    } catch (err: any) {
      setError(err.message || "Failed to update exit status");
    }
  }

  if (loading || !entity) return <div className="text-gray-500 text-sm">Loading…</div>;

  // Exited members (stake sold/transferred) stay on the roster but out of the totals —
  // otherwise a seller and their buyer would both be counted.
  const active = partners.filter((p) => !p.exited_on);
  const exitedCount = partners.length - active.length;
  const totalCommitted = active.reduce((s, p) => s + (p.latest_commitment_cents || 0), 0);
  const totalCapital = active.reduce((s, p) => s + (p.latest_value_cents || 0), 0);

  return (
    <div>
      <EntityHeader entity={entity} active="partners" />

      {error && <p className="text-sm text-red-600 mb-3">{error}</p>}
      {notice && <p className="text-sm text-green-600 mb-3">{notice}</p>}

      <div className="flex items-center justify-between mb-3">
        <p className="text-sm text-gray-500">
          {partners.length} member{partners.length === 1 ? "" : "s"} with access to this fund.
        </p>
        <div className="flex items-center gap-4">
          <p className="text-sm text-gray-700">
            Total committed: <span className="font-medium">{formatMoneyExact(totalCommitted)}</span>
            <span className="mx-2 text-gray-300">·</span>
            Total capital: <span className="font-medium">{formatMoneyExact(totalCapital)}</span>
            {exitedCount > 0 && (
              <span className="ml-2 text-xs text-gray-400">
                (excludes {exitedCount} exited)
              </span>
            )}
          </p>
          {isWriter && partners.length > 0 && (
            <button
              onClick={clearAllPartners}
              disabled={clearing}
              className="px-3 py-1.5 border border-red-300 text-red-600 text-sm rounded hover:bg-red-50 disabled:opacity-50"
            >
              {clearing ? "Clearing…" : "Clear all partners"}
            </button>
          )}
        </div>
      </div>

      <div className="bg-white border border-gray-200 rounded-lg overflow-x-auto">
        <table className="w-full text-sm">
          <thead className="bg-gray-50 text-gray-500 text-left">
            <tr>
              <th className="px-4 py-2 font-medium">Member</th>
              <th className="px-4 py-2 font-medium">Investor ID</th>
              <th className="px-4 py-2 font-medium">Login</th>
              <th className="px-4 py-2 font-medium">Status</th>
              <th className="px-4 py-2 font-medium">As of</th>
              <th className="px-4 py-2 font-medium text-right">Committed</th>
              <th className="px-4 py-2 font-medium text-right">Paid-in</th>
              <th className="px-4 py-2 font-medium text-right">Distributions</th>
              <th className="px-4 py-2 font-medium text-right">Capital value</th>
            </tr>
          </thead>
          <tbody>
            {partners.map((p) => (
              <tr key={p.user_id} className={`border-t border-gray-100 ${p.exited_on ? "text-gray-400" : ""}`}>
                <td className="px-4 py-2">
                  <div className={p.exited_on ? "text-gray-500" : "text-gray-900"}>{p.name}</div>
                  <div className="text-xs text-gray-400">{p.username}</div>
                </td>
                <td className="px-4 py-2 text-gray-600">{p.external_investor_id ?? "—"}</td>
                <td className="px-4 py-2">
                  {!p.is_active ? (
                    <span className="text-gray-400">Disabled</span>
                  ) : p.login_enabled ? (
                    <span className="text-green-600">Active</span>
                  ) : (
                    <span className="text-amber-600">No login yet</span>
                  )}
                </td>
                <td className="px-4 py-2 whitespace-nowrap">
                  {p.exited_on ? (
                    <span>
                      <span className="text-xs font-medium uppercase text-gray-500 bg-gray-100 px-1.5 py-0.5 rounded">
                        Exited {formatDate(p.exited_on)}
                      </span>
                      {isWriter && (
                        <button
                          onClick={() => saveExit(p.user_id, null)}
                          className="ml-2 text-xs text-accent-600 hover:text-accent-700"
                        >
                          Undo
                        </button>
                      )}
                    </span>
                  ) : exitingId === p.user_id ? (
                    <span className="flex items-center gap-1.5">
                      <input
                        type="date"
                        value={exitDate}
                        onChange={(e) => setExitDate(e.target.value)}
                        className="px-1.5 py-0.5 border border-gray-300 rounded text-xs"
                      />
                      <button
                        onClick={() => exitDate && saveExit(p.user_id, exitDate)}
                        className="text-xs text-accent-600 hover:text-accent-700 font-medium"
                      >
                        Save
                      </button>
                      <button
                        onClick={() => setExitingId(null)}
                        className="text-xs text-gray-400 hover:text-gray-600"
                      >
                        Cancel
                      </button>
                    </span>
                  ) : (
                    <span>
                      <span className="text-gray-600">Member</span>
                      {isWriter && (
                        <button
                          onClick={() => setExitingId(p.user_id)}
                          className="ml-2 text-xs text-gray-400 hover:text-gray-600"
                        >
                          Mark exited
                        </button>
                      )}
                    </span>
                  )}
                </td>
                <td className="px-4 py-2 text-gray-500">
                  {p.latest_as_of ? formatDate(p.latest_as_of) : "—"}
                </td>
                <td className="px-4 py-2 text-right text-gray-900">
                  {p.latest_commitment_cents != null ? formatMoneyExact(p.latest_commitment_cents) : "—"}
                </td>
                <td className="px-4 py-2 text-right text-gray-600">
                  {p.latest_contributions_cents != null ? formatMoneyExact(p.latest_contributions_cents) : "—"}
                </td>
                <td className="px-4 py-2 text-right text-gray-600">
                  {p.latest_distributions_cents != null ? formatMoneyExact(p.latest_distributions_cents) : "—"}
                </td>
                <td className="px-4 py-2 text-right text-gray-900">
                  {p.latest_value_cents != null ? formatMoneyExact(p.latest_value_cents) : "—"}
                </td>
              </tr>
            ))}
            {partners.length === 0 && (
              <tr>
                <td colSpan={9} className="px-4 py-6 text-center text-gray-400">
                  No members yet. Import the eNAV ALLOC SI tab from “Import Statements,” or grant
                  access on the Access Grid.
                </td>
              </tr>
            )}
          </tbody>
        </table>
      </div>
    </div>
  );
}