/* ═══════════════════════════════════════════════════════════════
   ADMIN — ENTITY LIST

   One component for organizations, events and people. The :entity
   route param picks the manifest; nothing here knows what a
   chapter or a retreat is.

   The "New X" link follows the same rule as EntityEdit's save
   button: atLeast(user, "editor"), matching requireRole("editor")
   on POST /api/admin/:entity. Drawing it is not permission — the
   server decides — it only avoids offering a click that 403s, and
   avoids hiding one that wouldn't.
   ═══════════════════════════════════════════════════════════════ */

import { useCallback, useEffect, useState } from "react";
import { Link, useNavigate, useParams, useSearchParams } from "react-router-dom";

import { get, ApiError } from "../../lib/api.js";
import { isUnauthorized, useAuth } from "../../lib/auth.tsx";
import { ADMIN_ENTITIES } from "../../lib/adminSchema.js";
import { atLeast } from "../../lib/roles.ts";

export default function EntityList() {
  const { entity: entityKey } = useParams();
  const manifest = ADMIN_ENTITIES[entityKey];
  const navigate = useNavigate();
  const { user } = useAuth();

  const [params, setParams] = useSearchParams();
  const [rows, setRows] = useState([]);
  const [options, setOptions] = useState({});
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState(null);
  const [query, setQuery] = useState(params.get("q") ?? "");

  // Minimum rank, never equality. POST /api/admin/:entity is gated
  // at "editor", so anyone from editor upward may create — and the
  // equality test this replaced hid the button from superadmins as
  // well as editors, which is the failure mode an == against a
  // ladder always produces once a rank is added above it.
  const canWrite = atLeast(user, "editor");

  const load = useCallback(async () => {
    if (!manifest) return;
    setLoading(true);
    setError(null);
    try {
      const [list, opts] = await Promise.all([
        get(`/admin/${manifest.key}?${params}`, { ttl: 0 }),
        get("/admin/options", { ttl: 60_000 }),
      ]);
      setRows(list.rows);
      setOptions(opts.options);
    } catch (err) {
      if (isUnauthorized(err)) return navigate("/admin/login", { replace: true });
      setError(err instanceof ApiError ? err.message : "Couldn't reach the server.");
    } finally {
      setLoading(false);
    }
  }, [manifest, params, navigate]);

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

  if (!manifest) {
    return <p className="text-[#4a6b72]">No such thing to edit.</p>;
  }

  function setParam(key, value) {
    const next = new URLSearchParams(params);
    if (value) next.set(key, value);
    else next.delete(key);
    setParams(next, { replace: true });
  }

  function labelFor(filter, value) {
    if (filter.optionsFrom) {
      return (options[filter.optionsFrom] ?? []).map((o) => [o.id, o.label]);
    }
    return filter.options.map((o) => (Array.isArray(o) ? o : [o, o]));
  }

  return (
    <div>
      <div className="flex flex-wrap items-center gap-4">
        <h1 className="text-3xl font-bold text-[#138ba0]">{manifest.label}</h1>
        {canWrite && (
          <Link
            to={`/admin/${manifest.key}/new`}
            className="ml-auto rounded-full bg-[#138ba0] px-4 py-2 text-sm font-semibold text-white transition-colors hover:bg-[#0f7183]"
          >
            New {manifest.singular}
          </Link>
        )}
      </div>

      {/* Filters */}
      <div className="mt-6 flex flex-wrap items-end gap-3">
        {manifest.list.filters.map((filter) => (
          <label key={filter.key} className="text-xs text-[#4a6b72]">
            <span className="block">{filter.label}</span>
            <select
              value={params.get(filter.key) ?? ""}
              onChange={(e) => setParam(filter.key, e.target.value)}
              className="mt-1 rounded-lg border border-[#4a6b72]/25 bg-white px-3 py-1.5 text-sm text-[#26454c] outline-none focus:border-[#138ba0]"
            >
              <option value="">All</option>
              {labelFor(filter).map(([value, label]) => (
                <option key={value} value={value}>
                  {label}
                </option>
              ))}
            </select>
          </label>
        ))}

        <div className="ml-auto flex gap-2">
          <input
            type="search"
            value={query}
            placeholder="Search"
            onChange={(e) => setQuery(e.target.value)}
            onKeyDown={(e) => e.key === "Enter" && setParam("q", query.trim())}
            className="rounded-full border border-[#4a6b72]/25 bg-white px-4 py-1.5 text-sm text-[#26454c] outline-none focus:border-[#138ba0]"
          />
          <button
            type="button"
            onClick={() => setParam("q", query.trim())}
            className="rounded-full border border-[#4a6b72]/25 px-4 py-1.5 text-sm text-[#4a6b72] hover:border-[#138ba0]/50"
          >
            Search
          </button>
        </div>
      </div>

      {error && (
        <p
          role="alert"
          className="mt-6 rounded-xl border border-[#b3261e]/30 bg-[#fdf3f2] px-4 py-3 text-sm text-[#b3261e]"
        >
          {error}
        </p>
      )}

      {/* Rows */}
      <div className="mt-6 overflow-x-auto rounded-2xl border border-[#138ba0]/20 bg-white">
        <table className="w-full text-left text-sm">
          <thead className="border-b border-[#4a6b72]/15 text-xs text-[#4a6b72]">
            <tr>
              {manifest.list.columns.map((column) => (
                <th key={column.key} className="px-4 py-3 font-medium">
                  {column.label}
                </th>
              ))}
              <th className="px-4 py-3 font-medium">Slug</th>
            </tr>
          </thead>
          <tbody>
            {rows.map((row) => (
              <tr
                key={row.id}
                className="cursor-pointer border-b border-[#4a6b72]/10 last:border-0 hover:bg-[#f6fbfc]"
                onClick={() => navigate(`/admin/${manifest.key}/${row.id}`)}
              >
                {manifest.list.columns.map((column) => (
                  <td
                    key={column.key}
                    className={`px-4 py-3 ${
                      column.primary ? "font-medium text-[#26454c]" : "text-[#4a6b72]"
                    }`}
                  >
                    {column.widget === "bool"
                      ? row[column.key]
                        ? "Yes"
                        : "—"
                      : row[column.key] || "—"}
                  </td>
                ))}
                <td className="px-4 py-3 font-mono text-xs text-[#4a6b72]">{row.id}</td>
              </tr>
            ))}
          </tbody>
        </table>

        {!loading && rows.length === 0 && (
          <p className="px-4 py-8 text-center text-[#4a6b72]">Nothing matches.</p>
        )}
        {loading && <p className="px-4 py-8 text-center text-[#4a6b72]">Loading…</p>}
      </div>
    </div>
  );
}