"use client";

import { useCallback, useEffect, useState } from "react";
import { c2api } from "@/lib/c2api";
import { useAuth } from "@/components/AuthProvider";
import type { UserRecord, UserRole } from "@/lib/types";
import { Card } from "@/components/ui/Card";
import { Badge } from "@/components/ui/Badge";
import { Button } from "@/components/ui/Button";
import { EmptyState, ErrorBanner } from "@/components/ui/EmptyState";
import { SkeletonRow } from "@/components/ui/Skeleton";

const ROLE_TONE: Record<UserRole, "brand" | "success" | "neutral"> = {
  admin: "brand",
  operator: "success",
  viewer: "neutral",
};

const ROLE_LABEL: Record<UserRole, string> = { admin: "Admin", operator: "Operator", viewer: "Viewer" };

function InviteModal({ onClose, onCreated }: { onClose: () => void; onCreated: (u: UserRecord) => void }) {
  const [email, setEmail] = useState("");
  const [role, setRole] = useState<UserRole>("viewer");
  const [saving, setSaving] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [inviteLink, setInviteLink] = useState<string | null>(null);

  async function handleSubmit(e: React.FormEvent) {
    e.preventDefault();
    setSaving(true);
    setError(null);
    try {
      const created = await c2api.createUser({ email, role });
      onCreated(created);
      if (created.invite_link) setInviteLink(created.invite_link);
      else onClose();
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
    } finally {
      setSaving(false);
    }
  }

  if (inviteLink) {
    return (
      <div className="fixed inset-0 z-50 bg-black/70 flex items-center justify-center p-4">
        <Card padding="lg" className="w-full max-w-md space-y-4">
          <h2 className="text-white font-semibold">Member invited</h2>
          <p className="text-xs text-gray-400">Share this one-time invite link so they can set their password. It expires after use.</p>
          <div className="bg-gray-800 border border-gray-700 rounded-lg p-3">
            <p className="text-xs text-indigo-300 break-all">{inviteLink}</p>
          </div>
          <Button onClick={onClose} fullWidth>Done</Button>
        </Card>
      </div>
    );
  }

  return (
    <div className="fixed inset-0 z-50 bg-black/70 flex items-center justify-center p-4">
      <Card padding="lg" className="w-full max-w-md">
        <h2 className="text-white font-semibold mb-4">Invite a member</h2>
        <form onSubmit={handleSubmit} className="space-y-4">
          <div>
            <label className="text-xs text-gray-400 block mb-1">Email</label>
            <input
              type="email" required value={email} onChange={(e) => setEmail(e.target.value)}
              className="w-full bg-gray-800 border border-gray-700 rounded-lg px-3 py-2 text-white text-sm focus:outline-none focus:border-indigo-500"
              placeholder="teammate@example.com"
            />
          </div>
          <div>
            <label className="text-xs text-gray-400 block mb-1">Role</label>
            <select
              value={role} onChange={(e) => setRole(e.target.value as UserRole)}
              className="w-full bg-gray-800 border border-gray-700 rounded-lg px-3 py-2 text-white text-sm focus:outline-none focus:border-indigo-500"
            >
              <option value="admin">Admin — full access</option>
              <option value="operator">Operator — owns nodes</option>
              <option value="viewer">Viewer — read-only</option>
            </select>
          </div>
          {error && <p className="text-red-400 text-xs">{error}</p>}
          <div className="flex gap-3 pt-1">
            <Button type="submit" disabled={saving} fullWidth>{saving ? "Sending…" : "Send invite"}</Button>
            <Button type="button" variant="secondary" onClick={onClose} fullWidth>Cancel</Button>
          </div>
        </form>
      </Card>
    </div>
  );
}

export default function MembersSettingsPage() {
  const { user } = useAuth();
  const [users, setUsers] = useState<UserRecord[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [showInvite, setShowInvite] = useState(false);
  const [savingUid, setSavingUid] = useState<string | null>(null);

  const load = useCallback(async () => {
    try {
      setUsers(await c2api.listUsers());
    } catch (e) {
      setError(e instanceof Error ? e.message : String(e));
    } finally {
      setLoading(false);
    }
  }, []);

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

  async function handleRoleChange(u: UserRecord, role: UserRole) {
    setSavingUid(u.uid);
    try {
      const updated = await c2api.updateUser(u.uid, { role, owned_node_ids: role === "operator" ? u.owned_node_ids : [] });
      setUsers((prev) => prev.map((x) => (x.uid === u.uid ? { ...x, ...updated } : x)));
    } catch (e) {
      setError(e instanceof Error ? e.message : String(e));
    } finally {
      setSavingUid(null);
    }
  }

  return (
    <div className="space-y-4">
      {showInvite && (
        <InviteModal onClose={() => setShowInvite(false)} onCreated={(u) => setUsers((prev) => [...prev, u])} />
      )}

      <div className="flex items-center justify-between">
        <p className="text-sm text-gray-500">
          {loading ? "Loading members…" : `${users.length} member${users.length !== 1 ? "s" : ""}`}
        </p>
        <Button size="sm" onClick={() => setShowInvite(true)}>+ Invite member</Button>
      </div>

      {error && <ErrorBanner message={error} />}

      {!loading && users.length === 0 ? (
        <EmptyState title="No members yet" description="Invite your team to give them dashboard access." />
      ) : (
        <Card padding="none" className="overflow-hidden">
          <table className="w-full text-sm">
            <thead>
              <tr className="text-xs text-gray-500 uppercase tracking-wider border-b border-gray-800 bg-gray-900">
                <th className="px-4 py-3 text-left">Member</th>
                <th className="px-4 py-3 text-left">Role</th>
                <th className="px-4 py-3 text-left hidden sm:table-cell">Owned nodes</th>
                <th className="px-4 py-3 text-left hidden md:table-cell">Status</th>
              </tr>
            </thead>
            <tbody>
              {loading
                ? Array.from({ length: 3 }).map((_, i) => <SkeletonRow key={i} cols={4} />)
                : users.map((u) => (
                    <tr key={u.uid} className="border-b border-gray-800 last:border-0">
                      <td className="px-4 py-3">
                        <p className="text-white">{u.display_name || u.email}</p>
                        {u.display_name && <p className="text-gray-600 text-xs">{u.email}</p>}
                      </td>
                      <td className="px-4 py-3">
                        {u.uid === user?.uid ? (
                          <Badge tone={ROLE_TONE[u.role]}>{ROLE_LABEL[u.role]}</Badge>
                        ) : (
                          <select
                            value={u.role}
                            disabled={savingUid === u.uid}
                            onChange={(e) => handleRoleChange(u, e.target.value as UserRole)}
                            className="bg-gray-800 border border-gray-700 rounded-lg px-2 py-1 text-xs text-white focus:outline-none focus:border-indigo-500 disabled:opacity-50"
                          >
                            <option value="admin">Admin</option>
                            <option value="operator">Operator</option>
                            <option value="viewer">Viewer</option>
                          </select>
                        )}
                      </td>
                      <td className="px-4 py-3 text-gray-400 text-xs hidden sm:table-cell">
                        {u.role === "operator" ? u.owned_node_ids.length : "—"}
                      </td>
                      <td className="px-4 py-3 hidden md:table-cell">
                        {u.disabled ? <Badge tone="danger">Disabled</Badge> : <Badge tone="success">Active</Badge>}
                      </td>
                    </tr>
                  ))}
            </tbody>
          </table>
        </Card>
      )}

      <p className="text-xs text-gray-600 font-mono">
        Need to disable or delete a member? Use the full user admin panel under Admin → Users.
      </p>
    </div>
  );
}