"use client";

import { useState } from "react";
import Link from "next/link";
import { usePathname, useRouter } from "next/navigation";
import { useUnconfiguredNodes } from "@/lib/useNodes";
import { useUnacknowledgedAlerts } from "@/lib/useAlerts";
import { useAuth } from "@/components/AuthProvider";
import { useTheme } from "@/components/ThemeProvider";
import { FOUNDING_ORG_ID } from "@/lib/tenancy";

// Links visible to all authenticated roles (viewer+)
const viewerLinks = [
  { href: "/dashboard", label: "Dashboard" },
  { href: "/calls",     label: "Calls" },
  { href: "/incidents", label: "Incidents" },
  { href: "/map",       label: "Map" },
  { href: "/alerts",    label: "Alerts" },
];

// Trips is an internal utility feature, not a tenant-scoped product surface
// (see [[trips-feature-intentional]] and SAAS_PLAN.md B7) — shown only to
// the founding org, matching routers/trips.py's own gating.
const tripsLink = { href: "/trips", label: "Trips" };

// Additional links for operators and admins
const operatorLinks = [
  { href: "/nodes",   label: "Nodes" },
  { href: "/systems", label: "Systems" },
  { href: "/tokens",  label: "Tokens" },
];

// Platform-admin-only link. Settings is handled separately below — it's
// customer-facing for org owners too, not admin-only (SAAS_PLAN.md B7).
const adminLinks = [
  { href: "/admin", label: "Admin" },
];

function SunIcon() {
  return (
    <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
      <circle cx="12" cy="12" r="5"/>
      <line x1="12" y1="1" x2="12" y2="3"/>
      <line x1="12" y1="21" x2="12" y2="23"/>
      <line x1="4.22" y1="4.22" x2="5.64" y2="5.64"/>
      <line x1="18.36" y1="18.36" x2="19.78" y2="19.78"/>
      <line x1="1" y1="12" x2="3" y2="12"/>
      <line x1="21" y1="12" x2="23" y2="12"/>
      <line x1="4.22" y1="19.78" x2="5.64" y2="18.36"/>
      <line x1="18.36" y1="5.64" x2="19.78" y2="4.22"/>
    </svg>
  );
}

function MoonIcon() {
  return (
    <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
      <path d="M21 12.79A9 9 0 1 1 11.21 3 7 7 0 0 0 21 12.79z"/>
    </svg>
  );
}

export function Nav() {
  const { user, isAdmin, isOperator, isOrgOwner, orgId, signOut, refreshClaims } = useAuth();
  const pathname = usePathname();
  const router = useRouter();
  const { nodes: pending } = useUnconfiguredNodes();
  const unackedAlerts = useUnacknowledgedAlerts();
  const { theme, toggle } = useTheme();
  const [mobileOpen, setMobileOpen] = useState(false);
  const [profileMenuOpen, setProfileMenuOpen] = useState(false);
  const [refreshing, setRefreshing] = useState(false);

  if (!user) return null;

  async function handleSignOut() {
    setProfileMenuOpen(false);
    await signOut();
    router.push("/login");
  }

  // Re-fetches the ID token so a claims change made server-side (e.g. an
  // admin granting a role, or org_id being provisioned) takes effect without
  // a full sign-out/sign-in. See AuthProvider.refreshClaims.
  async function handleRefreshClaims() {
    setRefreshing(true);
    try {
      await refreshClaims();
    } finally {
      setRefreshing(false);
      setProfileMenuOpen(false);
    }
  }

  const allLinks = [
    ...viewerLinks,
    ...(orgId === FOUNDING_ORG_ID || isAdmin ? [tripsLink] : []),
    ...(isAdmin || isOperator ? operatorLinks : []),
    ...(isAdmin ? adminLinks : []),
    ...(isAdmin || isOrgOwner ? [{ href: "/settings", label: "Settings" }] : []),
  ];

  function navLinkClass(href: string) {
    return `text-sm font-mono transition-colors shrink-0 ${
      pathname.startsWith(href) ? "text-white" : "text-gray-500 hover:text-gray-300"
    }`;
  }

  return (
    <nav className="sticky top-0 z-40 border-b border-gray-800 bg-gray-950/95 backdrop-blur">
      {/* Main bar */}
      <div className="px-4 md:px-6 py-3 flex items-center gap-4 md:gap-6">
        <span className="font-mono font-bold text-white tracking-tight shrink-0">DRB</span>

        {/* Desktop links */}
        <div className="hidden md:flex items-center gap-6 overflow-x-auto">
          {allLinks.map(({ href, label }) => (
            <Link key={href} href={href} className={navLinkClass(href)}>
              {label}
              {label === "Nodes" && pending.length > 0 && (
                <span className="ml-1.5 inline-flex items-center justify-center w-4 h-4 rounded-full bg-yellow-500 text-gray-950 text-xs font-bold">
                  {pending.length}
                </span>
              )}
              {label === "Alerts" && unackedAlerts.length > 0 && (
                <span className="ml-1.5 inline-flex items-center justify-center min-w-[1rem] h-4 rounded-full bg-red-600 text-white text-xs font-bold px-1">
                  {unackedAlerts.length}
                </span>
              )}
            </Link>
          ))}
        </div>

        <div className="ml-auto flex items-center gap-3 shrink-0">
          {/* Theme toggle */}
          <button
            onClick={toggle}
            className="text-gray-500 hover:text-gray-300 transition-colors"
            title={theme === "dark" ? "Switch to light mode" : "Switch to dark mode"}
          >
            {theme === "dark" ? <SunIcon /> : <MoonIcon />}
          </button>

          {/* Profile avatar + dropdown (desktop) */}
          <div className="hidden md:block relative">
            <button
              onClick={() => setProfileMenuOpen((v) => !v)}
              className={`flex items-center justify-center w-7 h-7 rounded-full text-xs font-bold transition-colors ${
                pathname.startsWith("/profile") || profileMenuOpen
                  ? "bg-indigo-600 text-white"
                  : "bg-gray-800 text-gray-300 hover:bg-gray-700"
              }`}
              title="Account"
            >
              {(user?.displayName || user?.email || "?")[0].toUpperCase()}
            </button>

            {profileMenuOpen && (
              <>
                {/* Click-away backdrop */}
                <div className="fixed inset-0 z-40" onClick={() => setProfileMenuOpen(false)} />
                <div className="absolute right-0 mt-2 w-48 bg-gray-900 border border-gray-800 rounded-lg shadow-lg z-50 py-1 font-mono text-sm">
                  <Link
                    href="/profile"
                    onClick={() => setProfileMenuOpen(false)}
                    className="block px-3 py-2 text-gray-300 hover:bg-gray-800 hover:text-white transition-colors"
                  >
                    Profile
                  </Link>
                  <button
                    onClick={handleRefreshClaims}
                    disabled={refreshing}
                    className="w-full text-left px-3 py-2 text-gray-300 hover:bg-gray-800 hover:text-white transition-colors disabled:opacity-50"
                    title="Pick up a role or org change made server-side, without signing out"
                  >
                    {refreshing ? "Refreshing…" : "Refresh access"}
                  </button>
                  <div className="border-t border-gray-800 my-1" />
                  <button
                    onClick={handleSignOut}
                    className="w-full text-left px-3 py-2 text-red-500 hover:bg-gray-800 hover:text-red-400 transition-colors"
                  >
                    Sign out
                  </button>
                </div>
              </>
            )}
          </div>

          {/* Hamburger (mobile) */}
          <button
            onClick={() => setMobileOpen((v) => !v)}
            className="md:hidden text-gray-400 hover:text-gray-200 transition-colors p-1"
            aria-label="Toggle menu"
          >
            {mobileOpen ? (
              <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round">
                <line x1="18" y1="6" x2="6" y2="18"/><line x1="6" y1="6" x2="18" y2="18"/>
              </svg>
            ) : (
              <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round">
                <line x1="3" y1="12" x2="21" y2="12"/><line x1="3" y1="6" x2="21" y2="6"/><line x1="3" y1="18" x2="21" y2="18"/>
              </svg>
            )}
          </button>
        </div>
      </div>

      {/* Mobile drawer */}
      {mobileOpen && (
        <div className="md:hidden border-t border-gray-800 bg-gray-950 px-4 py-3 flex flex-col gap-1">
          {allLinks.map(({ href, label }) => (
            <Link
              key={href}
              href={href}
              onClick={() => setMobileOpen(false)}
              className={`py-2 text-sm font-mono transition-colors flex items-center gap-2 ${
                pathname.startsWith(href) ? "text-white" : "text-gray-500"
              }`}
            >
              {label}
              {label === "Nodes" && pending.length > 0 && (
                <span className="inline-flex items-center justify-center w-4 h-4 rounded-full bg-yellow-500 text-gray-950 text-xs font-bold">
                  {pending.length}
                </span>
              )}
              {label === "Alerts" && unackedAlerts.length > 0 && (
                <span className="inline-flex items-center justify-center min-w-[1rem] h-4 rounded-full bg-red-600 text-white text-xs font-bold px-1">
                  {unackedAlerts.length}
                </span>
              )}
            </Link>
          ))}
          <div className="border-t border-gray-800 pt-3 mt-1 flex flex-col gap-1">
            <Link
              href="/profile"
              onClick={() => setMobileOpen(false)}
              className={`py-2 text-sm font-mono transition-colors flex items-center gap-2 ${
                pathname.startsWith("/profile") ? "text-white" : "text-gray-500"
              }`}
            >
              Profile
            </Link>
            <button
              onClick={() => { setMobileOpen(false); handleRefreshClaims(); }}
              disabled={refreshing}
              className="py-2 text-sm font-mono text-gray-500 text-left disabled:opacity-50"
            >
              {refreshing ? "Refreshing…" : "Refresh access"}
            </button>
            <button
              onClick={() => { setMobileOpen(false); handleSignOut(); }}
              className="py-2 text-sm font-mono text-red-500 text-left"
            >
              Sign out
            </button>
          </div>
        </div>
      )}
    </nav>
  );
}