// components/NavBar.tsx
// Top-of-page navigation. Logo lockup on the left, primary nav
// center, secondary status on the right. Sticky on scroll with the
// signature hairline border-bottom.
//
// Mobile (<md): a fixed bottom tab bar with inline-SVG icons (Overview
// · Directors · Companies · Onboarding). The second-row horizontal
// scroller from earlier turns has been replaced because the tab bar
// is the standard mobile-app pattern and reclaims vertical screen
// real estate.
//
// Icons use stroke-currentColor at 1.6px per the design system
// (anti-slop rule: emoji and gradient icons are forbidden). Brand
// mark "Y" pill in the top-left stays on all viewports.

"use client";

import Link from "next/link";
import { usePathname } from "next/navigation";
import { useTheme } from "next-themes";
import { useEffect, useState } from "react";
import type { ReactNode } from "react";

const LINKS = [
  { href: "/", label: "Overview", icon: IconHome },
  { href: "/bizportal", label: "BizPortal", icon: IconSearch },
  { href: "/bizportal-2", label: "BizPortal 2.0", icon: IconSearch, badge: "test" },
  { href: "/tasks", label: "Tasks", icon: IconClipboard },
  { href: "/directors", label: "Directors", icon: IconUsers },
  { href: "/companies", label: "Companies", icon: IconBuilding },
  { href: "/groups", label: "Groups", icon: IconTag },
  { href: "/resolutions", label: "Resolutions", icon: IconDocument },
] as const;

export default function NavBar() {
  const pathname = usePathname() ?? "/";

  return (
    <>
      <header
        data-od-id="navbar"
        className="sticky top-0 z-30 bg-surface border-b border-border"
      >
        <div className="container-x flex items-center justify-between h-20">
          <Link
            href="/"
            data-od-id="brand-mark"
            className="flex items-center gap-2 no-underline"
          >
            <span
              aria-hidden="true"
              className="inline-flex items-center justify-center w-8 h-8 rounded-pill bg-accent text-accent-on font-bold text-sm"
            >
              Y
            </span>
            <span className="text-lg font-bold text-fg tracking-tight">
              Workflow
            </span>
          </Link>

          <nav
            className="hidden md:flex items-center gap-2"
            aria-label="Primary"
          >
            {LINKS.map((link) => {
              const isActive = isActiveLink(pathname, link.href);
              return (
                <Link
                  key={link.href}
                  href={link.href}
                  data-od-id={`nav-${link.label.toLowerCase().replace(/\s+/g, "-")}`}
                  className={
                    "px-4 py-2 rounded-md text-sm font-semibold no-underline transition-colors inline-flex items-center gap-2 " +
                    (isActive
                      ? "bg-surface-warm text-fg"
                      : "text-fg hover:bg-surface-warm")
                  }
                >
                  <span>{link.label}</span>
                  {"badge" in link && link.badge ? (
                    <span className="text-[10px] font-bold uppercase tracking-wider px-1.5 py-0.5 rounded bg-amber-100 text-amber-800 border border-amber-300">
                      {link.badge}
                    </span>
                  ) : null}
                </Link>
              );
            })}
          </nav>

          {/* Right-side desktop cluster: label + theme toggle. Hidden
              on mobile — the bottom tab bar carries the brand context. */}
          <div className="hidden md:flex items-center gap-3">
            <span className="text-xs text-muted">Registry Browser</span>
            <ThemeToggle />
          </div>

          {/* Spacer for mobile so the brand lockup stays left-aligned
              and the bottom-bar height is the only vertical change. */}
          <div className="md:hidden" aria-hidden="true" />
        </div>
      </header>

      {/* Mobile bottom tab bar */}
      <nav
        className="md:hidden fixed inset-x-0 bottom-0 z-30 bg-surface border-t border-border pb-[env(safe-area-inset-bottom)]"
        aria-label="Primary"
      >
        <ul className="container-x flex items-stretch justify-between h-16 px-2">
          {LINKS.map((link) => {
            const isActive = isActiveLink(pathname, link.href);
            const Icon = link.icon;
            return (
              <li key={link.href} className="flex-1">
                <Link
                  href={link.href}
                  aria-current={isActive ? "page" : undefined}
                  aria-label={link.label}
                  className={
                    "group flex flex-col items-center justify-center gap-1 h-full no-underline transition-colors " +
                    (isActive
                      ? "text-accent"
                      : "text-muted hover:text-fg")
                  }
                >
                  <Icon
                    className={
                      "w-5 h-5 transition-transform " +
                      (isActive ? "scale-110" : "scale-100")
                    }
                    active={isActive}
                  />
                  <span className="text-[11px] font-semibold tracking-wide">
                    {link.label}
                  </span>
                </Link>
              </li>
            );
          })}
        </ul>
      </nav>
    </>
  );
}

function isActiveLink(pathname: string, href: string): boolean {
  if (href === "/") return pathname === "/";
  return pathname === href || pathname.startsWith(href + "/");
}

/* ─── Icon set (inline SVG, stroke-currentColor, 1.6px stroke) ──── */

interface IconProps {
  className?: string;
  /** Active state hints — used to swap fill behavior on the home icon
   *  and to thicken the stroke on outlined icons. Always defaults to
   *  the brand "muted" rendering since the active state is owned by
   *  the parent (text color + scale already encodes it). */
  active?: boolean;
}

function IconHome({ className, active }: IconProps): ReactNode {
  return (
    <svg
      viewBox="0 0 24 24"
      fill={active ? "currentColor" : "none"}
      stroke="currentColor"
      strokeWidth={1.6}
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <path d="M3 11.5L12 4l9 7.5" />
      <path d="M5 10.5V20a1 1 0 0 0 1 1h4v-6h4v6h4a1 1 0 0 0 1-1v-9.5" />
    </svg>
  );
}

function IconUsers({ className }: IconProps): ReactNode {
  return (
    <svg
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth={1.6}
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <circle cx="9" cy="9" r="3.2" />
      <path d="M3.5 19c.7-3 3-4.6 5.5-4.6S13.8 16 14.5 19" />
      <circle cx="16.5" cy="9" r="2.6" />
      <path d="M15.2 14.4c2 0 4 1.4 4.6 4" />
    </svg>
  );
}

function IconBuilding({ className }: IconProps): ReactNode {
  return (
    <svg
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth={1.6}
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <rect x="4" y="3" width="16" height="18" rx="1.5" />
      <path d="M8 7h2M8 11h2M8 15h2M14 7h2M14 11h2M14 15h2" />
      <path d="M10 21v-3h4v3" />
    </svg>
  );
}

function IconDocument({ className }: IconProps): ReactNode {
  return (
    <svg
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth="1.6"
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z" />
      <polyline points="14,2 14,8 20,8" />
      <line x1="9" y1="13" x2="15" y2="13" />
      <line x1="9" y1="17" x2="13" y2="17" />
    </svg>
  );
}

function IconClipboard({ className }: IconProps): ReactNode {
  return (
    <svg
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth="1.6"
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <rect x="8" y="2" width="8" height="4" rx="1" />
      <path d="M16 4h2a2 2 0 0 1 2 2v14a2 2 0 0 1-2 2H6a2 2 0 0 1-2-2V6a2 2 0 0 1 2-2h2" />
      <line x1="9" y1="13" x2="15" y2="13" />
      <line x1="9" y1="17" x2="12" y2="17" />
    </svg>
  );
}

function IconSearch({ className }: IconProps): ReactNode {
  return (
    <svg
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth="1.6"
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <circle cx="11" cy="11" r="7" />
      <line x1="21" y1="21" x2="16.65" y2="16.65" />
    </svg>
  );
}

function IconTag({ className }: IconProps): ReactNode {
  return (
    <svg
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth="1.6"
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <path d="M20.59 13.41l-7.17 7.17a2 2 0 0 1-2.83 0L2 12V2h10l8.59 8.59a2 2 0 0 1 0 2.82z" />
      <line x1="7" y1="7" x2="7.01" y2="7" />
    </svg>
  );
}

/* ─── Theme toggle ────────────────────────────────────────────────── */

/**
 * Sun/moon button. Uses next-themes' `resolvedTheme` so system
 * preference is honoured. The icon shown represents the mode you'd
 * switch TO (moon in light, sun in dark).
 *
 * `mounted` guard avoids SSR/CSR mismatch — `useTheme` returns
 * undefined on the first render. Until mounted, we render a neutral
 * placeholder so the button's box doesn't pop in late.
 */
function ThemeToggle() {
  const [mounted, setMounted] = useState(false);
  const { resolvedTheme, setTheme } = useTheme();
  useEffect(() => setMounted(true), []);

  const isDark = mounted && resolvedTheme === "dark";
  const next = isDark ? "light" : "dark";

  return (
    <button
      type="button"
      onClick={() => setTheme(next)}
      aria-label={mounted ? `Switch to ${next} mode` : "Toggle theme"}
      title={`Switch to ${next} mode`}
      data-od-id="theme-toggle"
      className="inline-flex items-center justify-center w-9 h-9 rounded-md text-fg hover:bg-surface-warm transition-colors"
    >
      {mounted ? (
        isDark ? (
          <IconSun className="w-5 h-5" />
        ) : (
          <IconMoon className="w-5 h-5" />
        )
      ) : (
        // Neutral placeholder slot — same dimensions so layout doesn't shift.
        <span className="w-5 h-5 block" aria-hidden="true" />
      )}
    </button>
  );
}

function IconSun({ className }: IconProps): ReactNode {
  return (
    <svg
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth="1.6"
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <circle cx="12" cy="12" r="4" />
      <path d="M12 2v2M12 20v2M4.93 4.93l1.41 1.41M17.66 17.66l1.41 1.41M2 12h2M20 12h2M4.93 19.07l1.41-1.41M17.66 6.34l1.41-1.41" />
    </svg>
  );
}

function IconMoon({ className }: IconProps): ReactNode {
  return (
    <svg
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth="1.6"
      strokeLinecap="round"
      strokeLinejoin="round"
      className={className}
      aria-hidden="true"
    >
      <path d="M21 12.8A9 9 0 1 1 11.2 3a7 7 0 0 0 9.8 9.8z" />
    </svg>
  );
}