'use client';

import { useState } from 'react';
import Link from 'next/link';
import { usePathname } from 'next/navigation';
import {
  Brain,
  Activity,
  ListTodo,
  GitBranch,
  Database,
  Settings,
  ChevronLeft,
  ChevronRight,
  Rocket,
  Github,
  X,
  Menu,
} from 'lucide-react';

const NAV_ITEMS = [
  { href: '/',          icon: Brain,     label: 'Agent',       desc: 'Run AI tasks' },
  { href: '/health',    icon: Activity,  label: 'Health',      desc: 'System status' },
  { href: '/queue',     icon: ListTodo,  label: 'Queue',       desc: 'Job queue' },
  { href: '/memory',    icon: Database,  label: 'Memory',      desc: 'Episodic memory' },
  { href: '/workspace', icon: GitBranch, label: 'Workspace',   desc: 'Projects' },
];

interface AppShellProps {
  children: React.ReactNode;
}

export default function AppShell({ children }: AppShellProps) {
  const pathname = usePathname();
  const [collapsed, setCollapsed] = useState(false);
  const [mobileOpen, setMobileOpen] = useState(false);

  return (
    <div className="flex min-h-screen">
      {/* ── Mobile overlay ── */}
      {mobileOpen && (
        <div
          className="fixed inset-0 z-30 bg-black/60 lg:hidden"
          onClick={() => setMobileOpen(false)}
        />
      )}

      {/* ── Left Sidebar ── */}
      <aside
        className={`
          fixed top-0 left-0 z-40 h-full flex flex-col
          bg-slate-900 border-r border-white/5
          transition-all duration-200 ease-in-out
          ${collapsed ? 'w-16' : 'w-56'}
          ${mobileOpen ? 'translate-x-0' : '-translate-x-full'}
          lg:translate-x-0 lg:static lg:h-auto lg:min-h-screen
        `}
      >
        {/* Logo */}
        <div className={`flex items-center gap-2 px-3 py-4 border-b border-white/5 ${collapsed ? 'justify-center' : ''}`}>
          <div className="flex items-center justify-center w-8 h-8 rounded-lg bg-brand-600/30 text-brand-400 shrink-0">
            <Rocket className="h-4 w-4" />
          </div>
          {!collapsed && (
            <div className="min-w-0">
              <p className="text-sm font-bold truncate">OpenHands</p>
              <p className="text-[10px] text-slate-500 truncate">Genspark AI OS</p>
            </div>
          )}
          {/* Collapse toggle — desktop only */}
          <button
            onClick={() => setCollapsed(v => !v)}
            className="ml-auto hidden lg:flex items-center justify-center w-6 h-6 rounded hover:bg-white/5 text-slate-500 hover:text-slate-300"
          >
            {collapsed ? <ChevronRight className="h-3.5 w-3.5" /> : <ChevronLeft className="h-3.5 w-3.5" />}
          </button>
          {/* Mobile close */}
          <button
            onClick={() => setMobileOpen(false)}
            className="ml-auto lg:hidden flex items-center justify-center w-6 h-6 rounded hover:bg-white/5 text-slate-500"
          >
            <X className="h-3.5 w-3.5" />
          </button>
        </div>

        {/* Phase badge */}
        {!collapsed && (
          <div className="mx-3 my-2">
            <span className="inline-flex items-center gap-1 text-[10px] bg-brand-600/20 text-brand-300 border border-brand-600/30 px-2 py-0.5 rounded-full w-full justify-center">
              ✅ Phase 4 Live
            </span>
          </div>
        )}

        {/* Nav items */}
        <nav className="flex-1 px-2 py-2 space-y-0.5 overflow-y-auto">
          {NAV_ITEMS.map(({ href, icon: Icon, label, desc }) => {
            const active = pathname === href || (href !== '/' && pathname.startsWith(href));
            return (
              <Link
                key={href}
                href={href}
                onClick={() => setMobileOpen(false)}
                className={`
                  flex items-center gap-3 rounded-lg px-2 py-2 text-sm transition-colors
                  ${active
                    ? 'bg-brand-600/20 text-brand-300 border border-brand-600/20'
                    : 'text-slate-400 hover:text-slate-200 hover:bg-white/5'
                  }
                  ${collapsed ? 'justify-center' : ''}
                `}
                title={collapsed ? label : undefined}
              >
                <Icon className={`h-4 w-4 shrink-0 ${active ? 'text-brand-400' : ''}`} />
                {!collapsed && (
                  <div className="min-w-0">
                    <p className="font-medium leading-none">{label}</p>
                    <p className="text-[10px] text-slate-500 mt-0.5 truncate">{desc}</p>
                  </div>
                )}
              </Link>
            );
          })}
        </nav>

        {/* Bottom — Settings link */}
        <div className="border-t border-white/5 px-2 py-2 space-y-0.5">
          <Link
            href="/settings"
            onClick={() => setMobileOpen(false)}
            className={`
              flex items-center gap-3 rounded-lg px-2 py-2 text-sm transition-colors
              ${pathname === '/settings'
                ? 'bg-slate-700/50 text-slate-200'
                : 'text-slate-500 hover:text-slate-300 hover:bg-white/5'
              }
              ${collapsed ? 'justify-center' : ''}
            `}
            title={collapsed ? 'Settings' : undefined}
          >
            <Settings className="h-4 w-4 shrink-0" />
            {!collapsed && <span className="font-medium">Settings</span>}
          </Link>

          {!collapsed && (
            <a
              href="https://github.com/pyaesonegtckglay-dotcom/Onehands-development"
              target="_blank"
              rel="noreferrer"
              className="flex items-center gap-3 rounded-lg px-2 py-1.5 text-xs text-slate-600 hover:text-slate-400 hover:bg-white/5 transition-colors"
            >
              <Github className="h-3.5 w-3.5 shrink-0" />
              <span>GitHub</span>
            </a>
          )}
        </div>
      </aside>

      {/* ── Main content area ── */}
      <div className="flex-1 flex flex-col min-w-0">
        {/* Mobile top bar */}
        <header className="lg:hidden flex items-center gap-3 px-4 py-3 border-b border-white/5 bg-slate-900/80 backdrop-blur sticky top-0 z-20">
          <button
            onClick={() => setMobileOpen(true)}
            className="flex items-center justify-center w-8 h-8 rounded-lg hover:bg-white/5 text-slate-400"
          >
            <Menu className="h-5 w-5" />
          </button>
          <div className="flex items-center gap-2">
            <Rocket className="h-4 w-4 text-brand-400" />
            <span className="font-bold text-sm">OpenHands</span>
          </div>
          <div className="ml-auto">
            <span className="text-[10px] text-brand-400 border border-brand-600/30 bg-brand-600/10 px-2 py-0.5 rounded-full">
              Phase 4
            </span>
          </div>
        </header>

        {/* Page content */}
        <main className="flex-1 overflow-auto">
          {children}
        </main>
      </div>
    </div>
  );
}