import { Outlet, NavLink, useNavigate } from 'react-router-dom'
import { useAuthStore } from '../stores/authStore'
import { Workflow, Play, Settings, LogOut, Menu, Database, Code, Key, FolderKanban} from 'lucide-react'
import { useState, useEffect } from 'react'
import { useQuery } from '@tanstack/react-query'
import { useProjectStore } from '../stores/projectStore'
import { projectsApi } from '../api/users'
import clsx from 'clsx'
import { ThemeToggle } from './ThemeToggle'

export default function Layout() {
  const { user, logout } = useAuthStore()
  const navigate = useNavigate()
  const projectId = useProjectStore((s) => s.projectId)
  const setProject = useProjectStore((s) => s.setProject)

  const { data: projects = [] } = useQuery({
    queryKey: ['projects'],
    queryFn: () => projectsApi.list(),
    staleTime: 5 * 60 * 1000,
  })

  // A project that has gone - deleted, or access removed - would otherwise
  // leave the selector showing a blank and every page filtering to nothing.
  useEffect(() => {
    if (projectId && projects.length && !projects.some((p) => p._id === projectId)) {
      setProject(null)
    }
  }, [projectId, projects, setProject])
  const [sidebarOpen, setSidebarOpen] = useState(false)

  const handleLogout = () => {
    logout()
    navigate('/login')
  }

  const navItems = [
    { to: '/workflows', icon: Workflow, label: 'Workflows' },
    { to: '/executions', icon: Play, label: 'Executions' },
    { to: '/nodes', icon: Code, label: 'Nodes' },
    { to: '/credentials', icon: Key, label: 'Credentials' },
    { to: '/projects', icon: FolderKanban, label: 'Projects' },
    { to: '/database', icon: Database, label: 'Database' },
    { to: '/settings', icon: Settings, label: 'Settings' },
  ]

  return (
    <div className="h-screen bg-gray-50 dark:bg-slate-900 flex transition-colors overflow-hidden">
      {/* Mobile sidebar backdrop */}
      {sidebarOpen && (
        <div
          className="fixed inset-0 bg-black/50 z-20 lg:hidden"
          onClick={() => setSidebarOpen(false)}
        />
      )}

      {/* Sidebar */}
      <aside
        className={clsx(
          'fixed lg:static inset-y-0 left-0 z-30 w-64 bg-white dark:bg-slate-800 border-r border-gray-200 dark:border-slate-700 transform transition-transform lg:transform-none',
          sidebarOpen ? 'translate-x-0' : '-translate-x-full lg:translate-x-0'
        )}
      >
        <div className="flex flex-col h-full">
          {/* Logo */}
          <div className="flex items-center h-16 px-6 border-b border-gray-200 dark:border-slate-700">
            <span className="text-xl font-bold text-primary-600 dark:text-primary-400">SmartBotic</span>
          </div>

          {/* Which project everything below is showing. Above the navigation
              rather than inside a page, because it decides what several pages
              show and used to be visible on only one of them. */}
          <div className="px-4 pt-4">
            <label className="block text-[11px] uppercase tracking-wide text-gray-400 dark:text-gray-500 mb-1">
              Project
            </label>
            <select
              value={projectId ?? ''}
              onChange={(e) => setProject(e.target.value || null)}
              className="w-full px-2 py-1.5 text-sm border border-gray-300 dark:border-slate-600 rounded-lg bg-white dark:bg-slate-900 text-gray-900 dark:text-gray-100"
              title={
                projectId
                  ? 'Workflows, folders and executions are limited to this project'
                  : 'Showing every project you can reach'
              }
            >
              <option value="">All projects</option>
              {projects.map((p) => (
                <option key={p._id} value={p._id}>{p.name}</option>
              ))}
            </select>
          </div>

          {/* Navigation */}
          <nav className="flex-1 p-4 space-y-1">
            {navItems.map((item) => (
              <NavLink
                key={item.to}
                to={item.to}
                className={({ isActive }) =>
                  clsx(
                    'flex items-center gap-3 px-4 py-2 rounded-lg transition-colors',
                    isActive
                      ? 'bg-primary-50 dark:bg-primary-900/30 text-primary-700 dark:text-primary-400'
                      : 'text-gray-600 dark:text-gray-400 hover:bg-gray-100 dark:hover:bg-slate-700'
                  )
                }
                onClick={() => setSidebarOpen(false)}
              >
                <item.icon className="w-5 h-5" />
                {item.label}
              </NavLink>
            ))}
          </nav>

          {/* Theme toggle */}
          <div className="px-4 pb-2">
            <ThemeToggle />
          </div>

          {/* User section */}
          <div className="p-4 border-t border-gray-200 dark:border-slate-700">
            <div className="flex items-center justify-between">
              <div className="flex items-center gap-3">
                <div className="w-8 h-8 bg-primary-100 dark:bg-primary-900/50 rounded-full flex items-center justify-center">
                  <span className="text-primary-700 dark:text-primary-400 font-medium text-sm">
                    {user?.username?.[0]?.toUpperCase()}
                  </span>
                </div>
                <div>
                  <p className="text-sm font-medium text-gray-900 dark:text-gray-100">{user?.username}</p>
                  <p className="text-xs text-gray-500 dark:text-gray-400">{user?.role}</p>
                </div>
              </div>
              <button
                onClick={handleLogout}
                className="p-2 text-gray-400 hover:text-gray-600 dark:hover:text-gray-300 rounded-lg hover:bg-gray-100 dark:hover:bg-slate-700"
                title="Logout"
              >
                <LogOut className="w-5 h-5" />
              </button>
            </div>
          </div>
        </div>
      </aside>

      {/* Main content */}
      <div className="flex-1 flex flex-col min-w-0">
        {/* Mobile header */}
        <header className="lg:hidden flex items-center h-16 px-4 bg-white dark:bg-slate-800 border-b border-gray-200 dark:border-slate-700">
          <button
            onClick={() => setSidebarOpen(true)}
            className="p-2 text-gray-600 dark:text-gray-400 hover:bg-gray-100 dark:hover:bg-slate-700 rounded-lg"
          >
            <Menu className="w-6 h-6" />
          </button>
          <span className="ml-4 text-lg font-semibold text-gray-900 dark:text-gray-100">SmartBotic</span>
        </header>

        {/* Page content */}
        <main className="flex-1 overflow-hidden">
          <Outlet />
        </main>
      </div>
    </div>
  )
}