import React, { useState } from 'react';
import { NavLink, Outlet } from 'react-router-dom';
import { useUIStore } from '@/store/uiStore';
import { ChevronRight, ChevronDown, Zap, Play, History, GitBranch, Settings2, Activity, Clock, ArrowLeft } from 'lucide-react';

interface AutomationNode {
  title: string;
  path?: string;
  icon?: React.ReactNode;
  children?: AutomationNode[];
}

const AUTOMATION_TREE: AutomationNode[] = [
  {
    title: 'Automation',
    icon: <Zap className="w-4 h-4" />,
    children: [
      { title: 'Übersicht', path: '/automation/overview' },
      { title: 'Ausführungen', path: '/automation/runs' },
      { title: 'Versionen', path: '/automation/versions' },
    ],
  },
  {
    title: 'Einstellungen',
    icon: <Settings2 className="w-4 h-4" />,
    children: [
      { title: 'Trigger', path: '/automation/triggers' },
      { title: 'Aktionen', path: '/automation/actions' },
      { title: 'Bedingungen', path: '/automation/conditions' },
    ],
  },
];

function TreeItem({ node, depth }: { node: AutomationNode; depth: number }) {
  const [expanded, setExpanded] = useState(depth < 1);
  const hasChildren = node.children && node.children.length > 0;
  const paddingLeft = depth * 16 + 12;

  if (hasChildren) {
    return (
      <div>
        <button
          onClick={() => setExpanded(!expanded)}
          className="w-full flex items-center gap-2 px-3 py-2 rounded-lg text-sm font-medium text-secondary-700 hover:bg-secondary-100 transition-colors min-h-touch"
          style={{ paddingLeft }}
          aria-expanded={expanded}
        >
          {expanded ? <ChevronDown className="w-3.5 h-3.5 flex-shrink-0" /> : <ChevronRight className="w-3.5 h-3.5 flex-shrink-0" />}
          {node.icon}
          <span>{node.title}</span>
        </button>
        {expanded && (
          <div>
            {node.children!.map((child) => (
              <TreeItem key={child.path || child.title} node={child} depth={depth + 1} />
            ))}
          </div>
        )}
      </div>
    );
  }

  return (
    <NavLink
      to={node.path!}
      className={({ isActive }) =>
        `flex items-center gap-2 px-3 py-2 rounded-lg text-sm transition-colors min-h-touch ${
          isActive
            ? 'bg-primary-100 text-primary-700 font-medium'
            : 'text-secondary-600 hover:bg-secondary-100 hover:text-secondary-900'
        }`
      }
      style={{ paddingLeft: paddingLeft + 20 }}
    >
      {node.icon}
      <span>{node.title}</span>
    </NavLink>
  );
}

export function AutomationPage() {
  const sidebarOpen = useUIStore((state) => state.sidebarOpen);

  return (
    <div className="flex h-full overflow-hidden" data-testid="automation-page">
      <aside className={`${sidebarOpen ? 'w-64 border-r border-secondary-200' : 'w-0'} flex-shrink-0 min-h-[calc(100vh-4rem)] transition-all duration-200 overflow-hidden`}>
        <div className="w-64 flex-shrink-0 p-4">
          <div className="flex items-center gap-2 mb-4">
            <button
              onClick={() => window.location.href = '/start'}
              className="p-1.5 rounded-md text-secondary-400 hover:bg-secondary-100 hover:text-secondary-700 flex items-center justify-center focus:outline-none"
              aria-label="Zurück zur Startseite"
              title="Zurück zur Startseite"
            >
              <ArrowLeft className="w-4 h-4" />
            </button>
            <h1 className="text-xl font-bold text-secondary-900">Automation</h1>
          </div>
          <nav className="space-y-0.5 overflow-y-auto" role="navigation" aria-label="Automation Navigation">
            {AUTOMATION_TREE.map((node) => (
              <TreeItem key={node.title} node={node} depth={0} />
            ))}
          </nav>
        </div>
      </aside>
      <main className="flex-1 p-6 overflow-y-auto" data-testid="automation-content">
        <Outlet />
      </main>
    </div>
  );
}