import React, { useState, useEffect, useContext } from 'react';
import Head from 'next/head';
import { 
  LayoutDashboard, 
  FolderKanban, 
  CheckSquare, 
  Users, 
  Settings, 
  Bell, 
  Search, 
  Menu,
  Moon,
  Sun,
  Plus,
  TrendingUp,
  TrendingDown,
  DollarSign,
  Activity,
  Calendar,
  MoreHorizontal,
  ChevronRight,
  Filter,
  Download,
  RefreshCw
} from 'lucide-react';
import { ThemeContext } from './_app';
import Sidebar from '@/components/Sidebar';
import Header from '@/components/Header';
import StatCard from '@/components/StatCard';
import RevenueChart from '@/components/RevenueChart';
import ProjectTable from '@/components/ProjectTable';
import TaskBoard from '@/components/TaskBoard';
import TeamPerformance from '@/components/TeamPerformance';
import RecentActivity from '@/components/RecentActivity';

export default function Home() {
  const { darkMode, toggleTheme } = useContext(ThemeContext);
  const [sidebarOpen, setSidebarOpen] = useState(false);
  const [loading, setLoading] = useState(true);
  const [stats, setStats] = useState(null);
  const [projects, setProjects] = useState([]);

  useEffect(() => {
    const fetchData = async () => {
      try {
        await new Promise(resolve => setTimeout(resolve, 1000));
        
        const statsRes = await fetch('/api/stats');
        const statsData = await statsRes.json();
        setStats(statsData);

        const projectsRes = await fetch('/api/projects');
        const projectsData = await projectsRes.json();
        setProjects(projectsData);
      } catch (error) {
        console.error('Error fetching data:', error);
      } finally {
        setLoading(false);
      }
    };

    fetchData();
  }, []);

  return (
    <div className={`min-h-screen flex ${darkMode ? 'dark' : ''}`}>
      {sidebarOpen && (
        <div 
          className="fixed inset-0 z-40 bg-gray-600 bg-opacity-75 lg:hidden"
          onClick={() => setSidebarOpen(false)}
        ></div>
      )}

      <Sidebar 
        isOpen={sidebarOpen} 
        onClose={() => setSidebarOpen(false)} 
      />

      <div className="flex-1 flex flex-col lg:pl-64 transition-all duration-300">
        <Header 
          onMenuClick={() => setSidebarOpen(true)} 
          onThemeToggle={toggleTheme}
          isDark={darkMode}
        />

        <main className="flex-1 p-4 lg:p-8 overflow-y-auto bg-gray-50 dark:bg-dark-bg">
          <div className="max-w-7xl mx-auto space-y-8 animate-fade-in">
            
            <div className="flex flex-col md:flex-row md:items-center md:justify-between animate-slide-up">
              <div>
                <h1 className="text-3xl font-bold text-gray-900 dark:text-white">
                  Dashboard Overview
                </h1>
                <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">
                  Welcome back, here's what's happening today.
                </p>
              </div>
              <div className="mt-4 md:mt-0 flex space-x-3">
                <button className="btn btn-secondary flex items-center">
                  <RefreshCw className="w-4 h-4 mr-2" />
                  Refresh
                </button>
                <button className="btn btn-primary flex items-center">
                  <Plus className="w-4 h-4 mr-2" />
                  New Project
                </button>
              </div>
            </div>

            {loading ? (
              <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-6">
                {[1, 2, 3, 4].map((i) => (
                  <div key={i} className="h-32 bg-gray-200 dark:bg-gray-700 rounded-lg animate-pulse"></div>
                ))}
              </div>
            ) : (
              <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-6 animate-slide-up" style={{animationDelay: '0.1s'}}>
                <StatCard 
                  title="Total Revenue" 
                  value={stats?.revenue} 
                  change="+12.5%" 
                  positive={true}
                  icon={<DollarSign className="w-6 h-6 text-primary-600" />}
                />
                <StatCard 
                  title="Active Projects" 
                  value={stats?.projects} 
                  change="+2.4%" 
                  positive={true}
                  icon={<FolderKanban className="w-6 h-6 text-green-600" />}
                />
                <StatCard 
                  title="Tasks Completed" 
                  value={stats?.tasks} 
                  change="-0.8%" 
                  positive={false}
                  icon={<CheckSquare className="w-6 h-6 text-blue-600" />}
                />
                <StatCard 
                  title="Team Velocity" 
                  value={stats?.velocity} 
                  change="+5.2%" 
                  positive={true}
                  icon={<Activity className="w-6 h-6 text-purple-600" />}
                />
              </div>
            )}

            <div className="grid grid-cols-1 lg:grid-cols-3 gap-8 animate-slide-up" style={{animationDelay: '0.2s'}}>
              <div className="lg:col-span-2 card">
                <div className="flex items-center justify-between mb-6">
                  <h3 className="text-lg font-semibold text-gray-900 dark:text-white">
                    Revenue Analytics
                  </h3>
                  <select className="input-field w-auto py-1 pl-3 pr-8 text-sm">
                    <option>Last 7 Days</option>
                    <option>Last 30 Days</option>
                    <option>This Year</option>
                  </select>
                </div>
                <div className="h-80">
                  <RevenueChart />
                </div>
              </div>

              <div className="card">
                <h3 className="text-lg font-semibold text-gray-900 dark:text-white mb-6">
                  Team Performance
                </h3>
                <div className="space-y-6">
                  <TeamPerformance />
                </div>
              </div>
            </div>

            <div className="grid grid-cols-1 lg:grid-cols-3 gap-8 animate-slide-up" style={{animationDelay: '0.3s'}}>
              <div className="lg:col-span-2 card">
                <div className="flex items-center justify-between mb-6">
                  <h3 className="text-lg font-semibold text-gray-900 dark:text-white">
                    Current Projects
                  </h3>
                  <button className="text-sm text-primary-600 hover:text-primary-700 font-medium flex items-center">
                    View All <ChevronRight className="w-4 h-4 ml-1" />
                  </button>
                </div>
                <ProjectTable projects={projects} loading={loading} />
              </div>

              <div className="card">
                <h3 className="text-lg font-semibold text-gray-900 dark:text-white mb-6">
                  Recent Activity
                </h3>
                <RecentActivity />
              </div>
            </div>

            <div className="card animate-slide-up" style={{animationDelay: '0.4s'}}>
              <div className="flex items-center justify-between mb-6">
                <h3 className="text-lg font-semibold text-gray-900 dark:text-white">
                  Sprint Task Board
                </h3>
                <div className="flex space-x-2">
                   <button className="p-2 text-gray-400 hover:text-gray-500 dark:hover:text-gray-300">
                     <Filter className="w-5 h-5" />
                   </button>
                   <button className="p-2 text-gray-400 hover:text-gray-500 dark:hover:text-gray-300">
                     <Download className="w-5 h-5" />
                   </button>
                </div>
              </div>
              <TaskBoard />
            </div>

          </div>
        </main>
      </div>
    </div>
  );
}