import { redirect } from 'next/navigation';
import Image from 'next/image';
import Link from 'next/link';
import {
  Calendar,
  Trophy,
  Users,
  Star,
  Clock,
  Flag,
  TrendingUp,
  ChevronRight,
  Zap,
  Target,
  Award,
  Activity,
  Play,
  Bell,
  Medal,
  Crown,
  Heart,
  MessageCircle,
  UserPlus,
} from 'lucide-react';

import Card from '@/components/ui/Card';
import Button from '@/components/ui/Button';
import { getAuthService } from '@/lib/auth';
import { getGetDashboardOverviewUseCase } from '@/lib/di-container';
import { DashboardOverviewPresenter } from '@/lib/presenters/DashboardOverviewPresenter';
import type {
  DashboardOverviewViewModel,
  DashboardFeedItemSummaryViewModel,
} from '@gridpilot/racing/application/presenters/IDashboardOverviewPresenter';

export const dynamic = 'force-dynamic';

// Helper functions
function getCountryFlag(countryCode: string): string {
  const code = countryCode.toUpperCase();
  if (code.length === 2) {
    const codePoints = [...code].map(char => 127397 + char.charCodeAt(0));
    return String.fromCodePoint(...codePoints);
  }
  return '🏁';
}

function timeUntil(date: Date): string {
  const now = new Date();
  const diffMs = date.getTime() - now.getTime();
  
  if (diffMs < 0) return 'Started';
  
  const diffHours = Math.floor(diffMs / (1000 * 60 * 60));
  const diffDays = Math.floor(diffHours / 24);
  
  if (diffDays > 0) {
    return `${diffDays}d ${diffHours % 24}h`;
  }
  if (diffHours > 0) {
    const diffMinutes = Math.floor((diffMs % (1000 * 60 * 60)) / (1000 * 60));
    return `${diffHours}h ${diffMinutes}m`;
  }
  const diffMinutes = Math.floor(diffMs / (1000 * 60));
  return `${diffMinutes}m`;
}

function timeAgo(timestamp: Date | string): string {
  const time = typeof timestamp === 'string' ? new Date(timestamp) : timestamp;
  const diffMs = Date.now() - time.getTime();
  const diffMinutes = Math.floor(diffMs / 60000);
  if (diffMinutes < 1) return 'Just now';
  if (diffMinutes < 60) return `${diffMinutes}m ago`;
  const diffHours = Math.floor(diffMinutes / 60);
  if (diffHours < 24) return `${diffHours}h ago`;
  const diffDays = Math.floor(diffHours / 24);
  return `${diffDays}d ago`;
}

function getGreeting(): string {
  const hour = new Date().getHours();
  if (hour < 12) return 'Good morning';
  if (hour < 18) return 'Good afternoon';
  return 'Good evening';
}

export default async function DashboardPage() {
  const authService = getAuthService();
  const session = await authService.getCurrentSession();

  if (!session) {
    redirect('/auth/iracing?returnTo=/dashboard');
  }

  const currentDriverId = session.user.primaryDriverId ?? '';

  const useCase = getGetDashboardOverviewUseCase();
  const presenter = new DashboardOverviewPresenter();
  await useCase.execute({ driverId: currentDriverId }, presenter);
  const viewModel = presenter.getViewModel();

  if (!viewModel) {
    return null;
  }

  const {
    currentDriver,
    myUpcomingRaces,
    otherUpcomingRaces,
    nextRace: nextRaceSummary,
    recentResults,
    leagueStandingsSummaries,
    feedSummary,
    friends,
    upcomingRaces,
    activeLeaguesCount,
  } = viewModel;

  const nextRace =
    nextRaceSummary != null
      ? {
          ...nextRaceSummary,
          scheduledAt: new Date(nextRaceSummary.scheduledAt),
        }
      : null;

  const upcomingRacesForDisplay = upcomingRaces.map(race => ({
    ...race,
    scheduledAt: new Date(race.scheduledAt),
  }));

  const totalRaces = currentDriver?.totalRaces ?? 0;
  const wins = currentDriver?.wins ?? 0;
  const podiums = currentDriver?.podiums ?? 0;
  const rating = currentDriver?.rating ?? 1500;
  const globalRank = currentDriver?.globalRank ?? 0;
  const consistency = currentDriver?.consistency ?? 0;

  return (
    <main className="min-h-screen bg-deep-graphite">
      {/* Hero Section */}
      <section className="relative overflow-hidden">
        {/* Background Pattern */}
        <div className="absolute inset-0 bg-gradient-to-br from-primary-blue/10 via-deep-graphite to-purple-600/5" />
        <div className="absolute inset-0 opacity-5">
          <div className="absolute inset-0" style={{
            backgroundImage: `url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.4'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E")`,
          }} />
        </div>

        <div className="relative max-w-7xl mx-auto px-6 py-10">
          <div className="flex flex-col lg:flex-row lg:items-center lg:justify-between gap-8">
            {/* Welcome Message */}
            <div className="flex items-start gap-5">
              {currentDriver && (
                <div className="relative">
                  <div className="w-20 h-20 rounded-2xl bg-gradient-to-br from-primary-blue to-purple-600 p-0.5 shadow-xl shadow-primary-blue/20">
                    <div className="w-full h-full rounded-xl overflow-hidden bg-iron-gray">
                      <Image
                        src={currentDriver.avatarUrl}
                        alt={currentDriver.name}
                        width={80}
                        height={80}
                        className="w-full h-full object-cover"
                      />
                    </div>
                  </div>
                  <div className="absolute -bottom-1 -right-1 w-5 h-5 rounded-full bg-performance-green border-3 border-deep-graphite" />
                </div>
              )}
              <div>
                <p className="text-gray-400 text-sm mb-1">{getGreeting()},</p>
                <h1 className="text-3xl md:text-4xl font-bold text-white mb-2">
                  {currentDriver?.name ?? 'Racer'}
                  <span className="ml-3 text-2xl">{currentDriver ? getCountryFlag(currentDriver.country) : '🏁'}</span>
                </h1>
                <div className="flex flex-wrap items-center gap-3">
                  <div className="flex items-center gap-1.5 px-3 py-1 rounded-full bg-primary-blue/10 border border-primary-blue/30">
                    <Star className="w-3.5 h-3.5 text-primary-blue" />
                    <span className="text-sm font-semibold text-primary-blue">{rating}</span>
                  </div>
                  <div className="flex items-center gap-1.5 px-3 py-1 rounded-full bg-yellow-400/10 border border-yellow-400/30">
                    <Trophy className="w-3.5 h-3.5 text-yellow-400" />
                    <span className="text-sm font-semibold text-yellow-400">#{globalRank}</span>
                  </div>
                  <span className="text-xs text-gray-500">{totalRaces} races completed</span>
                </div>
              </div>
            </div>

            {/* Quick Actions */}
            <div className="flex flex-wrap gap-3">
              <Link href="/leagues">
                <Button variant="secondary" className="flex items-center gap-2">
                  <Flag className="w-4 h-4" />
                  Browse Leagues
                </Button>
              </Link>
              <Link href="/profile">
                <Button variant="primary" className="flex items-center gap-2">
                  <Activity className="w-4 h-4" />
                  View Profile
                </Button>
              </Link>
            </div>
          </div>

          {/* Quick Stats Row */}
          <div className="grid grid-cols-2 md:grid-cols-4 gap-4 mt-8">
            <div className="p-4 rounded-xl bg-iron-gray/50 border border-charcoal-outline backdrop-blur-sm">
              <div className="flex items-center gap-3">
                <div className="flex h-10 w-10 items-center justify-center rounded-lg bg-performance-green/20">
                  <Trophy className="w-5 h-5 text-performance-green" />
                </div>
                <div>
                  <p className="text-2xl font-bold text-white">{wins}</p>
                  <p className="text-xs text-gray-500">Wins</p>
                </div>
              </div>
            </div>
            <div className="p-4 rounded-xl bg-iron-gray/50 border border-charcoal-outline backdrop-blur-sm">
              <div className="flex items-center gap-3">
                <div className="flex h-10 w-10 items-center justify-center rounded-lg bg-warning-amber/20">
                  <Medal className="w-5 h-5 text-warning-amber" />
                </div>
                <div>
                  <p className="text-2xl font-bold text-white">{podiums}</p>
                  <p className="text-xs text-gray-500">Podiums</p>
                </div>
              </div>
            </div>
            <div className="p-4 rounded-xl bg-iron-gray/50 border border-charcoal-outline backdrop-blur-sm">
              <div className="flex items-center gap-3">
                <div className="flex h-10 w-10 items-center justify-center rounded-lg bg-primary-blue/20">
                  <Target className="w-5 h-5 text-primary-blue" />
                </div>
                <div>
                  <p className="text-2xl font-bold text-white">{consistency}%</p>
                  <p className="text-xs text-gray-500">Consistency</p>
                </div>
              </div>
            </div>
            <div className="p-4 rounded-xl bg-iron-gray/50 border border-charcoal-outline backdrop-blur-sm">
              <div className="flex items-center gap-3">
                <div className="flex h-10 w-10 items-center justify-center rounded-lg bg-purple-500/20">
                  <Users className="w-5 h-5 text-purple-400" />
                </div>
                <div>
                  <p className="text-2xl font-bold text-white">{activeLeaguesCount}</p>
                  <p className="text-xs text-gray-500">Active Leagues</p>
                </div>
              </div>
            </div>
          </div>
        </div>
      </section>

      {/* Main Content */}
      <section className="max-w-7xl mx-auto px-6 py-8">
        <div className="grid grid-cols-1 lg:grid-cols-3 gap-6">
          {/* Left Column - Main Content */}
          <div className="lg:col-span-2 space-y-6">
            {/* Next Race Card */}
            {nextRace && (
              <Card className="relative overflow-hidden bg-gradient-to-br from-iron-gray to-iron-gray/80 border-primary-blue/30">
                <div className="absolute top-0 right-0 w-40 h-40 bg-gradient-to-bl from-primary-blue/20 to-transparent rounded-bl-full" />
                <div className="relative">
                  <div className="flex items-center gap-2 mb-4">
                    <div className="flex items-center gap-2 px-3 py-1 rounded-full bg-primary-blue/20 border border-primary-blue/30">
                      <Play className="w-3.5 h-3.5 text-primary-blue" />
                      <span className="text-xs font-semibold text-primary-blue uppercase tracking-wider">Next Race</span>
                    </div>
                    {nextRace.isMyLeague && (
                      <span className="px-2 py-0.5 rounded-full bg-performance-green/20 text-performance-green text-xs font-medium">
                        Your League
                      </span>
                    )}
                  </div>
                  
                  <div className="flex flex-col md:flex-row md:items-end md:justify-between gap-4">
                    <div>
                      <h2 className="text-2xl font-bold text-white mb-2">{nextRace.track}</h2>
                      <p className="text-gray-400 mb-3">{nextRace.car}</p>
                      <div className="flex flex-wrap items-center gap-4 text-sm">
                        <span className="flex items-center gap-1.5 text-gray-400">
                          <Calendar className="w-4 h-4" />
                          {nextRace.scheduledAt.toLocaleDateString('en-US', {
                            weekday: 'long',
                            month: 'short',
                            day: 'numeric',
                          })}
                        </span>
                        <span className="flex items-center gap-1.5 text-gray-400">
                          <Clock className="w-4 h-4" />
                          {nextRace.scheduledAt.toLocaleTimeString('en-US', {
                            hour: '2-digit',
                            minute: '2-digit',
                          })}
                        </span>
                      </div>
                    </div>
                    
                    <div className="flex flex-col items-end gap-3">
                      <div className="text-right">
                        <p className="text-xs text-gray-500 uppercase tracking-wider mb-1">Starts in</p>
                        <p className="text-3xl font-bold text-primary-blue font-mono">{timeUntil(nextRace.scheduledAt)}</p>
                      </div>
                      <Link href={`/races/${nextRace.id}`}>
                        <Button variant="primary" className="flex items-center gap-2">
                          View Details
                          <ChevronRight className="w-4 h-4" />
                        </Button>
                      </Link>
                    </div>
                  </div>
                </div>
              </Card>
            )}

            {/* League Standings Preview */}
            {leagueStandingsSummaries.length > 0 && (
              <Card>
                <div className="flex items-center justify-between mb-4">
                  <h2 className="text-lg font-semibold text-white flex items-center gap-2">
                    <Award className="w-5 h-5 text-yellow-400" />
                    Your Championship Standings
                  </h2>
                  <Link href="/profile/leagues" className="text-sm text-primary-blue hover:underline flex items-center gap-1">
                    View all <ChevronRight className="w-4 h-4" />
                  </Link>
                </div>
                <div className="space-y-3">
                  {leagueStandingsSummaries.map(({ leagueId, leagueName, position, points, totalDrivers }) => (
                    <Link
                      key={leagueId}
                      href={`/leagues/${leagueId}/standings`}
                      className="flex items-center gap-4 p-4 rounded-xl bg-deep-graphite border border-charcoal-outline hover:border-primary-blue/30 transition-colors group"
                    >
                      <div className={`flex h-12 w-12 items-center justify-center rounded-xl font-bold text-xl ${
                        position === 1 ? 'bg-yellow-400/20 text-yellow-400' :
                        position === 2 ? 'bg-gray-300/20 text-gray-300' :
                        position === 3 ? 'bg-orange-400/20 text-orange-400' :
                        'bg-iron-gray text-gray-400'
                      }`}>
                        {position > 0 ? `P${position}` : '-'}
                      </div>
                      <div className="flex-1 min-w-0">
                        <p className="text-white font-semibold truncate group-hover:text-primary-blue transition-colors">
                          {leagueName}
                        </p>
                        <p className="text-sm text-gray-500">
                          {points} points • {totalDrivers} drivers
                        </p>
                      </div>
                      <div className="flex items-center gap-2">
                        {position <= 3 && position > 0 && (
                          <Crown className={`w-5 h-5 ${
                            position === 1 ? 'text-yellow-400' :
                            position === 2 ? 'text-gray-300' :
                            'text-orange-400'
                          }`} />
                        )}
                        <ChevronRight className="w-5 h-5 text-gray-500 group-hover:text-primary-blue transition-colors" />
                      </div>
                    </Link>
                  ))}
                </div>
              </Card>
            )}

            {/* Activity Feed */}
            <Card>
              <div className="flex items-center justify-between mb-4">
                <h2 className="text-lg font-semibold text-white flex items-center gap-2">
                  <Activity className="w-5 h-5 text-neon-aqua" />
                  Recent Activity
                </h2>
              </div>
              {feedSummary.items.length > 0 ? (
                <div className="space-y-4">
                  {feedSummary.items.slice(0, 5).map((item) => (
                    <FeedItemRow key={item.id} item={item} />
                  ))}
                </div>
              ) : (
                <div className="text-center py-8">
                  <Activity className="w-12 h-12 text-gray-600 mx-auto mb-3" />
                  <p className="text-gray-400 mb-2">No activity yet</p>
                  <p className="text-sm text-gray-500">Join leagues and add friends to see activity here</p>
                </div>
              )}
            </Card>
          </div>

          {/* Right Column - Sidebar */}
          <div className="space-y-6">
            {/* Upcoming Races */}
            <Card>
              <div className="flex items-center justify-between mb-4">
                <h3 className="text-lg font-semibold text-white flex items-center gap-2">
                  <Calendar className="w-5 h-5 text-red-400" />
                  Upcoming Races
                </h3>
                <Link href="/races" className="text-xs text-primary-blue hover:underline">
                  View all
                </Link>
              </div>
              {upcomingRacesForDisplay.length > 0 ? (
                <div className="space-y-3">
                  {upcomingRacesForDisplay.slice(0, 5).map((race) => {
                    const isMyRace = race.isMyLeague;
                    return (
                      <Link
                        key={race.id}
                        href={`/races/${race.id}`}
                        className="block p-3 rounded-lg bg-deep-graphite border border-charcoal-outline hover:border-primary-blue/30 transition-colors"
                      >
                        <div className="flex items-start justify-between gap-2 mb-2">
                          <p className="text-white font-medium text-sm truncate">{race.track}</p>
                          {isMyRace && (
                            <span className="flex-shrink-0 w-2 h-2 rounded-full bg-performance-green" title="Your league" />
                          )}
                        </div>
                        <p className="text-xs text-gray-500 truncate mb-2">{race.car}</p>
                        <div className="flex items-center justify-between text-xs">
                          <span className="text-gray-400">
                            {race.scheduledAt.toLocaleDateString('en-US', { month: 'short', day: 'numeric' })}
                          </span>
                          <span className="text-primary-blue font-medium">{timeUntil(race.scheduledAt)}</span>
                        </div>
                      </Link>
                    );
                  })}
                </div>
              ) : (
                <p className="text-gray-500 text-sm text-center py-4">No upcoming races</p>
              )}
            </Card>

            {/* Friends */}
            <Card>
              <div className="flex items-center justify-between mb-4">
                <h3 className="text-lg font-semibold text-white flex items-center gap-2">
                  <Users className="w-5 h-5 text-purple-400" />
                  Friends
                </h3>
                <span className="text-xs text-gray-500">{friends.length} friends</span>
              </div>
              {friends.length > 0 ? (
                <div className="space-y-2">
                  {friends.slice(0, 6).map((friend) => (
                    <Link
                      key={friend.id}
                      href={`/drivers/${friend.id}`}
                      className="flex items-center gap-3 p-2 rounded-lg hover:bg-deep-graphite transition-colors"
                    >
                      <div className="w-9 h-9 rounded-full overflow-hidden bg-gradient-to-br from-primary-blue to-purple-600">
                        <Image
                          src={friend.avatarUrl}
                          alt={friend.name}
                          width={36}
                          height={36}
                          className="w-full h-full object-cover"
                        />
                      </div>
                      <div className="flex-1 min-w-0">
                        <p className="text-white text-sm font-medium truncate">{friend.name}</p>
                        <p className="text-xs text-gray-500">{getCountryFlag(friend.country)}</p>
                      </div>
                    </Link>
                  ))}
                  {friends.length > 6 && (
                    <Link
                      href="/profile"
                      className="block text-center py-2 text-sm text-primary-blue hover:underline"
                    >
                      +{friends.length - 6} more
                    </Link>
                  )}
                </div>
              ) : (
                <div className="text-center py-6">
                  <UserPlus className="w-10 h-10 text-gray-600 mx-auto mb-2" />
                  <p className="text-sm text-gray-400 mb-2">No friends yet</p>
                  <Link href="/drivers">
                    <Button variant="secondary" className="text-xs">
                      Find Drivers
                    </Button>
                  </Link>
                </div>
              )}
            </Card>
          </div>
        </div>
      </section>
    </main>
  );
}

// Feed Item Row Component
function FeedItemRow({ item }: { item: DashboardFeedItemSummaryViewModel }) {
  const getActivityIcon = (type: string) => {
    if (type.includes('win')) return { icon: Trophy, color: 'text-yellow-400 bg-yellow-400/10' };
    if (type.includes('podium')) return { icon: Medal, color: 'text-warning-amber bg-warning-amber/10' };
    if (type.includes('join')) return { icon: UserPlus, color: 'text-performance-green bg-performance-green/10' };
    if (type.includes('friend')) return { icon: Heart, color: 'text-pink-400 bg-pink-400/10' };
    if (type.includes('league')) return { icon: Flag, color: 'text-primary-blue bg-primary-blue/10' };
    if (type.includes('race')) return { icon: Play, color: 'text-red-400 bg-red-400/10' };
    return { icon: Activity, color: 'text-gray-400 bg-gray-400/10' };
  };

  const { icon: Icon, color } = getActivityIcon(item.type);

  return (
    <div className="flex gap-3 p-3 rounded-lg bg-deep-graphite/50 border border-charcoal-outline">
      <div className={`flex h-10 w-10 items-center justify-center rounded-lg ${color} flex-shrink-0`}>
        <Icon className="w-5 h-5" />
      </div>
      <div className="flex-1 min-w-0">
        <p className="text-sm text-white">{item.headline}</p>
        {item.body && (
          <p className="text-xs text-gray-500 mt-1 line-clamp-2">{item.body}</p>
        )}
        <p className="text-xs text-gray-500 mt-1">{timeAgo(item.timestamp)}</p>
      </div>
      {item.ctaHref && (
        <Link href={item.ctaHref} className="flex-shrink-0">
          <Button variant="secondary" className="text-xs px-3 py-1.5">
            {item.ctaLabel || 'View'}
          </Button>
        </Link>
      )}
    </div>
  );
}