import { useState, useEffect } from 'react'
import { Link } from 'react-router-dom'
import { marathonsApi } from '@/api'
import type { MarathonListItem } from '@/types'
import { NeonButton, GlassCard, StatsCard } from '@/components/ui'
import { Plus, Users, Calendar, Loader2, Trophy, Gamepad2, ChevronRight, Hash, Sparkles } from 'lucide-react'
import { TelegramBotBanner } from '@/components/TelegramBotBanner'
import { AnnouncementBanner } from '@/components/AnnouncementBanner'
import { format } from 'date-fns'
import { ru } from 'date-fns/locale'

export function MarathonsPage() {
  const [marathons, setMarathons] = useState<MarathonListItem[]>([])
  const [isLoading, setIsLoading] = useState(true)
  const [joinCode, setJoinCode] = useState('')
  const [joinError, setJoinError] = useState<string | null>(null)
  const [isJoining, setIsJoining] = useState(false)
  const [showJoinSection, setShowJoinSection] = useState(false)

  useEffect(() => {
    loadMarathons()
  }, [])

  const loadMarathons = async () => {
    try {
      const data = await marathonsApi.list()
      setMarathons(data)
    } catch (error) {
      console.error('Failed to load marathons:', error)
    } finally {
      setIsLoading(false)
    }
  }

  const handleJoin = async () => {
    if (!joinCode.trim()) return

    setJoinError(null)
    setIsJoining(true)
    try {
      await marathonsApi.join(joinCode.trim())
      setJoinCode('')
      setShowJoinSection(false)
      await loadMarathons()
    } catch (err: unknown) {
      const error = err as { response?: { data?: { detail?: string } } }
      setJoinError(error.response?.data?.detail || 'Не удалось присоединиться')
    } finally {
      setIsJoining(false)
    }
  }

  const getStatusConfig = (status: string) => {
    switch (status) {
      case 'preparing':
        return {
          color: 'bg-yellow-500/20 text-yellow-400 border-yellow-500/30',
          text: 'Подготовка',
          dot: 'bg-yellow-500',
        }
      case 'active':
        return {
          color: 'bg-neon-500/20 text-neon-400 border-neon-500/30',
          text: 'Активен',
          dot: 'bg-neon-500 animate-pulse',
        }
      case 'finished':
        return {
          color: 'bg-gray-500/20 text-gray-400 border-gray-500/30',
          text: 'Завершён',
          dot: 'bg-gray-500',
        }
      default:
        return {
          color: 'bg-gray-500/20 text-gray-400 border-gray-500/30',
          text: status,
          dot: 'bg-gray-500',
        }
    }
  }

  // Stats
  const activeCount = marathons.filter(m => m.status === 'active').length
  const completedCount = marathons.filter(m => m.status === 'finished').length
  const totalParticipants = marathons.reduce((acc, m) => acc + m.participants_count, 0)

  if (isLoading) {
    return (
      <div className="flex flex-col items-center justify-center py-24">
        <Loader2 className="w-12 h-12 animate-spin text-neon-500 mb-4" />
        <p className="text-gray-400">Загрузка марафонов...</p>
      </div>
    )
  }

  return (
    <div className="max-w-5xl mx-auto">
      {/* Header */}
      <div className="flex flex-col md:flex-row justify-between items-start md:items-center gap-4 mb-8">
        <div>
          <h1 className="text-3xl font-bold text-white mb-2">Мои марафоны</h1>
          <p className="text-gray-400">Управляйте своими игровыми соревнованиями</p>
        </div>
        <div className="flex gap-3">
          <NeonButton
            variant="outline"
            onClick={() => setShowJoinSection(!showJoinSection)}
            icon={<Hash className="w-4 h-4" />}
          >
            По коду
          </NeonButton>
          <Link to="/marathons/create">
            <NeonButton icon={<Plus className="w-4 h-4" />}>
              Создать
            </NeonButton>
          </Link>
        </div>
      </div>

      {/* Stats */}
      {marathons.length > 0 && (
        <div className="grid grid-cols-2 md:grid-cols-4 gap-4 mb-8">
          <StatsCard
            label="Всего"
            value={marathons.length}
            icon={<Gamepad2 className="w-6 h-6" />}
            color="default"
          />
          <StatsCard
            label="Активных"
            value={activeCount}
            icon={<Sparkles className="w-6 h-6" />}
            color="neon"
          />
          <StatsCard
            label="Завершено"
            value={completedCount}
            icon={<Trophy className="w-6 h-6" />}
            color="purple"
          />
          <StatsCard
            label="Участников"
            value={totalParticipants}
            icon={<Users className="w-6 h-6" />}
            color="pink"
          />
        </div>
      )}

      {/* Announcement Banner */}
      <div className="mb-4">
        <AnnouncementBanner />
      </div>

      {/* Telegram Bot Banner */}
      <div className="mb-8">
        <TelegramBotBanner />
      </div>

      {/* Join marathon */}
      {showJoinSection && (
        <GlassCard className="mb-8 animate-slide-in-down" variant="neon">
          <div className="flex items-center gap-3 mb-4">
            <div className="w-10 h-10 rounded-xl bg-accent-500/20 flex items-center justify-center">
              <Hash className="w-5 h-5 text-accent-400" />
            </div>
            <div>
              <h3 className="font-semibold text-white">Присоединиться к марафону</h3>
              <p className="text-sm text-gray-400">Введите код приглашения</p>
            </div>
          </div>
          <div className="flex gap-3">
            <input
              type="text"
              value={joinCode}
              onChange={(e) => setJoinCode(e.target.value.toUpperCase())}
              onKeyDown={(e) => e.key === 'Enter' && handleJoin()}
              placeholder="XXXXXX"
              className="input flex-1 font-mono text-center tracking-widest uppercase"
              maxLength={10}
            />
            <NeonButton
              onClick={handleJoin}
              isLoading={isJoining}
              color="purple"
            >
              Присоединиться
            </NeonButton>
          </div>
          {joinError && (
            <p className="mt-3 text-sm text-red-400 flex items-center gap-2">
              <span className="w-1.5 h-1.5 bg-red-500 rounded-full" />
              {joinError}
            </p>
          )}
        </GlassCard>
      )}

      {/* Marathon list */}
      {marathons.length === 0 ? (
        <GlassCard className="text-center py-16">
          <div className="w-20 h-20 mx-auto mb-6 rounded-2xl bg-dark-700 flex items-center justify-center">
            <Gamepad2 className="w-10 h-10 text-gray-600" />
          </div>
          <h3 className="text-xl font-semibold text-white mb-2">Нет марафонов</h3>
          <p className="text-gray-400 mb-6 max-w-sm mx-auto">
            Создайте свой первый марафон или присоединитесь к существующему по коду
          </p>
          <div className="flex gap-3 justify-center">
            <NeonButton
              variant="outline"
              onClick={() => setShowJoinSection(true)}
              icon={<Hash className="w-4 h-4" />}
            >
              Ввести код
            </NeonButton>
            <Link to="/marathons/create">
              <NeonButton icon={<Plus className="w-4 h-4" />}>
                Создать марафон
              </NeonButton>
            </Link>
          </div>
        </GlassCard>
      ) : (
        <div className="space-y-4">
          {marathons.map((marathon, index) => {
            const status = getStatusConfig(marathon.status)
            return (
              <Link key={marathon.id} to={`/marathons/${marathon.id}`}>
                <div
                  className="group glass rounded-xl p-5 border border-dark-600 transition-all duration-300 hover:border-neon-500/30 hover:-translate-y-0.5 hover:shadow-[0_10px_40px_rgba(34,211,238,0.08)]"
                  style={{ animationDelay: `${index * 50}ms` }}
                >
                  <div className="flex items-center justify-between">
                    <div className="flex items-center gap-4">
                      {/* Icon */}
                      <div className="w-14 h-14 rounded-xl bg-gradient-to-br from-neon-500/20 to-accent-500/20 flex items-center justify-center border border-neon-500/20 group-hover:border-neon-500/40 transition-colors">
                        <Gamepad2 className="w-7 h-7 text-neon-400" />
                      </div>

                      {/* Info */}
                      <div>
                        <h3 className="text-lg font-semibold text-white group-hover:text-neon-400 transition-colors mb-1">
                          {marathon.title}
                        </h3>
                        <div className="flex flex-wrap items-center gap-4 text-sm text-gray-400">
                          <span className="flex items-center gap-1.5">
                            <Users className="w-4 h-4" />
                            {marathon.participants_count}
                          </span>
                          {marathon.start_date && (
                            <span className="flex items-center gap-1.5">
                              <Calendar className="w-4 h-4" />
                              {format(new Date(marathon.start_date), 'd MMM yyyy', { locale: ru })}
                            </span>
                          )}
                        </div>
                      </div>
                    </div>

                    {/* Status & Arrow */}
                    <div className="flex items-center gap-4">
                      <span className={`px-3 py-1.5 rounded-full text-sm font-medium border flex items-center gap-2 ${status.color}`}>
                        <span className={`w-2 h-2 rounded-full ${status.dot}`} />
                        {status.text}
                      </span>
                      <ChevronRight className="w-5 h-5 text-gray-600 group-hover:text-neon-400 transition-colors" />
                    </div>
                  </div>
                </div>
              </Link>
            )
          })}
        </div>
      )}
    </div>
  )
}
