import { useEffect, useState } from 'react'
import { View, Text, ScrollView, StyleSheet, TouchableOpacity, RefreshControl, ActivityIndicator } from 'react-native'
import { COLORS, PRIORITY_COLOR } from '../../constants/Config'
import { getDashboard, getLicenseStatus } from '../../services/api'
import { useAuth } from '../../hooks/useAuth'

interface Stats {
  total_tasks: number
  open_tasks: number
  in_progress_tasks: number
  completed_today: number
  critical_count: number
  pending_approvals: number
  recent_tasks?: any[]
}

function StatCard({ icon, label, value, color }: { icon: string; label: string; value: number | string; color: string }) {
  return (
    <View style={[s.statCard, { borderLeftColor: color, borderLeftWidth: 3 }]}>
      <Text style={s.statIcon}>{icon}</Text>
      <Text style={s.statValue}>{value}</Text>
      <Text style={s.statLabel}>{label}</Text>
    </View>
  )
}

export default function Dashboard() {
  const { user } = useAuth()
  const [stats,    setStats]    = useState<Stats | null>(null)
  const [license,  setLicense]  = useState<any>(null)
  const [loading,  setLoading]  = useState(true)
  const [refresh,  setRefresh]  = useState(false)

  const load = async (isRefresh = false) => {
    if (isRefresh) setRefresh(true)
    else setLoading(true)
    try {
      const [d, l] = await Promise.allSettled([getDashboard(), getLicenseStatus()])
      if (d.status === 'fulfilled') setStats(d.value.data)
      if (l.status === 'fulfilled') setLicense(l.value.data)
    } catch {}
    setLoading(false)
    setRefresh(false)
  }

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

  if (loading) return (
    <View style={s.center}>
      <ActivityIndicator size="large" color={COLORS.accent} />
      <Text style={{ color: COLORS.muted, marginTop: 12 }}>로딩 중...</Text>
    </View>
  )

  return (
    <ScrollView
      style={s.scroll}
      refreshControl={<RefreshControl refreshing={refresh} onRefresh={() => load(true)} />}
    >
      {/* 인사말 */}
      <View style={s.header}>
        <Text style={s.greeting}>안녕하세요, {user?.display_name ?? user?.username}님 👋</Text>
        <Text style={s.subGreet}>GUARDiA ITSM 현황을 확인하세요</Text>
      </View>

      {/* 라이선스 배너 */}
      {license?.upgrade_banner?.show && (
        <View style={s.licenseBanner}>
          <Text style={s.licenseBannerText}>⚠️ {license.upgrade_banner.message}</Text>
        </View>
      )}
      {license?.valid && (
        <View style={s.licenseBar}>
          <Text style={s.licenseEdition}>{license.edition}</Text>
          <Text style={s.licenseDays}>{license.days_remaining}일 남음</Text>
        </View>
      )}

      {/* 통계 카드 */}
      <View style={s.statsGrid}>
        <StatCard icon="📋" label="전체 SR"    value={stats?.total_tasks    ?? '-'} color={COLORS.accent} />
        <StatCard icon="🔄" label="진행 중"    value={stats?.in_progress_tasks ?? '-'} color={COLORS.warning} />
        <StatCard icon="🚨" label="긴급"       value={stats?.critical_count ?? '-'} color={COLORS.danger} />
        <StatCard icon="✅" label="오늘 완료"  value={stats?.completed_today ?? '-'} color={COLORS.success} />
      </View>

      {/* 최근 SR */}
      {stats?.recent_tasks && stats.recent_tasks.length > 0 && (
        <View style={s.section}>
          <Text style={s.sectionTitle}>📋 최근 서비스 요청</Text>
          {stats.recent_tasks.slice(0, 5).map((sr: any) => (
            <View key={sr.id} style={s.srItem}>
              <View style={[s.priorityDot, { backgroundColor: PRIORITY_COLOR[sr.priority] ?? COLORS.muted }]} />
              <View style={{ flex: 1 }}>
                <Text style={s.srTitle} numberOfLines={1}>{sr.title}</Text>
                <Text style={s.srMeta}>{sr.sr_id} · {sr.status}</Text>
              </View>
            </View>
          ))}
        </View>
      )}

      {/* 빠른 실행 */}
      <View style={s.section}>
        <Text style={s.sectionTitle}>⚡ 빠른 실행</Text>
        <View style={s.quickRow}>
          {[
            { icon: '📝', label: 'SR 등록' },
            { icon: '🤖', label: 'AI 질문' },
            { icon: '📊', label: '리포트' },
            { icon: '🔒', label: '감사로그' },
          ].map(q => (
            <TouchableOpacity key={q.label} style={s.quickBtn}>
              <Text style={s.quickIcon}>{q.icon}</Text>
              <Text style={s.quickLabel}>{q.label}</Text>
            </TouchableOpacity>
          ))}
        </View>
      </View>

      <View style={{ height: 24 }} />
    </ScrollView>
  )
}

const s = StyleSheet.create({
  scroll:        { flex: 1, backgroundColor: COLORS.bg },
  center:        { flex: 1, justifyContent: 'center', alignItems: 'center', backgroundColor: COLORS.bg },
  header:        { backgroundColor: COLORS.primary, padding: 24, paddingTop: 16 },
  greeting:      { fontSize: 20, fontWeight: '700', color: '#fff' },
  subGreet:      { fontSize: 13, color: '#aac4e8', marginTop: 4 },
  licenseBanner: { backgroundColor: '#fff3cd', padding: 12, marginHorizontal: 16, marginTop: 12,
                   borderRadius: 8, borderLeftWidth: 3, borderLeftColor: COLORS.warning },
  licenseBannerText: { fontSize: 12, color: '#856404' },
  licenseBar:    { flexDirection: 'row', justifyContent: 'space-between', alignItems: 'center',
                   backgroundColor: COLORS.light, marginHorizontal: 16, marginTop: 8,
                   paddingHorizontal: 14, paddingVertical: 8, borderRadius: 8 },
  licenseEdition: { fontSize: 12, fontWeight: '700', color: COLORS.accent },
  licenseDays:   { fontSize: 12, color: COLORS.muted },
  statsGrid:     { flexDirection: 'row', flexWrap: 'wrap', padding: 12, gap: 8 },
  statCard:      { width: '47%', backgroundColor: '#fff', borderRadius: 10, padding: 14,
                   shadowColor: '#000', shadowOffset: { width: 0, height: 2 },
                   shadowOpacity: .06, shadowRadius: 6, elevation: 2 },
  statIcon:      { fontSize: 22, marginBottom: 6 },
  statValue:     { fontSize: 26, fontWeight: '800', color: COLORS.text },
  statLabel:     { fontSize: 11, color: COLORS.muted, marginTop: 2 },
  section:       { backgroundColor: '#fff', marginHorizontal: 16, marginTop: 12,
                   borderRadius: 12, padding: 16, elevation: 1 },
  sectionTitle:  { fontSize: 14, fontWeight: '700', color: COLORS.text, marginBottom: 12 },
  srItem:        { flexDirection: 'row', alignItems: 'center', gap: 10,
                   paddingVertical: 8, borderBottomWidth: 1, borderBottomColor: '#f1f5f9' },
  priorityDot:   { width: 8, height: 8, borderRadius: 4 },
  srTitle:       { fontSize: 13, fontWeight: '500', color: COLORS.text },
  srMeta:        { fontSize: 11, color: COLORS.muted, marginTop: 2 },
  quickRow:      { flexDirection: 'row', justifyContent: 'space-around' },
  quickBtn:      { alignItems: 'center', padding: 12 },
  quickIcon:     { fontSize: 28, marginBottom: 4 },
  quickLabel:    { fontSize: 11, color: COLORS.muted },
})