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[]
}

/* Variant 스타일 StatCard — screenshot9 패턴 */
function StatCard({ icon, label, value, color }: { icon: string; label: string; value: number | string; color: string }) {
  return (
    <View style={[s.statCard, { borderTopColor: color, borderTopWidth: 3 }]}>
      {/* 아이콘 박스 — 연파랑 컨테이너 */}
      <View style={[s.statIconBox, { backgroundColor: color + '18' }]}>
        <Text style={s.statIcon}>{icon}</Text>
      </View>
      {/* 라벨 (위) */}
      <Text style={s.statLabel}>{label}</Text>
      {/* 수치 (아래) */}
      <Text style={[s.statValue, { color }]}>{value}</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 },
  /* 헤더 — Variant 딥네이비 그라디언트 */
  header: {
    backgroundColor: '#001530',
    padding: 24, paddingTop: 20,
    borderBottomLeftRadius: 20, borderBottomRightRadius: 20,
  },
  greeting:      { fontSize: 20, fontWeight: '800', color: '#fff', letterSpacing: -0.5 },
  subGreet:      { fontSize: 13, color: 'rgba(0,160,200,.85)', marginTop: 4 },
  licenseBanner: { backgroundColor: '#fff3cd', padding: 12, marginHorizontal: 16, marginTop: 12,
                   borderRadius: 10, borderLeftWidth: 3, borderLeftColor: COLORS.warning },
  licenseBannerText: { fontSize: 12, color: '#856404' },
  licenseBar: {
    flexDirection: 'row', justifyContent: 'space-between', alignItems: 'center',
    backgroundColor: COLORS.light, marginHorizontal: 16, marginTop: 10,
    paddingHorizontal: 14, paddingVertical: 8, borderRadius: 10,
    borderWidth: 1, borderColor: 'rgba(0,160,200,.2)',
  },
  licenseEdition: { fontSize: 12, fontWeight: '700', color: COLORS.accent },
  licenseDays:    { fontSize: 12, color: COLORS.muted },
  /* 통계 그리드 */
  statsGrid:     { flexDirection: 'row', flexWrap: 'wrap', padding: 14, gap: 10 },
  /* Variant StatCard — 상단 컬러 바 + 아이콘 박스 */
  statCard: {
    width: '47%', backgroundColor: '#fff', borderRadius: 12, padding: 14,
    shadowColor: '#003366', shadowOffset: { width: 0, height: 2 },
    shadowOpacity: .08, shadowRadius: 8, elevation: 3,
  },
  statIconBox: { width: 40, height: 40, borderRadius: 10, marginBottom: 10,
                 alignItems: 'center', justifyContent: 'center' },
  statIcon:    { fontSize: 20 },
  statValue:   { fontSize: 28, fontWeight: '900', letterSpacing: -0.5 },
  statLabel:   { fontSize: 11, fontWeight: '600', color: COLORS.muted,
                 letterSpacing: 0.3, textTransform: 'uppercase', marginBottom: 4 },
  /* 섹션 */
  section: {
    backgroundColor: '#fff', marginHorizontal: 16, marginTop: 12,
    borderRadius: 14, padding: 16,
    shadowColor: '#003366', shadowOffset: { width: 0, height: 2 },
    shadowOpacity: .05, shadowRadius: 6, elevation: 2,
  },
  sectionTitle: {
    fontSize: 14, fontWeight: '800', color: COLORS.primary,
    marginBottom: 12, letterSpacing: -0.3,
  },
  srItem:      { flexDirection: 'row', alignItems: 'center', gap: 10,
                 paddingVertical: 9, borderBottomWidth: 1, borderBottomColor: '#f1f5f9' },
  priorityDot: { width: 8, height: 8, borderRadius: 4 },
  srTitle:     { fontSize: 13, fontWeight: '600', color: COLORS.text },
  srMeta:      { fontSize: 11, color: COLORS.muted, marginTop: 2 },
  /* 빠른 실행 */
  quickRow:  { flexDirection: 'row', justifyContent: 'space-around' },
  quickBtn: {
    alignItems: 'center', padding: 12,
    backgroundColor: COLORS.bg, borderRadius: 12,
    flex: 1, marginHorizontal: 3,
  },
  quickIcon:  { fontSize: 26, marginBottom: 5 },
  quickLabel: { fontSize: 11, fontWeight: '600', color: COLORS.primary },
})