import React, { useState, useCallback } from 'react'
import { View, Text, FlatList, StyleSheet, RefreshControl, TouchableOpacity } from 'react-native'
import { useFocusEffect } from 'expo-router'
import { COLORS } from '../../constants/Config'
import client from '../../services/api'

const SEV_COLOR: Record<string, string> = { CRITICAL: COLORS.danger, HIGH: '#f97316', MEDIUM: COLORS.warning, LOW: COLORS.muted }

export default function ThreatFeedScreen() {
  const [items, setItems]   = useState<any[]>([])
  const [expanded, setExpanded] = useState<number | null>(null)
  const [loading, setLoading] = useState(false)

  const load = useCallback(async () => {
    setLoading(true)
    try { const r = await client.get('/api/ai-soc/threats'); setItems(r.data?.threats ?? r.data?.items ?? []) }
    catch { setItems([]) } finally { setLoading(false) }
  }, [])

  useFocusEffect(useCallback(() => { load() }, [load]))

  return (
    <FlatList
      data={items}
      keyExtractor={(_, i) => String(i)}
      refreshControl={<RefreshControl refreshing={loading} onRefresh={load} />}
      ListEmptyComponent={<Text style={s.empty}>위협 인텔리전스 피드가 없습니다.</Text>}
      style={{ backgroundColor: COLORS.bg }}
      contentContainerStyle={{ padding: 12 }}
      renderItem={({ item, index }) => {
        const sev = item.severity ?? item.level ?? 'MEDIUM'
        const color = SEV_COLOR[sev] ?? COLORS.muted
        const isOpen = expanded === index
        return (
          <TouchableOpacity onPress={() => setExpanded(isOpen ? null : index)} style={s.card} activeOpacity={0.8}>
            <View style={s.row}>
              <View style={[s.sevDot, { backgroundColor: color }]} />
              <View style={{ flex: 1 }}>
                <Text style={s.title} numberOfLines={isOpen ? undefined : 1}>{item.title ?? item.threat_name}</Text>
                <Text style={s.meta}>{item.source ?? 'TI Feed'} · {item.detected_at?.slice(0, 10) ?? ''}</Text>
              </View>
              <Text style={[s.sev, { color }]}>{sev}</Text>
            </View>
            {isOpen && (
              <View style={s.detail}>
                <Text style={s.detailText}>{item.description ?? item.details ?? '상세 정보 없음'}</Text>
                {item.ioc && <Text style={s.ioc}>IoC: {item.ioc}</Text>}
                {item.mitigation && <Text style={s.mitigation}>대응: {item.mitigation}</Text>}
              </View>
            )}
          </TouchableOpacity>
        )
      }}
    />
  )
}

const s = StyleSheet.create({
  card:       { backgroundColor: '#fff', borderRadius: 10, padding: 14, marginBottom: 8, elevation: 1 },
  row:        { flexDirection: 'row', alignItems: 'center', gap: 8 },
  sevDot:     { width: 10, height: 10, borderRadius: 5 },
  title:      { fontSize: 13, fontWeight: '700', color: COLORS.text, flex: 1 },
  meta:       { fontSize: 11, color: COLORS.muted, marginTop: 2 },
  sev:        { fontSize: 11, fontWeight: '700' },
  detail:     { marginTop: 10, paddingTop: 10, borderTopWidth: 1, borderTopColor: COLORS.border },
  detailText: { fontSize: 13, color: COLORS.text, lineHeight: 20, marginBottom: 6 },
  ioc:        { fontSize: 12, color: COLORS.danger, fontFamily: 'monospace' },
  mitigation: { fontSize: 12, color: COLORS.success, marginTop: 4 },
  empty:      { textAlign: 'center', color: COLORS.muted, marginTop: 40 },
})