import { useEffect, useRef, useState } from 'react';
import {
  View,
  Text,
  TouchableOpacity,
  ScrollView,
  Animated,
  ActivityIndicator,
  Easing,
} from 'react-native';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import { Ionicons } from '@expo/vector-icons';
import { useTranslation } from 'react-i18next';
import Svg, { Path, Circle } from 'react-native-svg';
import type { ProtectionState } from '../../lib/protection';
import { apiFetch } from '../../lib/api';
import { useColors } from '../../lib/theme';
import { FormSheet } from '../FormSheet';

type Props = {
  visible: boolean;
  state: ProtectionState;
  onClose: () => void;
  onRequestDeactivation: () => void;
  onTalkToLyra: () => void;
};

type StatsResponse = {
  current: number;
  weeklyAdded: number;
  monthlyAdded: number;
  history: { label: string; count: number }[];
  submissions: { inVote: number; inReview: number };
  mySubmissions: { active: number; inVote: number; inReview: number };
  avgPerUser: number;
  avgApprovalWaitDays: number;
};

// Brand colors
const HERO_COLOR = '#f97316'; // orange-500 (counter accent)
const SEG_ACTIVE = '#16a34a';
const SEG_VOTE = '#3b82f6';
const SEG_REVIEW = '#f59e0b';

export function ProtectionDetailsSheet({
  visible,
  state,
  onClose,
  onRequestDeactivation,
}: Props) {
  const { t, i18n } = useTranslation();
  const colors = useColors();
  const insets = useSafeAreaInsets();
  const localeTag = i18n.language === 'de' ? 'de-DE' : 'en-US';

  const [stats, setStats] = useState<StatsResponse | null>(null);
  const [loadingStats, setLoadingStats] = useState(false);

  useEffect(() => {
    if (!visible) return;
    let alive = true;
    setLoadingStats(true);
    apiFetch<StatsResponse>('/api/blocklist/stats')
      .then((res) => { if (alive) setStats(res); })
      .catch(() => { /* silent */ })
      .finally(() => { if (alive) setLoadingStats(false); });
    return () => { alive = false; };
  }, [visible]);

  const globalCount = stats?.current ?? state.blocklistCount;
  const weeklyAdded = stats?.weeklyAdded ?? 0;
  const monthlyAdded = stats?.monthlyAdded ?? 0;
  const myActive = stats?.mySubmissions?.active ?? 0;
  const myInVote = stats?.mySubmissions?.inVote ?? 0;
  const myInReview = stats?.mySubmissions?.inReview ?? 0;
  const avgPerUser = stats?.avgPerUser ?? 0;
  const avgWait = stats?.avgApprovalWaitDays ?? 0;

  return (
    <FormSheet
      visible={visible}
      onClose={onClose}
      title={t('blocker.details_title')}
      initialHeightPct={0.75}
      minHeightPct={0.3}
      safeAreaBottom={false}
    >
      <ScrollView
        style={{ flex: 1 }}
        contentContainerStyle={{ padding: 20, paddingBottom: Math.max(insets.bottom, 16) + 32, gap: 18 }}
        showsVerticalScrollIndicator
      >
            {loadingStats && !stats ? (
              <View style={{ padding: 40, alignItems: 'center' }}>
                <ActivityIndicator color="#737373" />
              </View>
            ) : null}

            {/* HERO – Globale geblockte Domains: Counter (slow, color) + 2 Delta-Badges */}
            <View
              style={{
                padding: 20,
                borderRadius: 16,
                backgroundColor: '#0a0a0a',
                gap: 14,
              }}
            >
              <View>
                <Text style={{ fontSize: 11, color: '#a3a3a3', fontFamily: 'Nunito_700Bold', letterSpacing: 0.5, textTransform: 'uppercase' }}>
                  {t('blocker.kpi_global_label')}
                </Text>
                <AnimatedCounter
                  value={globalCount}
                  locale={localeTag}
                  durationMs={2400}
                  style={{ fontSize: 38, color: HERO_COLOR, fontFamily: 'Nunito_900Black', letterSpacing: -1, marginTop: 2 }}
                />
              </View>

              <View style={{ flexDirection: 'row', gap: 10 }}>
                <DeltaBadge value={weeklyAdded} label={t('blocker.delta_week')} locale={localeTag} />
                <DeltaBadge value={monthlyAdded} label={t('blocker.delta_month')} locale={localeTag} />
              </View>
            </View>

            {/* SUBMISSIONS – Half Donut mit center-number + center-legend */}
            <View
              style={{
                padding: 18,
                borderRadius: 16,
                borderWidth: 1,
                borderColor: colors.border,
                backgroundColor: colors.bg,
                gap: 8,
              }}
            >
              <View>
                <Text style={{ fontSize: 13, color: colors.text, fontFamily: 'Nunito_700Bold' }}>
                  {t('blocker.kpi_submissions_title')}
                </Text>
                <Text style={{ fontSize: 11, color: colors.textMuted, fontFamily: 'Nunito_400Regular', marginTop: 2 }}>
                  {t('blocker.kpi_submissions_subtitle')}
                </Text>
              </View>

              <HalfDonut
                segments={[
                  { value: myActive, color: SEG_ACTIVE },
                  { value: myInVote, color: SEG_VOTE },
                  { value: myInReview, color: SEG_REVIEW },
                ]}
                centerValue={myActive + myInVote + myInReview}
                centerLabel={t('blocker.kpi_my_submissions')}
              />

              {/* Centered Legend */}
              <View
                style={{
                  flexDirection: 'row',
                  justifyContent: 'center',
                  alignItems: 'flex-start',
                  gap: 14,
                  marginTop: 4,
                }}
              >
                <LegendItem color={SEG_ACTIVE} label={t('blocker.kpi_status_active')} value={myActive} />
                <LegendItem color={SEG_VOTE} label={t('blocker.kpi_status_vote')} value={myInVote} />
                <LegendItem color={SEG_REVIEW} label={t('blocker.kpi_status_review')} value={myInReview} />
              </View>
            </View>

            {/* AVG KPIs – kleiner */}
            <View style={{ flexDirection: 'row', gap: 10 }}>
              <KpiCard
                icon="person-circle-outline"
                label={t('blocker.kpi_avg_per_user')}
                value={avgPerUser}
                locale={localeTag}
                decimals={1}
              />
              <KpiCard
                icon="time-outline"
                label={t('blocker.kpi_avg_wait')}
                value={avgWait}
                locale={localeTag}
                decimals={1}
                suffix={t('blocker.kpi_days_suffix')}
              />
            </View>

            {/* FAQ-Banner: Heading-Row mit Help-Icon rechts (kein gestapeltes Layout) */}
            <View style={{ alignSelf: 'stretch', gap: 8, marginTop: 4 }}>
              <View
                style={{
                  alignSelf: 'stretch',
                  flexDirection: 'row',
                  alignItems: 'center',
                  marginBottom: 4,
                }}
              >
                <Text
                  style={{
                    flex: 1,
                    fontSize: 11,
                    fontFamily: 'Nunito_700Bold',
                    color: colors.textMuted,
                    letterSpacing: 0.5,
                    textTransform: 'uppercase',
                  }}
                >
                  {t('blocker.faq_heading')}
                </Text>
                <Ionicons name="help-circle-outline" size={18} color={colors.textMuted} />
              </View>
              {[1, 2, 3, 4].map((n) => (
                <FaqItem
                  key={n}
                  question={t(`blocker.faq${n}_q`)}
                  answer={t(`blocker.faq${n}_a`)}
                />
              ))}
            </View>

            {/* "Schutz deaktivieren" – outline button: TouchableOpacity=card, inner View=flex-row */}
            <TouchableOpacity
              onPress={onRequestDeactivation}
              activeOpacity={0.75}
              style={{ marginTop: 4 }}
            >
              <View style={{
                paddingVertical: 14,
                paddingHorizontal: 16,
                borderRadius: 12,
                borderWidth: 1.5,
                borderColor: HERO_COLOR,
                backgroundColor: colors.surface,
                flexDirection: 'row',
                alignItems: 'center',
                justifyContent: 'center',
                gap: 8,
              }}>
                <Ionicons name="lock-open-outline" size={18} color={HERO_COLOR} />
                <Text style={{ fontSize: 14, fontFamily: 'Nunito_700Bold', color: HERO_COLOR }}>
                  {t('blocker.more_info_title')}
                </Text>
              </View>
            </TouchableOpacity>
      </ScrollView>
    </FormSheet>
  );
}

// ─── Animated Counter ──────────────────────────────────────────────────────
function AnimatedCounter({
  value,
  locale,
  decimals = 0,
  durationMs = 1200,
  style,
}: {
  value: number;
  locale: string;
  decimals?: number;
  durationMs?: number;
  style?: any;
}) {
  const anim = useRef(new Animated.Value(0)).current;
  const [display, setDisplay] = useState(0);

  useEffect(() => {
    anim.setValue(0);
    const listener = anim.addListener(({ value: v }) => {
      setDisplay(v * value);
    });
    Animated.timing(anim, {
      toValue: 1,
      duration: durationMs,
      easing: Easing.out(Easing.cubic),
      useNativeDriver: false,
    }).start();
    return () => anim.removeListener(listener);
  }, [value, anim, durationMs]);

  const formatted = display.toLocaleString(locale, {
    minimumFractionDigits: decimals,
    maximumFractionDigits: decimals,
  });

  return <Text style={style}>{formatted}</Text>;
}

// ─── Delta Badge (e.g. "+25 diese Woche ↗") ────────────────────────────────
function DeltaBadge({
  value,
  label,
  locale,
}: {
  value: number;
  label: string;
  locale: string;
}) {
  const formatted = `+${value.toLocaleString(locale)}`;
  return (
    <View
      style={{
        flex: 1,
        flexDirection: 'row',
        alignItems: 'center',
        gap: 8,
        paddingVertical: 10,
        paddingHorizontal: 12,
        borderRadius: 10,
        backgroundColor: '#1f1f1f',
        borderWidth: 1,
        borderColor: '#262626',
      }}
    >
      <View
        style={{
          width: 24,
          height: 24,
          borderRadius: 12,
          backgroundColor: 'rgba(22,163,74,0.15)',
          alignItems: 'center',
          justifyContent: 'center',
        }}
      >
        <Ionicons name="arrow-up" size={14} color="#22c55e" />
      </View>
      <View style={{ flex: 1 }}>
        <Text style={{ fontSize: 13, color: '#fff', fontFamily: 'Nunito_900Black', letterSpacing: -0.3 }}>
          {formatted}
        </Text>
        <Text style={{ fontSize: 10, color: '#a3a3a3', fontFamily: 'Nunito_400Regular' }}>
          {label}
        </Text>
      </View>
    </View>
  );
}

// ─── KPI Card (small) ──────────────────────────────────────────────────────
function KpiCard({
  icon,
  label,
  value,
  locale,
  decimals = 0,
  suffix,
}: {
  icon: any;
  label: string;
  value: number;
  locale: string;
  decimals?: number;
  suffix?: string;
}) {
  const colors = useColors();
  return (
    <View
      style={{
        flex: 1,
        padding: 12,
        borderRadius: 12,
        borderWidth: 1,
        borderColor: colors.border,
        backgroundColor: colors.surface,
        gap: 6,
      }}
    >
      <View style={{ flexDirection: 'row', alignItems: 'center', gap: 6 }}>
        <Ionicons name={icon} size={14} color={colors.textMuted} />
        <Text style={{ flex: 1, fontSize: 10, color: colors.textMuted, fontFamily: 'Nunito_400Regular', lineHeight: 13 }}>
          {label}
        </Text>
      </View>
      <View style={{ flexDirection: 'row', alignItems: 'baseline', gap: 4 }}>
        <AnimatedCounter
          value={value}
          locale={locale}
          decimals={decimals}
          style={{ fontSize: 18, fontFamily: 'Nunito_900Black', color: colors.text, letterSpacing: -0.3 }}
        />
        {suffix ? (
          <Text style={{ fontSize: 10, color: colors.textMuted, fontFamily: 'Nunito_700Bold' }}>{suffix}</Text>
        ) : null}
      </View>
    </View>
  );
}

// ─── Legend Item (compact, centered row) ───────────────────────────────────
function LegendItem({
  color,
  label,
  value,
}: {
  color: string;
  label: string;
  value: number;
}) {
  const colors = useColors();
  return (
    <View style={{ alignItems: 'center', gap: 4 }}>
      <View style={{ flexDirection: 'row', alignItems: 'center', gap: 5 }}>
        <View style={{ width: 8, height: 8, borderRadius: 4, backgroundColor: color }} />
        <Text style={{ fontSize: 11, color: colors.textMuted, fontFamily: 'Nunito_700Bold' }}>{value}</Text>
      </View>
      <Text style={{ fontSize: 10, color: colors.textMuted, fontFamily: 'Nunito_400Regular' }}>{label}</Text>
    </View>
  );
}

// ─── Half Donut (multi-segment) ────────────────────────────────────────────
function HalfDonut({
  segments,
  centerValue,
  centerLabel,
}: {
  segments: { value: number; color: string }[];
  centerValue: number;
  centerLabel: string;
}) {
  const colors = useColors();
  const total = Math.max(1, segments.reduce((s, x) => s + x.value, 0));

  const W = 220;
  const H = 130;
  const cx = W / 2;
  const cy = H - 8;
  const r = 90;
  const stroke = 18;

  // Compute cumulative angles in [180, 360]
  let cumAngle = 180;
  const arcs = segments.map((seg) => {
    const startAngle = cumAngle;
    const endAngle = cumAngle + 180 * (seg.value / total);
    cumAngle = endAngle;
    return { ...seg, startAngle, endAngle };
  });

  const animProgress = useRef(new Animated.Value(0)).current;
  const [progress, setProgress] = useState(0);

  useEffect(() => {
    animProgress.setValue(0);
    const l = animProgress.addListener(({ value }) => setProgress(value));
    Animated.timing(animProgress, {
      toValue: 1,
      duration: 1100,
      easing: Easing.out(Easing.cubic),
      useNativeDriver: false,
    }).start();
    return () => animProgress.removeListener(l);
  }, [centerValue, animProgress]);

  return (
    <View style={{ alignItems: 'center', justifyContent: 'center' }}>
      <Svg width={W} height={H}>
        {/* Background track */}
        <Path
          d={arcPath(cx, cy, r, 180, 360)}
          stroke={colors.surfaceElevated}
          strokeWidth={stroke}
          fill="none"
          strokeLinecap="round"
        />
        {arcs.map((a, i) => {
          const animatedEnd =
            a.startAngle + (a.endAngle - a.startAngle) * progress;
          if (animatedEnd <= a.startAngle + 0.5) return null;
          return (
            <Path
              key={i}
              d={arcPath(cx, cy, r, a.startAngle, animatedEnd)}
              stroke={a.color}
              strokeWidth={stroke}
              fill="none"
              strokeLinecap="round"
            />
          );
        })}
        {centerValue === 0 && (
          <Circle cx={cx} cy={cy - r + stroke / 2} r={3} fill="#d4d4d8" />
        )}
      </Svg>

      {/* Center number — exactly centered horizontally + vertically inside semicircle */}
      <View
        pointerEvents="none"
        style={{
          position: 'absolute',
          left: 0,
          right: 0,
          top: H / 2 + 4,
          alignItems: 'center',
        }}
      >
        <Text style={{ fontSize: 30, fontFamily: 'Nunito_900Black', color: colors.text, letterSpacing: -0.5 }}>
          {centerValue}
        </Text>
        <Text style={{ fontSize: 10, color: colors.textMuted, fontFamily: 'Nunito_400Regular', marginTop: -2 }}>
          {centerLabel}
        </Text>
      </View>
    </View>
  );
}

function arcPath(cx: number, cy: number, r: number, startDeg: number, endDeg: number) {
  const start = polar(cx, cy, r, startDeg);
  const end = polar(cx, cy, r, endDeg);
  const largeArc = endDeg - startDeg > 180 ? 1 : 0;
  return `M ${start.x} ${start.y} A ${r} ${r} 0 ${largeArc} 1 ${end.x} ${end.y}`;
}

function polar(cx: number, cy: number, r: number, angleDeg: number) {
  const rad = (angleDeg * Math.PI) / 180;
  return { x: cx + r * Math.cos(rad), y: cy + r * Math.sin(rad) };
}

// ─── FAQ Item (chevron AT END of header row, on right) ─────────────────────
function FaqItem({ question, answer }: { question: string; answer: string }) {
  const colors = useColors();
  const [open, setOpen] = useState(false);
  const rotateAnim = useRef(new Animated.Value(0)).current;

  useEffect(() => {
    Animated.timing(rotateAnim, {
      toValue: open ? 1 : 0,
      duration: 200,
      useNativeDriver: true,
    }).start();
  }, [open, rotateAnim]);

  const rotate = rotateAnim.interpolate({
    inputRange: [0, 1],
    outputRange: ['0deg', '180deg'],
  });

  return (
    <View
      style={{
        alignSelf: 'stretch',
        borderWidth: 1,
        borderColor: colors.border,
        borderRadius: 12,
        overflow: 'hidden',
        backgroundColor: colors.bg,
      }}
    >
      <TouchableOpacity
        onPress={() => setOpen((v) => !v)}
        activeOpacity={0.75}
      >
        <View style={{ flexDirection: 'row', alignItems: 'center', paddingHorizontal: 14, paddingVertical: 14 }}>
          <View style={{ flex: 1, paddingRight: 12 }}>
            <Text style={{ fontSize: 13, fontFamily: 'Nunito_700Bold', color: colors.text, lineHeight: 18 }}>
              {question}
            </Text>
          </View>
          <Animated.View
            style={{
              width: 28,
              height: 28,
              borderRadius: 14,
              backgroundColor: colors.surfaceElevated,
              alignItems: 'center',
              justifyContent: 'center',
              transform: [{ rotate }],
            }}
          >
            <Ionicons name="chevron-down" size={16} color={colors.textMuted} />
          </Animated.View>
        </View>
      </TouchableOpacity>
      {open && (
        <View style={{ paddingHorizontal: 14, paddingBottom: 14, paddingTop: 0 }}>
          <Text style={{ fontSize: 13, fontFamily: 'Nunito_400Regular', color: colors.textMuted, lineHeight: 19 }}>
            {answer}
          </Text>
        </View>
      )}
    </View>
  );
}