import { useEffect, useRef } from 'react';
import { View, Text, Pressable, Modal, FlatList, Animated, Image } from 'react-native';
import { Ionicons } from '@expo/vector-icons';
import { useRouter, type RelativePathString } from 'expo-router';
import { useTranslation } from 'react-i18next';
import { useNotificationStore, type AppNotification } from '../stores/notifications';
import { resolveAvatar } from '../lib/resolveAvatar';
import { HeroShieldCheck } from './HeroShieldCheck';
import { useColors } from '../lib/theme';

type Props = {
  visible: boolean;
  onClose: () => void;
  /** Distanz vom oberen Rand bis Dropdown anchor (Header-Höhe inkl. SafeArea) */
  topOffset: number;
};

export function NotificationsDropdown({ visible, onClose, topOffset }: Props) {
  const { t } = useTranslation();
  const colors = useColors();
  const router = useRouter();
  const items = useNotificationStore((s) => s.items);
  const loaded = useNotificationStore((s) => s.loaded);
  const load = useNotificationStore((s) => s.load);
  const markRead = useNotificationStore((s) => s.markRead);
  const unread = useNotificationStore((s) => s.unread);

  const opacity = useRef(new Animated.Value(0)).current;
  const translateY = useRef(new Animated.Value(-8)).current;

  useEffect(() => {
    if (visible) {
      if (!loaded) load();
      // Mark as read with delay so user sees the unread highlight briefly
      const tm = setTimeout(() => {
        if (unread > 0) markRead();
      }, 600);
      Animated.parallel([
        Animated.timing(opacity, { toValue: 1, duration: 140, useNativeDriver: true }),
        Animated.timing(translateY, { toValue: 0, duration: 160, useNativeDriver: true }),
      ]).start();
      return () => clearTimeout(tm);
    }
    opacity.setValue(0);
    translateY.setValue(-8);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [visible]);

  function handleNavigate(n: AppNotification) {
    onClose();
    if (n.type === 'domain_accepted' || n.type === 'domain_rejected') {
      router.push('/blocker' as RelativePathString);
    } else if (n.postId) {
      router.push(`/?postId=${n.postId}` as RelativePathString);
    }
  }

  return (
    <Modal
      visible={visible}
      transparent
      animationType="none"
      statusBarTranslucent
      onRequestClose={onClose}
    >
      <Pressable
        onPress={onClose}
        style={{ flex: 1, backgroundColor: 'rgba(0,0,0,0.18)' }}
      >
        <Animated.View
          onStartShouldSetResponder={() => true}
          style={{
            position: 'absolute',
            top: topOffset + 6,
            right: 12,
            backgroundColor: colors.bg,
            borderRadius: 18,
            shadowColor: '#000',
            shadowOffset: { width: 0, height: 8 },
            shadowOpacity: 0.18,
            shadowRadius: 20,
            elevation: 12,
            width: 320,
            maxHeight: 480,
            overflow: 'hidden',
            opacity,
            transform: [{ translateY }],
          }}
        >
          {/* Header */}
          <View
            style={{
              flexDirection: 'row',
              alignItems: 'center',
              paddingHorizontal: 16,
              paddingVertical: 12,
              borderBottomWidth: 1,
              borderBottomColor: colors.border,
            }}
          >
            <Text
              style={{ flex: 1, fontSize: 14, fontFamily: 'Nunito_700Bold', color: colors.text }}
            >
              {t('notifications.title')}
            </Text>
            {unread > 0 && (
              <Pressable onPress={() => markRead()} hitSlop={6}>
                <Text
                  style={{ fontSize: 11, fontFamily: 'Nunito_600SemiBold', color: '#007AFF' }}
                >
                  {t('notifications.mark_all_read')}
                </Text>
              </Pressable>
            )}
          </View>

          {items.length === 0 ? (
            <View style={{ paddingVertical: 32, alignItems: 'center' }}>
              <Ionicons name="notifications-off-outline" size={28} color={colors.textMuted} />
              <Text
                style={{
                  marginTop: 8,
                  fontSize: 13,
                  fontFamily: 'Nunito_600SemiBold',
                  color: colors.textMuted,
                }}
              >
                {t('notifications.empty_title')}
              </Text>
              <Text
                style={{
                  marginTop: 2,
                  fontSize: 11,
                  fontFamily: 'Nunito_400Regular',
                  color: colors.textMuted,
                  textAlign: 'center',
                  paddingHorizontal: 20,
                }}
              >
                {t('notifications.empty_subtitle')}
              </Text>
            </View>
          ) : (
            <FlatList
              data={items}
              keyExtractor={(n) => n.id}
              renderItem={({ item }) => (
                <NotificationRow
                  notif={item}
                  onPress={() => handleNavigate(item)}
                  t={t}
                />
              )}
            />
          )}
        </Animated.View>
      </Pressable>
    </Modal>
  );
}

function notifLabel(n: AppNotification, t: (k: string, opts?: any) => string): string {
  switch (n.type) {
    case 'new_like':
      return `${n.actorName} ${t('notifications.liked_post')}`;
    case 'new_comment':
      return `${n.actorName} ${t('notifications.commented_post')}`;
    case 'domain_vote':
      return `${n.actorName} ${t('notifications.voted_domain')}`;
    case 'domain_accepted':
      return n.preview
        ? `${n.preview} ${t('notifications.domain_accepted')}`
        : t('notifications.domain_accepted');
    case 'domain_rejected':
      return n.preview
        ? `${n.preview} ${t('notifications.domain_rejected')}`
        : t('notifications.domain_rejected');
    case 'new_follower':
      return `${n.actorName} ${t('notifications.new_follower')}`;
    default:
      return `${n.actorName} ${t('notifications.generic')}`;
  }
}

function notifIcon(type: string): {
  icon: React.ComponentProps<typeof Ionicons>['name'];
  color: string;
  bg: string;
} {
  switch (type) {
    case 'new_like':
      return { icon: 'heart', color: '#dc2626', bg: '#fee2e2' };
    case 'new_comment':
      return { icon: 'chatbubble-ellipses', color: '#2563eb', bg: '#dbeafe' };
    case 'domain_accepted':
      return { icon: 'shield-checkmark', color: '#16a34a', bg: '#dcfce7' };
    case 'domain_rejected':
      return { icon: 'close-circle', color: '#dc2626', bg: '#fee2e2' };
    case 'domain_vote':
      return { icon: 'thumbs-up', color: '#d97706', bg: '#fef3c7' };
    case 'new_follower':
      return { icon: 'person-add', color: '#7c3aed', bg: '#ede9fe' };
    default:
      return { icon: 'notifications', color: '#737373', bg: '#f5f5f5' };
  }
}

function timeAgo(dateStr: string, t: (k: string, opts?: any) => string): string {
  const m = Math.floor((Date.now() - new Date(dateStr).getTime()) / 60000);
  if (m < 1) return t('notifications.just_now');
  if (m < 60) return t('notifications.min_ago', { n: m });
  const h = Math.floor(m / 60);
  if (h < 24) return t('notifications.hours_ago', { n: h });
  return t('notifications.days_ago', { n: Math.floor(h / 24) });
}

function NotificationRow({
  notif,
  onPress,
  t,
}: {
  notif: AppNotification;
  onPress: () => void;
  t: (k: string, opts?: any) => string;
}) {
  const colors = useColors();
  const isUnread = !notif.readAt;
  const { icon, color, bg } = notifIcon(notif.type);
  const isSocial =
    notif.type === 'new_like' ||
    notif.type === 'new_comment' ||
    notif.type === 'new_follower' ||
    notif.type === 'domain_vote';
  // System-Notifications (von ReBreak selbst) bekommen das App-Icon als Avatar
  const isSystem =
    notif.type === 'domain_accepted' ||
    notif.type === 'domain_rejected' ||
    (notif.actorName ?? '').toLowerCase().startsWith('rebreak');
  const avatarUrl = isSocial ? resolveAvatar(notif.actorAvatar, notif.actorName) : null;

  return (
    <Pressable
      onPress={onPress}
      style={({ pressed }) => ({
        opacity: pressed ? 0.65 : 1,
      })}
    >
      <View
        style={{
          flexDirection: 'row',
          alignItems: 'flex-start',
          paddingHorizontal: 14,
          paddingVertical: 11,
          borderBottomWidth: 1,
          borderBottomColor: colors.border,
          backgroundColor: isUnread ? colors.surface : colors.bg,
        }}
      >
        {/* Avatar-Logik:
            - Social: User-Avatar mit kleinem Type-Badge
            - System (ReBreak): App-Icon mit kleinem Type-Badge
            - Sonst: Typed Icon */}
        {avatarUrl ? (
          // Social: Avatar mit kleinem Mini-Badge — Badge ohne weißen Ring (clean).
          <View style={{ marginRight: 10, position: 'relative' }}>
            <Image
              source={{ uri: avatarUrl }}
              style={{ width: 32, height: 32, borderRadius: 16, backgroundColor: '#f5f5f5' }}
            />
            <View
              style={{
                position: 'absolute',
                bottom: -2,
                right: -2,
                width: 16,
                height: 16,
                borderRadius: 8,
                backgroundColor: bg,
                alignItems: 'center',
                justifyContent: 'center',
              }}
            >
              <Ionicons name={icon} size={9} color={color} />
            </View>
          </View>
        ) : (
          // System (domain_accepted/rejected/etc.) + Fallback: NUR clean Icon,
          // kein Avatar-Overlay mehr — vorher hatte ReBreak-App-Icon mit
          // Shield-Badge-Overlay den Logo verdeckt (User-Feedback 2026-05-05).
          <View style={{ marginRight: 12, alignItems: 'center', justifyContent: 'center', width: 32 }}>
            {notif.type === 'domain_accepted' ? (
              <HeroShieldCheck size={24} color={color} />
            ) : (
              <Ionicons name={icon} size={24} color={color} />
            )}
          </View>
        )}
        <View style={{ flex: 1, minWidth: 0 }}>
          <Text
            style={{
              fontSize: 12,
              fontFamily: 'Nunito_600SemiBold',
              color: colors.text,
              lineHeight: 16,
            }}
            numberOfLines={2}
          >
            {notifLabel(notif, t)}
          </Text>
          <Text
            style={{
              fontSize: 10,
              fontFamily: 'Nunito_400Regular',
              color: colors.textMuted,
              marginTop: 2,
            }}
          >
            {timeAgo(notif.createdAt, t)}
          </Text>
        </View>
      </View>
    </Pressable>
  );
}