import React from 'react';
import { FlatList, ScrollView, StyleSheet, Text, View, Pressable } from 'react-native';
import { NativeStackScreenProps } from '@react-navigation/native-stack';
import { Icon } from '../../../components/Icon';

import { Input, ScreenShell } from '../../../components';
import { ServicesStackParamList } from '../../../navigation/types';
import { useTheme, fontFamily } from '../../../theme';
import { AwarenessCard } from '../components/AwarenessCard';
import { useAwareness } from '../hooks/useAwareness';
import { AwarenessCategory } from '../types';

type Props = NativeStackScreenProps<ServicesStackParamList, 'AwarenessList'>;

const CATEGORIES: (AwarenessCategory | 'All')[] = ['All', 'RBI', 'NPCI', 'Fraud Alert', 'Best Practices'];

export default function AwarenessListScreen({ navigation }: Props) {
  const theme = useTheme();
  const { articles, filter, setFilter, bookmarks, toggleBookmark, urgentArticles } = useAwareness();

  const handleSearch = (query: string) => {
    setFilter({ ...filter, searchQuery: query });
  };

  const handleCategoryPress = (category: AwarenessCategory | 'All') => {
    setFilter({ ...filter, category });
  };

  return (
    <ScreenShell
      // The body is a FlatList, so it owns the scrolling.
      scrollable={false}
      title="Security aware" subtitle="Learn to protect your digital banking">
      <View style={styles.searchContainer}>
        <Input
          placeholder="Search safety tips, fraud alerts..."
          value={filter.searchQuery}
          onChangeText={handleSearch}
          leftAccessory={<Icon name="search-outline" size={20} color={theme.colors.textMuted} />}
        />
      </View>

      <View style={styles.filterWrapper}>
        <ScrollView horizontal showsHorizontalScrollIndicator={false} contentContainerStyle={styles.filterContainer}>
          {CATEGORIES.map((cat) => {
            const isActive = filter.category === cat;
            return (
              <Pressable
                key={cat}
                onPress={() => handleCategoryPress(cat)}
                style={[
                  styles.filterChip,
                  {
                    backgroundColor: isActive ? theme.colors.primary : theme.colors.surfaceMuted,
                    borderColor: isActive ? theme.colors.primary : theme.colors.cardBorder,
                  },
                ]}
              >
                <Text
                  style={[
                    styles.filterText,
                    { color: isActive ? theme.colors.white : theme.colors.textSecondary },
                  ]}
                >
                  {cat}
                </Text>
              </Pressable>
            );
          })}
        </ScrollView>
      </View>

      <FlatList
        data={articles}
        keyExtractor={(item) => item.id}
        renderItem={({ item }) => (
          <AwarenessCard
            article={item}
            isBookmarked={bookmarks.includes(item.id)}
            onToggleBookmark={() => toggleBookmark(item.id)}
            onPress={() => navigation.navigate('AwarenessDetail', { articleId: item.id })}
          />
        )}
        ListHeaderComponent={
          <>
            {urgentArticles.length > 0 && filter.category === 'All' && filter.searchQuery === '' && (
              <View style={styles.urgentSection}>
                <View style={styles.sectionHeader}>
                  <Icon name="alert-circle" size={18} color={theme.colors.error} />
                  <Text style={[styles.sectionTitle, { color: theme.colors.textPrimary }]}>
                    Critical Security Alerts
                  </Text>
                </View>
                <ScrollView horizontal showsHorizontalScrollIndicator={false} contentContainerStyle={styles.urgentCarousel}>
                  {urgentArticles.map((article) => (
                    <Pressable
                      key={article.id}
                      onPress={() => navigation.navigate('AwarenessDetail', { articleId: article.id })}
                      style={[styles.urgentCard, { backgroundColor: theme.tint(theme.colors.error, 0.03), borderColor: theme.tint(theme.colors.error, 0.13) }]}
                    >
                      <View style={[styles.urgentIcon, { backgroundColor: theme.tint(theme.colors.error, 0.08) }]}>
                        <Icon name={article.icon as any} size={20} color={theme.colors.error} />
                      </View>
                      <Text style={[styles.urgentCardTitle, { color: theme.colors.textPrimary }]} numberOfLines={1}>
                        {article.title}
                      </Text>
                      <Text style={[styles.urgentCardDesc, { color: theme.colors.textSecondary }]} numberOfLines={1}>
                        {article.description}
                      </Text>
                    </Pressable>
                  ))}
                </ScrollView>
              </View>
            )}
            <View style={styles.sectionHeader}>
              <Text style={[styles.sectionTitle, { color: theme.colors.textPrimary }]}>
                {filter.category === 'All' ? 'Latest Awareness Articles' : `${filter.category} Guidelines`}
              </Text>
            </View>
          </>
        }
        contentContainerStyle={styles.listContent}
        ListEmptyComponent={
          <View style={styles.emptyContainer}>
            <Icon name="search-outline" size={48} color={theme.colors.textMuted} />
            <Text style={[styles.emptyTitle, { color: theme.colors.textPrimary }]}>No results found</Text>
            <Text style={[styles.emptySubtitle, { color: theme.colors.textSecondary }]}>
              Try adjusting your search or filters to find what you're looking for.
            </Text>
          </View>
        }
        scrollEnabled={false} // Since it's inside ScreenShell's ScrollView
      />
    </ScreenShell>
  );
}

const styles = StyleSheet.create({
  searchContainer: {
    paddingHorizontal: 16,
    marginBottom: 16,
  },
  filterWrapper: {
    marginBottom: 20,
  },
  filterContainer: {
    paddingHorizontal: 16,
    gap: 10,
  },
  filterChip: {
    paddingHorizontal: 16,
    paddingVertical: 8,
    borderRadius: 20,
    borderWidth: 1,
  },
  filterText: {
    fontSize: 13,
    fontFamily: fontFamily.bold,
  },
  listContent: {
    paddingHorizontal: 16,
    paddingBottom: 100,
  },
  urgentSection: {
    marginBottom: 24,
    gap: 12,
  },
  sectionHeader: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 8,
    marginBottom: 12,
  },
  sectionTitle: {
    fontSize: 16,
    fontFamily: fontFamily.bold,
    letterSpacing: -0.3,
  },
  urgentCarousel: {
    gap: 12,
  },
  urgentCard: {
    width: 260,
    padding: 16,
    borderRadius: 16,
    borderWidth: 1,
    gap: 8,
  },
  urgentIcon: {
    width: 36,
    height: 36,
    borderRadius: 10,
    alignItems: 'center',
    justifyContent: 'center',
  },
  urgentCardTitle: {
    fontSize: 15,
    fontFamily: fontFamily.bold,
  },
  urgentCardDesc: {
    fontSize: 12,
  },
  emptyContainer: {
    alignItems: 'center',
    justifyContent: 'center',
    paddingVertical: 60,
    gap: 12,
  },
  emptyTitle: {
    fontSize: 18,
    fontFamily: fontFamily.bold,
  },
  emptySubtitle: {
    fontSize: 14,
    textAlign: 'center',
    paddingHorizontal: 40,
  },
});