import React, { useCallback } from 'react';
import {
  View,
  ScrollView,
  Text,
  StyleSheet,
  SafeAreaView,
  TouchableOpacity,
  RefreshControl,
} from 'react-native';
import { useResources } from '../../hooks/useResources';
import { LoadingState } from '../../components/ui/LoadingState';
import { ErrorState } from '../../components/ui/ErrorState';
import { EmptyState } from '../../components/ui/EmptyState';

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#f5f5f5',
  },
  header: {
    backgroundColor: '#fff',
    padding: 16,
    borderBottomWidth: 1,
    borderBottomColor: '#e0e0e0',
  },
  headerTitle: {
    fontSize: 24,
    fontWeight: '700',
    color: '#000',
    marginBottom: 8,
  },
  headerDescription: {
    fontSize: 14,
    color: '#666',
    lineHeight: 20,
  },
  section: {
    paddingHorizontal: 16,
    marginTop: 16,
  },
  sectionTitle: {
    fontSize: 16,
    fontWeight: '600',
    color: '#000',
    marginBottom: 12,
  },
  resourceCard: {
    backgroundColor: '#fff',
    borderRadius: 12,
    padding: 16,
    marginBottom: 12,
    borderLeftWidth: 4,
    borderLeftColor: '#0066cc',
  },
  resourceTitle: {
    fontSize: 15,
    fontWeight: '600',
    color: '#000',
    marginBottom: 6,
  },
  resourceDescription: {
    fontSize: 13,
    color: '#666',
    lineHeight: 18,
  },
  resourceLink: {
    marginTop: 10,
    paddingVertical: 8,
    paddingHorizontal: 12,
    backgroundColor: '#f0f0f0',
    borderRadius: 6,
  },
  resourceLinkText: {
    color: '#0066cc',
    fontSize: 12,
    fontWeight: '600',
    textAlign: 'center',
  },
});

export default function ResourcesScreen() {
  const { data: resources, isLoading, isError, refetch } = useResources();

  const onRefresh = useCallback(() => {
    refetch();
  }, [refetch]);

  if (isLoading) {
    return <LoadingState message="Loading resources..." />;
  }

  if (isError) {
    return <ErrorState message="Failed to load resources" onRetry={refetch} />;
  }

  return (
    <SafeAreaView style={styles.container}>
      <ScrollView
        showsVerticalScrollIndicator={false}
        refreshControl={
          <RefreshControl refreshing={isLoading} onRefresh={onRefresh} />
        }
      >
        <View style={styles.header}>
          <Text style={styles.headerTitle}>Resources</Text>
          <Text style={styles.headerDescription}>
            We know how scary and overwhelming it can be to receive a diagnosis. We've curated helpful resources to make your journey a little easier.
          </Text>
        </View>

        {!resources || resources.length === 0 ? (
          <EmptyState title="No Resources Found" message="Check back later for updates." />
        ) : (
          resources.map((resource) => (
            <View key={resource.id} style={styles.section}>
              <View style={styles.resourceCard}>
                <Text style={styles.resourceTitle}>{resource.title}</Text>
                <Text style={styles.resourceDescription}>{resource.description}</Text>
                <TouchableOpacity style={styles.resourceLink}>
                  <Text style={styles.resourceLinkText}>Learn More →</Text>
                </TouchableOpacity>
              </View>
            </View>
          ))
        )}

        <View style={[styles.section, { marginBottom: 40 }]}>
          <Text style={styles.sectionTitle}>More Coming Soon</Text>
          <Text style={{ fontSize: 14, color: '#666', lineHeight: 20 }}>
            Be sure to check back often or sign up to receive updates as we're adding new resources all the time!
          </Text>
        </View>
      </ScrollView>
    </SafeAreaView>
  );
}