import { Ionicons } from '@expo/vector-icons';
import { useRouter } from 'expo-router';
import { Pressable, ScrollView, StyleSheet, Text, View } from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';
import { useState } from 'react';
import { useLegalData } from '../../src/hooks';
import { LoadingState, ErrorState, EmptyState } from '../../src/components/StateView';
import { colors } from '../../src/theme';
import type { LegalFAQ } from '../../src/types';

/* ===================== 顶部导航 ===================== */

function Header({ onBack }: { onBack: () => void }) {
  return (
    <View style={styles.header}>
      <Pressable style={styles.headerBtn} onPress={onBack} hitSlop={8}>
        <Ionicons name="chevron-back" size={24} color={colors.textPrimary} />
      </Pressable>
      <Text style={styles.headerTitle}>常见问题</Text>
      <View style={styles.headerBtn} />
    </View>
  );
}

/* ===================== FAQ 项 ===================== */

function FAQItem({ faq }: { faq: LegalFAQ }) {
  const [expanded, setExpanded] = useState(false);
  return (
    <Pressable style={styles.faqItem} onPress={() => setExpanded((v) => !v)}>
      <View style={styles.faqRow}>
        <Text style={styles.faqQ}>{faq.question}</Text>
        <Ionicons
          name={expanded ? 'chevron-up' : 'chevron-down'}
          size={18}
          color={colors.textHint}
        />
      </View>
      {expanded && <Text style={styles.faqA}>{faq.answer}</Text>}
    </Pressable>
  );
}

/* ===================== 页面 ===================== */

export default function LegalFaqScreen() {
  const router = useRouter();
  const { faqs, loading, error, refresh } = useLegalData();

  return (
    <SafeAreaView style={styles.safeArea} edges={['top']}>
      <Header onBack={() => router.back()} />
      {loading ? (
        <LoadingState text="加载问题中…" />
      ) : error ? (
        <ErrorState message="加载失败，请重试" onRetry={refresh} />
      ) : faqs.length === 0 ? (
        <EmptyState icon="help-circle-outline" title="暂无常见问题" subtitle="如有疑问，可前往法律咨询" />
      ) : (
        <ScrollView
          style={styles.scroll}
          contentContainerStyle={styles.content}
          showsVerticalScrollIndicator={false}
        >
          <View style={styles.faqCard}>
            {faqs.map((faq) => (
              <FAQItem key={faq.id} faq={faq} />
            ))}
          </View>
        </ScrollView>
      )}
    </SafeAreaView>
  );
}

const styles = StyleSheet.create({
  safeArea: {
    flex: 1,
    backgroundColor: colors.pageBg,
  },
  header: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    paddingHorizontal: 8,
    height: 48,
    backgroundColor: colors.white,
    borderBottomWidth: 1,
    borderBottomColor: colors.borderLight,
  },
  headerBtn: {
    width: 40,
    height: 40,
    alignItems: 'center',
    justifyContent: 'center',
  },
  headerTitle: {
    fontSize: 17,
    fontWeight: '700',
    color: colors.textPrimary,
  },
  scroll: {
    flex: 1,
  },
  content: {
    padding: 8,
    paddingBottom: 24,
  },
  faqCard: {
    backgroundColor: colors.white,
    borderRadius: 8,
    paddingHorizontal: 8,
  },
  faqItem: {
    paddingVertical: 12,
    borderBottomWidth: 1,
    borderBottomColor: colors.borderLight,
  },
  faqRow: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
  },
  faqQ: {
    flex: 1,
    fontSize: 14,
    fontWeight: '600',
    color: colors.textPrimary,
    marginRight: 8,
  },
  faqA: {
    marginTop: 8,
    fontSize: 13,
    lineHeight: 19,
    color: colors.textSecondary,
  },
});