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

/* ===================== 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}>文书预览</Text>
      <View style={styles.headerBtn} />
    </View>
  );
}

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

export default function LegalTemplateScreen() {
  const router = useRouter();
  const { id } = useLocalSearchParams();
  const { templates, loading, error, refresh } = useLegalData();

  const templateId = Array.isArray(id) ? id[0] : id;
  const template = templateId ? templates.find((t) => t.id === templateId) : undefined;

  return (
    <SafeAreaView style={styles.safeArea} edges={['top']}>
      <Header onBack={() => router.back()} />
      {loading ? (
        <LoadingState text="加载模板中…" />
      ) : error ? (
        <ErrorState message="加载失败，请重试" onRetry={refresh} />
      ) : !template ? (
        <EmptyState icon="document-text-outline" title="未找到该模板" subtitle="请返回重新选择" />
      ) : (
        <ScrollView
          style={styles.scroll}
          contentContainerStyle={styles.content}
          showsVerticalScrollIndicator={false}
        >
          <View style={styles.headCard}>
            <Ionicons name={template.icon as never} size={28} color={colors.primary} />
            <View style={styles.headBody}>
              <Text style={styles.name}>{template.name}</Text>
              <Text style={styles.desc}>{template.description}</Text>
            </View>
          </View>

          <View style={styles.contentCard}>
            {/* selectable：长按正文即可复制，无需额外原生模块（mock 阶段） */}
            <Text style={styles.contentText} selectable>
              {template.content}
            </Text>
          </View>

          <Text style={styles.tip}>
            长按正文即可复制；正式下载 / 导出为 Word·PDF 需后端文件支持，当前为内容预览。
          </Text>
        </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: 12,
    paddingBottom: 24,
  },
  headCard: {
    flexDirection: 'row',
    alignItems: 'center',
    padding: 16,
    borderRadius: 12,
    backgroundColor: colors.white,
    marginBottom: 12,
  },
  headBody: {
    flex: 1,
    marginLeft: 12,
  },
  name: {
    fontSize: 16,
    fontWeight: '700',
    color: colors.textPrimary,
  },
  desc: {
    marginTop: 2,
    fontSize: 12,
    color: colors.textSecondary,
  },
  contentCard: {
    padding: 16,
    borderRadius: 12,
    backgroundColor: colors.white,
    borderWidth: 1,
    borderColor: colors.borderLight,
  },
  contentText: {
    fontSize: 14,
    lineHeight: 22,
    color: colors.textPrimary,
  },
  tip: {
    marginTop: 12,
    fontSize: 12,
    color: colors.textHint,
    lineHeight: 18,
  },
});