import { useMemo, useState } from 'react';
import { Pressable, StyleSheet, Text, View } from 'react-native';
import { useRouter } from 'expo-router';
import { useTranslation } from 'react-i18next';

import { setOnboardingCompleted } from '@/src/storage/appStorage';

type OnboardingPage = {
  title: string;
  desc: string;
};

export default function OnboardingScreen() {
  const router = useRouter();
  const { t } = useTranslation();

  // 3–5 页：这里默认 4 页，后续可按产品调整为 3 或 5
  const pages = useMemo<OnboardingPage[]>(
    () => [
      { title: t('onboarding.q1Title'), desc: t('onboarding.q1Desc') },
      { title: t('onboarding.q2Title'), desc: t('onboarding.q2Desc') },
      { title: t('onboarding.q3Title'), desc: t('onboarding.q3Desc') },
      { title: t('onboarding.q4Title'), desc: t('onboarding.q4Desc') }
    ],
    [t]
  );

  const total = pages.length;
  const [step, setStep] = useState(0);
  const page = pages[Math.min(step, total - 1)];

  async function finishAndNext() {
    await setOnboardingCompleted(true);
    router.replace('/(onboarding)/push-prompt');
  }

  async function onNext() {
    if (step >= total - 1) {
      await finishAndNext();
      return;
    }
    setStep((s) => s + 1);
  }

  async function onSkipPage() {
    // 每页可跳过：直接进入下一页（最后一页则结束）
    await onNext();
  }

  async function onSkipAll() {
    // 一键跳过整个 Onboarding
    await finishAndNext();
  }

  return (
    <View style={styles.container}>
      <Text style={styles.progress}>
        {t('onboarding.progress', { current: step + 1, total })}
      </Text>

      <View style={styles.card}>
        <Text style={styles.title}>{page.title}</Text>
        <Text style={styles.desc}>{page.desc}</Text>
      </View>

      <View style={styles.actions}>
        <Pressable style={[styles.btn, styles.secondary]} onPress={onSkipPage}>
          <Text style={[styles.btnText, styles.secondaryText]}>{t('onboarding.skip')}</Text>
        </Pressable>
        <Pressable style={[styles.btn, styles.primary]} onPress={onNext}>
          <Text style={styles.btnText}>{t('onboarding.next')}</Text>
        </Pressable>
      </View>

      <Pressable style={styles.skipAll} onPress={onSkipAll}>
        <Text style={styles.skipAllText}>{t('onboarding.skipAll')}</Text>
      </Pressable>
    </View>
  );
}

const styles = StyleSheet.create({
  container: { flex: 1, padding: 20, justifyContent: 'center', gap: 16 },
  progress: { textAlign: 'center', color: '#6B7280' },
  card: {
    borderRadius: 18,
    padding: 20,
    backgroundColor: '#FFFFFF',
    borderWidth: StyleSheet.hairlineWidth,
    borderColor: '#E5E7EB',
    gap: 10
  },
  title: { fontSize: 22, fontWeight: '700', color: '#111827' },
  desc: { fontSize: 16, lineHeight: 22, color: '#374151' },
  actions: { flexDirection: 'row', gap: 12 },
  btn: { flex: 1, paddingVertical: 14, borderRadius: 14, alignItems: 'center' },
  primary: { backgroundColor: '#111827' },
  secondary: { backgroundColor: '#F3F4F6' },
  btnText: { fontSize: 16, fontWeight: '600', color: '#FFFFFF' },
  secondaryText: { color: '#111827' },
  skipAll: { alignItems: 'center', paddingTop: 10 },
  skipAllText: { color: '#6B7280', textDecorationLine: 'underline' }
});