import { Ionicons } from '@expo/vector-icons';
import { LinearGradient } from 'expo-linear-gradient';
import { useRouter } from 'expo-router';
import { useRef, useState } from 'react';
import {
  Pressable,
  ScrollView,
  StyleSheet,
  Text,
  useWindowDimensions,
  View,
} from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';
import { colors, headerGradientShort } from '../src/theme';
import { useAuth } from '../src/context/AuthContext';

interface GuideSlide {
  icon: string;
  title: string;
  desc: string;
}

/** 引导页内容：聚焦职来四大差异化能力 */
const SLIDES: GuideSlide[] = [
  {
    icon: 'compass-outline',
    title: '双向透明求职生态',
    desc: '看真实公司评价与行业声誉，让信息差不再成为求职的障碍。',
  },
  {
    icon: 'options-outline',
    title: '自定义评价维度',
    desc: '按你的关注点设置权重，实时算出综合得分，找到最匹配的公司。',
  },
  {
    icon: 'game-controller-outline',
    title: '通关小游戏',
    desc: '7 关闯关引导你走完「认识自己 → 签约」的完整求职链路。',
  },
  {
    icon: 'shield-checkmark-outline',
    title: '阿布阿诺 AI 法律服务',
    desc: '免费咨询与模板，付费律师与合同审核，求职权益有保障。',
  },
];

export default function GuideScreen() {
  const router = useRouter();
  const { completeOnboarding } = useAuth();
  const { width } = useWindowDimensions();
  const [page, setPage] = useState(0);
  const scrollRef = useRef<ScrollView>(null);

  const isLast = page === SLIDES.length - 1;

  const finish = () => {
    completeOnboarding();
    router.replace('/login');
  };

  const goNext = () => {
    if (isLast) {
      finish();
      return;
    }
    const next = page + 1;
    setPage(next);
    scrollRef.current?.scrollTo({ x: next * width, animated: true });
  };

  return (
    <SafeAreaView style={styles.container} edges={['top', 'bottom']}>
      <View style={styles.topBar}>
        <View style={styles.topSpacer} />
        <Pressable onPress={finish} hitSlop={8}>
          <Text style={styles.skipText}>跳过</Text>
        </Pressable>
      </View>

      <ScrollView
        ref={scrollRef}
        horizontal
        pagingEnabled
        showsHorizontalScrollIndicator={false}
        onMomentumScrollEnd={(e) => {
          const index = Math.round(e.nativeEvent.contentOffset.x / width);
          setPage(index);
        }}
        style={styles.pager}
      >
        {SLIDES.map((slide) => (
          <View key={slide.title} style={[styles.slide, { width }]}>
            <LinearGradient colors={[...headerGradientShort]} style={styles.illus}>
              <Ionicons
                name={slide.icon as keyof typeof Ionicons.glyphMap}
                size={56}
                color={colors.textInverse}
              />
            </LinearGradient>
            <Text style={styles.slideTitle}>{slide.title}</Text>
            <Text style={styles.slideDesc}>{slide.desc}</Text>
          </View>
        ))}
      </ScrollView>

      <View style={styles.bottom}>
        <View style={styles.dots}>
          {SLIDES.map((slide, i) => (
            <View key={slide.title} style={[styles.dot, i === page && styles.dotActive]} />
          ))}
        </View>
        <Pressable style={styles.nextBtn} onPress={goNext} hitSlop={6}>
          <LinearGradient colors={[...headerGradientShort]} style={styles.nextGradient}>
            <Text style={styles.nextText}>{isLast ? '立即体验' : '下一步'}</Text>
          </LinearGradient>
        </Pressable>
        <Text style={styles.pageHint}>
          {page + 1} / {SLIDES.length}
        </Text>
      </View>
    </SafeAreaView>
  );
}

const styles = StyleSheet.create({
  container: { flex: 1, backgroundColor: colors.white },
  topBar: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    paddingHorizontal: 16,
    paddingVertical: 10,
  },
  topSpacer: { width: 40 },
  skipText: { fontSize: 14, color: colors.textSecondary, paddingHorizontal: 4 },
  pager: { flex: 1 },
  slide: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    paddingHorizontal: 36,
  },
  illus: {
    width: 132,
    height: 132,
    borderRadius: 36,
    alignItems: 'center',
    justifyContent: 'center',
    marginBottom: 36,
  },
  slideTitle: {
    fontSize: 22,
    fontWeight: '800',
    color: colors.textPrimary,
    textAlign: 'center',
    marginBottom: 14,
  },
  slideDesc: {
    fontSize: 15,
    color: colors.textSecondary,
    textAlign: 'center',
    lineHeight: 24,
  },
  bottom: {
    alignItems: 'center',
    paddingHorizontal: 36,
    paddingBottom: 28,
  },
  dots: { flexDirection: 'row', gap: 8, marginBottom: 24 },
  dot: {
    width: 8,
    height: 8,
    borderRadius: 4,
    backgroundColor: colors.border,
  },
  dotActive: { width: 22, backgroundColor: colors.primary },
  nextBtn: {
    width: '100%',
    height: 50,
    borderRadius: 25,
    overflow: 'hidden',
  },
  nextGradient: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
  },
  nextText: { fontSize: 16, fontWeight: '700', color: colors.textInverse },
  pageHint: {
    marginTop: 16,
    fontSize: 13,
    color: colors.textHint,
  },
});