mydreamjob/components/onboarding/ui/WheelPicker.tsx

import { useEffect, useRef } from 'react';
import type { NativeScrollEvent, NativeSyntheticEvent } from 'react-native';
import { ScrollView, StyleSheet, Text, View } from 'react-native';
import { colors, spacing } from '../../../src/theme';
import { CURRENT_YEAR } from '../../../src/constants';

const ITEM_H = 44;

function Column({
  items,
  value,
  onValueChange,
  width,
  restingIndex,
}: {
  items: string[];
  value: string;
  onValueChange: (v: string) => void;
  width: number;
  /** 未选中时滚轮的停留位置（只影响视觉停留，不等于已选中） */
  restingIndex: number;
}) {
  const scrollRef = useRef<ScrollView>(null);
  // 未选中（''）与用户手滑到第 0 项是两回事：这里不再把空值钳到索引 0，
  // 而是保留「无选中项」状态，只在视觉上停在 restingIndex。
  const idx = items.indexOf(value);
  const initialIndex = idx >= 0 ? idx : restingIndex;

  // contentOffset 只在 iOS 生效，Android 上不定位会让滚轮停在第一项、
  // 与高亮框里的文字对不上，故挂载时用 scrollTo 补一次（两端通用）。
  useEffect(() => {
    scrollRef.current?.scrollTo({ y: initialIndex * ITEM_H, animated: false });
    // 仅挂载时定位：后续滚动由用户驱动，避免每次选值把滚轮拽回去
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  const handleEnd = (e: NativeSyntheticEvent<NativeScrollEvent>) => {
    const y = e.nativeEvent.contentOffset.y;
    const i = Math.min(items.length - 1, Math.max(0, Math.round(y / ITEM_H)));
    const v = items[i];
    if (v !== value) onValueChange(v);
  };

  return (
    <View style={[styles.col, { width }]}>
      <View style={[styles.highlight, idx < 0 && styles.highlightIdle]} pointerEvents="none" />
      <ScrollView
        ref={scrollRef}
        style={styles.scroll}
        showsVerticalScrollIndicator={false}
        snapToInterval={ITEM_H}
        snapToAlignment="center"
        decelerationRate="fast"
        contentOffset={{ x: 0, y: initialIndex * ITEM_H }}
        contentContainerStyle={{ paddingVertical: ITEM_H }}
        onMomentumScrollEnd={handleEnd}
      >
        {items.map((it) => (
          <View key={it} style={styles.item}>
            <Text style={[styles.itemText, it === value && styles.itemTextActive]}>{it}</Text>
          </View>
        ))}
      </ScrollView>
    </View>
  );
}

interface DualProps {
  year: string;
  month: string;
  onYearChange: (v: string) => void;
  onMonthChange: (v: string) => void;
  /**
   * 未选择年份时滚轮的停留项。默认停在当年（适合「入职时间」这类近期场景）；
   * 「出生年月」应传一个合理的起始年份，否则用户要空滑二十多行。
   */
  restingYear?: string;
  /**
   * 可选年份跨度：往过去几年、往未来几年。
   * 原实现固定 40 项（当年往前 39 年），只能覆盖 0–39 岁 ——
   * 46 岁的求职者选不了自己的出生年；而「入职时间」也选不到明年。
   */
  pastYears?: number;
  futureYears?: number;
}

/** 年月双滚轮：用于出生年月 / 首次参加工作 / 入职时间 */
export function YearMonthWheel({
  year,
  month,
  onYearChange,
  onMonthChange,
  restingYear = `${CURRENT_YEAR}年`,
  pastYears = 60,
  futureYears = 0,
}: DualProps) {
  const years = Array.from(
    { length: pastYears + futureYears + 1 },
    (_, i) => `${CURRENT_YEAR + futureYears - i}年`,
  );
  const months = Array.from({ length: 12 }, (_, i) => `${i + 1}月`);
  const unselected = !year || !month;
  const restingYearIndex = Math.max(0, years.indexOf(restingYear));

  return (
    <View>
      <View style={styles.dual}>
        <Column
          items={years}
          value={year}
          onValueChange={onYearChange}
          width={130}
          restingIndex={restingYearIndex}
        />
        <Column items={months} value={month} onValueChange={onMonthChange} width={110} restingIndex={0} />
      </View>
      {/* 未选中时滚轮无高亮项，需要文字提示「要滑动才有值」，否则用户会以为已经选好了 */}
      {unselected ? <Text style={styles.hint}>请滑动选择</Text> : null}
    </View>
  );
}

const styles = StyleSheet.create({
  col: { height: ITEM_H * 3, position: 'relative' },
  scroll: { flex: 1 },
  highlight: {
    position: 'absolute',
    top: ITEM_H,
    left: 0,
    right: 0,
    height: ITEM_H,
    borderTopWidth: 1,
    borderBottomWidth: 1,
    borderColor: colors.border,
    backgroundColor: colors.primaryLight,
    opacity: 0.45,
  },
  // 未选中：高亮框退成中性描边，不再用主色底暗示「已经选好了」
  highlightIdle: { backgroundColor: colors.white, opacity: 0.6 },
  item: { height: ITEM_H, alignItems: 'center', justifyContent: 'center' },
  itemText: { fontSize: 18, color: colors.textHint },
  itemTextActive: { fontSize: 20, fontWeight: '700', color: colors.textPrimary },
  dual: { flexDirection: 'row', justifyContent: 'center', gap: spacing.block },
  hint: { fontSize: 13, color: colors.textHint, textAlign: 'center', marginTop: spacing.sm },
});