refactor: apply the new accessor to replace length - 1 / length -2

@libs/indicators/MAX.ts

@@ -13,28 +13,31 @@ export const useMAX = (source: Series, period: number) => {
   // 单调队列: 保存当前窗口期内，比最新的元素小的元素的索引
   const queue = useRef<number[]>([]);
   useEffect(() => {
-    const i = source.length - 2;
-    if (i < 0) return;
+    const previousIndex = source.previousIndex;
+    if (previousIndex < 0) return;
     // 从栈顶开始，移除所有小于当前值的元素
     while (
       queue.current.length > 0 &&
-      source[queue.current[queue.current.length - 1]] <= source[i]
+      source[queue.current[queue.current.length - 1]] <= source.previousValue
     ) {
       queue.current.pop();
     }
     // 将当前值入栈
-    queue.current.push(i);
+    queue.current.push(previousIndex);
     // 移除超出窗口期的元素 (通常一次只会移除一个)
-    while (queue.current.length > 0 && queue.current[0] <= i - period) {
+    while (
+      queue.current.length > 0 &&
+      queue.current[0] <= previousIndex - period
+    ) {
       queue.current.shift();
     }
   }, [source.length]);
   useEffect(() => {
-    const i = source.length - 1;
-    if (i < 0) return;
+    const currentIndex = source.currentIndex;
+    if (currentIndex < 0) return;
     // 队首元素即为当前窗口期内的最小值
-    MAX[i] = Math.max(
-      source[source.length - 1],
+    MAX[currentIndex] = Math.max(
+      source.currentValue,
       source[queue.current[0]] || -Infinity
     );
   });

@libs/indicators/MIN.ts

@@ -13,28 +13,31 @@ export const useMIN = (source: Series, period: number) => {
   // 单调队列: 保存当前窗口期内，比最新的元素小的元素的索引
   const queue = useRef<number[]>([]);
   useEffect(() => {
-    const i = source.length - 2;
-    if (i < 0) return;
+    const previousIndex = source.previousIndex;
+    if (previousIndex < 0) return;
     // 从栈顶开始，移除所有大于当前值的元素
     while (
       queue.current.length > 0 &&
-      source[queue.current[queue.current.length - 1]] >= source[i]
+      source[queue.current[queue.current.length - 1]] >= source.previousValue
     ) {
       queue.current.pop();
     }
     // 将当前值入栈
-    queue.current.push(i);
+    queue.current.push(previousIndex);
     // 移除超出窗口期的元素 (通常一次只会移除一个)
-    while (queue.current.length > 0 && queue.current[0] <= i - period) {
+    while (
+      queue.current.length > 0 &&
+      queue.current[0] <= previousIndex - period
+    ) {
       queue.current.shift();
     }
   }, [source.length]);
   useEffect(() => {
-    const i = source.length - 1;
-    if (i < 0) return;
+    const currentIndex = source.currentIndex;
+    if (currentIndex < 0) return;
     // 队首元素即为当前窗口期内的最小值
-    MIN[i] = Math.min(
-      source[source.length - 1],
+    MIN[currentIndex] = Math.min(
+      source.currentValue,
       source[queue.current[0]] || Infinity
     );
   });

@libs/indicators/RANGE.ts

@@ -13,9 +13,9 @@ export const useRANGE = (source: Series, period: number) => {
     chart: "new",
   });
   useEffect(() => {
-    const i = source.length - 1;
-    if (i < 0) return;
-    Range[i] = max[i] - min[i];
+    const currentIndex = source.currentIndex;
+    if (currentIndex < 0) return;
+    Range[currentIndex] = max.currentValue - min.currentValue;
   });
   return Range;
 };

@libs/indicators/SAR.ts

@@ -22,72 +22,76 @@ export const useSAR = (
   const direction = useSeries("direction", high); // 1 for upward, -1 for downward, 0 for unknown
 
   useEffect(() => {
-    const i = high.length - 1;
+    const i = high.currentIndex;
     if (i < 0) return;
 
     if (i === 0) {
-      MAX[i] = high[i];
-      MIN[i] = low[i];
+      MAX[i] = high.currentValue;
+      MIN[i] = low.currentValue;
       AF[i] = start;
-      U[i] = high[i];
-      D[i] = low[i];
+      U[i] = high.currentValue;
+      D[i] = low.currentValue;
       direction[i] = 0;
       return;
     }
     // U[i] = U[i - 1];
     // D[i] = D[i - 1];
 
-    if (direction[i - 1] !== 1) {
+    if (direction.previousValue !== 1) {
       // 按下行处理
 
       // 检查是否向上反转
-      if (high[i] >= U[i - 1]) {
+      if (high.currentValue >= U.previousValue) {
         direction[i] = 1;
-        MAX[i] = high[i];
-        MIN[i] = low[i];
+        MAX[i] = high.currentValue;
+        MIN[i] = low.currentValue;
         U[i] = NaN; // MAX[i];
-        D[i] = MIN[i - 1]; // 从上一个区间的最小值开始
+        D[i] = MIN.previousValue; // 从上一个区间的最小值开始
         AF[i] = start;
         return;
       }
-      direction[i] = direction[i - 1];
+      direction[i] = direction.previousValue;
       // 检查是否创新低
-      if (low[i] < MIN[i - 1]) {
-        AF[i] = Math.min(max, AF[i - 1] + increment);
+      if (low.currentValue < MIN.previousValue) {
+        AF[i] = Math.min(max, AF.previousValue + increment);
       } else {
-        AF[i] = AF[i - 1];
+        AF[i] = AF.previousValue;
       }
       // 维护区间极值
-      MAX[i] = Math.max(MAX[i - 1], high[i]);
-      MIN[i] = Math.min(MIN[i - 1], low[i]);
+      MAX[i] = Math.max(MAX.previousValue, high.currentValue);
+      MIN[i] = Math.min(MIN.previousValue, low.currentValue);
 
-      U[i] = U[i - 1] + AF[i] * (MIN[i - 1] - U[i - 1]);
+      U[i] =
+        U.previousValue +
+        AF.currentValue * (MIN.previousValue - U.previousValue);
       D[i] = NaN; // MIN[i];
     } else {
       // 按上行处理
 
       // 检查是否向下反转
-      if (low[i] <= D[i - 1]) {
+      if (low.currentValue <= D.previousValue) {
         direction[i] = -1;
-        MAX[i] = high[i];
-        MIN[i] = low[i];
+        MAX[i] = high.currentValue;
+        MIN[i] = low.currentValue;
         AF[i] = start;
-        U[i] = MAX[i - 1]; // 从上一个区间的最大值开始
+        U[i] = MAX.previousValue; // 从上一个区间的最大值开始
         D[i] = NaN; // MIN[i];
         return;
       }
-      direction[i] = direction[i - 1];
+      direction[i] = direction.previousValue;
       // 检查是否创新高
-      if (high[i] < MAX[i - 1]) {
-        AF[i] = Math.min(max, AF[i - 1] + increment);
+      if (high.currentValue < MAX.previousValue) {
+        AF[i] = Math.min(max, AF.previousValue + increment);
       } else {
-        AF[i] = AF[i - 1];
+        AF[i] = AF.previousValue;
       }
       // 维护区间极值
-      MAX[i] = Math.max(MAX[i - 1], high[i]);
-      MIN[i] = Math.min(MIN[i - 1], low[i]);
+      MAX[i] = Math.max(MAX.previousValue, high.currentValue);
+      MIN[i] = Math.min(MIN.previousValue, low.currentValue);
       U[i] = NaN; //MAX[i];
-      D[i] = D[i - 1] + AF[i] * (MAX[i - 1] - D[i - 1]);
+      D[i] =
+        D.previousValue +
+        AF.currentValue * (MAX.previousValue - D.previousValue);
     }
   });
   return { U, D, direction, MAX, MIN, AF };

@libs/indicators/TD.ts

@@ -6,14 +6,14 @@ export const useTD = (source: Series) => {
   });
 
   useEffect(() => {
-    const i = source.length - 1;
-    if (i < 0) return;
-    TD[i] = 0;
-    if (source[i] > source[i - 4]) {
-      TD[i] = Math.max(0, TD[i - 1] ?? 0) + 1;
+    const currentIndex = source.currentIndex;
+    if (currentIndex < 0) return;
+    TD[currentIndex] = 0;
+    if (source.currentValue > source[currentIndex - 4]) {
+      TD[currentIndex] = Math.max(0, TD.previousValue ?? 0) + 1;
     }
-    if (source[i] < source[i - 4]) {
-      TD[i] = Math.min(0, TD[i - 1] ?? 0) - 1;
+    if (source.currentValue < source[currentIndex - 4]) {
+      TD[currentIndex] = Math.min(0, TD.previousValue ?? 0) - 1;
     }
   });
 

@libs/indicators/ZIGZAG.ts

@@ -26,7 +26,7 @@ export const useZigZag = (high: Series, low: Series, period: number) => {
   useEffect(() => {
     for (
       let i = Math.max(0, lastLowPeak.length) - 1;
-      i < high.length - 1;
+      i < high.currentIndex;
       i++
     ) {
       if (i <= 0) {
@@ -100,11 +100,11 @@ export const useZigZag = (high: Series, low: Series, period: number) => {
       }
     }
     if (high.length >= 1) {
-      lastHighPeak[high.length - 1] = NaN;
-      lastLowPeak[high.length - 1] = NaN;
-      currentZigzagValue[high.length - 1] = NaN;
-      lastZigzagValue[high.length - 1] = NaN;
-      secondLastZigzagValue[high.length - 1] = NaN;
+      lastHighPeak[high.currentIndex] = NaN;
+      lastLowPeak[high.currentIndex] = NaN;
+      currentZigzagValue[high.currentIndex] = NaN;
+      lastZigzagValue[high.currentIndex] = NaN;
+      secondLastZigzagValue[high.currentIndex] = NaN;
     }
   });
 

@libs/utils/useSeriesMap.ts

@@ -10,7 +10,7 @@ export const useSeriesMap = (
 ) => {
   const series = useSeries(name, parent, tags);
   useEffect(() => {
-    const i = parent.length - 1;
+    const i = parent.currentIndex;
     if (i < 0) return;
     series[i] = fn(i, series);
   });

@libs/utils/useThrottle.ts

@@ -7,19 +7,19 @@ export const useThrottle = (series: Series, period: number) => {
   const ret = useSeries(`THROTTLE(${series.name},${period})`, series, {});
   const openIdxRef = useRef(0);
   useEffect(() => {
-    const i = series.length - 1;
-    if (i < 0) return;
-    if (i < openIdxRef.current) {
-      ret[i] = NaN;
+    const currentIndex = series.currentIndex;
+    if (currentIndex < 0) return;
+    if (currentIndex < openIdxRef.current) {
+      ret[currentIndex] = NaN;
       return;
     }
-    if (series[i - 1]) {
-      openIdxRef.current = i + period;
-      ret[i - 1] = series[i - 1];
-      ret[i] = NaN;
+    if (series[currentIndex - 1]) {
+      openIdxRef.current = currentIndex + period;
+      ret[currentIndex - 1] = series.previousValue;
+      ret[currentIndex] = NaN;
       return;
     }
-    ret[i] = series[i];
+    ret[currentIndex] = series.currentValue;
   });
   return ret;
 };

@libs/utils/useTopK.ts

@@ -7,26 +7,26 @@
 export const useTopK = (series: Series, k: number, period: number) => {
   const indexes = useRef<number[]>([]);
   const ret = useSeries(`TOP_K(${series.name},${k},${period})`, series, {});
-  const i = series.length - 1;
+  const currentIndex = series.currentIndex;
   useEffect(() => {
-    if (i < 0) return;
+    if (currentIndex < 0) return;
     let isChanged = false;
     // remove expired indexes
-    if (indexes.current[0] <= i - period) {
+    if (indexes.current[0] <= currentIndex - period) {
       indexes.current.shift();
       isChanged = true;
     }
-    if (series[i - 1]) {
-      indexes.current.push(i - 1);
+    if (series.previousValue) {
+      indexes.current.push(currentIndex - 1);
       isChanged = true;
     }
 
     if (isChanged) {
       const sorted = [...indexes.current].sort((a, b) => series[b] - series[a]);
-      ret[i] = series[sorted[Math.min(k, sorted.length) - 1]];
+      ret[currentIndex] = series[sorted[Math.min(k, sorted.length) - 1]];
     } else {
-      ret[i] = ret[i - 1] ?? NaN;
+      ret[currentIndex] = ret.previousValue ?? NaN;
     }
-  }, [i]);
+  }, [currentIndex]);
   return ret;
 };

@models/CCI-trending.ts

@@ -37,7 +37,6 @@ import {
  */
 export default () => {
   const { product_id, high, low, close } = useParamOHLC("SomeKey");
-  const idx = close.length - 2;
 
   const cciFast = useCCI(high, low, close, 18);
   const cciSlow = useCCI(high, low, close, 54);
@@ -48,42 +47,52 @@ export default () => {
     accountInfo.account_id,
     product_id
   );
-  const stopLossPrice = useRef(close[idx] - 6 * atr108[idx]);
+  const stopLossPrice = useRef(close.previousValue - 6 * atr108.previousValue);
 
   useEffect(() => {
-    if (idx < 108) return; // 确保ATR有足够的数据
+    if (close.previousIndex < 108) return; // 确保ATR有足够的数据
 
     // 空头信号：当CCI快线进入正200以上，且下穿慢线时，建立空单。
-    if (cciFast[idx] > 200 && cciFast[idx] < cciSlow[idx]) {
+    if (
+      cciFast.previousValue > 200 &&
+      cciFast.previousValue < cciSlow.previousValue
+    ) {
       setTargetVolume(-1);
-      stopLossPrice.current = close[idx] + 6 * atr108[idx]; // 使用6倍ATR的值作为停损点位。
+      stopLossPrice.current = close.previousValue + 6 * atr108.previousValue; // 使用6倍ATR的值作为停损点位。
     }
 
     // 多头信号：当CCI快线进入负200以下，且上穿慢线时，建立多单。
-    if (cciFast[idx] < -200 && cciFast[idx] > cciSlow[idx]) {
+    if (
+      cciFast.previousValue < -200 &&
+      cciFast.previousValue > cciSlow.previousValue
+    ) {
       setTargetVolume(1);
-      stopLossPrice.current = close[idx] - 6 * atr108[idx]; // 使用6倍ATR的值作为停损点位。
+      stopLossPrice.current = close.previousValue - 6 * atr108.previousValue; // 使用6倍ATR的值作为停损点位。
     }
 
     // 多单平仓：当CCI快线进入正200以上，且下穿慢线时，平多单。
-    if (targetVolume > 0 && cciFast[idx] > 200 && cciFast[idx] < cciSlow[idx]) {
+    if (
+      targetVolume > 0 &&
+      cciFast.previousValue > 200 &&
+      cciFast.previousValue < cciSlow.previousValue
+    ) {
       setTargetVolume(0);
     }
     // 空单平仓：当CCI快线进入负200以下，且上穿慢线时，平空单。
     if (
       targetVolume < 0 &&
-      cciFast[idx] < -200 &&
-      cciFast[idx] > cciSlow[idx]
+      cciFast.previousValue < -200 &&
+      cciFast.previousValue > cciSlow.previousValue
     ) {
       setTargetVolume(0);
     }
 
     // 停损条件
     if (
-      (targetVolume > 0 && close[idx] < stopLossPrice.current) ||
-      (targetVolume < 0 && close[idx] > stopLossPrice.current)
+      (targetVolume > 0 && close.previousValue < stopLossPrice.current) ||
+      (targetVolume < 0 && close.previousValue > stopLossPrice.current)
     ) {
       setTargetVolume(0);
     }
-  }, [idx]);
+  }, [close.previousIndex]);
 };