如何让Pine Script代码支持多时间框架并设置跨周期警报？

我需要修改以下Pine Script代码，使其支持多时间框架运行。具体要求是：设置警报时，买入信号需先在小时时间框架生成，随后在更低级别时间框架（例如5分钟）触发。请帮忙修复这段代码。

代码如下：

amplitude = 10
channelDeviation = input(title='Channel Deviation', defval=2)
showArrows = input(title='Show Arrows', defval=true)

var int trend = 1
var int nextTrend = 1
var float maxLowPrice = nz(low[1], low)
var float minHighPrice = nz(high[1], high)

var float up = 1.0
var float down = 1.0
float atrHigh = 1.0
float atrLow = 1.0
float arrowUp = na
float arrowDown = na

atr2 = ta.atr(100) / 2
dev = channelDeviation * atr2

highPrice = high[math.abs(ta.highestbars(amplitude))]
lowPrice = low[math.abs(ta.lowestbars(amplitude))]
highma = ta.sma(high, amplitude)
lowma = ta.sma(low, amplitude)

if nextTrend == 1
    maxLowPrice := math.max(lowPrice, maxLowPrice)

    if highma < maxLowPrice and close < nz(low[1], low)
        trend := 1
        nextTrend := 0
        minHighPrice := highPrice
        minHighPrice
else
    minHighPrice := math.min(highPrice, minHighPrice)

    if lowma > minHighPrice and close > nz(high[1], high)
        trend := 0
        nextTrend := 1
        maxLowPrice := lowPrice
        maxLowPrice

if trend == 0
    if not na(trend[1]) and trend[1] != 0
        up := na(down[1]) ? down : down[1]
        arrowUp := up - atr2
        arrowUp
    else
        up := na(up[1]) ? maxLowPrice : math.max(maxLowPrice, up[1])
        up
    atrHigh := up + dev
    atrLow := up - dev
    atrLow
else
    if not na(trend[1]) and trend[1] != 1
        down := na(up[1]) ? up : up[1]
        arrowDown := down + atr2
        arrowDown
    else
        down := na(down[1]) ? minHighPrice : math.min(minHighPrice, down[1])
        down
    atrHigh := down + dev
    atrLow := down - dev
    atrLow

ht = trend == 0 ? up : down

var color buyColor = color.blue
var color sellColor = color.red

htColor = trend == 1 ? buyColor : sellColor


buySignal = not na(arrowUp) and trend == 1 and trend[1] == 0
sellSignal = not na(arrowDown) and trend == 0 and trend[1] == 1

plotshape(showArrows and buySignal ? atrLow : na, title='Arrow Up', style=shape.triangleup, location=location.absolute, size=size.small, color=color.new(buyColor, 0))
plotshape(showArrows and sellSignal ? atrHigh : na, title='Arrow Down', style=shape.triangledown, location=location.absolute, size=size.small, color=color.new(sellColor, 0))

alertcondition(buySignal, title='Alert: Buy', message='Buy')
alertcondition(sellSignal, title='Alert: Sell', message='Sell')

内容的提问来源于stack exchange，提问作者salem A