MACD + Support / Resistance Short Strategy

// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © krosenfeld7

//@version=4
strategy("MACD + Support / Resistance Short Strategy", overlay = true, pyramiding = 0, 
         margin_long = 100, margin_short = 100, 
         default_qty_type = strategy.percent_of_equity, 
         default_qty_value = 20, initial_capital = 2000, 
         process_orders_on_close = true)

// Set the starting point for backtesting
start = input(title = "Backtesting Start", type = input.time,
     defval = timestamp("1 Jan 2015"))
maxTimeOpen = input(title = "Order Expiration", type = input.integer,
     defval = 100, minval = 1)
tpSlStrategy = input(title = "Take Profit Strategy", type = input.string,
     defval = "Percent", options = ["Percent", "ATR"])
trailingStop = input(title = "Trailing Stop", type = input.string,
     defval = "Fixed", options = ["Fixed", "Trail"])

// ATR For Stop Loss
atrLength = input(title = "ATR SL Length", defval = 14,
     minval = 1)
atrMultiplier = input(title = "ATR Multiplier", type = input.float, 
     defval = 1, minval = 0.1)
riskLevel = input(title = "Risk Level", type = input.float, 
     defval = 1, minval = 0.1)

shortProfitPercent = input(title = "Take Profit %",
     type = input.float, minval = 0.0, step = 0.1, defval = 10) / 100
shortLossPercent = input(title = "Stop Loss %",
     type = input.float, minval = 0.0, step = 0.1, defval = 10) / 100

// Algorithm / Strategy Goes here
// Set short variables to execute positions below
lookback = input(title = "Pivot Lookback", type = input.integer, defval = 10, minval = 1)
epsilon  = input(title = "Price Epsilon (%)", type = input.float, defval = 0.5, minval = 0.1)
emaRes = input(title = "EMA Resolution", type = input.resolution, defval = "D")
emaSrc = input(title = "EMA Source", type = input.source, defval = close)
emaLength = input(title = "EMA Length", type = input.integer, defval = 100, minval = 1)

ema100 = ema(emaSrc, emaLength)

ema100Daily = security(syminfo.tickerid, emaRes, ema100[barstate.isrealtime ? 1 : 0], barmerge.gaps_off, barmerge.lookahead_off)

emaLong = close > ema100Daily
emaShort = close < ema100Daily

plot(ema100Daily, "EMA", color = color.white, linewidth = 2)

epsilon /= 100

// 100 EMA, MACD, previous high or low

prevHigh = pivothigh(close, lookback, lookback)
prevLow  = pivotlow(close,  lookback, lookback)

// MACD
// Getting inputs
macdRes = input(title = "MACD Resolution", type = input.resolution, defval = "30")
fast_length = input(title="MACD Fast Length", type=input.integer, defval=12)
slow_length = input(title="MACD Slow Length", type=input.integer, defval=26)
src = input(title="MACD Source", type=input.source, defval=close)
signal_length = input(title="MACD Signal Smoothing", type=input.integer, minval = 1, maxval = 50, defval = 9)
sma_source = input(title="MACD Simple MA (Oscillator)", type=input.bool, defval=false)
sma_signal = input(title="MACD Simple MA (Signal Line)", type=input.bool, defval=false)
displayPivots = input(title = "Display Pivot Labels", type = input.bool, defval = false)

// Calculating
fast_ma = sma_source ? sma(src, fast_length) : ema(src, fast_length)
slow_ma = sma_source ? sma(src, slow_length) : ema(src, slow_length)
macd = fast_ma - slow_ma
signal = sma_signal ? sma(macd, signal_length) : ema(macd, signal_length)
hist = macd - signal

macdSec   = security(syminfo.tickerid, macdRes, macd[barstate.isrealtime ? 1 : 0],   barmerge.gaps_off, barmerge.lookahead_off)
signalSec = security(syminfo.tickerid, macdRes, signal[barstate.isrealtime ? 1 : 0], barmerge.gaps_off, barmerge.lookahead_off)

macdCrossDown = crossunder(macdSec, signalSec)
macdCrossUp   = crossover(macdSec,  signalSec)

var bool highPointReached = na
var bool lowPointReached  = na

if (high + (epsilon * high)) >= prevHigh
    if displayPivots
        label.new(bar_index, y = na, yloc = yloc.abovebar, color = color.green, style = label.style_triangledown)
    highPointReached := true
else
    highPointReached := na
if (low - (epsilon * low)) <= prevLow
    if displayPivots
        label.new(bar_index, y = na, yloc = yloc.belowbar, color = color.red, style = label.style_triangleup)
    lowPointReached := true
else
    lowPointReached := na

macdPriceLong = false
macdPriceShort = false

if macdCrossDown and barssince(not na(highPointReached)) < lookback
    macdPriceShort := true

if macdCrossUp and barssince(not na(lowPointReached)) < lookback
    macdPriceLong := true

if not na(prevHigh) and displayPivots
    label.new(bar_index - lookback, y = na, yloc = yloc.abovebar, style = label.style_triangledown)
if not na(prevLow) and displayPivots
    label.new(bar_index - lookback, y = na, yloc = yloc.belowbar, style = label.style_triangleup)

long  = macdPriceLong and emaLong
short = macdPriceShort and emaShort

// End Algorithm

shortExitPrice = 0.0
shortStopPrice = 0.0

shortExitPercentPrice = strategy.position_avg_price * (1 - 
     (shortProfitPercent * riskLevel))
shortStopPercentPrice = strategy.position_avg_price * (1 + 
     shortLossPercent)

// Profit & Loss via ATR
atr = atr(atrLength)

atr := valuewhen(strategy.position_size == 0, atr, 0)

shortExitAtrPrice = strategy.position_avg_price - (atr * 
     atrMultiplier * riskLevel)
shortStopAtrPrice = strategy.position_avg_price + (atr * 
     atrMultiplier)

if tpSlStrategy == "Percent"
    shortExitPrice := shortExitPercentPrice
    
    if trailingStop == "Fixed"
        shortStopPrice := shortStopPercentPrice
    else if trailingStop == "Trail"
        stopValue      = close * (1 + shortLossPercent)
        shortStopPrice := (strategy.position_size < 0) ? 
             min(stopValue, shortStopPrice[1]) : 999999

else if tpSlStrategy == "ATR"
    if strategy.position_size < 0
        shortExitPrice := shortExitAtrPrice
        
    if trailingStop == "Fixed"
        shortStopPrice := shortStopAtrPrice
    else if trailingStop == "Trail"
        stopValue      = close + (atr * atrMultiplier)
        shortStopPrice := (strategy.position_size < 0) ? 
             min(stopValue, shortStopPrice[1]) : 999999

// Plotting profit / loss targets
plot(series = (strategy.position_size < 0) ? shortExitPrice : na, 
     color = color.green, style = plot.style_linebr, linewidth = 3, 
     title = "Short Target")
plot(series = (strategy.position_size < 0) ? shortStopPrice : na, 
     color = color.red, style = plot.style_linebr, linewidth = 3, 
     title = "Short Stop Loss")

// Submit entry orders
if time >= start
    strategy.entry(id = "Short", long = strategy.short, 
         comment = "Short Open", when = short)

// Submit exit orders
strategy.exit(id = "Short", limit = shortExitPrice, stop = shortStopPrice, 
     comment = "Short Close", when = strategy.position_size < 0)
strategy.close(id = "Short", comment = "Expired: >" + tostring(maxTimeOpen), 
     when = (barssince(change(strategy.opentrades)) + 1) >= maxTimeOpen)