Parabolic SAR - Eterna

//@version=5
strategy("Parabolic SAR - Eterna", 
         overlay=true, 
         initial_capital=10000,
         default_qty_type=strategy.percent_of_equity, 
         default_qty_value=10,
         commission_type=strategy.commission.percent,
         commission_value=0.075)

// ==================== Parameters ====================
sarStart = input.float(0.02, "SAR Start", minval=0.001, step=0.001)
sarIncrement = input.float(0.02, "SAR Increment", minval=0.001, step=0.001)
sarMaximum = input.float(0.2, "SAR Maximum", minval=0.01, step=0.01)
trendFilter = input.int(50, "Trend Filter EMA", minval=1)
useTrendFilter = input.bool(true, "Use Trend Filter")
leverage = input.int(5, "Leverage", minval=1, maxval=100)
positionSize = input.float(0.01, "Position Size", minval=0.001, step=0.001)

webhookMessage = input.string('{"action":"{{strategy.order.action}}", "symbol":"{{ticker}}", "size":' + str.tostring(positionSize) + ', "leverage":' + str.tostring(leverage) + '}', 
                               "Webhook JSON", group="Webhook")

// ==================== Indicators ====================
sarValue = ta.sar(sarStart, sarIncrement, sarMaximum)
trendEMA = ta.ema(close, trendFilter)

// ==================== Entry Conditions ====================
// SAR flips indicate trend change
sarBullish = sarValue < close
sarBearish = sarValue > close

// Detect SAR flip
sarFlipUp = ta.crossover(close, sarValue)
sarFlipDown = ta.crossunder(close, sarValue)

// Optional trend filter
longCondition = useTrendFilter ? (sarFlipUp and close > trendEMA) : sarFlipUp
shortCondition = useTrendFilter ? (sarFlipDown and close < trendEMA) : sarFlipDown

// ==================== Strategy Execution ====================
if longCondition
    strategy.entry("Long", strategy.long, alert_message=str.replace(webhookMessage, "{{strategy.order.action}}", "buy"))

if shortCondition
    strategy.entry("Short", strategy.short, alert_message=str.replace(webhookMessage, "{{strategy.order.action}}", "sell"))

// ==================== Plotting ====================
plot(sarValue, "SAR", style=plot.style_cross, color=sarBullish ? color.green : color.red, linewidth=2)
plot(useTrendFilter ? trendEMA : na, "Trend EMA", color=color.orange, linewidth=1)

plotshape(longCondition, "Long", shape.triangleup, location.belowbar, color.green, size=size.normal)
plotshape(shortCondition, "Short", shape.triangledown, location.abovebar, color.red, size=size.normal)

bgcolor(sarBullish ? color.new(color.green, 95) : color.new(color.red, 95))

// SAR dots
plotchar(sarValue, "SAR Dots", "•", location=sarBullish ? location.belowbar : location.abovebar, 
         color=sarBullish ? color.green : color.red, size=size.tiny)