//////////////////////////////////////////////////////////
// Linear regression slope with custom period
//////////////////////////////////////////////////////////
var LinearRegressionSlope(vars Data, int Period)
{
	var sumX = 0;
	var sumY = 0;
	var sumXY = 0;
	var sumX2 = 0;
	int i;

	for(i = 0; i < Period; i++) {
		sumX += i;
		sumY += Data[i];
		sumXY += i * Data[i];
		sumX2 += i * i;
	}

	var numerator = Period * sumXY - sumX * sumY;
	var denominator = Period * sumX2 - sumX * sumX;

	if(denominator != 0)
		return numerator / denominator;
	else
		return 0;
}

//////////////////////////////////////////////////////////
// Global Parameters (editable via panel)
//////////////////////////////////////////////////////////

int EnableTrade    = 1;    // trading on/off
var InputRiskPct   = 1.0;  // risk per trade in percent

int SlopePeriod    = 10;   // bars used for regression slope
int SmaPeriod      = 20;   // SMA period
int RsiPeriod      = 14;   // RSI period
int AtrPeriod      = 14;   // ATR period

var StopATRMult    = 2.0;  // stop = ATR * this
var StopMin        = 10;   // min stop (price distance)
var StopMax        = 50;   // max stop

var PosMin         = 1;    // min position size
var PosMax         = 5;    // max position size

var DisplaySlope   = 0;    // for live slope display in the panel

//////////////////////////////////////////////////////////
// Click handler for panel interactions
//////////////////////////////////////////////////////////
function click(int row,int col)
{
	string Text;

	if(!is(RUNNING)) return;   // ignore when script not running
	if(row < 0) return;        // ignore Result/Action/Asset events

	Text = panelGet(row,col);

	// Row / column mapping
	// 0: Enable trading (button)
	// 1: Risk %
	// 2: Slope period
	// 3: SMA period
	// 4: RSI period
	// 5: ATR period
	// 6: Stop ATR mult
	// 7: Stop min
	// 8: Stop max
	// 9: Pos min
	// 10: Pos max
	// 11: Reset equity button

	if(row == 0 && col == 1) {
		// Toggle trading
		if(EnableTrade)
			EnableTrade = 0;
		else
			EnableTrade = 1;

		panelSet(0,1, ifelse(EnableTrade,"On","Off"),0,0,4);
	}
	else if(row == 1 && col == 1) {
		InputRiskPct = atof(Text);
	}
	else if(row == 2 && col == 1) {
		SlopePeriod = atoi(Text);
	}
	else if(row == 3 && col == 1) {
		SmaPeriod = atoi(Text);
	}
	else if(row == 4 && col == 1) {
		RsiPeriod = atoi(Text);
	}
	else if(row == 5 && col == 1) {
		AtrPeriod = atoi(Text);
	}
	else if(row == 6 && col == 1) {
		StopATRMult = atof(Text);
	}
	else if(row == 7 && col == 1) {
		StopMin = atof(Text);
	}
	else if(row == 8 && col == 1) {
		StopMax = atof(Text);
	}
	else if(row == 9 && col == 1) {
		PosMin = atof(Text);
	}
	else if(row == 10 && col == 1) {
		PosMax = atof(Text);
	}
	else if(row == 11 && col == 0) {
		// Reset equity button
		Capital = 100000; // demo reset
	}
}

//////////////////////////////////////////////////////////
// Main strategy
//////////////////////////////////////////////////////////
function run() 
{
	vars Price;
	var sma, rsi, slopeVal, trend, atr, stopLevel, normRSI;
	var tradeRisk, posSize;
	string txt;

	set(PARAMETERS);
	BarPeriod = 15;
	StartDate = 20220101;
	asset("EUR/USD");

	// Clamp and sanitize parameter ranges to avoid nonsense
	SlopePeriod = clamp(SlopePeriod, 5, 200);
	SmaPeriod   = clamp(SmaPeriod,   2, 200);
	RsiPeriod   = clamp(RsiPeriod,   2, 200);
	AtrPeriod   = clamp(AtrPeriod,   2, 200);

	StopATRMult = clamp(StopATRMult, 0.5, 10);
	StopMin     = clamp(StopMin,     1,  500);
	StopMax     = clamp(StopMax,     StopMin, 1000);

	PosMin      = clamp(PosMin, 0.01, 100);
	PosMax      = clamp(PosMax, PosMin, 1000);

	InputRiskPct = clamp(InputRiskPct, 0.1, 20); // 0.1% .. 20%

	Price = series(priceClose());
	sma   = SMA(Price, SmaPeriod);
	rsi   = RSI(Price, RsiPeriod);

	slopeVal    = LinearRegressionSlope(Price, SlopePeriod);
	DisplaySlope = slopeVal;
	trend       = sign(slopeVal);

	atr       = ATR(AtrPeriod);
	stopLevel = clamp(atr * StopATRMult, StopMin, StopMax);
	normRSI   = clamp(rsi / 100, 0, 1);

	// Risk-based position sizing using percentage from panel
	tradeRisk = InputRiskPct / 100 * Equity;
	posSize   = clamp(tradeRisk / fix0(stopLevel), PosMin, PosMax);

	// Panel setup only once at init
	if(is(INITRUN))
	{
		// 12 rows, 2 columns, default color (0), cell width 80 px
		panel(12,2,0,80);

		// Row 0: Enable trading button
		panelSet(0,0,"Enable",0,0,1);
		panelSet(0,1, ifelse(EnableTrade,"On","Off"),0,0,4);

		// Row 1: Risk %
		panelSet(1,0,"Risk %",0,0,1);
		txt = strf("%.2f",InputRiskPct);
		panelSet(1,1,txt,0,0,2);

		// Row 2: Slope period
		panelSet(2,0,"SlopePer",0,0,1);
		txt = strf("%i",SlopePeriod);
		panelSet(2,1,txt,0,0,2);

		// Row 3: SMA period
		panelSet(3,0,"SMA Per",0,0,1);
		txt = strf("%i",SmaPeriod);
		panelSet(3,1,txt,0,0,2);

		// Row 4: RSI period
		panelSet(4,0,"RSI Per",0,0,1);
		txt = strf("%i",RsiPeriod);
		panelSet(4,1,txt,0,0,2);

		// Row 5: ATR period
		panelSet(5,0,"ATR Per",0,0,1);
		txt = strf("%i",AtrPeriod);
		panelSet(5,1,txt,0,0,2);

		// Row 6: Stop ATR mult
		panelSet(6,0,"Stop xATR",0,0,1);
		txt = strf("%.2f",StopATRMult);
		panelSet(6,1,txt,0,0,2);

		// Row 7: Stop min
		panelSet(7,0,"StopMin",0,0,1);
		txt = strf("%.2f",StopMin);
		panelSet(7,1,txt,0,0,2);

		// Row 8: Stop max
		panelSet(8,0,"StopMax",0,0,1);
		txt = strf("%.2f",StopMax);
		panelSet(8,1,txt,0,0,2);

		// Row 9: Pos min
		panelSet(9,0,"PosMin",0,0,1);
		txt = strf("%.2f",PosMin);
		panelSet(9,1,txt,0,0,2);

		// Row 10: Pos max
		panelSet(10,0,"PosMax",0,0,1);
		txt = strf("%.2f",PosMax);
		panelSet(10,1,txt,0,0,2);

		// Row 11: Reset + Slope display (label; value updated each bar)
		panelSet(11,0,"ResetEq",0,0,4);
		txt = strf("%.4f",DisplaySlope);
		panelSet(11,1,txt,0,0,1);
	}

	// Update slope display every bar
	txt = strf("%.4f",DisplaySlope);
	panelSet(11,1,txt,0,0,1);

	// Trading logic
	if(EnableTrade && crossOver(Price, sma) && normRSI < 0.7)
		enterLong(posSize);

	plot("RSI", normRSI, NEW, RED);
}