Fast Cross (9/20) + EMA 50

// version=5
indicator("Engineer's System: Fast Cross (9/20) + EMA 50", overlay=true)

// ==========================================
// 1. SETTINGS
// ==========================================

group_ma = "Moving Averages"
maLength = input.int(20, title="Main MA (EMA 20)", group=group_ma)
ema9Length = input.int(9, title="Signal MA (EMA 9)", group=group_ma)
ema50Length = input.int(50, title="Trend MA (EMA 50)", group=group_ma)
ema200Length = input.int(200, title="Filter MA (EMA 200)", group=group_ma)

group_macd = "MACD Logic"
fastLen = input.int(12, title="MACD Fast", group=group_macd)
slowLen = input.int(26, title="MACD Slow", group=group_macd)
sigLen = input.int(9, title="MACD Signal", group=group_macd)

group_ut = "UT Bot Settings"
ut_key = input.float(1.0, title="Key Value", step=0.1, group=group_ut)
ut_period = input.int(10, title="ATR Period", group=group_ut)
ut_showLine = input.bool(false, title="Show Trailing Line?", group=group_ut)

// ==========================================
// 2. CALCULATIONS
// ==========================================

maVal = ta.ema(close, maLength) // EMA 20
ema9Val = ta.ema(close, ema9Length) // EMA 9
ema50Val = ta.ema(close, ema50Length) // EMA 50
ema200Val = ta.ema(close, ema200Length) // EMA 200

// MACD for Colors
[macdLine, signalLine, _] = ta.macd(close, fastLen, slowLen, sigLen)
bool isGreenZone = macdLine > signalLine

// UT Bot Logic
xATR = ta.atr(ut_period)
nLoss = ut_key * xATR
src = close
xATRTrailingStop = 0.0
xATRTrailingStop := if src > nz(xATRTrailingStop[1], 0) and src[1] > nz(xATRTrailingStop[1], 0)
math.max(nz(xATRTrailingStop[1]), src - nLoss)
else if src < nz(xATRTrailingStop[1], 0) and src[1] < nz(xATRTrailingStop[1], 0)
math.min(nz(xATRTrailingStop[1]), src + nLoss)
else if src > nz(xATRTrailingStop[1], 0)
src - nLoss
else
src + nLoss
pos = 0
pos := if src[1] < nz(xATRTrailingStop[1], 0) and src > nz(xATRTrailingStop[1], 0)
1
else if src[1] > nz(xATRTrailingStop[1], 0) and src < nz(xATRTrailingStop[1], 0)
-1
else
nz(pos[1], 0)
utBuy = (pos == 1) and (pos[1] == -1)
utSell = (pos == -1) and (pos[1] == 1)

// ==========================================
// 3. PLOTTING
// ==========================================

// Plot Lines
plot(ema200Val, title="EMA 200", color=color.white, linewidth=2)
plot(ema50Val, title="EMA 50", color=color.blue, linewidth=2)

// EMA 9 & 20 with Cloud
color mainColor = isGreenZone ? color.lime : color.red
color ema9Color = ema9Val >= maVal ? color.aqua : color.purple
p_ema20 = plot(maVal, title="EMA 20", color=mainColor, linewidth=3)
p_ema9 = plot(ema9Val, title="EMA 9", color=ema9Color, linewidth=2)
fillColor = ema9Val >= maVal ? color.new(color.aqua, 85) : color.new(color.purple, 85)
fill(p_ema9, p_ema20, color=fillColor, title="Cloud EMA 9-20")

// ==========================================
// 4. SIGNALS (UPDATED)
// ==========================================

// --- สัญญาณหลัก (Fast Cross) ---
// แสดงทันทีที่ 9 ตัด 20 (ไม่ต้องสนเส้น 50)
fastBuy = ta.crossover(ema9Val, maVal)
fastSell = ta.crossunder(ema9Val, maVal)

plotshape(fastBuy, title="Fast Buy", style=shape.labelup, location=location.belowbar, color=color.lime, text="BUY", textcolor=color.white, size=size.tiny)
plotshape(fastSell, title="Fast Sell", style=shape.labeldown, location=location.abovebar, color=color.red, text="SELL", textcolor=color.white, size=size.tiny)

// --- UT Bot Signals (Dots) ---
// ยังคงกรองด้วย EMA 200 เพื่อความปลอดภัย
validBuy = utBuy and (close > ema200Val)
validSell = utSell and (close < ema200Val)

plotshape(validBuy, title="Trend Buy Dot", style=shape.circle, location=location.belowbar, color=color.lime, size=size.tiny)
plotshape(validSell, title="Trend Sell Dot", style=shape.circle, location=location.abovebar, color=color.red, size=size.tiny)

// ==========================================
// 5. ALERTS
// ==========================================

alertcondition(fastBuy, title="Buy Signal", message="Engineer System: BUY (9 Cross 20) 🚀")
alertcondition(fastSell, title="Sell Signal", message="Engineer System: SELL (9 Cross 20) 🔻")
alertcondition(validBuy, title="Trend Buy Dot", message="Trend System: UT Bot BUY (Above EMA 200) 🟢")
alertcondition(validSell, title="Trend Sell Dot", message="Trend System: UT Bot SELL (Below EMA 200) 🔴")