FVG Strategy

//@version=5
// =====================================================
// FVG (Fair Value Gap) Strategy - Strategy Lab
// =====================================================
// Detects gaps formed across 3 candles, enters on mitigation.
// Bullish FVG: candle[2].high < candle[0].low
// Bearish FVG: candle[2].low  > candle[0].high
// =====================================================

strategy("FVG Strategy", overlay=true, initial_capital=1000,
         default_qty_type=strategy.percent_of_equity, default_qty_value=10,
         commission_type=strategy.commission.percent, commission_value=0.05)

// ============ INPUTS ============
minGapAtr     = input.float(0.3, "Min Gap (ATR multiple)", minval=0.0, step=0.1)
useTrendFilter= input.bool(true, "Use EMA Trend Filter")
emaPeriod     = input.int(200, "EMA Period", minval=20)
atrPeriod     = input.int(14, "ATR Period")
slAtrMult     = input.float(0.5, "SL ATR Multiplier", minval=0.1, step=0.1)
tp1RR         = input.float(2.0, "TP1 Risk:Reward")
tp2RR         = input.float(3.0, "TP2 Risk:Reward")
tp3RR         = input.float(5.0, "TP3 Risk:Reward")

// ============ INDICATORS ============
emaTrend = ta.ema(close, emaPeriod)
atrVal   = ta.atr(atrPeriod)
trendUp  = close > emaTrend
trendDn  = close < emaTrend

// ============ FVG DETECTION ============
// candle[2] = 2 candles ago, candle[0] = now
bullFVG = high[2] < low[0] and (low[0] - high[2]) >= atrVal * minGapAtr
bearFVG = low[2]  > high[0] and (low[2] - high[0]) >= atrVal * minGapAtr

// Draw box
var box[] bullBoxes = array.new<box>()
var box[] bearBoxes = array.new<box>()

if bullFVG
    b = box.new(bar_index - 2, low[0], bar_index + 20, high[2],
                bgcolor=color.new(color.green, 80), border_color=color.green)
    array.push(bullBoxes, b)

if bearFVG
    b = box.new(bar_index - 2, low[2], bar_index + 20, high[0],
                bgcolor=color.new(color.red, 80), border_color=color.red)
    array.push(bearBoxes, b)

// ============ STATE TRACKING ============
var float lastBullMid    = na
var float lastBullBottom = na
var float lastBullTop    = na
var float lastBearMid    = na
var float lastBearBottom = na
var float lastBearTop    = na
var bool  bullActive     = false
var bool  bearActive     = false

if bullFVG
    lastBullBottom := high[2]
    lastBullTop    := low[0]
    lastBullMid    := (high[2] + low[0]) / 2
    bullActive     := true

if bearFVG
    lastBearBottom := high[0]
    lastBearTop    := low[2]
    lastBearMid    := (low[2] + high[0]) / 2
    bearActive     := true

// ============ ENTRY LOGIC ============
longCond  = bullActive and low <= lastBullMid and high > lastBullBottom
           and (not useTrendFilter or trendUp)
shortCond = bearActive and high >= lastBearMid and low < lastBearTop
           and (not useTrendFilter or trendDn)

// ============ RISK / TARGETS ============
if longCond and strategy.position_size == 0
    sl   = lastBullBottom - slAtrMult * atrVal
    risk = lastBullMid - sl
    tp1  = lastBullMid + risk * tp1RR
    tp2  = lastBullMid + risk * tp2RR
    tp3  = lastBullMid + risk * tp3RR
    strategy.entry("FVG Long", strategy.long, limit=lastBullMid)
    strategy.exit("Exit Long", "FVG Long", stop=sl, limit=tp2)
    bullActive := false

if shortCond and strategy.position_size == 0
    sl   = lastBearTop + slAtrMult * atrVal
    risk = sl - lastBearMid
    tp1  = lastBearMid - risk * tp1RR
    tp2  = lastBearMid - risk * tp2RR
    tp3  = lastBearMid - risk * tp3RR
    strategy.entry("FVG Short", strategy.short, limit=lastBearMid)
    strategy.exit("Exit Short", "FVG Short", stop=sl, limit=tp2)
    bearActive := false

// ============ PLOTS ============
plot(emaTrend, "EMA Trend", color=color.yellow, linewidth=2)
plotshape(longCond,  "Long Setup",  shape.triangleup,   location.belowbar, color.green, size=size.small)
plotshape(shortCond, "Short Setup", shape.triangledown, location.abovebar, color.red,   size=size.small)

// ============ ALERTS ============
alertcondition(longCond,  "FVG Long Entry",  "FVG Bullish mitigation - LONG entry")
alertcondition(shortCond, "FVG Short Entry", "FVG Bearish mitigation - SHORT entry")