Fair Value Gap (FVG)

// This Pine Script™ code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © TigerX - Fair Value Gap Indicator

//@version=5
indicator("Fair Value Gap (FVG)", overlay=true, max_boxes_count=500)

// ─────────────────────────────────────────────────────────────────────────────
// INPUTS
// ─────────────────────────────────────────────────────────────────────────────

showBullishFVG      = input.bool(true, "Show Bullish FVG", group="Detection")
showBearishFVG      = input.bool(true, "Show Bearish FVG", group="Detection")
filterByATR         = input.bool(true, "Filter by ATR", group="Detection")
atrMultiplier       = input.float(0.5, "Min ATR Multiplier", minval=0.0, step=0.1, group="Detection", tooltip="Minimum gap size as ATR multiple. Higher = fewer FVGs. Try 0.3-1.0")
maxBoxes            = input.int(50, "Max Boxes to Show", minval=1, maxval=500, group="Detection")

bullishColor        = input.color(color.new(#00ff00, 80), "Bullish FVG Color", group="Appearance")
bearishColor        = input.color(color.new(#ff0000, 80), "Bearish FVG Color", group="Appearance")
boxWidth            = input.int(5, "Box Width (candles)", minval=1, maxval=100, group="Appearance", tooltip="Number of candles the FVG box spans")
showMidline         = input.bool(false, "Show Midline", group="Appearance")
midlineStyle        = input.string("Dotted", "Midline Style", options=["Solid", "Dotted", "Dashed"], group="Appearance")

deleteMitigated     = input.bool(true, "Delete Mitigated FVG", group="Mitigation")
mitigationType      = input.string("Wick", "Mitigation Type", options=["Wick", "Close"], group="Mitigation")

// ─────────────────────────────────────────────────────────────────────────────
// CALCULATIONS
// ─────────────────────────────────────────────────────────────────────────────

atr = ta.atr(14)

// Get midline style
getMidlineStyle() =>
    switch midlineStyle
        "Solid" => line.style_solid
        "Dotted" => line.style_dotted
        "Dashed" => line.style_dashed

// ─────────────────────────────────────────────────────────────────────────────
// FVG DETECTION
// ─────────────────────────────────────────────────────────────────────────────

// Bullish FVG: Gap between candle 1's high and candle 3's low
// Candle 1 = bar_index[2], Candle 2 = bar_index[1], Candle 3 = bar_index (current)
bullishFVGCondition = low > high[2]
bullishTop = low
bullishBottom = high[2]
bullishGapSize = bullishTop - bullishBottom

// Bearish FVG: Gap between candle 1's low and candle 3's high  
// Candle 1 = bar_index[2], Candle 2 = bar_index[1], Candle 3 = bar_index (current)
bearishFVGCondition = high < low[2]
bearishTop = low[2]
bearishBottom = high
bearishGapSize = bearishTop - bearishBottom

// Apply ATR filter if enabled
bullishValid = bullishFVGCondition and (not filterByATR or bullishGapSize > atr * atrMultiplier)
bearishValid = bearishFVGCondition and (not filterByATR or bearishGapSize > atr * atrMultiplier)

// ─────────────────────────────────────────────────────────────────────────────
// FVG STORAGE
// ─────────────────────────────────────────────────────────────────────────────

var box[] bullBoxes = array.new_box()
var line[] bullMidlines = array.new_line()
var float[] bullTops = array.new_float()
var float[] bullBottoms = array.new_float()
var int[] bullBars = array.new_int()

var box[] bearBoxes = array.new_box()
var line[] bearMidlines = array.new_line()
var float[] bearTops = array.new_float()
var float[] bearBottoms = array.new_float()
var int[] bearBars = array.new_int()

// ─────────────────────────────────────────────────────────────────────────────
// CREATE FVG BOXES
// ─────────────────────────────────────────────────────────────────────────────

// Create Bullish FVG
if bullishValid and showBullishFVG
    // Create box
    newBox = box.new(
         left=bar_index - 2,
         top=bullishTop,
         right=bar_index - 2 + boxWidth,
         bottom=bullishBottom,
         bgcolor=bullishColor,
         border_color=color.new(color.green, 100),
         border_width=1
         )
    
    array.push(bullBoxes, newBox)
    array.push(bullTops, bullishTop)
    array.push(bullBottoms, bullishBottom)
    array.push(bullBars, bar_index)
    
    // Create midline if enabled
    if showMidline
        midPrice = (bullishTop + bullishBottom) / 2
        newLine = line.new(
             x1=bar_index - 2,
             y1=midPrice,
             x2=bar_index - 2 + boxWidth,
             y2=midPrice,
             color=color.new(color.green, 50),
             style=getMidlineStyle()
             )
        array.push(bullMidlines, newLine)
    else
        array.push(bullMidlines, line(na))
    
    // Limit number of boxes
    if array.size(bullBoxes) > maxBoxes
        box.delete(array.shift(bullBoxes))
        line.delete(array.shift(bullMidlines))
        array.shift(bullTops)
        array.shift(bullBottoms)
        array.shift(bullBars)

// Create Bearish FVG
if bearishValid and showBearishFVG
    // Create box
    newBox = box.new(
         left=bar_index - 2,
         top=bearishTop,
         right=bar_index - 2 + boxWidth,
         bottom=bearishBottom,
         bgcolor=bearishColor,
         border_color=color.new(color.red, 100),
         border_width=1
         )
    
    array.push(bearBoxes, newBox)
    array.push(bearTops, bearishTop)
    array.push(bearBottoms, bearishBottom)
    array.push(bearBars, bar_index)
    
    // Create midline if enabled
    if showMidline
        midPrice = (bearishTop + bearishBottom) / 2
        newLine = line.new(
             x1=bar_index - 2,
             y1=midPrice,
             x2=bar_index - 2 + boxWidth,
             y2=midPrice,
             color=color.new(color.red, 50),
             style=getMidlineStyle()
             )
        array.push(bearMidlines, newLine)
    else
        array.push(bearMidlines, line(na))
    
    // Limit number of boxes
    if array.size(bearBoxes) > maxBoxes
        box.delete(array.shift(bearBoxes))
        line.delete(array.shift(bearMidlines))
        array.shift(bearTops)
        array.shift(bearBottoms)
        array.shift(bearBars)

// ─────────────────────────────────────────────────────────────────────────────
// MITIGATION CHECK
// ─────────────────────────────────────────────────────────────────────────────

// Check Bullish FVG mitigation (price comes down to fill the gap)
if deleteMitigated and array.size(bullBoxes) > 0
    for i = array.size(bullBoxes) - 1 to 0
        fvgTop = array.get(bullTops, i)
        fvgBottom = array.get(bullBottoms, i)
        fvgBar = array.get(bullBars, i)
        
        // Skip mitigation check on the bar when FVG was created
        if bar_index <= fvgBar
            continue
        
        bool isMitigated = false
        
        if mitigationType == "Close"
            // Full mitigation: price closes inside or below the FVG
            isMitigated := close <= fvgTop
        else
            // Wick mitigation: price wick enters the FVG zone
            isMitigated := low <= fvgTop
        
        if isMitigated
            box.delete(array.get(bullBoxes, i))
            line.delete(array.get(bullMidlines, i))
            array.remove(bullBoxes, i)
            array.remove(bullMidlines, i)
            array.remove(bullTops, i)
            array.remove(bullBottoms, i)
            array.remove(bullBars, i)

// Check Bearish FVG mitigation (price comes up to fill the gap)
if deleteMitigated and array.size(bearBoxes) > 0
    for i = array.size(bearBoxes) - 1 to 0
        fvgTop = array.get(bearTops, i)
        fvgBottom = array.get(bearBottoms, i)
        fvgBar = array.get(bearBars, i)
        
        // Skip mitigation check on the bar when FVG was created
        if bar_index <= fvgBar
            continue
        
        bool isMitigated = false
        
        if mitigationType == "Close"
            // Full mitigation: price closes inside or above the FVG
            isMitigated := close >= fvgBottom
        else
            // Wick mitigation: price wick enters the FVG zone
            isMitigated := high >= fvgBottom
        
        if isMitigated
            box.delete(array.get(bearBoxes, i))
            line.delete(array.get(bearMidlines, i))
            array.remove(bearBoxes, i)
            array.remove(bearMidlines, i)
            array.remove(bearTops, i)
            array.remove(bearBottoms, i)
            array.remove(bearBars, i)



// ─────────────────────────────────────────────────────────────────────────────
// ALERTS
// ─────────────────────────────────────────────────────────────────────────────

alertcondition(bullishValid, title="Bullish FVG", message="Bullish Fair Value Gap detected!")
alertcondition(bearishValid, title="Bearish FVG", message="Bearish Fair Value Gap detected!")

// ─────────────────────────────────────────────────────────────────────────────
// INFO TABLE
// ─────────────────────────────────────────────────────────────────────────────

showTable = input.bool(true, "Show Info Table", group="Table")

if showTable and barstate.islast
    var table infoTable = table.new(position.top_right, 2, 3, bgcolor=color.new(color.gray, 85))
    
    table.cell(infoTable, 0, 0, "FVG Type", text_color=color.white, text_size=size.small)
    table.cell(infoTable, 1, 0, "Count", text_color=color.white, text_size=size.small)
    
    table.cell(infoTable, 0, 1, "🟢 Bullish", text_color=color.green, text_size=size.small)
    table.cell(infoTable, 1, 1, str.tostring(array.size(bullBoxes)), text_color=color.green, text_size=size.small)
    
    table.cell(infoTable, 0, 2, "🔴 Bearish", text_color=color.red, text_size=size.small)
    table.cell(infoTable, 1, 2, str.tostring(array.size(bearBoxes)), text_color=color.red, text_size=size.small)