Zen MIG Reversal

//@version=5
indicator(title="Zen MIG Reversal v2.0 · 20260923", shorttitle="Zen MIG Reversal", overlay=true, max_boxes_count=500)

// =====================================================
// Moving Average
// =====================================================
maType   = input.string("EMA", title="MA Type", options=["SMA", "EMA", "SMMA (RMA)", "WMA", "VWMA"], group="Moving Average")
maLength = input.int(20, title="MA Length", minval=1, group="Moving Average")
showMA   = input.bool(true, title="Show MA Line", group="Moving Average")

ma(source, length, type) =>
    switch type
        "SMA"        => ta.sma(source, length)
        "EMA"        => ta.ema(source, length)
        "SMMA (RMA)" => ta.rma(source, length)
        "WMA"        => ta.wma(source, length)
        "VWMA"       => ta.vwma(source, length)

maLine = ma(close, maLength, maType)
plot(showMA ? maLine : na, title="MA", color=color.blue)

// =====================================================
// Signal Settings
// =====================================================
gapMode     = input.string("Micro gap (Brooks)", title="Gap Rule", options=["Micro gap (Brooks)", "Visible gap (strict)"], group="Signal")
maTest      = input.string("Tail beyond MA", title="MA Test", options=["Tail beyond MA", "Close beyond MA", "Whole bar beyond MA"], group="Signal")
confirmOnly = input.bool(true, title="Signal on bar close only", group="Signal")

// =====================================================
// Display
// =====================================================
showArrows = input.bool(true,  title="Show Arrows", group="Display")
showBoxes  = input.bool(true,  title="Show Gap Boxes", group="Display")
bullCol    = input.color(color.blue, title="Bull Colour", group="Display")
bearCol    = input.color(color.red,  title="Bear Colour", group="Display")

// =====================================================
// Logic
// =====================================================
isBull(i) => close[i] > open[i]
isBear(i) => close[i] < open[i]

bullBars = isBull(0) and isBull(1) and isBull(2)
bearBars = isBear(0) and isBear(1) and isBear(2)

bullGap = gapMode == "Visible gap (strict)" ? (low > high[2] and low[1] > high[2]) : low > high[2]
bearGap = gapMode == "Visible gap (strict)" ? (high < low[2] and high[1] < low[2]) : high < low[2]

bullMA = maTest == "Close beyond MA" ? close < maLine : maTest == "Whole bar beyond MA" ? high < maLine : low < maLine
bearMA = maTest == "Close beyond MA" ? close > maLine : maTest == "Whole bar beyond MA" ? low > maLine : high > maLine

confirmed = not confirmOnly or barstate.isconfirmed

bullReversal = bullBars and bullGap and bullMA and confirmed
bearReversal = bearBars and bearGap and bearMA and confirmed

// =====================================================
// Drawing
// =====================================================
if bullReversal and showBoxes
    box.new(left=bar_index[2], right=bar_index, top=low, bottom=high[2], border_color=bullCol, bgcolor=color.new(bullCol, 80))

if bearReversal and showBoxes
    box.new(left=bar_index[2], right=bar_index, top=low[2], bottom=high, border_color=bearCol, bgcolor=color.new(bearCol, 80))

plotshape(showArrows and bullReversal, title="Bull Arrow", style=shape.arrowup, location=location.belowbar, color=bullCol, size=size.small)
plotshape(showArrows and bearReversal, title="Bear Arrow", style=shape.arrowdown, location=location.abovebar, color=bearCol, size=size.small)

// =====================================================
// Alerts
// =====================================================
alertcondition(bullReversal, title="Bull MIG Reversal", message="Bull MIG Reversal — {{ticker}} {{interval}} @ {{close}}")
alertcondition(bearReversal, title="Bear MIG Reversal", message="Bear MIG Reversal — {{ticker}} {{interval}} @ {{close}}")
alertcondition(bullReversal or bearReversal, title="Any MIG Reversal", message="MIG Reversal — {{ticker}} {{interval}} @ {{close}}")