Zen Breakout Follow Through

//@version=6
// Zen Breakout Follow Through v1.1 - 20260913
// Zen Trading Tech
//
// Bull sequence, four bars:
//   Bar A = prior bar, no conditions
//   Bar B = breakout:      high(B) > high(A) AND low(B) >= low(A)
//   Bar C = follow-through: high(C) > high(B) AND low(C) >= low(B)
//   Bar D = entry:          price trades above high(C)
// Bear sequence is the mirror.
//
// Outside bars are excluded automatically (they break the low/high condition).
// Inside bars are excluded automatically (they break the high/low condition).
// Detection uses closed bars only. The entry fires intrabar on the break of the level.
//
// v1.1 changes from v1.0:
//   - Sequence extended by one bar. The line now sits at the high/low of the
//     follow-through bar (Bar C), not the breakout bar (Bar B).
//   - Line width fixed to a single input, default 1.
//   - Line length fixed at 3 bars, no extension on trigger.

indicator("Zen Breakout Follow Through v1.1", shorttitle = "Zen BOFT", overlay = true, max_lines_count = 500, max_labels_count = 500)

// ============================================================
// INPUTS
// ============================================================

var string GRP_S = "Signal"
bool   i_showBull  = input.bool(true, "Bull setups", group = GRP_S)
bool   i_showBear  = input.bool(true, "Bear setups", group = GRP_S)
int    i_expBars   = input.int(1, "Bars allowed for entry", minval = 1, maxval = 20, group = GRP_S, tooltip = "1 = the entry must trigger on the bar straight after the follow-through bar. Raise it to let the setup stay live longer.")
bool   i_strictFT  = input.bool(true, "Follow-through bar must hold above the breakout bar low", group = GRP_S, tooltip = "On = the same rule applied twice, so the follow-through bar cannot be an outside bar. Off = the follow-through bar only has to take out the breakout bar high.")
bool   i_reqClose  = input.bool(false, "Breakout and follow-through bars must close in direction", group = GRP_S, tooltip = "Off = pure high/low geometry, no close filter.")

var string GRP_D = "Drawing"
int    i_lineBars  = input.int(3, "Line length (bars)", minval = 1, maxval = 50, group = GRP_D)
int    i_width     = input.int(1, "Line width", minval = 1, maxval = 4, group = GRP_D)
color  i_bullPend  = input.color(color.new(#009688, 55), "Bull  pending", group = GRP_D, inline = "bull")
color  i_bullTrig  = input.color(#009688, "triggered", group = GRP_D, inline = "bull")
color  i_bearPend  = input.color(color.new(#E53935, 55), "Bear  pending", group = GRP_D, inline = "bear")
color  i_bearTrig  = input.color(#E53935, "triggered", group = GRP_D, inline = "bear")
bool   i_markers   = input.bool(true, "Trigger markers", group = GRP_D)

var string GRP_A = "Alerts"
bool   i_alerts    = input.bool(true, "Fire alert on trigger", group = GRP_A)

// ============================================================
// STATE
// ============================================================

var array<float> bullLvl  = array.new<float>()
var array<int>   bullBar  = array.new<int>()
var array<line>  bullLine = array.new<line>()

var array<float> bearLvl  = array.new<float>()
var array<int>   bearBar  = array.new<int>()
var array<line>  bearLine = array.new<line>()

var float lastBullTrigLvl = na
var float lastBearTrigLvl = na

bool bullTrig = false
bool bearTrig = false

// ============================================================
// SEQUENCE DETECTION
// Bar C = bar_index - 1, Bar B = bar_index - 2, Bar A = bar_index - 3
// ============================================================

bool enoughBars = bar_index >= 3

// Bar B: breakout of Bar A
bool bullBreak = enoughBars and high[2] > high[3] and low[2] >= low[3] and (not i_reqClose or close[2] > open[2])
bool bearBreak = enoughBars and low[2] < low[3] and high[2] <= high[3] and (not i_reqClose or close[2] < open[2])

// Bar C: follow-through of Bar B
bool bullFT = enoughBars and high[1] > high[2] and (not i_strictFT or low[1] >= low[2]) and (not i_reqClose or close[1] > open[1])
bool bearFT = enoughBars and low[1] < low[2] and (not i_strictFT or high[1] <= high[2]) and (not i_reqClose or close[1] < open[1])

bool bullSetup = bullBreak and bullFT
bool bearSetup = bearBreak and bearFT

// ============================================================
// REGISTER NEW PENDING SETUPS
// ============================================================

if i_showBull and bullSetup
    float lvl = high[1]
    line ln = line.new(bar_index - 1, lvl, bar_index - 1 + i_lineBars - 1, lvl, xloc = xloc.bar_index, color = i_bullPend, width = i_width, style = line.style_solid)
    array.push(bullLvl, lvl)
    array.push(bullBar, bar_index)
    array.push(bullLine, ln)

if i_showBear and bearSetup
    float lvl = low[1]
    line ln = line.new(bar_index - 1, lvl, bar_index - 1 + i_lineBars - 1, lvl, xloc = xloc.bar_index, color = i_bearPend, width = i_width, style = line.style_solid)
    array.push(bearLvl, lvl)
    array.push(bearBar, bar_index)
    array.push(bearLine, ln)

// ============================================================
// EXPIRY AND TRIGGER - BULL
// ============================================================

if array.size(bullLvl) > 0
    for i = array.size(bullLvl) - 1 to 0
        float lv = array.get(bullLvl, i)
        int   st = array.get(bullBar, i)
        line  ln = array.get(bullLine, i)
        if bar_index > st + i_expBars - 1
            line.delete(ln)
            array.remove(bullLvl, i)
            array.remove(bullBar, i)
            array.remove(bullLine, i)
        else if high > lv
            line.set_color(ln, i_bullTrig)
            bullTrig := true
            lastBullTrigLvl := lv
            array.remove(bullLvl, i)
            array.remove(bullBar, i)
            array.remove(bullLine, i)

// ============================================================
// EXPIRY AND TRIGGER - BEAR
// ============================================================

if array.size(bearLvl) > 0
    for i = array.size(bearLvl) - 1 to 0
        float lv = array.get(bearLvl, i)
        int   st = array.get(bearBar, i)
        line  ln = array.get(bearLine, i)
        if bar_index > st + i_expBars - 1
            line.delete(ln)
            array.remove(bearLvl, i)
            array.remove(bearBar, i)
            array.remove(bearLine, i)
        else if low < lv
            line.set_color(ln, i_bearTrig)
            bearTrig := true
            lastBearTrigLvl := lv
            array.remove(bearLvl, i)
            array.remove(bearBar, i)
            array.remove(bearLine, i)

// ============================================================
// MARKERS
// ============================================================

plotshape(i_markers and bullTrig, title = "Bull entry", style = shape.triangleup, location = location.belowbar, color = i_bullTrig, size = size.tiny)
plotshape(i_markers and bearTrig, title = "Bear entry", style = shape.triangledown, location = location.abovebar, color = i_bearTrig, size = size.tiny)

// ============================================================
// ALERTS
// ============================================================

if i_alerts and bullTrig
    alert("Zen BOFT bull entry " + syminfo.ticker + " " + timeframe.period + " above " + str.tostring(lastBullTrigLvl, format.mintick), alert.freq_once_per_bar)

if i_alerts and bearTrig
    alert("Zen BOFT bear entry " + syminfo.ticker + " " + timeframe.period + " below " + str.tostring(lastBearTrigLvl, format.mintick), alert.freq_once_per_bar)

// ============================================================
// DATA WINDOW
// ============================================================

plot(bullSetup ? 1 : 0, title = "Bull setup complete (prev bar)", display = display.data_window)
plot(bearSetup ? 1 : 0, title = "Bear setup complete (prev bar)", display = display.data_window)
plot(bullTrig ? 1 : 0, title = "Bull entry trigger", display = display.data_window)
plot(bearTrig ? 1 : 0, title = "Bear entry trigger", display = display.data_window)
plot(array.size(bullLvl), title = "Bull pending count", display = display.data_window)
plot(array.size(bearLvl), title = "Bear pending count", display = display.data_window)
plot(lastBullTrigLvl, title = "Last bull entry level", display = display.data_window)
plot(lastBearTrigLvl, title = "Last bear entry level", display = display.data_window)