Capital41 Structure Swings v3

// Copyright (c) 2026 Capital41 | MIT License
// CAPITAL41 STRUCTURE SWINGS v3

// What it does:
// - Marks swing highs/lows and optional break of structure (BOS).
// - Helps visualize market structure for entries and targets.
//
// v2 changes:
// - FIXED: Level lines now only draw on new swing detection (was drawing every bar,
//   rapidly hitting max_lines_count and causing older lines to vanish).
// - FIXED: Added barstate.isconfirmed on BOS for non-repainting signals.
// - ADDED: Persistent var line references (delete old, draw new on each swing).
// - ADDED: Alert conditions for BOS up/down and new swing detection.
// - ADDED: Separate toggle for level lines vs BOS markers.
//
// TradingView setup:
// 1) Open TradingView -> Pine Editor.
// 2) Paste this script, Save, and Add to chart.
// 3) Use 30m or 4h on BTC or US stocks.
//
// Usage guide (30m/4h):
// - Swing points help identify support/resistance and structure shifts.
// - BOS markers show when price breaks a recent swing level.
// - Level lines persist at the most recent swing high/low until a new swing forms.



//@version=6
indicator("Capital41 Structure Swings v3", overlay = true, max_labels_count = 200, max_lines_count = 200)

// Inputs
pivotLen    = input.int(5, "Pivot length", minval = 2, maxval = 20)
showSwings  = input.bool(true, "Show swing points")
showBOS     = input.bool(true, "Show break of structure")
showLevels  = input.bool(true, "Show level lines at swings")

colorBull = color.new(color.lime, 0)
colorBear = color.new(color.red, 0)

// Swing detection
ph = ta.pivothigh(high, pivotLen, pivotLen)
pl = ta.pivotlow(low, pivotLen, pivotLen)

if showSwings and not na(ph)
    label.new(bar_index - pivotLen, ph, "SH", style = label.style_label_down,
              color = color.new(colorBear, 0), textcolor = color.white, size = size.tiny)

if showSwings and not na(pl)
    label.new(bar_index - pivotLen, pl, "SL", style = label.style_label_up,
              color = color.new(colorBull, 0), textcolor = color.white, size = size.tiny)

// Track last swing levels with persistent line references
// v2 FIX: var lines are created once, then deleted/redrawn only when a new swing appears.
var float lastHigh = na
var float lastLow  = na
var line  highLine = na
var line  lowLine  = na

if not na(ph)
    lastHigh := ph
    if showLevels
        line.delete(highLine)
        highLine := line.new(bar_index - pivotLen, ph, bar_index, ph,
                     color = color.new(colorBear, 50), style = line.style_dotted, extend = extend.right)

if not na(pl)
    lastLow := pl
    if showLevels
        line.delete(lowLine)
        lowLine := line.new(bar_index - pivotLen, pl, bar_index, pl,
                     color = color.new(colorBull, 50), style = line.style_dotted, extend = extend.right)

// Break of structure (v2: non-repainting with barstate.isconfirmed)
bosUp   = barstate.isconfirmed and not na(lastHigh) and close > lastHigh and close[1] <= lastHigh
bosDown = barstate.isconfirmed and not na(lastLow) and close < lastLow and close[1] >= lastLow

plotshape(showBOS and bosUp, title = "BOS Up", style = shape.triangleup,
          location = location.belowbar, color = colorBull, size = size.tiny, text = "BOS")

plotshape(showBOS and bosDown, title = "BOS Down", style = shape.triangledown,
          location = location.abovebar, color = colorBear, size = size.tiny, text = "BOS")

// v2: Alert conditions
alertcondition(bosUp, title = "BOS Up",
               message = "Structure Swings: bullish BOS on {{ticker}} ({{interval}})")

alertcondition(bosDown, title = "BOS Down",
               message = "Structure Swings: bearish BOS on {{ticker}} ({{interval}})")

alertcondition(not na(ph), title = "New Swing High",
               message = "Structure Swings: new Swing High on {{ticker}} ({{interval}})")

alertcondition(not na(pl), title = "New Swing Low",
               message = "Structure Swings: new Swing Low on {{ticker}} ({{interval}})")