Bridge 04 - Bollinger Squeeze

//@version=5
// Bollinger band squeeze + directional breakout. Fires when:
// - BB width is below its N-period mean (squeeze regime)
// - Price closes outside the band (squeeze release)
// Best for volatility-compression regimes (consolidating markets that
// then break out with momentum). Default tuned for FX timeframes.
//
// Schema target: TVAlert (services/tradingview-bridge/src/tradingview_bridge/schemas.py)

strategy(
     title="bridge/04 - Bollinger squeeze",
     shorttitle="04-BB",
     overlay=true,
     default_qty_type=strategy.percent_of_equity,
     default_qty_value=10,
     initial_capital=10000,
     commission_type=strategy.commission.percent,
     commission_value=0.02)

// === Inputs ===
length       = input.int(20,  "BB length",        minval=2)
mult         = input.float(2.0, "BB stdev",       minval=0.5, step=0.1)
squeeze_lookback = input.int(50, "Squeeze lookback", minval=10)
squeeze_pct      = input.float(0.7, "Squeeze threshold (width pct)", minval=0.1, maxval=1.0,
     tooltip="Squeeze fires when current BB width < this fraction of the mean width over lookback")

ASSET_CLASS   = input.string("fx", "Asset class",
     options=["stock", "etf", "bond", "fx", "crypto", "prediction"])
STRATEGY_NAME = input.string("bollinger-squeeze-20", "Strategy name (for journal)")
SECRET        = input.string("REPLACE_WITH_YOUR_TVBRIDGE_TV_WEBHOOK_SECRET", "Webhook shared secret")

// === Bands ===
basis = ta.sma(close, length)
dev   = mult * ta.stdev(close, length)
upper = basis + dev
lower = basis - dev
width = upper - lower

plot(basis, "Basis", color=color.new(color.gray,   60))
plot(upper, "Upper", color=color.new(color.red,    30))
plot(lower, "Lower", color=color.new(color.green,  30))

// === Squeeze regime ===
mean_width = ta.sma(width, squeeze_lookback)
in_squeeze = width < (mean_width * squeeze_pct)
bgcolor(in_squeeze ? color.new(color.yellow, 85) : na)

// === Signals — squeeze release ===
long_signal  = in_squeeze[1] and close > upper
short_signal = in_squeeze[1] and close < lower

// === Alert message ===
build_alert(action) =>
    '{' +
      '"alert_id":"' + STRATEGY_NAME + '-' + str.tostring(time, "yyyyMMdd-HHmm") + '-' + action + '",' +
      '"secret":"'        + SECRET        + '",' +
      '"strategy_name":"' + STRATEGY_NAME + '",' +
      '"asset_class":"'   + ASSET_CLASS   + '",' +
      '"symbol":"{{ticker}}",' +
      '"action":"'        + action        + '",' +
      '"size":"{{strategy.position_size}}",' +
      '"size_type":"units",' +
      '"price_hint":"{{close}}",' +
      '"order_type":"market",' +
      '"time":"{{time}}",' +
      '"metadata":{"bb_width":"' + str.tostring(width, "#.####") + '","mean_width":"' + str.tostring(mean_width, "#.####") + '"}' +
    '}'

if long_signal
    strategy.entry("L", strategy.long,  alert_message=build_alert("buy"))
if short_signal
    strategy.entry("S", strategy.short, alert_message=build_alert("sell"))