GOM BB Prediction (300 bars)

//@version=6
// GOM_BB_PREDICTION.pine — Calcule les Bollinger Bands futures (300 bougies)
// À ajouter comme étude separate ou fusionner dans GOM_KOLA_script.pine

indicator("GOM BB Prediction (300 bars)", shorttitle="GOM BB Pred", overlay=false)

// Entrées
pred_horizon = input.int(300, "Horizon prediction (bougies)", minval=50, maxval=500)
pred_method = input.string("linear", "Méthode", options=["linear", "trend", "sma"])
bb_period = input.int(20, "Période Bollinger", minval=5, maxval=50)
bb_dev = input.float(2.0, "Déviation Bollinger", minval=0.5, maxval=4.0)

// Calculer BB actuels
[bb_mid, bb_up, bb_dn] = ta.bb(close, bb_period, bb_dev)

// ═══════════════════════════════════════════════════════════════
// PRÉDICTION LINÉAIRE — extrapolation simple
// ═══════════════════════════════════════════════════════════════
// Pente simple sur les 20 dernières bougies
lookback_slope = 20

// Mid-line trend
slope_mid = 0.0
if bb_period <= bar_index
    slope_mid := (bb_mid - bb_mid[lookback_slope]) / lookback_slope

// Upper trend
slope_up = 0.0
if bb_period <= bar_index
    slope_up := (bb_up - bb_up[lookback_slope]) / lookback_slope

// Lower trend
slope_dn = 0.0
if bb_period <= bar_index
    slope_dn := (bb_dn - bb_dn[lookback_slope]) / lookback_slope

// ─────────────────────────────────────────────────────────────
// Prédictions futures (300 bars)
// ─────────────────────────────────────────────────────────────
var array<float> pred_bb_mid = array.new<float>()
var array<float> pred_bb_up  = array.new<float>()
var array<float> pred_bb_dn  = array.new<float>()
var array<int>   pred_times  = array.new<int>()

if barstate.islast
    // Effacer anciens
    array.clear(pred_bb_mid)
    array.clear(pred_bb_up)
    array.clear(pred_bb_dn)
    array.clear(pred_times)

    // Générer 300 points prédits
    current_mid = bb_mid
    current_up  = bb_up
    current_dn  = bb_dn

    for i = 1 to pred_horizon
        // Extrapolation linéaire
        future_mid = current_mid + slope_mid * i
        future_up  = current_up + slope_up * i
        future_dn  = current_dn + slope_dn * i

        array.push(pred_bb_mid, future_mid)
        array.push(pred_bb_up,  future_up)
        array.push(pred_bb_dn,  future_dn)
        array.push(pred_times,  bar_index + i)

// ─────────────────────────────────────────────────────────────
// EXPORT JSON pour webhook
// ─────────────────────────────────────────────────────────────
// Construire une chaîne JSON compacte (JSON complet = trop lourd)

pred_json = ""
if barstate.islast and array.size(pred_bb_mid) > 0
    // Format compact: "mid:[1,2,3]|up:[1,2,3]|dn:[1,2,3]"
    mid_str = ""
    up_str  = ""
    dn_str  = ""

    // Limiter à 100 points pour rester dans les limites
    steps = math.max(1, array.size(pred_bb_mid) / 100)

    for i = 0 to array.size(pred_bb_mid) - 1 by steps
        if mid_str != ""
            mid_str += ","
            up_str  += ","
            dn_str  += ","
        mid_str += str.tostring(math.round(array.get(pred_bb_mid, i) * 100) / 100)
        up_str  += str.tostring(math.round(array.get(pred_bb_up, i) * 100) / 100)
        dn_str  += str.tostring(math.round(array.get(pred_bb_dn, i) * 100) / 100)

    pred_json = "PRED_BB|" + syminfo.ticker + "|" + timeframe.period + "|MID:[" + mid_str + "]|UP:[" + up_str + "]|DN:[" + dn_str + "]"

// Plot pour debug (affiche les prédictions)
plot(barstate.islast ? bb_mid : na, "BB Mid Current", color=color.blue, linewidth=2)
plot(barstate.islast ? bb_up : na, "BB Up Current", color=color.red, linewidth=1)
plot(barstate.islast ? bb_dn : na, "BB Down Current", color=color.green, linewidth=1)

// Export via alerte
if barstate.isconfirmed and pred_json != ""
    alert(pred_json, alert.freq_once_per_bar_close)

// Affichage debug
var label pred_lbl = na
if barstate.islast
    if not na(pred_lbl)
        label.delete(pred_lbl)
    pred_lbl := label.new(bar_index, bb_mid,
         "Pred: " + str.tostring(array.size(pred_bb_mid)) + " points",
         color=color.new(color.blue, 80), textcolor=color.white, size=size.small)