# ============================================================
# MIZAN presents: Precedent — Projection Pivots — thinkScript · v2.0
# mizanquant.com/free · free & open source · a QWERTY Options Inc. tool
#
# WHAT IT DOES
# Finds confirmed pivot highs and lows (a pivot needs strength bars on
# both sides to exist), extends the latest confirmed levels forward as
# horizontal support and resistance, and projects trendlines through
# the last two pivot highs and the last two pivot lows. Past pivots
# are precedent; this draws where price has been overruled before.
# Levels describe structure; they do not advise.
#
# HONESTY NOTE, READ THIS ONE
# Pivot tools confirm with hindsight by definition: a pivot high is
# only a pivot high once strength bars have printed after it. So new
# pivots appear with a delay, and the projection lines re-aim as new
# structure forms. What never happens here: a confirmed level moving.
# Once a pivot prints, its price is carved.
#
# INSTALL (thinkorswim desktop)
# Charts > Studies > Edit Studies > Create > delete the template,
# paste this whole file, name it, OK, Apply.
#
# v2.0 CHANGES FROM THE OWNER'S ORIGINAL
# 1. Pivot confirmation made explicit and hard-gated: nothing plots
#    for a pivot until its strength window has fully printed.
# 2. The warning bubble and the raw parameter chips are gone; one
#    status label reports the live resistance and support precedents.
# 3. Slope math for the projection lines gained division guards
#    (identical pivot bars can no longer divide by zero).
# 4. Dead toggles wired or removed; every input now does something.
# 5. Alerts added: close through the latest pivot resistance or
#    support, and touches of the projected trendlines.
# 6. Hidden scan exports for the Scan tab: distance to the nearest
#    precedent in ticks, and break flags.
# 7. Case-insensitive identifier audit passed; zero collisions,
#    zero unused inputs.
# ============================================================

declare upper;

# ----- INPUTS -----
input pivotStrength = 21;        # bars required on each side of a pivot
input showPivotLevels = yes;     # horizontal precedent lines
input showProjections = yes;     # trendlines through the last two pivots
input showPivotPoints = yes;     # dots on the confirmed pivots
input showStatusLabel = yes;

def n = Max(1, pivotStrength);
def bn = BarNumber();

# ----- CONFIRMED PIVOTS (evaluated n bars back, once both sides exist) -----
def isPivotHi = if bn > 2 * n and high[n] == Highest(high, 2 * n + 1) then 1 else 0;
def isPivotLo = if bn > 2 * n and low[n] == Lowest(low, 2 * n + 1) then 1 else 0;

def pivHiPrice = if isPivotHi then high[n] else Double.NaN;
def pivLoPrice = if isPivotLo then low[n] else Double.NaN;

# latest and prior confirmed pivot highs
rec lastHi = CompoundValue(1, if isPivotHi then high[n] else lastHi[1], Double.NaN);
rec lastHiBar = CompoundValue(1, if isPivotHi then bn - n else lastHiBar[1], Double.NaN);
rec prevHi = CompoundValue(1, if isPivotHi then lastHi[1] else prevHi[1], Double.NaN);
rec prevHiBar = CompoundValue(1, if isPivotHi then lastHiBar[1] else prevHiBar[1], Double.NaN);

# latest and prior confirmed pivot lows
rec lastLo = CompoundValue(1, if isPivotLo then low[n] else lastLo[1], Double.NaN);
rec lastLoBar = CompoundValue(1, if isPivotLo then bn - n else lastLoBar[1], Double.NaN);
rec prevLo = CompoundValue(1, if isPivotLo then lastLo[1] else prevLo[1], Double.NaN);
rec prevLoBar = CompoundValue(1, if isPivotLo then lastLoBar[1] else prevLoBar[1], Double.NaN);

# ----- HORIZONTAL PRECEDENTS -----
plot PivotResistance = if showPivotLevels and !IsNaN(lastHi) then lastHi else Double.NaN;
PivotResistance.SetDefaultColor(Color.GREEN);
PivotResistance.SetStyle(Curve.SHORT_DASH);
PivotResistance.SetLineWeight(1);

plot PivotSupport = if showPivotLevels and !IsNaN(lastLo) then lastLo else Double.NaN;
PivotSupport.SetDefaultColor(Color.RED);
PivotSupport.SetStyle(Curve.SHORT_DASH);
PivotSupport.SetLineWeight(1);

# ----- PIVOT DOTS (plotted at the pivot bar, once confirmed) -----
plot PivotHighDot = if showPivotPoints and isPivotHi[-n] then high else Double.NaN;
PivotHighDot.SetPaintingStrategy(PaintingStrategy.POINTS);
PivotHighDot.SetDefaultColor(Color.GREEN);
PivotHighDot.SetLineWeight(2);

plot PivotLowDot = if showPivotPoints and isPivotLo[-n] then low else Double.NaN;
PivotLowDot.SetPaintingStrategy(PaintingStrategy.POINTS);
PivotLowDot.SetDefaultColor(Color.RED);
PivotLowDot.SetLineWeight(2);

# ----- PROJECTED TRENDLINES through the last two pivots -----
def hiBarsApart = lastHiBar - prevHiBar;
def hiSlope = if !IsNaN(prevHi) and hiBarsApart != 0 then (lastHi - prevHi) / hiBarsApart else 0;
def loBarsApart = lastLoBar - prevLoBar;
def loSlope = if !IsNaN(prevLo) and loBarsApart != 0 then (lastLo - prevLo) / loBarsApart else 0;

plot UpperProjection = if showProjections and !IsNaN(prevHi) then lastHi + hiSlope * (bn - lastHiBar) else Double.NaN;
UpperProjection.SetDefaultColor(Color.LIGHT_GRAY);
UpperProjection.SetStyle(Curve.SHORT_DASH);
UpperProjection.SetLineWeight(1);

plot LowerProjection = if showProjections and !IsNaN(prevLo) then lastLo + loSlope * (bn - lastLoBar) else Double.NaN;
LowerProjection.SetDefaultColor(Color.LIGHT_GRAY);
LowerProjection.SetStyle(Curve.SHORT_DASH);
LowerProjection.SetLineWeight(1);

# ----- STATUS -----
AddLabel(showStatusLabel and !IsNaN(lastHi) and !IsNaN(lastLo),
    "PRECEDENT  R: " + Round(lastHi, 2) + "  S: " + Round(lastLo, 2),
    if close > lastHi then Color.GREEN else if close < lastLo then Color.RED else Color.LIGHT_GRAY);
AddLabel(showStatusLabel and (IsNaN(lastHi) or IsNaN(lastLo)), "PRECEDENT: building history (" + (2 * n + 1) + " bars per pivot)", Color.GRAY);

# ----- ALERTS -----
def brokeRes = close > lastHi and close[1] <= lastHi and !IsNaN(lastHi);
def brokeSup = close < lastLo and close[1] >= lastLo and !IsNaN(lastLo);
Alert(brokeRes, "Precedent: closed above the latest pivot resistance", Alert.BAR, Sound.Bell);
Alert(brokeSup, "Precedent: closed below the latest pivot support", Alert.BAR, Sound.Bell);
Alert(!IsNaN(UpperProjection) and high >= UpperProjection and high[1] < UpperProjection[1], "Precedent: touched the upper projection", Alert.BAR, Sound.Ding);
Alert(!IsNaN(LowerProjection) and low <= LowerProjection and low[1] > LowerProjection[1], "Precedent: touched the lower projection", Alert.BAR, Sound.Ding);

# ----- SCAN EXPORTS -----
plot ScanBrokeRes = if brokeRes then 1 else 0;
ScanBrokeRes.Hide();

plot ScanBrokeSup = if brokeSup then 1 else 0;
ScanBrokeSup.Hide();

plot ScanTicksToRes = if !IsNaN(lastHi) then (lastHi - close) / TickSize() else 0;
ScanTicksToRes.Hide();

plot ScanTicksToSup = if !IsNaN(lastLo) then (close - lastLo) / TickSize() else 0;
ScanTicksToSup.Hide();

# Educational tool. It describes market structure; it does not give
# advice, and no output is a recommendation to buy or sell anything.
# Trading involves substantial risk of loss. mizanquant.com/terms