RSI = Relative Strength Index

// This Pine Script® code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © Piotr Kowalski "piecioshka"
// Docs (EN): https://github.com/piecioshka/tradingview-pine-scripts/blob/main/indicators/oscillators/rsi/rsi.md
// Docs (PL): https://github.com/piecioshka/tradingview-pine-scripts/blob/main/indicators/oscillators/rsi/rsi.pl.md

//@version=6
// No "timeframe" argument (MTF): Pine forbids it in scripts that create
// drawings - and the price markers, threshold-cross labels, and the status
// table here are all label/table objects.
indicator('RSI = Relative Strength Index', overlay=false, precision=2, max_lines_count=100, max_labels_count=100)

// --- Color palette (single place for the theme) ---
cRsi = color.rgb(255, 245, 157)  // RSI line
cOb  = color.red                 // overbought / upper zone
cOs  = color.green               // oversold / lower zone
cMid = color.gray                // midline and neutral elements
cMa  = color.yellow              // smoothing MA
cBb  = color.green               // Bollinger Bands

// --- Inputs ---
gCalc = 'Calculation'
rsiSource = input.source(close, 'Source', group=gCalc, tooltip='Price the RSI is calculated from (candle close by default).')
rsiLength = input.int(14, 'Length', minval=1, group=gCalc, tooltip='Number of candles in the RSI window. Fewer = more sensitive, more = smoother.')

gLevels = 'Levels'
obLevel  = input.int(70, 'Overbought', minval=50, maxval=100, group=gLevels, tooltip='Above this level the market is considered overbought.')
osLevel  = input.int(30, 'Oversold',   minval=0,  maxval=50,  group=gLevels, tooltip='Below this level the market is considered oversold.')
midLevel = 50  // deliberately NOT an input - 50 is the RSI's definitional axis of symmetry

gSmooth = 'Smoothing'
TT_BB = 'Applies only to the "SMA + Bollinger Bands" variant. Sets the distance of the bands from the SMA.'
maTypeInput = input.string('SMA', 'Type', options=['None', 'SMA', 'SMA + Bollinger Bands', 'EMA', 'SMMA (RMA)', 'WMA', 'VWMA'], group=gSmooth, display=display.none, tooltip='Moving average calculated from the RSI. "None" disables smoothing.')
var isBB = maTypeInput == 'SMA + Bollinger Bands'
maLengthInput = input.int(14, 'Length', minval=1, group=gSmooth, display=display.none, active=maTypeInput != 'None')
bbMultInput = input.float(2.0, 'BB StdDev', minval=0.001, maxval=50, step=0.5, tooltip=TT_BB, group=gSmooth, display=display.none, active=isBB)
var enableMA = maTypeInput != 'None'

gDiv = 'Divergences'
calculateDivergence = input.bool(false, 'Calculate divergences', group=gDiv, display=display.none, tooltip='Regular bull/bear divergences (RSI pivots vs price). Required for divergence alerts to work.')

gView = 'Display'
showZones   = input.bool(true, 'Zone gradient',                 group=gView, tooltip='Vertical gradient in the overbought/oversold zone (between the RSI line and the threshold).')
showSignals = input.bool(true, 'Signals (markers on price)',    group=gView, tooltip='Markers on the price panel (mean reversion): green below the candle when the RSI drops below the oversold level, red above the candle when it rises above the overbought level. Shape and size in the Appearance group.')
showLabels  = input.bool(false, 'BUY CLOSE / BUY OPEN markers', group=gView, tooltip='Markers on the RSI panel where the threshold is crossed. Off by default.')
showTable   = input.bool(true,  'Status table',                 group=gView, tooltip='Small corner panel with the current RSI value and state.')

gA = 'Appearance'
shapeName = input.string('Triangle', 'Marker shape', options=['Triangle', 'Arrow', 'Label arrow', 'Circle', 'Diamond'], group=gA, tooltip='Triangle - solid triangle.\nArrow - small thin arrow.\nLabel arrow - arrow-shaped label bubble.\nCircle / Diamond - neutral dot markers.')
sizeName  = input.string('Small', 'Marker size', options=['Tiny', 'Small', 'Normal', 'Large'], group=gA)

// Markers as labels - the shape is picked from an input, which plotshape() cannot do (its style must be a constant).
upStyle    = shapeName == 'Arrow' ? label.style_arrowup : shapeName == 'Label arrow' ? label.style_label_up : shapeName == 'Circle' ? label.style_circle : shapeName == 'Diamond' ? label.style_diamond : label.style_triangleup
downStyle  = shapeName == 'Arrow' ? label.style_arrowdown : shapeName == 'Label arrow' ? label.style_label_down : shapeName == 'Circle' ? label.style_circle : shapeName == 'Diamond' ? label.style_diamond : label.style_triangledown
markerSize = sizeName == 'Tiny' ? size.tiny : sizeName == 'Normal' ? size.normal : sizeName == 'Large' ? size.large : size.small

// --- Calculations ---
rsi     = ta.rsi(rsiSource, rsiLength)
crossOb = ta.crossover(rsi, obLevel)    // entering the overbought zone
crossOs = ta.crossunder(rsi, osLevel)   // entering the oversold zone

// --- RSI line and hidden thresholds (fill boundaries) ---
rsiPlot = plot(rsi, 'RSI', color=cRsi, linewidth=1)
pOb = plot(obLevel, 'Overbought threshold', color=na, display=display.none, editable=false)
pOs = plot(osLevel, 'Oversold threshold',   color=na, display=display.none, editable=false)

// --- Reference levels ---
hline(obLevel,  'Overbought', color=cOb,  linestyle=hline.style_dotted)
hline(osLevel,  'Oversold',   color=cOs,  linestyle=hline.style_dotted)
hline(midLevel, 'Midline',    color=cMid, linestyle=hline.style_dotted)

// --- Vertical zone gradient (bottom->top), only while RSI is in the zone ---
// Red: pale at the overbought threshold, strong toward 100
fill(rsiPlot, pOb, top_value=100, bottom_value=obLevel, top_color = showZones and rsi > obLevel ? color.new(cOb, 20) : na, bottom_color = showZones and rsi > obLevel ? color.new(cOb, 90) : na, title='Overbought zone')
// Green: pale at the oversold threshold, strong toward 0
fill(rsiPlot, pOs, top_value=osLevel, bottom_value=0, top_color = showZones and rsi < osLevel ? color.new(cOs, 90) : na, bottom_color = showZones and rsi < osLevel ? color.new(cOs, 20) : na, title='Oversold zone')

// --- Smoothing (MA of the RSI, optionally Bollinger Bands) ---
ma(source, length, MAtype) =>
    switch MAtype
        'SMA'                   => ta.sma(source, length)
        'SMA + Bollinger Bands' => ta.sma(source, length)
        'EMA'                   => ta.ema(source, length)
        'SMMA (RMA)'            => ta.rma(source, length)
        'WMA'                   => ta.wma(source, length)
        'VWMA'                  => ta.vwma(source, length)

smoothingMA    = enableMA ? ma(rsi, maLengthInput, maTypeInput) : na
smoothingStDev = isBB ? ta.stdev(rsi, maLengthInput) * bbMultInput : na
plot(smoothingMA, 'RSI-based MA', color=cMa, display = enableMA ? display.all : display.none, editable=enableMA)
bbUpperBand = plot(smoothingMA + smoothingStDev, 'Upper Bollinger Band', color=cBb, display = isBB ? display.all : display.none, editable=isBB)
bbLowerBand = plot(smoothingMA - smoothingStDev, 'Lower Bollinger Band', color=cBb, display = isBB ? display.all : display.none, editable=isBB)
fill(bbUpperBand, bbLowerBand, color = isBB ? color.new(cBb, 90) : na, title='Bollinger Bands background', display = isBB ? display.all : display.none, editable=isBB)

// --- Signals (markers as labels - the shape comes from the Appearance inputs) ---
// Marker positions clipped to the 0..100 scale so they stay inside the panel at RSI extremes
obLabelY = math.min(rsi + 5, 100)
osLabelY = math.max(rsi - 5, 0)

// Markers on the price panel (force_overlay): overbought = red above the candle, oversold = green below
if showSignals and crossOb
    label.new(bar_index, na, '', yloc=yloc.abovebar, style=downStyle, color=cOb, size=markerSize, force_overlay=true)
if showSignals and crossOs
    label.new(bar_index, na, '', yloc=yloc.belowbar, style=upStyle, color=cOs, size=markerSize, force_overlay=true)

// Markers on the RSI panel where the threshold is crossed (BUY CLOSE above, BUY OPEN below)
if showLabels and crossOb
    label.new(bar_index, obLabelY, '', style=downStyle, color=cOb, size=markerSize)
if showLabels and crossOs
    label.new(bar_index, osLabelY, '', style=upStyle, color=cOs, size=markerSize)

// --- Divergences (regular, on RSI pivots vs price) ---
lookbackRight = 5
lookbackLeft  = 5
rangeUpper    = 60
rangeLower    = 5
noneColor     = color.new(color.white, 100)

_inRange(bool cond) =>
    bars = ta.barssince(cond)
    rangeLower <= bars and bars <= rangeUpper

plFound  = false
phFound  = false
bullCond = false
bearCond = false

rsiLBR = rsi[lookbackRight]

if calculateDivergence
    // Bull: RSI makes a higher low, price a lower low
    plFound := not na(ta.pivotlow(rsi, lookbackLeft, lookbackRight))
    rsiHL   = rsiLBR > ta.valuewhen(plFound, rsiLBR, 1) and _inRange(plFound[1])
    lowLBR  = low[lookbackRight]
    priceLL = lowLBR < ta.valuewhen(plFound, lowLBR, 1)
    bullCond := priceLL and rsiHL and plFound

    // Bear: RSI makes a lower high, price a higher high
    phFound := not na(ta.pivothigh(rsi, lookbackLeft, lookbackRight))
    rsiLH   = rsiLBR < ta.valuewhen(phFound, rsiLBR, 1) and _inRange(phFound[1])
    highLBR = high[lookbackRight]
    priceHH = highLBR > ta.valuewhen(phFound, highLBR, 1)
    bearCond := priceHH and rsiLH and phFound

plot(plFound ? rsiLBR : na, offset=-lookbackRight, title='Bullish divergence', linewidth=2, color = bullCond ? cOs : noneColor, display=display.pane, editable=calculateDivergence)
plotshape(bullCond ? rsiLBR : na, offset=-lookbackRight, title='Bullish divergence label', text=' Bull ', style=shape.labelup, location=location.absolute, color=cOs, textcolor=color.white, display=display.pane, editable=calculateDivergence)

plot(phFound ? rsiLBR : na, offset=-lookbackRight, title='Bearish divergence', linewidth=2, color = bearCond ? cOb : noneColor, display=display.pane, editable=calculateDivergence)
plotshape(bearCond ? rsiLBR : na, offset=-lookbackRight, title='Bearish divergence label', text=' Bear ', style=shape.labeldown, location=location.absolute, color=cOb, textcolor=color.white, display=display.pane, editable=calculateDivergence)

// --- Alerts ---
alertcondition(crossOb, 'RSI: Overbought', 'RSI crossed the overbought threshold up')
alertcondition(crossOs, 'RSI: Oversold',   'RSI crossed the oversold threshold down')
alertcondition(bullCond, 'RSI: Bullish divergence', 'Regular bullish divergence - "Pivot Lookback Right" candles to the left of the current candle')
alertcondition(bearCond, 'RSI: Bearish divergence', 'Regular bearish divergence - "Pivot Lookback Right" candles to the left of the current candle')

// --- Status table (top-right corner) ---
status      = rsi >= obLevel ? 'Overbought' : rsi <= osLevel ? 'Oversold' : 'Neutral'
statusColor = rsi >= obLevel ? cOb : rsi <= osLevel ? cOs : cMid

var table infoTable = table.new(position.top_right, 2, 2, border_width=1, border_color=color.new(cMid, 70))
if showTable and barstate.islast
    table.cell(infoTable, 0, 0, 'RSI',    text_color=cMid,        text_size=size.small)
    table.cell(infoTable, 1, 0, str.tostring(rsi, '#.##'), text_color=color.white, text_size=size.small)
    table.cell(infoTable, 0, 1, 'Status', text_color=cMid,        text_size=size.small)
    table.cell(infoTable, 1, 1, status,   text_color=statusColor, text_size=size.small)