// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/
// © Venture Lab – https://venturelab-bots.pages.dev/pine/
//
// RSI with regular divergence marks.
// What it does: plots the RSI and marks REGULAR divergences between two confirmed pivots:
//   bullish = price makes a lower low while the RSI makes a higher low,
//   bearish = price makes a higher high while the RSI makes a lower high.
// What it does NOT do: it does not predict price, it is not a trading system and it is not financial advice.
// A pivot is only confirmed "Pivot lookback right" bars after it happened, so every mark appears that many
// bars late in real time (it is drawn back at the pivot bar). Hidden divergences are not detected.

//@version=6
indicator("RSI with Divergence Marks [Venture Lab]", shorttitle = "RSI Div", overlay = false, max_lines_count = 500)

// ---- Inputs
int   rsiLen   = input.int(14, "RSI length", minval = 2)
float src      = input.source(close, "RSI source")
int   lbL      = input.int(5, "Pivot lookback left", minval = 1)
int   lbR      = input.int(5, "Pivot lookback right", minval = 1)
int   rangeMin = input.int(5, "Min bars between pivots", minval = 1)
int   rangeMax = input.int(60, "Max bars between pivots", minval = 2)
bool  showBull = input.bool(true, "Show bullish divergence")
bool  showBear = input.bool(true, "Show bearish divergence")

// ---- RSI and pivots (calculated on every bar, outside of any condition)
float rsi   = ta.rsi(src, rsiLen)
float plRsi = ta.pivotlow(rsi, lbL, lbR)
float phRsi = ta.pivothigh(rsi, lbL, lbR)

// ---- State of the previous confirmed pivots
var float prevLowRsi    = na
var float prevLowPrice  = na
var int   prevLowBar    = na
var float prevHighRsi   = na
var float prevHighPrice = na
var int   prevHighBar   = na

bool bullDiv = false
bool bearDiv = false

if not na(plRsi)
    float curPrice = low[lbR]
    int   curBar   = bar_index - lbR
    if not na(prevLowBar)
        int gap = curBar - prevLowBar
        bullDiv := gap >= rangeMin and gap <= rangeMax and curPrice < prevLowPrice and plRsi > prevLowRsi
        if bullDiv and showBull
            line.new(prevLowBar, prevLowRsi, curBar, plRsi, color = color.green, width = 2)
    prevLowRsi   := plRsi
    prevLowPrice := curPrice
    prevLowBar   := curBar

if not na(phRsi)
    float curPrice = high[lbR]
    int   curBar   = bar_index - lbR
    if not na(prevHighBar)
        int gap = curBar - prevHighBar
        bearDiv := gap >= rangeMin and gap <= rangeMax and curPrice > prevHighPrice and phRsi < prevHighRsi
        if bearDiv and showBear
            line.new(prevHighBar, prevHighRsi, curBar, phRsi, color = color.red, width = 2)
    prevHighRsi   := phRsi
    prevHighPrice := curPrice
    prevHighBar   := curBar

// ---- Plots
plot(rsi, "RSI", color = color.purple, linewidth = 2)
hline(70, "Overbought", color = color.gray, linestyle = hline.style_dashed)
hline(50, "Middle", color = color.gray, linestyle = hline.style_dotted)
hline(30, "Oversold", color = color.gray, linestyle = hline.style_dashed)
plotshape(showBull and bullDiv ? plRsi : na, "Bullish divergence", shape.labelup, location.absolute, color.green, offset = -lbR, text = "Bull", textcolor = color.white, size = size.tiny)
plotshape(showBear and bearDiv ? phRsi : na, "Bearish divergence", shape.labeldown, location.absolute, color.red, offset = -lbR, text = "Bear", textcolor = color.white, size = size.tiny)

// ---- Alerts (fire on the bar where the divergence is confirmed, i.e. lbR bars after the pivot)
alertcondition(bullDiv, "Bullish RSI divergence", "Bullish RSI divergence confirmed on {{ticker}} ({{interval}})")
alertcondition(bearDiv, "Bearish RSI divergence", "Bearish RSI divergence confirmed on {{ticker}} ({{interval}})")