// This Pine Script® code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © AI_PIPS

//@version=6
indicator("AIPIPS Liquidity Engine", overlay=true, max_lines_count=500)

asian = input.session("0000-0500", "Asian session")
london = input.session("0700-1100", "London session")
newyork = input.session("1230-1630", "New York session")

sessionActive(sess) => time(timeframe.period, sess)

var float asiaHigh = na
var float asiaLow = na
var float londonHigh = na
var float londonLow = na
var float nyHigh = na
var float nyLow = na
var float asiaHighPrev = na
var float asiaLowPrev = na
var float londonHighPrev = na
var float londonLowPrev = na
var float nyHighPrev = na
var float nyLowPrev = na

fSessionUpdate(active, highRef, lowRef, prevHighRef, prevLowRef) =>
    if active
        highRef := na(highRef) ? high : math.max(highRef, high)
        lowRef := na(lowRef) ? low : math.min(lowRef, low)
    else if not active and not na(highRef)
        prevHighRef := highRef
        prevLowRef := lowRef
        highRef := na
        lowRef := na
    [highRef, lowRef, prevHighRef, prevLowRef]

[asiaHigh, asiaLow, asiaHighPrev, asiaLowPrev] := fSessionUpdate(sessionActive(asian), asiaHigh, asiaLow, asiaHighPrev, asiaLowPrev)
[londonHigh, londonLow, londonHighPrev, londonLowPrev] := fSessionUpdate(sessionActive(london), londonHigh, londonLow, londonHighPrev, londonLowPrev)
[nyHigh, nyLow, nyHighPrev, nyLowPrev] := fSessionUpdate(sessionActive(newyork), nyHigh, nyLow, nyHighPrev, nyLowPrev)

plot(asiaHighPrev, title="Asia High", color=color.new(color.blue, 0), linewidth=1, style=plot.style_linebr)
plot(asiaLowPrev, title="Asia Low", color=color.new(color.blue, 0), linewidth=1, style=plot.style_linebr)
plot(londonHighPrev, title="London High", color=color.new(color.green, 0), linewidth=1, style=plot.style_linebr)
plot(londonLowPrev, title="London Low", color=color.new(color.green, 0), linewidth=1, style=plot.style_linebr)
plot(nyHighPrev, title="NY High", color=color.new(color.red, 0), linewidth=1, style=plot.style_linebr)
plot(nyLowPrev, title="NY Low", color=color.new(color.red, 0), linewidth=1, style=plot.style_linebr)

liquidityTap = (not na(asiaHighPrev) and high >= asiaHighPrev) or (not na(asiaLowPrev) and low <= asiaLowPrev) or (not na(londonHighPrev) and high >= londonHighPrev) or (not na(londonLowPrev) and low <= londonLowPrev) or (not na(nyHighPrev) and high >= nyHighPrev) or (not na(nyLowPrev) and low <= nyLowPrev)
plotshape(liquidityTap, title="Liquidity tap", char="LQ", location=location.top, color=color.purple, size=size.tiny)