//@version=5
//ELB.8.30.23

//This indicator was originally a mod of the 'Williams Fractals' indicator - modified by Erek A.D., Nov. 2017
//This script does not locate 'fractals' which will often miss POS in the price flow (POS = Points of Separation)
//It was rewritten from the ground up by 'Brobear' in Sept./Oct. 2018
//This code marks 'rough' AND 'smooth' EVENTS in price flow
//EVENTS are naturally created in markets when SEPARATION occurs at candle tips
//SEPARATION happens when a high is flanked by lower highs or a low is flanked by higher lows
//EVENT LOCATORS like this provide an objective foundation for counting price movement
//This copy adds support/resistance lines from nearby highs and lows
//----------------------------------------------------------------------------------------------

indicator("Event Locator", overlay=true, max_lines_count=499)

//----- User inputs ---------------------
bool plotHigh = input.string("Off", "Plot High", options = ["On", "Off"]) == "On"
bool plotLow = input.string("Off", "Plot Low", options = ["On", "Off"]) == "On"

//----- Initialization --------------------

// Event types (using constants to define)
EVENT_NONE = 0  // No event on this candle/bar
EVENT_UP = 1  // Up fractal
EVENT_DOWN = 2  // Down fractal
EVENT_DMC = 3  // Double marked candle

//-------------------------------------------------------------- Main --------------------------------------------------------------------

// An "Up Fratcal" is where a high is flanked by lower highs.
// Create a boolean series for the presence of each Up Fractal.
// upFractal = high of two bars ago 'is less than' high of previous bar 'and' high of current bar 'is less than' high of previous bar
upFractal = high[2] < high[1] and high < high[1]

// A "Down Fractal" is where a low is flanked by higher lows
// Create a boolean series for the presence of each Down Fractal.
// downFractal = low of two bars ago 'is less than' low of previous bar 'and' low of current bar 'is less than' low of previous bar
downFractal = low[2] > low[1] and low > low[1]

// Double marked candle - both up and down fractals on the same bar
dmc = upFractal and downFractal

// Events collected in one series
// In the line below ':' separates each stmt. If the event is a 'dmc' then 'ev' gets assigned 'EVENT_DMC', then it tests for 'upFractal' and so on...
// If nothing applies, then 'ev' gets assigned 'EVENT_NONE' ('EVENT_NONE' is like the 'else' condition in an if...else construct)
ev = dmc ? EVENT_DMC : upFractal ? EVENT_UP : downFractal ? EVENT_DOWN : EVENT_NONE

// ---------------------------- Detect consecutive events of the same kind, e.g. 2 consecutive Up fractals etc., by comparing 'valuewhen' with the current event (ev) -----------------------------------------------------------------
//The logic for determining consecutive events is as follows:
//    1. The ev variable is assigned one of the event types (EVENT_UP, EVENT_DOWN, EVENT_DMC, or EVENT_NONE) based on the conditions met by the current bar. This involves checking for Up Fractals, Down Fractals, and DMCs.
//    2. The valuewhen_1 and valuewhen_2 variables are used to look back at the previous events that were not EVENT_NONE to see if they match the current event type. This is done using the ta.valuewhen() function, which returns
//        the value of a given series when a condition was true on a previous bar.
//    3. The evConsec variable then checks if the current event (ev) matches the type of the last event that was not EVENT_NONE (valuewhen_1). If it does, and the event type is either EVENT_UP, EVENT_DOWN, or EVENT_DMC, evConsec
//        is assigned the same event type, indicating a consecutive event. If not, evConsec is assigned EVENT_NONE.
valuewhen_1 = ta.valuewhen(ev != EVENT_NONE, ev, 1)
valuewhen_2 = ta.valuewhen(ev != EVENT_NONE, ev, 1)
evConsec = ev == EVENT_UP and ta.valuewhen(ev != EVENT_NONE, ev, 1) == EVENT_UP ? EVENT_UP :
   ev == EVENT_DOWN and valuewhen_1 == EVENT_DOWN ? EVENT_DOWN :
   ev == EVENT_DMC and valuewhen_2 == EVENT_DMC ? EVENT_DMC : EVENT_NONE
//-------------------------------------------------------------------------------------------------- END

//---------------------------------------------------------- Plot Events ----------------------------------------------------------------------
plotshape(ev == EVENT_UP, title="Up Event", style=shape.triangleup, location=location.abovebar, offset=-1, color=color.blue)
plotshape(ev == EVENT_DOWN, title="Down Event", style=shape.triangledown, location=location.belowbar, offset=-1, color=color.green)

plotshape(evConsec == EVENT_UP, title="Up Smooth", style=shape.triangledown, location=location.belowbar, offset=-2, color=color.orange)
plotshape(evConsec == EVENT_DOWN, title="Down Smooth", style=shape.triangleup, location=location.abovebar, offset=-2, color=color.orange)

plotshape(ev == EVENT_DMC, title="DMC Up", style=shape.triangleup, location=location.abovebar, offset=-1, color=color.red) 
plotshape(ev == EVENT_DMC, title="DMC Down", style=shape.triangledown, location=location.belowbar, offset=-1, color=color.red)

//----------------------------------------------- Plot Extremities
plot(plotHigh ? high : na, color=color.blue)
plot(plotLow ? low : na, color=color.blue)

//----------------------------------------- plot support/resistance levels -----------------------------------------
// can't use 'plot' in local scope, so we'll plot both at all times regardless of trend direction...
highestHigh = ta.highest(high, 50)
plot(highestHigh, color=color.blue)
lowestLow = ta.lowest(low, 50)
plot(lowestLow, color=color.green)

// 3-16-24 (additional comments supplied by GPT-4)