Swing Failure Pattern Inquisitor

//         SFP Inquisitor
//              v0.2a
//
//      coded by Bogdan Vaida

// Code for Swing High, Swing Low and Swing Failure Pattern.
// Note that we're still in the alpha version, bugs may appear.

// Note that the number you set in your Swing History variable
// will also be the minimum delay you see until the apples appear.
// This is because we're checking the forward "history" too.

// The SFP will only check for these conditions:
// - high above Swing History high and close below it
// - low below Swing History high and close above it

// In some cases you may see an apple before the SFP that "doesn't fit"
// with the SFP conditions. That's because that apple was drawn later and
// the SFP actually appeared because of the previous apple.
// 20 candles later.

// Legend:
//   🍏 - swing high
//   🍎 - swing low
//   🧺 - candle where the last swing was driven from
//   🍌 - swing failure pattern
//   🍎🍌 - hungry scenario: swing low but also a SFP compared to the last swing

// TODO:
//  - show potential swing highs/lows (where current bar is < Swing History
//  - fix banana happening when a potential swing low exists but didn't have
//  enough forward candles

//@version=5

indicator(title='🍏🍎🍌 Swing Failure Pattern Inquisitor', shorttitle='SFP-I', overlay=true)

swingHistory = input.int(20, title='Swing history:', minval=1)
plotSwings = input(true, title='Plot swings:')
plotFirstSFPOnly = input(true, title='Plot only first SFP candle:')

var lastSwingHigh = float(na)
var lastSwingLow = float(na)

// Swing Lows and Swing Highs code
isSwingHigh = false
isSwingLow = false
swingHigh = high[swingHistory]
swingLow = low[swingHistory]
range_1 = swingHistory * 2

for i = 0 to range_1 by 1
    isSwingHigh := true
    if i < swingHistory
        if high[i] > swingHigh
            isSwingHigh := false
            break
    if i > swingHistory
        if high[i] >= swingHigh
            isSwingHigh := false
            break

for i = 0 to range_1 by 1
    isSwingLow := true
    if i < swingHistory
        if low[i] < swingLow
            isSwingLow := false
            break
    if i > swingHistory
        if low[i] <= swingLow
            isSwingLow := false
            break

// Swing Failure Pattern
isSwingHighFailure = false
isSwingLowFailure = false

lastSwingHigh := isSwingHigh ? swingHigh : lastSwingHigh
lastSwingLow := isSwingLow ? swingLow : lastSwingLow

if lastSwingHigh < high and lastSwingHigh > close and ta.barssince(lastSwingHigh) <= swingHistory
    isSwingHighFailure := true
    if plotFirstSFPOnly
        lastSwingHigh := na
        lastSwingHigh

if lastSwingLow > low and lastSwingLow < close and ta.barssince(lastSwingLow) <= swingHistory
    isSwingLowFailure := true
    if plotFirstSFPOnly
        lastSwingLow := na
        lastSwingLow

// Debugging
// barssince(high > swingHigh)
plotchar(isSwingHighFailure, 'Swing High Failure', '', location.top)
plotchar(isSwingLowFailure, 'Swing Low Failure', '', location.top)
plotchar(lastSwingHigh, 'Last Swing High', '', location.top)
plotchar(lastSwingLow, 'Last Swing Low', '', location.top)

// Plotting
plotchar(series=plotSwings ? isSwingHigh : na, char='🍏', location=location.abovebar, size=size.tiny, offset=-swingHistory)
plotchar(series=plotSwings ? isSwingLow : na, char='🍎', location=location.belowbar, size=size.tiny, offset=-swingHistory)
plotchar(isSwingHighFailure, char='🍌', location=location.abovebar, size=size.tiny)
plotchar(isSwingLowFailure, char='🍌', location=location.belowbar, size=size.tiny)
// plotchar(swingHigh, char="🧺", location=location.abovebar, size=size.tiny) // location where the swing highs were drawn from
// plotchar(swingLow, char="🧺", location=location.belowbar, size=size.tiny) // location where the swing lows were drawn from