[RS]PA Zigzag Fibonacci FAN V0

study(title='[RS]PA Zigzag Fibonacci FAN V0', shorttitle='F', overlay=true)
useHA = input(false, title='Use Heikken Ashi Candles')
useAltTF = input(true, title='Use Alt Timeframe')
tf = input('D', title='Alt Timeframe')

zigzag() =>
    _isUp = close >= close[1]
    _isDown = close <= close[1]
    _direction = _isUp[1] and _isDown ? -1 : _isDown[1] and _isUp ? 1 : nz(_direction[1])
    _zigzag = _isUp[1] and _isDown and _direction[1] != -1 ? highest(2) : _isDown[1] and _isUp and _direction[1] != 1 ? lowest(2) : na

_ticker = useHA ? heikenashi(tickerid) : tickerid
sz = useAltTF ? (change(time(tf)) != 0 ? security(_ticker, tf, zigzag()) : na) : zigzag()

plot(sz, title='zigzag', color=black, linewidth=2)

//  ||---   Pattern Recognition:

x = valuewhen(sz, sz, 1) 
z = valuewhen(sz, sz, 0)
n_x = valuewhen(sz, n, 1) 
n_z = valuewhen(sz, n, 0)

price_range = z-x
bar_range = n_z-n_x
step = price_range/bar_range
projection = sz ? na : z + ((n-n_z)*step)
projection_n0236 = sz ? na : z + ((n-n_z)*step)*-0.236
projection_n0382 = sz ? na : z + ((n-n_z)*step)*-0.382
projection_n0500 = sz ? na : z + ((n-n_z)*step)*-0.500
projection_n0618 = sz ? na : z + ((n-n_z)*step)*-0.618
projection_n1000 = sz ? na : z + ((n-n_z)*step)*-1.000
projection_n1618 = sz ? na : z + ((n-n_z)*step)*-1.618
projection_n3141 = sz ? na : z + ((n-n_z)*step)*-3.141
plot(title='0.0', series=projection, style=linebr, color=blue)
plot(title='-0.236', series=projection_n0236, style=linebr, color=gray)
plot(title='-0.382', series=projection_n0382, style=linebr, color=yellow)
plot(title='-0.500', series=projection_n0500, style=linebr, color=orange)
plot(title='-0.618', series=projection_n0618, style=linebr, color=red)
plot(title='-1.000', series=projection_n1000, style=linebr, color=black)
plot(title='-1.618', series=projection_n1618, style=linebr, color=maroon)
plot(title='-3.141', series=projection_n3141, style=linebr, color=aqua)