// MACD plus 4 user-defined levels (horizontal lines)
// Indicator for the Mystery Strategy

//@version=5
indicator(title="Mystery Indicator", shorttitle="Mystery Indicator", timeframe="", timeframe_gaps=true)
// Getting inputs
fast_length = input(title="Fast Length", defval=25)
slow_length = input(title="Slow Length", defval=100)
src = input(title="Source", defval=close)
signal_length = input.int(title="Signal Smoothing",  minval = 1, maxval = 50, defval = 9)
sma_source = input.string(title="Oscillator MA Type",  defval="EMA", options=["SMA", "EMA"])
sma_signal = input.string(title="Signal Line MA Type", defval="EMA", options=["SMA", "EMA"])

// Levels to mark
minMoveLong = input.float(0)
minMoveShort = input.float(0)
switchOnLongsAbove = input.float(-100, step=0.1, tooltip="Allow longs only if MACD is above this level")
switchOnShortsBelow = input.float(100, step=0.1, tooltip="Allow shorts only if MACD is below this level")

// Scaling down the MACD to make a nice picture
macdScale = 0.5

// Plot colors
col_macd = input(#000000, "MACD Line  ", group="Color Settings", inline="MACD")
col_signal = input(#FF6D00, "Signal Line  ", group="Color Settings", inline="Signal")
col_grow_above = input(#26A69A, "Above   Grow", group="Histogram", inline="Above")
col_fall_above = input(#B2DFDB, "Fall", group="Histogram", inline="Above")
col_grow_below = input(#FFCDD2, "Below Grow", group="Histogram", inline="Below")
col_fall_below = input(#FF5252, "Fall", group="Histogram", inline="Below")
// Calculating
fast_ma = sma_source == "SMA" ? ta.sma(src, fast_length) : ta.ema(src, fast_length)
slow_ma = sma_source == "SMA" ? ta.sma(src, slow_length) : ta.ema(src, slow_length)
macd = fast_ma - slow_ma
signal = sma_signal == "SMA" ? ta.sma(macd, signal_length) : ta.ema(macd, signal_length)
hist = macd - signal

plot(hist, title="Histogram", style=plot.style_columns, color=(hist>=0 ? (hist[1] < hist ? col_grow_above : col_fall_above) : (hist[1] < hist ? col_grow_below : col_fall_below)))
macdPlot = plot(macd*macdScale, title="MACD (scaled)", color=col_macd)
//plot(signal, title="Signal", color=col_signal)

level1Plot = plot(minMoveLong, title="minMoveLong", color=color.blue)
level2Plot = plot(-minMoveShort, title="minMoveShort", color=color.blue)
fill(level1Plot, level2Plot, title="Level 1 to level 2", color=color.new(color.blue, 50))

level3Plot = plot(switchOnLongsAbove == -100 ? na : switchOnLongsAbove*macdScale, title="switchOnLongsAbove (scaled)", color=na)
level4Plot = plot(switchOnShortsBelow == 100 ? na : switchOnShortsBelow*macdScale, title="switchOnShortsBelow (scaled)", color=na)

fill(level3Plot, macdPlot, color=color.new(color.lime, macd >= switchOnLongsAbove ? 75 : 100))
fill(level4Plot, macdPlot, color=color.new(color.red, macd <= switchOnShortsBelow ? 75 : 100))