MACD

// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © claygrace74

//@version=6
indicator("MACD", overlay=false)

// ==================== MACD Settings ====================
var macd_group = "MACD Settings"
macdsrc       = input.source(close, "Source", group=macd_group)
macdfastlen   = input.int(12, "Fast Length", minval=1, group=macd_group)
macdslowlen   = input.int(26, "Slow Length", minval=1, group=macd_group)
macdsignallen = input.int(9, "Signal Smoothing", minval=1, maxval=50, group=macd_group)
sigType       = input.string("EMA", "Signal Line Type", options=["EMA", "SMA"], group=macd_group)

// ==================== Display Settings ====================
var disp_group = "Display Settings"
i_showCross      = input.bool(true, "Show MACD/Signal Cross", group=disp_group)
i_showZeroCross  = input.bool(true, "Show Zero-Line Cross", group=disp_group)
i_showDivergence = input.bool(false, "Show Divergence Signals", group=disp_group)
i_divLookback    = input.int(5, "Divergence Lookback", minval=3, group=disp_group)

// ==================================================================================
// Core Calculations
// ==================================================================================
fastavg    = ta.ema(macdsrc, macdfastlen)
slowavg    = ta.ema(macdsrc, macdslowlen)
macd       = fastavg - slowavg
macdsignal = sigType == "SMA" ? ta.sma(macd, macdsignallen) : ta.ema(macd, macdsignallen)
macdhist   = macd - macdsignal

// Cross detection
bullCross = ta.crossover(macd, macdsignal)   // MACD crosses above signal — bullish
bearCross = ta.crossunder(macd, macdsignal)  // MACD crosses below signal — bearish
zeroCrossUp   = ta.crossover(macd, 0)
zeroCrossDown = ta.crossunder(macd, 0)

// Histogram momentum — 4 states
histGrowBull   = macdhist >= 0 and macdhist > macdhist[1]  // Above zero, growing
histShrinkBull = macdhist >= 0 and macdhist <= macdhist[1] // Above zero, shrinking
histGrowBear   = macdhist < 0 and macdhist < macdhist[1]   // Below zero, growing (more negative)
histShrinkBear = macdhist < 0 and macdhist >= macdhist[1]  // Below zero, shrinking

histColor = histGrowBull ? color.rgb(0, 230, 64) : histShrinkBull ? color.rgb(0, 150, 40) : histGrowBear ? color.rgb(230, 30, 30) : color.rgb(150, 40, 40)

// Divergence detection
priceHigher  = high > ta.highest(high, i_divLookback)[1]
macdNotHigh  = macd < ta.highest(macd, i_divLookback)[1]
bearDiv      = priceHigher and macdNotHigh and macd > 0

priceLower   = low < ta.lowest(low, i_divLookback)[1]
macdNotLow   = macd > ta.lowest(macd, i_divLookback)[1]
bullDiv      = priceLower and macdNotLow and macd < 0

// ==================================================================================
// Plots
// ==================================================================================
hline(0, "Zero Line", color=color.new(#787B86, 50))

// Histogram — 4-color momentum
plot(macdhist, color=histColor, linewidth=1, style=plot.style_columns, title="Histogram")

// MACD and Signal lines
plot(macd,       color=color.rgb(44, 29, 255),    linewidth=2, title="MACD")
plot(macdsignal, color=color.rgb(255, 152, 36, 0), linewidth=1, title="Signal")

// MACD/Signal cross shapes
crossVal = bullCross or bearCross ? macdsignal : na
crossClr = bullCross ? color.green : color.red
plotshape(i_showCross and bullCross, style=shape.circle, location=location.absolute, color=color.green, size=size.tiny, title="Bull Cross")
plotshape(i_showCross and bearCross, style=shape.circle, location=location.absolute, color=color.red,   size=size.tiny, title="Bear Cross")

// Zero-line cross
plotshape(i_showZeroCross and zeroCrossUp,   style=shape.triangleup,   location=location.bottom, color=color.lime,   text="0+", textcolor=color.lime,   size=size.tiny, title="Zero Cross Up")
plotshape(i_showZeroCross and zeroCrossDown, style=shape.triangledown, location=location.top,    color=color.orange, text="0-", textcolor=color.orange, size=size.tiny, title="Zero Cross Down")

// Divergence
bgcolor(i_showDivergence and bearDiv ? color.new(color.orange, 85) : na, title="Bearish Divergence")
bgcolor(i_showDivergence and bullDiv ? color.new(color.teal, 85)   : na, title="Bullish Divergence")

// ==================================================================================
// Alert Conditions
// ==================================================================================
alertcondition(bullCross,     "MACD Bullish Cross",     "MACD crossed above signal line")
alertcondition(bearCross,     "MACD Bearish Cross",     "MACD crossed below signal line")
alertcondition(zeroCrossUp,   "MACD Above Zero",        "MACD crossed above zero line")
alertcondition(zeroCrossDown, "MACD Below Zero",        "MACD crossed below zero line")
alertcondition(bullDiv,       "Bullish Divergence",     "Price making new low but MACD is not")
alertcondition(bearDiv,       "Bearish Divergence",     "Price making new high but MACD is not")