//@version=5
indicator("Trend Identification Indicator", overlay=true, shorttitle="Trend ID Indicator [birdsongs]")

// User inputs to allow customization of moving averages
lengthSMA = input(50, title="Simple Moving Average Length")
lengthEMA = input(21, title="Exponential Moving Average Length")
src = input(close, title="Source")

// Calculate moving averages
sma = ta.sma(src, lengthSMA) // Simple Moving Average
ema = ta.ema(src, lengthEMA) // Exponential Moving Average

// Plot moving averages on the chart
plot(sma, color=color.blue, title="Simple Moving Average")
plot(ema, color=color.red, title="Exponential Moving Average")

// Generate buy and sell signals when moving averages cross
buySignal = ta.crossover(ema, sma) // EMA crosses above SMA
sellSignal = ta.crossunder(ema, sma) // EMA crosses below SMA

// State variable to track if the background should be colored
var inLongPosition = false // Initialize as false, meaning no position is open

// Update state based on signals
if (buySignal)
    inLongPosition := true // Set to true on a buy signal
if (sellSignal)
    inLongPosition := false // Set to false on a sell signal

// Plot buy and sell signals on the chart
plotshape(series=buySignal, location=location.belowbar, color=color.green, style=shape.labelup, title="Buy Signal", text="Buy")
plotshape(series=sellSignal, location=location.abovebar, color=color.red, style=shape.labeldown, title="Sell Signal", text="Close")

// Color the background green when in a long position
bgcolor(inLongPosition ? color.new(color.green, 90) : na)

// Alert conditions
alertcondition(buySignal, title="Buy Alert", message="EMA has crossed above SMA, consider a buy.")
alertcondition(sellSignal, title="Close Alert", message="EMA has crossed below SMA, consider closing the buy.")