This script looks for two entry signals. Long is when the previous breakout of the donchian channels was a low, price is above the input EMA, current price is equal or higher than the upper band and we're not in a position yet. Short is the other way around, so previous breakout of the donchian channels was a high, price is below the input EMA, current price is equal or lower than the lower band.
I haven't found a script that does take the previous highs and lows into consideration. Works for any markets in any conditions because the stop loss and profit targets are based on the upper and lower band of the donchian channels, which means the stop loss and profit targets move with the trend.
For more details see the script itself, I wrote a ton of comments.