Pinescript for supertrend and ema

Hi I’m looking for a trading view pinescript with alerts combining supertrend and ema.

Conditions buy if trend is +ve and bar close above ema. And exit bar close below ema only with -ve trend. So until unless the trend changes it shouldn’t exit and it should take more than 1 trade, ignoring all other trades occurred during that trend . Also if we get a signal when the trend is opposite, it should get activated only after the trend change. Like below image, only one sell signal should b activated and the buy signal should get activated only if the trend change.

Let me know if you can do it and how much does it cost