I need an expert advisor that uses the Nadaraya Watson Envelope indicator

Specs: 

• This will generate the buy signal when the price closes below the bottom line. the sell signal will be generated when the price closes above the top line of the indicator

• if the candle that closes outside the line to creates the buy or sell signal is greater than (x) times the ATR it does not open the trade
  
• limit the number of open positions
  
• stop loss and take profit two options
  1. pre set fix value with the option of trailing stop
  2. calculated from the ATR. Eg the stop lose is 2 times the value of the atr and the take profit is 4 times the atr
  
• Lot size to have two options 
  1. a set amount
  2> a % of the account balance