var fs = require('fs');

fs.readFile('textfile.txt','utf8', (err, data) =>
{
  if (err) throw err;
  var TempArray = data.split("\r\n")
  var LineCounter = 0;
  var IncreaseCounter = 0;
  var LastIncrease = 0;
  var Invested = false;

  for(var i = 0;i < TempArray.length;i++)
  {
    LineCounter++;
        if(TempArray[i] > TempArray[i-1] && !Invested)
        {
            if(IncreaseCounter > 0 && LastIncrease == LineCounter - 1)
            {
                IncreaseCounter++
            }
            else if(IncreaseCounter == 0)
            {
                IncreaseCounter++
            }
            else
            {
                IncreaseCounter == 0;
            }

            LastIncrease = LineCounter;
            if(IncreaseCounter == 3)
            {
                console.log("Purchase ducats on line ", LineCounter)
                Invested = true;
                IncreaseCounter = 0;
            }
        }
        if(Invested)
        {
            if(TempArray[i] < TempArray[i-1])
            {
                console.log("Sell ducats on line ", LineCounter);
                Invested = false;
            }
        }
    }
})