I wrote a program to calculate my tax 3 years ago, about a week before Coinbase released my tax report. At least the outcome of my program was the same as Coinbase's. Coinbase doesn't provide that information now and wants people to pay for this service.
It was a ~100 line nodejs program that took me 3 evenings to program it. TurboTax should have a solution already. They just need more time to test and verify different cases.
