My daughter leaves my grandson with me for up to27 days at time without contact when she does come around its to take him for 3 to 4 hours to take pics and post on Facebook, I have documented and have proof of this he is now one year can I seek legal custody and be able to win

You can seek legal custody, but whether you can win or not is guesswork. One of the problems is where is the father in this. He will probably need to be consulted.

I would first try for legal guardianship. Right now you have no legal rights to seek medical care or anything else for the child. If the child is living with you most of the time, you should have no problem getting guardianship. This will make the courts aware of the situation and they will probably put her on notice that she needs to clean up her act. They will probably set a date for review (6-12 months) and, at that time either make guardianship permanent or award custody.