Half Bad book by Sally Green

In a modern-day England where two warring factions of witches live alongside humans, one sixteen-year-old boy is trapped between the two sides. Nathan’s father is the world’s most powerful and cruel witch, and his mother is dead. Both groups of witches see Nathan as their greatest threat—or their greatest weapon. Trapped in a cage, beaten and handcuffed, he must escape before his seventeenth birthday, at which point he will receive three gifts from his father and come into his own as a witch—or else he will die. But how can Nathan find his father when his every action is tracked, when there is no one safe to trust, not even family, not even the girl he loves?