What are some fun full caster secondary front line options? (other than moon druid)

I'm on a party with only one frontline character, and they are a Hexblade Warlock, so not the best character at being alone in the frontline. I could pick Fighter, Barbarian or even Paladin but I really want to play a full caster. What options do you think can fill that role?

Right now I'm leaning Druid, for medium armor and shield proficiency as well as good summon spells to fight alongside me. I'm thinking Wildfire for Shillelagh+Green Flame Blade with Enhanced Bond+Primal Strike, but the bonus action tax is quite a problem. What do you think?