Chris Brown -- Fighting Back Against Bad Parenting Claims ... I'm a Good Father!

Chris Brown believes he's an exceptional father to his daughter Royalty and plans to fight his baby mama's attempt to limit his custody to just supervised visits.

According to our sources, Brown plans to file an opposition to Nia Guzman's request for full custody ... countering her claims that he's a bad father. Guzman has cited several issues with Chris' parenting and lifestyle, but we're told he has a comeback for each one.

First off, we're told Chris will argue he never puts his daughter in harm's way and has increased security at his home since the recent break-in.

Secondly, our sources says Chris will say he has never done drugs around Royalty.

Lastly, we're told Chris will argue he has never allowed "gang bangers" to be around his daughter.

Chris has filed his own docs to establish paternity so he can fight for joint custody, but so far a judge has not ruled.