Un ami vous a dit means "a friend told you ..."
I like you as a friend
"vous êtes un très mauvais ami" means you are a very bad friend ; do not write 'vous etes un ami très mauvais' before ami, unless you want this to read 'you are a friend very bad'
Vous êtes un ami
vous êtes un grand ami
tu es mon ami as you are my friend in French
It literally translates as 'A friend you always just call'.
je vous aime comme un ami
Vous avez un point de mon ami.
vous êtes mon meilleur ami > you are my best friend 'un gars' - plural 'des gars' means "guy / guys" in French.
un meilleur ami means a best friend in French.
"vous êtes un salaud" means "you are a bast*rd" in French.
"vous êtes un crétin" means "you are a blockhead" in French.