Programming :: Extract The Text From Files?

I have many files in a folder from which I need to extract some contents, these are basically text files wich have individual lines with (i.e)

name: john
address: whatever
phone: 123456

Some caveats

1. Sometimes a line might be missing.

name: johnn
phone: 123456

2. Lines are not in the same line-numbers across the files I did try some things with awk based on google searches but I couldn't extract the data of each file into a single line (this is the ultimate goal):

john,whatever,123456

I don't have knowledge other than having put some bash scripts together for backup jobs, so I am open to install anything that could to pull this off.