How to make multiple audio file cut same length as the first audio file and merge them?

Question

I have 3 audio files, I had merged the audio files into a single file using the below link

Merge Audio files

My issue here is, I need to merge it as a way like, I recorded a new audio (first) file and I have a second and third audio file that is predefined. I need the third audio file as the same length(duration) of the first. If third is larger than the first I need to crop the third to make it as the same length as first and If the third is smaller I need to repeat the audio for the same length as first. Finally, merge the 3 audio file and play.

Please note I am using FFmpeg with Android Studio to merge.

I searched for different solutions but, didn't find any for this.

Any Suggestion or solution is appreciated.