Determine how to uncompress an archive based on the file command - linux

Question

Im new to bash scripting, and I want to write a script called unpack, something like this:
unpack [-r] [-v] file [file...]
-v - verbose
-r - recursive - will traverse contents of folders recursively, performing unpack on each.
I need to determine what kind of compression was used and perform unpacking for those compression types.
Assuming file names and extensions could have no meaning - the only way to know what method to use is through the file command.
I have 4 unpacking options gunzip, bunzip2, unzip, uncompress
so I wrote a function called execute_unpacking
exectute_unpacking(){
for FILE in "${#}"
do
local FILE_TYPE=$(file "${FILE}")
# How to get the compression type of the file?
case "${FILE_TYPE}" in
*bzip2) bunzip2 ${RECURSIVE} "${FILE}" ;;
*gzip) gunzip ${RECURSIVE} "${FILE}" ;;
*Zip) unzip ${RECURSIVE} ${FILE} ;;
*compress) uncomprees ${RECURSIVE} ${FILE} ;;
?) echo "${FILE} cannot be extarcted" ;;
esac
done
}
So based on the $(file ${FILE}) i need to check for Zip, bzip2, compress, gzip
Is this the correct way to do it? (i don't want to use external tools like dtrx )
EDIT:
For example if I have 4 files:
$(file -i archive) => archive: text/plain; charset=us-ascii
$(file -i archive.bz2) => archive.bz2: application/x-bzip2; charset=binary
$(file -i archvive.gz) =>archive.gz: application/x-gzip; charset=binary
$(file -i archive.cmpr) => archive.cmpr: application/x-compress; charset=binary
So i need to assign to the FILE_TYPE variable 4 options gzip,compress,bzip2,txt and then match those pattern accordingly inside of my case statement

Answer 1

What I would do :
#!/bin/bash
set -v
case $1 in
*.tar) tar xvf "$1";;
*.tgz) tar zxvf "$1";;
*.tar.gz) tar zxvf "$1";;
*.xz) tar xJvf "$1";;
*.gz) gunzip "$1";;
*.zip) unzip "$1";;
*.rar) unrar x "$1";;
*tar.bz2) tar xjvf "$1";;
*.bz2) bzip2 -d "$1";;
*) echo >&2 "unknow $1"
exit 1
;;
esac
Could be enhanced using file -i :
case $(file -i "$1") in
*/x-bzip2*) bzip2 -d "$1";;
*/gzip*) gunzip "$1";;
*/zip*) unzip "$1"";;
*/x-xz*) tar xJvf "$1";;
?) echo "File $1 cannot be extracted";;
esac

Answer 2

With file -i as Gilles Quenot suggested:
for file; do
local file_type=$(file -i "$file")
case "$file_type" in
*application/x-bzip2*) echo "bzip2 file found";;
*application/gzip*) echo "gzip file found";;
*application/zip*) echo "zip file found";;
*application/x-xz*) echo "xz file found";;
*application/x-compress*) echo "compressed file found";;
?) echo "${file} cannot be extarcted";;
esac
done