How to decompress multiple nested archives of different formats?

I have hundreds of .zip and .tar archives nested in each other with the unknown depth and I need to decompress all of them to get to the last one, how can I achieve that? I have the part for the zip files:

while 'true' 
do
find . '(' -iname '*.zip' ')' -exec sh -c 'unzip -o -d "${0%.*}" "$0"' '{}' ';'
done

but once it stumbles upon the .tar file it expectedly does nothing. I'm running the script on mac.
The structure is just an archive in an archive, the extensions are not in any particular order, like:

a.zip/b.zip/c.tar/d.tar/e.zip/f.tar...

and so on

Solution

You can use an existing command like 7z x to extract either archive type or build your own using case "$file" in; *.zip) unzip ...;; *.tar) ... and so on.

The following script unpacks nested archives as long as the unpacked content is exactly one .tar or .zip archive. It stops when multiple archives, multiple files, or even directory containing just one .zip, were unpacked at once.

#! /usr/bin/env bash

# this function can be replaced by `7z x "$1"`
# if 7zip is installed (package managers often call it p7zip)
extract() {
  case "$1" in
    *.zip) unzip "$1" ;;
    *.tar) tar -xf "$1" ;;
    *) echo "Unknown archive type: $1"; exit 1 ;;
  esac
}
isOne() {
  [ $# = 1 ]
}

mkdir out tmp
ln {,out/}yourOutermostArchive.zip # <-- Adapt this line
cd out
shopt -s nullglob
while isOne * && isOne *.{zip,tar}
do
  a=(*)
  mv "$a" ../tmp/
  extract "../tmp/$a"
  rm "../tmp/$a"
done
rm -r ../tmp
cd ..