#!/bin/bash
# from https://gist.github.com/renzok/29c9e5744f1dffa392cf

if [ -z "${USER}" ]; then
  echo "We need USER to be set!"; exit 100
fi

# if both not set we do not need to do anything
if [ -z "${HOST_USER_ID}" -a -z "${HOST_USER_GID}" ]; then
    echo "Nothing to do here." ; exit 0
fi

# reset user_id to either new id or if empty old (still one of above might not be set)
USER_ID=${HOST_USER_ID:=$USER_ID}
USER_GID=${HOST_USER_GID:=$USER_GID}

LINE=$(grep -F "${USER}" /etc/passwd)
# replace all ':' with a space and create array
array=( ${LINE//:/ } )

# home is 5th element
USER_HOME=${array[4]}

sed -i -e "s/^${USER}:\([^:]*\):[0-9]*:[0-9]*/${USER}:\1:${USER_ID}:${USER_GID}/"  /etc/passwd
sed -i -e "s/^${USER}:\([^:]*\):[0-9]*/${USER}:\1:${USER_GID}/"  /etc/group

# for whatever reason recursively chowning the .opam directory takes forever; this is janky, but gets the job done
cd /home/docker/
cp -r .opam/ .opam-new
rm -r .opam
mv .opam-new/ .opam/
chown -R ${USER_ID}:${USER_GID} ${USER_HOME}

exec su - "${USER}"

