#!/usr/bin/env bash

# check for freesurfer home
[ ! -e "$FREESURFER_HOME" ] && echo "error: freesurfer has not been properly sourced" && exit 1

# Use FREESURFER_FSPYTHON if set in the environment, else if ../fspython subdir exists
# parallel to CMAKE_INSTALL_PREFIX, default to that relative path for FREESURFER_FSPYTHON.
# Then update environment - set PATH to contain FREESURFER_FSPYTHON/bin and force
# FREESURFER_HOME to FREESURFER_FPSYHTON in order to find model files, etc.

# set a variable to python dist in either the single or split install tree setup
export FREESURFER_HOME_FSPYTHON="${FREESURFER_HOME}"

func_setup_fspython_env()
{
   export FREESURFER_HOME_FSPYTHON="${FREESURFER_FSPYTHON}"
   export FREESURFER_HOME_FALLBACK="${FREESURFER_HOME}"
   export FREESURFER_HOME="${FREESURFER_FSPYTHON}"
   echo ${PATH} | grep "${FREESURFER_FSPYTHON}" > /dev/null
   if [ $? -ne 0 ]; then
      export PATH="${FREESURFER_FSPYTHON}/bin:${PATH}"
   fi
}
if [ ! -z "$FREESURFER_FSPYTHON" ]; then
   if [ -e "$FREESURFER_FSPYTHON" ]; then
      func_setup_fspython_env
   fi
elif [ -e "$FREESURFER_HOME/../fspython" ]; then
   ## no realpath on MacOS
   # export FREESURFER_FSPYTHON=`realpath "${FREESURFER_HOME}/../fspython"`
   export FREESURFER_FSPYTHON=`(cd "${FREESURFER_HOME}/../fspython" && pwd -P)`
   func_setup_fspython_env
fi

# point to freesurfer-installed packages and make sure that PYTHONPATH is entirely
# overwritten, since we don't want any user packages to interfere with things.
# Allow this to be overridden with the FS_LOCAL_PYTHONPATH env var
if [ -z "$FS_LOCAL_PYTHONPATH" ]; then
  export PYTHONPATH="${FREESURFER_HOME}/python/packages"
else
  export PYTHONPATH="${FS_LOCAL_PYTHONPATH}:${FREESURFER_HOME}/python/packages"
  echo "fspython local path #@# ======================================"
  echo fspython PYTHONPATH $PYTHONPATH  # echo for documentation
fi

# do a setenv FS_PYTHON_DEBUG 1 to turn this on for easier debugging
if [ ! -z "$FS_PYTHON_DEBUG" ]; then
  if [ ! $FS_PYTHON_DEBUG -eq 0 ]; then
    echo "Starting fspython #@# ======================================"
    echo ${FREESURFER_HOME}/python/bin/python3 
    printenv
  fi
fi

# futhermore, prevent local user packages from being accessed in fspython
# since we want a very isolated environment
export PYTHONNOUSERSITE=1
unset PYTHONUSERBASE

# don't check for pip upgrades, since it confuses people
export PIP_DISABLE_PIP_VERSION_CHECK=1

# run python
if [ -e "${FREESURFER_HOME}/python/bin/python3" ]; then
    exec ${FREESURFER_HOME}/python/bin/python3 "$@"
else
    echo "error: fspython has not been configured correctly - \$FREESURFER_HOME/python/bin/python3 does not exist"
    exit 1
fi