# VIRTUAL ENVIRONMENT MANAGER
# creates a new environment if it does not exist, then activates it
local venv_dir="${1:-.venv}"

if [[ ! -d "$venv_dir" ]]; then
    echo "initialising new virtual environment in ./$venv_dir..."
    python3 -m venv "$venv_dir"
fi

# ACTIVATE ENVIRONMENT
# source the activation script into the current shell session
if [[ -f "$venv_dir/bin/activate" ]]; then
    source "$venv_dir/bin/activate"
    echo "activated $venv_dir"
else
    echo "error: activation script not found in ./$venv_dir"
    return 1
fi