#!/usr/bin/env bash

declare -a py_versions=( \
      "2" \
      "3" \
      "3.5" \
      "3.6" \
      "3.7" \
      "3.8" \
    )

if [ -f /etc/os-release ]; then
  source /etc/os-release
fi

if which apt > /dev/null; then
  apt update -qq
  apt -y install \
    make \
    build-essential \
    libssl-dev \
    zlib1g-dev \
    libbz2-dev \
    libreadline-dev \
    libsqlite3-dev \
    wget \
    curl \
    llvm \
    libncurses5-dev \
    libncursesw5-dev \
    xz-utils \
    tk-dev \
    libffi-dev \
    liblzma-dev \
    python-openssl \
    git \
    graphviz \
    libxslt1-dev
fi

if which yum > /dev/null; then
  yum -y groupinstall "Development Tools"
  yum -y install \
    bzip2 \
    bzip2-devel \
    git \
    graphviz \
    libffi-devel \
    libxslt-devel \
    openldap-devel \
    openssl-devel \
    readline-devel \
    sqlite \
    sqlite-devel \
    xz \
    xz-devel \
    zlib-devel
fi

if [ ! -d ${HOME}/.pyenv ]; then
  git clone https://github.com/pyenv/pyenv.git ${HOME}/.pyenv
fi

cd ${HOME}/.pyenv
git pull
cd ~-

if [ ! -f ${HOME}/.pyenv/bin/get-pip.py ]; then
  wget -O ${HOME}/.pyenv/bin/get-pip.py https://bootstrap.pypa.io/get-pip.py
fi

export PYENV_ROOT="${HOME}/.pyenv"
export PATH="${PYENV_ROOT}/bin:${PATH}"

if command -v pyenv 1>/dev/null 2>&1; then eval "$(pyenv init -)"; fi

${PYENV_ROOT}/plugins/python-build/install.sh

for short_ver in "${py_versions[@]}"; do
  echo "Checking Python ${short_ver}";
  if [ -z "${short_ver##*.*}" ]; then
    export long_ver=$(pyenv install -l | \
      grep -Po "(?<=\s)[0-9\.]+$" | \
      grep "${short_ver}." | \
      tail -n1);
    echo "Installing /usr/local/bin/python${short_ver} (${long_ver}) via pyenv."
    if [ "${ID}" == "debian" ]; then
      CFLAGS=-I/usr/include/openssl LDFLAGS=-L/usr/lib python-build ${long_ver} /usr/local/
    else
      CFLAGS=-I/usr/include/openssl LDFLAGS=-L/usr/lib64 python-build ${long_ver} /usr/local/
    fi
    echo "Updating pip, setuptools, and virtualenv in /usr/local/bin/python${short_ver}"
    /usr/local/bin/python${short_ver} ${HOME}/.pyenv/bin/get-pip.py
    /usr/local/bin/python${short_ver} -m pip install -U pip setuptools virtualenv
  else
    if [ -f /usr/bin/python${short_ver} ]; then
      echo "Updating pip, setuptools, and virtualenv in /usr/bin/python${short_ver}"
      /usr/bin/python${short_ver} ${HOME}/.pyenv/bin/get-pip.py
      /usr/bin/python${short_ver} -m pip install -U pip setuptools virtualenv
    fi
  fi
done