#!/usr/bin/env bash

PYTHON_VERSION=($PYTHON_VERSION) # 'system' checks the base image first, else installs 'latest'
PYTHON_INSTALL_PATH=($PYTHON_INSTALL_PATH)
PYTHON_SETUP_LINKS=($PYTHON_SETUP_LINKS)

#PYTHON_VERSION=${1:-"latest"} # 'system' checks the base image first, else installs 'latest'
#PYTHON_INSTALL_PATH=${2:-"/usr/local/python"}
export PIPX_HOME=${3:-"/usr/local/py-utils"}
USERNAME=${4:-"automatic"}
UPDATE_RC=${5:-"true"}
INSTALL_PYTHON_TOOLS=${6:-"true"}
USE_ORYX_IF_AVAILABLE=${7:-"true"}
OPTIMIZE_BUILD_FROM_SOURCE=${8-"false"}

DEFAULT_UTILS=("pylint" "flake8" "autopep8" "black" "yapf" "mypy" "pydocstyle" "pycodestyle" "bandit" "pipenv" "virtualenv")
PYTHON_SOURCE_GPG_KEYS="64E628F8D684696D B26995E310250568 2D347EA6AA65421D FB9921286F5E1540 3A5CA953F73C700D 04C367C218ADD4FF 0EDDC5F26A45C816 6AF053F07D9DC8D2 C9BE28DEE6DF025C 126EB563A74B06BF D9866941EA5BBD71 ED9D77D5"
GPG_KEY_SERVERS="keyserver hkp://keyserver.ubuntu.com:80
keyserver hkps://keys.openpgp.org
keyserver hkp://keyserver.pgp.com"

set -e

if [ "$(id -u)" -ne 0 ]; then
    echo -e 'Script must be run as root. Use sudo, su, or add "USER root" to your Dockerfile before running this script.'
    exit 1
fi

# Ensure that login shells get the correct path if the user updated the PATH using ENV.
rm -f /etc/profile.d/00-restore-env.sh
echo "export PATH=${PATH//$(sh -lc 'echo $PATH')/\$PATH}" > /etc/profile.d/00-restore-env.sh
chmod +x /etc/profile.d/00-restore-env.sh

# Determine the appropriate non-root user
if [ "${USERNAME}" = "auto" ] || [ "${USERNAME}" = "automatic" ]; then
    USERNAME=""
    POSSIBLE_USERS=("vscode" "node" "codespace" "$(awk -v val=1000 -F ":" '$3==val{print $1}' /etc/passwd)")
    for CURRENT_USER in ${POSSIBLE_USERS[@]}; do
        if id -u ${CURRENT_USER} > /dev/null 2>&1; then
            USERNAME=${CURRENT_USER}
            break
        fi
    done
    if [ "${USERNAME}" = "" ]; then
        USERNAME=root
    fi
elif [ "${USERNAME}" = "none" ] || ! id -u ${USERNAME} > /dev/null 2>&1; then
    USERNAME=root
fi

updaterc() {
    if [ "${UPDATE_RC}" = "true" ]; then
        echo "Updating /etc/bash.bashrc and /etc/zsh/zshrc..."
        if [[ "$(cat /etc/bash.bashrc)" != *"$1"* ]]; then
            echo -e "$1" >> /etc/bash.bashrc
        fi
        if [ -f "/etc/zsh/zshrc" ] && [[ "$(cat /etc/zsh/zshrc)" != *"$1"* ]]; then
            echo -e "$1" >> /etc/zsh/zshrc
        fi
    fi
}

# Get central common setting
get_common_setting() {
    if [ "${common_settings_file_loaded}" != "true" ]; then
        curl -sfL "https://aka.ms/vscode-dev-containers/script-library/settings.env" 2>/dev/null -o /tmp/vsdc-settings.env || echo "Could not download settings file. Skipping."
        common_settings_file_loaded=true
    fi
    if [ -f "/tmp/vsdc-settings.env" ]; then
        local multi_line=""
        if [ "$2" = "true" ]; then multi_line="-z"; fi
        local result="$(grep ${multi_line} -oP "$1=\"?\K[^\"]+" /tmp/vsdc-settings.env | tr -d '\0')"
        if [ ! -z "${result}" ]; then declare -g $1="${result}"; fi
    fi
    echo "$1=${!1}"
}

# Import the specified key in a variable name passed in as 
receive_gpg_keys() {
    get_common_setting $1
    local keys=${!1}
    get_common_setting GPG_KEY_SERVERS true
    local keyring_args=""
    if [ ! -z "$2" ]; then
        mkdir -p "$(dirname \"$2\")"
        keyring_args="--no-default-keyring --keyring $2"
    fi

    # Use a temporary locaiton for gpg keys to avoid polluting image
    export GNUPGHOME="/tmp/tmp-gnupg"
    mkdir -p ${GNUPGHOME}
    chmod 700 ${GNUPGHOME}
    echo -e "disable-ipv6\n${GPG_KEY_SERVERS}" > ${GNUPGHOME}/dirmngr.conf
    # GPG key download sometimes fails for some reason and retrying fixes it.
    local retry_count=0
    local gpg_ok="false"
    set +e
    until [ "${gpg_ok}" = "true" ] || [ "${retry_count}" -eq "5" ]; 
    do
        echo "(*) Downloading GPG key..."
        ( echo "${keys}" | xargs -n 1 gpg -q ${keyring_args} --recv-keys) 2>&1 && gpg_ok="true"
        if [ "${gpg_ok}" != "true" ]; then
            echo "(*) Failed getting key, retring in 10s..."
            (( retry_count++ ))
            sleep 10s
        fi
    done
    set -e
    if [ "${gpg_ok}" = "false" ]; then
        echo "(!) Failed to get gpg key."
        exit 1
    fi
}

# Figure out correct version of a three part version number is not passed
find_version_from_git_tags() {
    local variable_name=$1
    local requested_version=${!variable_name}
    if [ "${requested_version}" = "none" ]; then return; fi
    local repository=$2
    local prefix=${3:-"tags/v"}
    local separator=${4:-"."}
    local last_part_optional=${5:-"false"}    
    if [ "$(echo "${requested_version}" | grep -o "." | wc -l)" != "2" ]; then
        local escaped_separator=${separator//./\\.}
        local last_part
        if [ "${last_part_optional}" = "true" ]; then
            last_part="(${escaped_separator}[0-9]+)?"
        else
            last_part="${escaped_separator}[0-9]+"
        fi
        local regex="${prefix}\\K[0-9]+${escaped_separator}[0-9]+${last_part}$"
        local version_list="$(git ls-remote --tags ${repository} | grep -oP "${regex}" | tr -d ' ' | tr "${separator}" "." | sort -rV)"
        if [ "${requested_version}" = "latest" ] || [ "${requested_version}" = "current" ] || [ "${requested_version}" = "lts" ]; then
            declare -g ${variable_name}="$(echo "${version_list}" | head -n 1)"
        else
            set +e
            declare -g ${variable_name}="$(echo "${version_list}" | grep -E -m 1 "^${requested_version//./\\.}([\\.\\s]|$)")"
            set -e
        fi
    fi
    if [ -z "${!variable_name}" ] || ! echo "${version_list}" | grep "^${!variable_name//./\\.}$" > /dev/null 2>&1; then
        echo -e "Invalid ${variable_name} value: ${requested_version}\nValid values:\n${version_list}" >&2
        exit 1
    fi
    echo "${variable_name}=${!variable_name}"
}

# Use Oryx to install something using a partial version match
oryx_install() {
    local platform=$1
    local requested_version=$2
    local target_folder=${3:-none}
    local ldconfig_folder=${4:-none}
    echo "(*) Installing ${platform} ${requested_version} using Oryx..."
    check_packages jq
    # Soft match if full version not specified
    if [ "$(echo "${requested_version}" | grep -o "." | wc -l)" != "2" ]; then
        local version_list="$(oryx platforms --json | jq -r ".[] | select(.Name == \"${platform}\") | .Versions | sort | reverse | @tsv" | tr '\t' '\n' | grep -E '^[0-9]+\.[0-9]+\.[0-9]+$')"
        if [ "${requested_version}" = "latest" ] || [ "${requested_version}" = "current" ] || [ "${requested_version}" = "lts" ]; then
            requested_version="$(echo "${version_list}" | head -n 1)"
        else
            set +e
            requested_version="$(echo "${version_list}" | grep -E -m 1 "^${requested_version//./\\.}([\\.\\s]|$)")"
            set -e
        fi
        if [ -z "${requested_version}" ] || ! echo "${version_list}" | grep "^${requested_version//./\\.}$" > /dev/null 2>&1; then
            echo -e "(!) Oryx does not support ${platform} version $2\nValid values:\n${version_list}" >&2
            return 1
        fi
        echo "(*) Using ${requested_version} in place of $2."
    fi

    export ORYX_ENV_TYPE=vsonline-present ORYX_PREFER_USER_INSTALLED_SDKS=true ENABLE_DYNAMIC_INSTALL=true DYNAMIC_INSTALL_ROOT_DIR=/opt
    oryx prep --skip-detection --platforms-and-versions "${platform}=${requested_version}"
    local opt_folder="/opt/${platform}/${requested_version}"
    if [ "${target_folder}" != "none" ] && [ "${target_folder}" != "${opt_folder}" ]; then
        ln -s "${opt_folder}" "${target_folder}"
    fi
    # Update library path add to conf
    if [ "${ldconfig_folder}" != "none" ]; then
        echo "/opt/${platform}/${requested_version}/lib" >> "/etc/ld.so.conf.d/${platform}.conf"
        ldconfig
    fi
}

# Function to run apt-get if needed
apt_get_update_if_needed()
{
    if [ ! -d "/var/lib/apt/lists" ] || [ "$(ls /var/lib/apt/lists/ | wc -l)" = "0" ]; then
        echo "Running apt-get update..."
        apt-get update
    else
        echo "Skipping apt-get update."
    fi
}

# Checks if packages are installed and installs them if not
check_packages() {
    if ! dpkg -s "$@" > /dev/null 2>&1; then
        apt_get_update_if_needed
        apt-get -y install --no-install-recommends "$@"
    fi
}

install_from_source() {
    if [ -d "${PYTHON_INSTALL_PATH}" ]; then
        echo "(!) Path ${PYTHON_INSTALL_PATH} already exists. Remove this existing path or select a different one."
        exit 1
    fi
    echo "(*) Building Python ${PYTHON_VERSION} from source..."
    # Install prereqs if missing
    check_packages curl ca-certificates gnupg2 tar make gcc libssl-dev zlib1g-dev libncurses5-dev \
                libbz2-dev libreadline-dev libxml2-dev xz-utils libgdbm-dev tk-dev dirmngr \
                libxmlsec1-dev libsqlite3-dev libffi-dev liblzma-dev uuid-dev 
    if ! type git > /dev/null 2>&1; then
        apt_get_update_if_needed
        apt-get -y install --no-install-recommends git
    fi

    # Find version using soft match
    find_version_from_git_tags PYTHON_VERSION "https://github.com/python/cpython"

    # Download tgz of source
    mkdir -p /tmp/python-src "${PYTHON_INSTALL_PATH}"
    cd /tmp/python-src
    local tgz_filename="Python-${PYTHON_VERSION}.tgz"
    local tgz_url="https://www.python.org/ftp/python/${PYTHON_VERSION}/${tgz_filename}"
    echo "Downloading ${tgz_filename}..."
    curl -sSL -o "/tmp/python-src/${tgz_filename}" "${tgz_url}"

    # Verify signature
    receive_gpg_keys PYTHON_SOURCE_GPG_KEYS
    echo "Downloading ${tgz_filename}.asc..."
    curl -sSL -o "/tmp/python-src/${tgz_filename}.asc" "${tgz_url}.asc"
    gpg --verify "${tgz_filename}.asc"

    # Update min protocol for testing only - https://bugs.python.org/issue41561
    cp /etc/ssl/openssl.cnf /tmp/python-src/
    sed -i -E 's/MinProtocol[=\ ]+.*/MinProtocol = TLSv1.0/g' /tmp/python-src/openssl.cnf
    export OPENSSL_CONF=/tmp/python-src/openssl.cnf

    # Untar and build
    tar -xzf "/tmp/python-src/${tgz_filename}" -C "/tmp/python-src" --strip-components=1
    local config_args=""
    if [ "${OPTIMIZE_BUILD_FROM_SOURCE}" = "true" ]; then
        config_args="--enable-optimizations"
    fi
    ./configure --prefix="${PYTHON_INSTALL_PATH}" --with-ensurepip=install ${config_args}
    make -j 8
    make install
    cd /tmp
    rm -rf /tmp/python-src ${GNUPGHOME} /tmp/vscdc-settings.env
    chown -R ${USERNAME} "${PYTHON_INSTALL_PATH}"
    ln -s ${PYTHON_INSTALL_PATH}/bin/python3 ${PYTHON_INSTALL_PATH}/bin/python
    ln -s ${PYTHON_INSTALL_PATH}/bin/pip3 ${PYTHON_INSTALL_PATH}/bin/pip
    ln -s ${PYTHON_INSTALL_PATH}/bin/idle3 ${PYTHON_INSTALL_PATH}/bin/idle
    ln -s ${PYTHON_INSTALL_PATH}/bin/pydoc3 ${PYTHON_INSTALL_PATH}/bin/pydoc
    ln -s ${PYTHON_INSTALL_PATH}/bin/python3-config ${PYTHON_INSTALL_PATH}/bin/python-config
}

install_using_oryx() {
    if [ -d "${PYTHON_INSTALL_PATH}" ]; then
        echo "(!) Path ${PYTHON_INSTALL_PATH} already exists. Remove this existing path or select a different one."
        exit 1
    fi
    oryx_install "python" "${PYTHON_VERSION}" "${PYTHON_INSTALL_PATH}" "lib" || return 1
    ln -s ${PYTHON_INSTALL_PATH}/bin/idle3 ${PYTHON_INSTALL_PATH}/bin/idle
    ln -s ${PYTHON_INSTALL_PATH}/bin/pydoc3 ${PYTHON_INSTALL_PATH}/bin/pydoc
    ln -s ${PYTHON_INSTALL_PATH}/bin/python3-config ${PYTHON_INSTALL_PATH}/bin/python-config
}

# Ensure apt is in non-interactive to avoid prompts
export DEBIAN_FRONTEND=noninteractive

# General requirements
check_packages curl ca-certificates gnupg2 tar make gcc libssl-dev zlib1g-dev libncurses5-dev \
            libbz2-dev libreadline-dev libxml2-dev xz-utils libgdbm-dev tk-dev dirmngr \
            libxmlsec1-dev libsqlite3-dev libffi-dev liblzma-dev uuid-dev 


# Install python from source if needed
if [ "${PYTHON_VERSION}" != "none" ]; then
    # If the os-provided versions are "good enough", detect that and bail out.
    if [ ${PYTHON_VERSION} = "os-provided" ] || [ ${PYTHON_VERSION} = "system" ]; then
        check_packages python3 python3-doc python3-pip python3-venv python3-dev python3-tk
        PYTHON_INSTALL_PATH="/usr"
        should_install_from_source=false
    elif [ "$(dpkg --print-architecture)" = "amd64" ] && [ "${USE_ORYX_IF_AVAILABLE}" = "true" ] && type oryx > /dev/null 2>&1; then
        install_using_oryx || should_install_from_source=true
    else
        should_install_from_source=true
    fi
    if [ "${should_install_from_source}" = "true" ]; then
        install_from_source
    fi
    updaterc "if [[ \"\${PATH}\" != *\"${PYTHON_INSTALL_PATH}/bin\"* ]]; then export PATH=${PYTHON_INSTALL_PATH}/bin:\${PATH}; fi"
fi

# If not installing python tools, exit
if [ "${INSTALL_PYTHON_TOOLS}" != "true" ]; then
    echo "Done!"
    exit 0
fi

export PIPX_BIN_DIR="${PIPX_HOME}/bin"
export PATH="${PYTHON_INSTALL_PATH}/bin:${PIPX_BIN_DIR}:${PATH}"

# Create pipx group, dir, and set sticky bit
if ! cat /etc/group | grep -e "^pipx:" > /dev/null 2>&1; then
    groupadd -r pipx
fi
usermod -a -G pipx ${USERNAME}
umask 0002
mkdir -p ${PIPX_BIN_DIR}
chown :pipx ${PIPX_HOME} ${PIPX_BIN_DIR}
chmod g+s ${PIPX_HOME} ${PIPX_BIN_DIR}

# Update pip if not using os provided python
if [ ${PYTHON_VERSION} != "os-provided" ] && [ ${PYTHON_VERSION} != "system" ]; then
    echo "Updating pip..."
    ${PYTHON_INSTALL_PATH}/bin/python3 -m pip install --no-cache-dir --upgrade pip
fi

# Install tools
echo "Installing Python tools..."
export PYTHONUSERBASE=/tmp/pip-tmp
export PIP_CACHE_DIR=/tmp/pip-tmp/cache
pipx_path=""
if ! type pipx > /dev/null 2>&1; then
    pip3 install --disable-pip-version-check --no-cache-dir --user pipx 2>&1
    /tmp/pip-tmp/bin/pipx install --pip-args=--no-cache-dir pipx
    pipx_path="/tmp/pip-tmp/bin/"
fi
for util in ${DEFAULT_UTILS[@]}; do
    if ! type ${util} > /dev/null 2>&1; then
        ${pipx_path}pipx install --system-site-packages --pip-args '--no-cache-dir --force-reinstall' ${util}
    else
        echo "${util} already installed. Skipping."
    fi
done
rm -rf /tmp/pip-tmp

echo "(*) Updating RC files."

updaterc "$(cat << EOF
export PIPX_HOME="${PIPX_HOME}"
export PIPX_BIN_DIR="${PIPX_BIN_DIR}"
if [[ "\${PATH}" != *"\${PIPX_BIN_DIR}"* ]]; then export PATH="\${PATH}:\${PIPX_BIN_DIR}"; fi
EOF
)"

echo "(*) About to do final Python setup."

INSTALLED_PYTHON_VERSION=$(${PYTHON_INSTALL_PATH}/bin/python --version 2>&1 | grep -Po '(?<=Python )(.+)')
if [[ ! -z "$INSTALLED_PYTHON_VERSION" ]] ; then
    echo "(*) Installed Python version is ${INSTALLED_PYTHON_VERSION}"
    PYTHON_MAJOR_VERSION=$(echo ${INSTALLED_PYTHON_VERSION} | cut -f1 -d'.')
    PYTHON_MINOR_VERSION=$(echo ${INSTALLED_PYTHON_VERSION} | cut -f2 -d'.')

    if [ "${PYTHON_SETUP_LINKS}" = "true" ]; then
        mkdir -p /opt/python
        ln -s /usr/share/python /opt/python/${INSTALLED_PYTHON_VERSION}
        ln -s /opt/python/${INSTALLED_PYTHON_VERSION} /opt/python/${PYTHON_MAJOR_VERSION}.${PYTHON_MINOR_VERSION}
        ln -s /opt/python/${PYTHON_MAJOR_VERSION}.${PYTHON_MINOR_VERSION} /opt/python/${PYTHON_MAJOR_VERSION}
        ln -s /opt/python/${INSTALLED_PYTHON_VERSION} /opt/python/latest
        ln -s /opt/python/${INSTALLED_PYTHON_VERSION} /opt/python/stable

        mkdir -p /home/${USERNAME}/.python
        ln -s /opt/python/${INSTALLED_PYTHON_VERSION} /home/${USERNAME}/.python/current
    fi
else
    echo "(*) Failed to get installed Python version."
fi

echo "(*) Done with Python feature."