#!/usr/bin/env bash
#-------------------------------------------------------------------------------------------------------------
# Copyright (c) Microsoft Corporation. All rights reserved.
# Licensed under the MIT License. See https://go.microsoft.com/fwlink/?linkid=2090316 for license information.
#-------------------------------------------------------------------------------------------------------------
#
# Docs: https://github.com/microsoft/vscode-dev-containers/blob/main/script-library/docs/kubectl-helm.md
# Maintainer: The VS Code and Codespaces Teams

set -e

# Clean up
rm -rf /var/lib/apt/lists/*

KUBECTL_VERSION="${VERSION:-"latest"}"
HELM_VERSION="${HELM:-"latest"}"
MINIKUBE_VERSION="${MINIKUBE:-"latest"}" # latest is also valid

KUBECTL_SHA256="${KUBECTL_SHA256:-"automatic"}"
HELM_SHA256="${HELM_SHA256:-"automatic"}"
MINIKUBE_SHA256="${MINIKUBE_SHA256:-"automatic"}"
USERNAME="${USERNAME:-"${_REMOTE_USER:-"automatic"}"}"

HELM_GPG_KEYS_URI="https://raw.githubusercontent.com/helm/helm/main/KEYS"

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

# 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

USERHOME="/home/$USERNAME"
if [ "$USERNAME" = "root" ]; then
    USERHOME="/root"
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}
    requested_version="${requested_version#v}"
    if [ "${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 semver logic to decrement a version number then look for the closest match
find_prev_version_from_git_tags() {
    local variable_name=$1
    local current_version=${!variable_name}
    local repository=$2
    # Normally a "v" is used before the version number, but support alternate cases
    local prefix=${3:-"tags/v"}
    # Some repositories use "_" instead of "." for version number part separation, support that
    local separator=${4:-"."}
    # Some tools release versions that omit the last digit (e.g. go)
    local last_part_optional=${5:-"false"}
    # Some repositories may have tags that include a suffix (e.g. actions/node-versions)
    local version_suffix_regex=$6
    # Try one break fix version number less if we get a failure. Use "set +e" since "set -e" can cause failures in valid scenarios.
    set +e
        major="$(echo "${current_version}" | grep -oE '^[0-9]+' || echo '')"
        minor="$(echo "${current_version}" | grep -oP '^[0-9]+\.\K[0-9]+' || echo '')"
        breakfix="$(echo "${current_version}" | grep -oP '^[0-9]+\.[0-9]+\.\K[0-9]+' 2>/dev/null || echo '')"

        if [ "${minor}" = "0" ] && [ "${breakfix}" = "0" ]; then
            ((major=major-1))
            declare -g ${variable_name}="${major}"
            # Look for latest version from previous major release
            find_version_from_git_tags "${variable_name}" "${repository}" "${prefix}" "${separator}" "${last_part_optional}"
        # Handle situations like Go's odd version pattern where "0" releases omit the last part
        elif [ "${breakfix}" = "" ] || [ "${breakfix}" = "0" ]; then
            ((minor=minor-1))
            declare -g ${variable_name}="${major}.${minor}"
            # Look for latest version from previous minor release
            find_version_from_git_tags "${variable_name}" "${repository}" "${prefix}" "${separator}" "${last_part_optional}"
        else
            ((breakfix=breakfix-1))
            if [ "${breakfix}" = "0" ] && [ "${last_part_optional}" = "true" ]; then
                declare -g ${variable_name}="${major}.${minor}"
            else 
                declare -g ${variable_name}="${major}.${minor}.${breakfix}"
            fi
        fi
    set -e
}

apt_get_update()
{
    if [ "$(find /var/lib/apt/lists/* | wc -l)" = "0" ]; then
        echo "Running apt-get update..."
        apt-get update -y
    fi
}

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

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

# Install dependencies
check_packages curl ca-certificates coreutils gnupg2 dirmngr bash-completion
if ! type git > /dev/null 2>&1; then
    check_packages git
fi

architecture="$(uname -m)"
case $architecture in
    x86_64) architecture="amd64";;
    aarch64 | armv8*) architecture="arm64";;
    aarch32 | armv7* | armvhf*) architecture="arm";;
    i?86) architecture="386";;
    *) echo "(!) Architecture $architecture unsupported"; exit 1 ;;
esac

if [ ${KUBECTL_VERSION} != "none" ]; then
    # Install the kubectl, verify checksum
    echo "Downloading kubectl..."
    if [ "${KUBECTL_VERSION}" = "latest" ] || [ "${KUBECTL_VERSION}" = "lts" ] || [ "${KUBECTL_VERSION}" = "current" ] || [ "${KUBECTL_VERSION}" = "stable" ]; then
        KUBECTL_VERSION="$(curl -sSL https://dl.k8s.io/release/stable.txt)"
    else
        find_version_from_git_tags KUBECTL_VERSION https://github.com/kubernetes/kubernetes
    fi
    if [ "${KUBECTL_VERSION::1}" != 'v' ]; then
        KUBECTL_VERSION="v${KUBECTL_VERSION}"
    fi
    curl -sSL -o /usr/local/bin/kubectl "https://dl.k8s.io/release/${KUBECTL_VERSION}/bin/linux/${architecture}/kubectl"
    chmod 0755 /usr/local/bin/kubectl
    if [ "$KUBECTL_SHA256" = "automatic" ]; then
        KUBECTL_SHA256="$(curl -sSL "https://dl.k8s.io/${KUBECTL_VERSION}/bin/linux/${architecture}/kubectl.sha256")"
    fi
    ([ "${KUBECTL_SHA256}" = "dev-mode" ] || (echo "${KUBECTL_SHA256} */usr/local/bin/kubectl" | sha256sum -c -))
    if ! type kubectl > /dev/null 2>&1; then
        echo '(!) kubectl installation failed!'
        exit 1
    fi

    # kubectl bash completion
    kubectl completion bash > /etc/bash_completion.d/kubectl

    # kubectl zsh completion
    if [ -e "${USERHOME}/.oh-my-zsh" ]; then
        mkdir -p "${USERHOME}/.oh-my-zsh/completions"
        kubectl completion zsh > "${USERHOME}/.oh-my-zsh/completions/_kubectl"
        chown -R "${USERNAME}" "${USERHOME}/.oh-my-zsh"
    fi
fi

# Function to fetch the version released prior to the latest version
get_previous_version() {
    local url=$1
    local repo_url=$2
    local variable_name=$3
    prev_version=${!variable_name#v}
    
    output=$(curl -s "$repo_url");

    check_packages jq

    message=$(echo "$output" | jq -r '.message')
    if [[ $message == "API rate limit exceeded"* ]]; then
        echo -e "\nAn attempt to find latest version using GitHub Api Failed... \nReason: ${message}"
        echo -e "\nAttempting to find latest version using GitHub tags."
        find_prev_version_from_git_tags prev_version "$url" "tags/v"
        declare -g ${variable_name}="v${prev_version}"
    else 
        echo -e "\nAttempting to find latest version using GitHub Api."
        version=$(echo "$output" | jq -r '.tag_name')
        declare -g ${variable_name}="${version}"
    fi  
    echo "${variable_name}=${!variable_name}"
}

get_github_api_repo_url() {
    local url=$1
    echo "${url/https:\/\/github.com/https:\/\/api.github.com\/repos}/releases/latest"
}

get_helm() {
    HELM_VERSION=$1
    helm_filename="helm-${HELM_VERSION}-linux-${architecture}.tar.gz"
    tmp_helm_filename="/tmp/helm/${helm_filename}"
    curl -sSL "https://get.helm.sh/${helm_filename}" -o "${tmp_helm_filename}"
    curl -sSL "https://github.com/helm/helm/releases/download/${HELM_VERSION}/${helm_filename}.asc" -o "${tmp_helm_filename}.asc"
}

# Get the list of GPG key servers that are reachable
get_gpg_key_servers() {
    declare -A keyservers_curl_map=(
        ["hkp://keyserver.ubuntu.com"]="http://keyserver.ubuntu.com:11371"
        ["hkp://keyserver.ubuntu.com:80"]="http://keyserver.ubuntu.com"
        ["hkps://keys.openpgp.org"]="https://keys.openpgp.org"
        ["hkp://keyserver.pgp.com"]="http://keyserver.pgp.com:11371"
    )

    local curl_args=""
    local keyserver_reachable=false  # Flag to indicate if any keyserver is reachable

    if [ ! -z "${KEYSERVER_PROXY}" ]; then
        curl_args="--proxy ${KEYSERVER_PROXY}"
    fi

    for keyserver in "${!keyservers_curl_map[@]}"; do
        local keyserver_curl_url="${keyservers_curl_map[${keyserver}]}"
        if curl -s ${curl_args} --max-time 5 ${keyserver_curl_url} > /dev/null; then
            echo "keyserver ${keyserver}"
            keyserver_reachable=true
        else
            echo "(*) Keyserver ${keyserver} is not reachable." >&2
        fi
    done

    if ! $keyserver_reachable; then
        echo "(!) No keyserver is reachable." >&2
        exit 1
    fi
}

if [ ${HELM_VERSION} != "none" ]; then
    # Install Helm, verify signature and checksum
    echo "Downloading Helm..."
    helm_url="https://github.com/helm/helm"
    find_version_from_git_tags HELM_VERSION "${helm_url}"
    if [ "${HELM_VERSION::1}" != 'v' ]; then
        HELM_VERSION="v${HELM_VERSION}"
    fi
    mkdir -p /tmp/helm
    get_helm "${HELM_VERSION}"
    if grep -q "BlobNotFound" "${tmp_helm_filename}"; then
        echo -e "\n(!) Failed to fetch the latest artifacts for helm ${HELM_VERSION}..."
        repo_url=$(get_github_api_repo_url "${helm_url}")
        get_previous_version "${helm_url}" "${repo_url}" HELM_VERSION
        echo -e "\nAttempting to install ${HELM_VERSION}"
        get_helm "${HELM_VERSION}"
    fi
    export GNUPGHOME="/tmp/helm/gnupg"
    mkdir -p "${GNUPGHOME}"
    chmod 700 ${GNUPGHOME}
    curl -sSL "${HELM_GPG_KEYS_URI}" -o /tmp/helm/KEYS
    echo -e "disable-ipv6\n$(get_gpg_key_servers)" > ${GNUPGHOME}/dirmngr.conf
    gpg -q --import "/tmp/helm/KEYS"
    if ! gpg --verify "${tmp_helm_filename}.asc" > ${GNUPGHOME}/verify.log 2>&1; then
        echo "Verification failed!"
        cat /tmp/helm/gnupg/verify.log
        exit 1
    fi

    if [ "${HELM_SHA256}" = "automatic" ]; then
        curl -sSL "https://get.helm.sh/${helm_filename}.sha256" -o "${tmp_helm_filename}.sha256"
        curl -sSL "https://github.com/helm/helm/releases/download/${HELM_VERSION}/${helm_filename}.sha256.asc" -o "${tmp_helm_filename}.sha256.asc"
        if ! gpg --verify "${tmp_helm_filename}.sha256.asc" > /tmp/helm/gnupg/verify.log 2>&1; then
            echo "Verification failed!"
            cat /tmp/helm/gnupg/verify.log
            exit 1
        fi
        HELM_SHA256="$(cat "${tmp_helm_filename}.sha256")"
    fi

    ([ "${HELM_SHA256}" = "dev-mode" ] || (echo "${HELM_SHA256} *${tmp_helm_filename}" | sha256sum -c -))
    tar xf "${tmp_helm_filename}" -C /tmp/helm
    mv -f "/tmp/helm/linux-${architecture}/helm" /usr/local/bin/
    chmod 0755 /usr/local/bin/helm
    rm -rf /tmp/helm
    if ! type helm > /dev/null 2>&1; then
        echo '(!) Helm installation failed!'
        exit 1
    fi

    # helm bash completion
    helm completion bash > /etc/bash_completion.d/helm

    # helm zsh completion
    if [ -e "${USERHOME}/.oh-my-zsh" ]; then
        mkdir -p "${USERHOME}/.oh-my-zsh/completions"
        helm completion zsh > "${USERHOME}/.oh-my-zsh/completions/_helm"
        chown -R "${USERNAME}" "${USERHOME}/.oh-my-zsh"
    fi
fi

# Install Minikube, verify checksum
if [ "${MINIKUBE_VERSION}" != "none" ]; then
    echo "Downloading minikube..."
    if [ "${MINIKUBE_VERSION}" = "latest" ] || [ "${MINIKUBE_VERSION}" = "lts" ] || [ "${MINIKUBE_VERSION}" = "current" ] || [ "${MINIKUBE_VERSION}" = "stable" ]; then
        MINIKUBE_VERSION="latest"
    else
        find_version_from_git_tags MINIKUBE_VERSION https://github.com/kubernetes/minikube
        if [ "${MINIKUBE_VERSION::1}" != "v" ]; then
            MINIKUBE_VERSION="v${MINIKUBE_VERSION}"
        fi
    fi
    # latest is also valid in the download URLs 
    curl -sSL -o /usr/local/bin/minikube "https://storage.googleapis.com/minikube/releases/${MINIKUBE_VERSION}/minikube-linux-${architecture}"    
    chmod 0755 /usr/local/bin/minikube
    if [ "$MINIKUBE_SHA256" = "automatic" ]; then
        MINIKUBE_SHA256="$(curl -sSL "https://storage.googleapis.com/minikube/releases/${MINIKUBE_VERSION}/minikube-linux-${architecture}.sha256")"
    fi
    ([ "${MINIKUBE_SHA256}" = "dev-mode" ] || (echo "${MINIKUBE_SHA256} */usr/local/bin/minikube" | sha256sum -c -))
    if ! type minikube > /dev/null 2>&1; then
        echo '(!) minikube installation failed!'
        exit 1
    fi
    # Create minkube folder with correct privs in case a volume is mounted here
    mkdir -p "${USERHOME}/.minikube"
    chown -R $USERNAME "${USERHOME}/.minikube"
    chmod -R u+wrx "${USERHOME}/.minikube"
fi

if ! type docker > /dev/null 2>&1; then
    echo -e '\n(*) Warning: The docker command was not found.\n\nYou can use one of the following scripts to install it:\n\nhttps://github.com/microsoft/vscode-dev-containers/blob/main/script-library/docs/docker-in-docker.md\n\nor\n\nhttps://github.com/microsoft/vscode-dev-containers/blob/main/script-library/docs/docker.md'
fi

# Clean up
rm -rf /var/lib/apt/lists/*

echo -e "\nDone!"
