setup_helpers.sh

###############################################################################
# Utility functions
###############################################################################
VERSION_PARSER='use version; my ($version) = $_ =~ /([0-9]+([.][0-9]+)+)/; if (version->parse($version) lt version->parse($min)) { exit 1 };'
CURL_RETRY_OPTIONS='--connect-timeout 5 --max-time 10 --retry 5 --retry-delay 0 --retry-max-time 60'

function print_kit_header () {
    cat << EOM
###
### Enterprise Config
###

EOM
}

function read_password () {
    local HOST=$1
    local TEST_FILE=$2
    local USER=$3
    local RETURN_PASSWORD="$4"
    echo -n 'Please enter your GitHub Enterprise password and press [ENTER]: '
    read -s PASSWORD
    echo ''
    if ! has_valid_credentials $TEST_FILE $USER "$PASSWORD"; then
        error_exit "Could not connect to $HOST. Wrong username or password? If you have enabled 2FA then you need to use a token instead of a password."
    fi

    eval $RETURN_PASSWORD="'$PASSWORD'"
}

function store_token () {
    local HOST=$1
    local USER=$2
    local TOKEN="$3"
    local HELPER=$(credential_helper)
    printf "protocol=https\nhost=$HOST\n\n" | git credential-$HELPER erase
    printf "protocol=https\nhost=$HOST\nusername=$USER\npassword=${TOKEN/\%/\%\%}\n\n" | git credential-$HELPER store
}

function get_credentials () {
    local HOST=$1
    local USER=$2
    printf "protocol=https\nhost=$HOST\nusername=$USER\n\n" \
        | git credential-$(credential_helper) get \
        | perl -0pe 's/.*password=//s'
}

function has_command() {
    which $1 > /dev/null 2>&1
}

function has_valid_credentials () {
    local TEST_FILE=$1
    local USER=$2
    local PASSWORD="$3"
    curl $CURL_RETRY_OPTIONS --silent --fail --user "$USER:$PASSWORD" $TEST_FILE > /dev/null
}

function is_ghe_token () {
    echo "$1" | perl -ne 'exit 1 if not /\b[0-9a-f]{40}\b/'
}

function is_ghe_token_with_user_email_scope () {
    local HOST=$1
    local USER=$2
    local PASSWORD="$3"
    curl $CURL_RETRY_OPTIONS --silent --fail --user "$USER:$PASSWORD" https://$HOST/api/v3/user -I \
        | grep '^X-OAuth-Scopes:.*user:email.*' > /dev/null
}

function get_ghe_name () {
    local HOST=$1
    local USER=$2
    local PASSWORD="$3"
    curl $CURL_RETRY_OPTIONS --silent --fail --user "$USER:$PASSWORD" https://$HOST/api/v3/user \
        | perl -ne 'print "$1" if m%^\s*"name":\s*"(.*)"[,]?$%i'
}

function get_ghe_email () {
    local HOST=$1
    local USER=$2
    local PASSWORD="$3"
    curl $CURL_RETRY_OPTIONS --silent --fail --user "$USER:$PASSWORD" https://$HOST/api/v3/user/emails \
        | perl -ne 'print "$1\n" if m%^\s*"email":\s*"(.*\@yourcompany\.com)"[,]?$%i' \
        | head -n 1
}

function create_ghe_token () {
    local HOST=$1
    local USER=$2
    local PASSWORD="$3"
    local CLIENT_ID=$4
    local CLIENT_SECRET=$5
    local COMPUTER_NAME=$(hostname)
    local FINGERPRINT=$(calc_md5sum "$COMPUTER_NAME")
    local TOKEN_URL="https://$HOST/api/v3/authorizations/clients/$CLIENT_ID/$FINGERPRINT"

    # Query all tokens of the current user and try to find a token for the
    # current machine
    #
    # ATTENTION: This only queries up to 100 tokens. If an account is used on
    # more machines then we need to implement proper pagination.
    # c.f. https://developer.github.com/v3/guides/traversing-with-pagination/
    TOKEN_ID=$(curl $CURL_RETRY_OPTIONS --silent --fail --user "$USER:$PASSWORD" "https://$HOST/api/v3/authorizations?per_page=100" \
        | perl -pe 'chomp' \
        | perl -sne 'print "$1\n" if m%^.*{\s*"id"\:\s+(\d+).*?"fingerprint":\s*"$fingerprint".*%i' -- -fingerprint=$FINGERPRINT \
    )

    # If a token for the current machine was found then delete it
    if [ -n "$TOKEN_ID" ]; then
        curl $CURL_RETRY_OPTIONS --silent --fail --user "$USER:$PASSWORD" -X DELETE https://$HOST/api/v3/authorizations/$TOKEN_ID
    fi

    # Request a new token
    curl $CURL_RETRY_OPTIONS --silent --fail --user "$USER:$PASSWORD" -X PUT \
            --data "{\"scopes\":[\"repo\",\"gist\",\"user:email\"], \"note\":\"Enterprise Config ($COMPUTER_NAME)\", \"client_secret\":\"$CLIENT_SECRET\"}" \
            $TOKEN_URL \
        | perl -ne 'print "$1\n" if m%^\s*"token":\s*"([0-9a-f]{40})"[,]?$%i' \
        | head -n 1
}

function calc_md5sum () {
    local STRING=$1
    if has_command md5sum; then
        printf '%s' "$STRING" | md5sum | cut -d ' ' -f 1
    elif has_command md5; then
        md5 -qs "$STRING"
    else
        error_exit 'No MD5 tool found.'
    fi
}

function check_sha256 () {
    local SHA256=$1
    local FILEPATH=$2
    if has_command sha256sum; then
        echo "$SHA256  $FILEPATH" | sha256sum --status --check -
    elif has_command shasum; then
        echo "$SHA256  $FILEPATH" | shasum --status --portable --algorithm 256 --check -
    else
        error_exit 'No SHA256 tool found.'
    fi
}

function fetch_git_lfs() {
    local VERSION=$1
    local SRC_FILE=$2
    local GIT_LFS_SHA256=$3

    local SRC_URL=https://github.com/github/git-lfs/releases/download/v$VERSION/$SRC_FILE

    # Deliberately no-local so that it can be accessed by caller
    DOWNLOAD_FILE=$(mktemp -t gitlfs_install_${VERSION}_XXXXXXX)

    echo "Downloading Git LFS version $VERSION"
    if ! curl --location --fail --output "$DOWNLOAD_FILE" "$SRC_URL"; then
        rm -f "$DOWNLOAD_FILE"
        error_exit "Git LFS download failed ($SRC_URL)."
    fi

    if ! check_sha256 $GIT_LFS_SHA256 "$DOWNLOAD_FILE"; then
        rm -f "$DOWNLOAD_FILE"
        error_exit "Git LFS does not have expected contents ($SRC_URL)." >&2
    fi
}

function git_version_greater_equal () {
    local VERSION=$1
    git --version | perl -pse "$VERSION_PARSER" -- -min=$VERSION > /dev/null
}

function check_git () {
    if ! git_version_greater_equal $MINIMUM_REQUIRED_GIT_VERSION ; then
        error_exit "Git version $MINIMUM_REQUIRED_GIT_VERSION is the minimum requirement (you have $(git --version))."
    elif ! git_version_greater_equal $MINIMUM_ADVISED_GIT_VERSION ; then
        warning "Your Git version is outdated. Please run 'git $KIT_ID upgrade'!"
    fi
}

function git_lfs_error_exit () {
    read -r -d '\0' MESSAGE <<EOM
Git LFS is not available or does not meet the minimum version ($MINIMUM_GIT_LFS_VERSION).
Automated install/update is not supported on your platform. Please see
the instructions on https://git-lfs.github.com/ for manual setup.\0
EOM
    error_exit "$MESSAGE"
}

function check_git_lfs () {
    if ! (has_command git-lfs) ||
       ! (git-lfs 2>&1 | grep "git-lfs" > /dev/null) ||
       ! (git-lfs version | perl -pse "$VERSION_PARSER" -- -min="$MINIMUM_GIT_LFS_VERSION" > /dev/null)
    then
        if [ "$1" != "no-install" ]; then
            install_git_lfs "$KIT_PATH" "$MINIMUM_GIT_LFS_VERSION"
        else
            git_lfs_error_exit
        fi
    fi
}

function check_dependency () {
    if ! which $1 > /dev/null 2>&1; then
        error_exit "$1 not installed."
    fi
}

function rewrite_ssh_to_https_if_required () {
    local HOST=$1

    # Check if we can access the host via SSH
    set +e
    ssh -T \
        -o BatchMode=yes \
        -o ConnectTimeout=5 \
        -o StrictHostKeyChecking=no \
        -o UserKnownHostsFile=/dev/null \
        git@$HOST > /dev/null 2>&1
    SSH_EXIT=$?
    set -e

    # SSH exits with "1" in case the user successfully authenticated because
    # GitHub does not provide shell access.
    if [ "$SSH_EXIT" -ne 1 ]; then
        echo "Configuring HTTPS URL rewrite for $HOST..."
        set +e
        git config --global --remove-section url."https://$HOST/" > /dev/null 2>&1
        set -e
        git config --global --add url."https://$HOST/".insteadOf "ssh://git@$HOST:"
        git config --global --add url."https://$HOST/".insteadOf "ssh://git@$HOST:/"
        git config --global --add url."https://$HOST/".insteadOf "git@$HOST:"
        git config --global --add url."https://$HOST/".insteadOf "git@$HOST:/"
        git config --global --add url."https://$HOST/".pushInsteadOf "ssh://git@$HOST:"
        git config --global --add url."https://$HOST/".pushInsteadOf "ssh://git@$HOST:/"
        git config --global --add url."https://$HOST/".pushInsteadOf "git@$HOST:"
        git config --global --add url."https://$HOST/".pushInsteadOf "git@$HOST:/"
    fi
}

function set_vanilla_environment () {
    git config --global --unset-all commit.template 2>/dev/null
}

function error_exit () {
    echo -e "\n$(tput setaf 1)###\n### ERROR\n###\n> $(tput sgr0)$1\n" >&2
    echo -e "$(tput setaf 1)$ERROR_HELP_MESSAGE$(tput sgr0)\n" >&2
    exit 1
}

function warning () {
    echo -e "\n$(tput setaf 3)###\n### WARNING\n###\n> $(tput sgr0)$1\n" >&2
}

function print_success () {
    echo -e "\n$(tput setaf 2)$1$(tput sgr0)\n"
}

# Parse the header of a script and print it to stdout
function print_usage()
{
    printf "$(grep '^#/' "$KIT_PATH/$(basename "$0")" |
        cut -c 4- |
        sed "s/\$KIT_ID/$KIT_ID/")\n\n"
}

###############################################################################
# Load platform-specifics
###############################################################################
function install_git_lfs () {
    git_lfs_error_exit
}

function install_git () {
    error_exit "Installing/Upgrading Git on your platform is not supported, yet. $ERROR_HELP_MESSAGE"
}

function credential_helper_parameters () {
    : # by default credentials helper have no parameters
}

function one_ping () {
    ping -c 1 $1
}

case $(uname -s) in
      MSYS_NT-*) . "$KIT_PATH/lib/win/setup_helpers.sh";;
    MINGW??_NT*) . "$KIT_PATH/lib/win/setup_helpers.sh";;
         Darwin) . "$KIT_PATH/lib/osx/setup_helpers.sh";;
          Linux) . "$KIT_PATH/lib/lnx/setup_helpers.sh";;
              *) . "$KIT_PATH/lib/other/setup_helpers.sh";;
esac