# If in automatic mode, determine if a user already exists, if not use root
detect_user() {
    local user_variable_name=${1:-username}
    local possible_users=${2:-("vscode" "node" "codespace" "$(awk -v val=1000 -F ":" '$3==val{print $1}' /etc/passwd)")}
    if [ "${!user_variable_name}" = "auto" ] || [ "${!user_variable_name}" = "automatic" ]; then
        declare -g ${user_variable_name}=""
        for current_user in ${possible_users[@]}; do
            if id -u "${current_user}" > /dev/null 2>&1; then
                declare -g ${user_variable_name}="${current_user}"
                break
            fi
        done
    fi
    if [ "${!user_variable_name}" = "" ] || [ "${!user_variable_name}" = "none" ] || ! id -u "${!user_variable_name}" > /dev/null 2>&1; then
        declare -g ${user_variable_name}=root
    fi
}

# 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
}

# Use SDKMAN to install something using a partial version match
sdk_install() {
    local install_type=$1
    local requested_version=$2
    local prefix=$3
    local suffix="${4:-"\\s*"}"
    local full_version_check=${5:-".*-[a-z]+"}
    if [ "${requested_version}" = "none" ]; then return; fi
    # Blank will install latest stable version
    if [ "${requested_version}" = "lts" ] || [ "${requested_version}" = "default" ]; then
         requested_version=""
    elif echo "${requested_version}" | grep -oE "${full_version_check}" > /dev/null 2>&1; then
        echo "${requested_version}"
    else
        local regex="${prefix}\\K[0-9]+\\.[0-9]+\\.[0-9]+${suffix}"
        local version_list="$(. ${SDKMAN_DIR}/bin/sdkman-init.sh && sdk list ${install_type} 2>&1 | grep -oP "${regex}" | tr -d ' ' | sort -rV)"
        if [ "${requested_version}" = "latest" ] || [ "${requested_version}" = "current" ]; 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 "Version $2 not found. Available versions:\n${version_list}" >&2
            exit 1
        fi
    fi
    su ${USERNAME} -c "umask 0002 && . ${SDKMAN_DIR}/bin/sdkman-init.sh && sdk install ${install_type} ${requested_version} && sdk flush archives && sdk flush temp"
}

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
        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}"
}

# 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
}

# Soft version matching that resolves a version for a given package in the *current apt-cache*
# Return value is stored in first argument (the unprocessed version)
apt_cache_version_soft_match() {
    
    # Version
    local variable_name="$1"
    local requested_version=${!variable_name}
    # Package Name
    local package_name="$2"
    # Exit on no match?
    local exit_on_no_match="${3:-true}"

    # Ensure we've exported useful variables
    . /etc/os-release
    local architecture="$(dpkg --print-architecture)"
    
    dot_escaped="${requested_version//./\\.}"
    dot_plus_escaped="${dot_escaped//+/\\+}"
    # Regex needs to handle debian package version number format: https://www.systutorials.com/docs/linux/man/5-deb-version/
    version_regex="^(.+:)?${dot_plus_escaped}([\\.\\+ ~:-]|$)"
    set +e # Don't exit if finding version fails - handle gracefully
        fuzzy_version="$(apt-cache madison ${package_name} | awk -F"|" '{print $2}' | sed -e 's/^[ \t]*//' | grep -E -m 1 "${version_regex}")"
    set -e
    if [ -z "${fuzzy_version}" ]; then
        echo "(!) No full or partial for package \"${package_name}\" match found in apt-cache for \"${requested_version}\" on OS ${ID} ${VERSION_CODENAME} (${architecture})."

        if $exit_on_no_match; then
            echo "Available versions:"
            apt-cache madison ${package_name} | awk -F"|" '{print $2}' | grep -oP '^(.+:)?\K.+'
            exit 1 # Fail entire script
        else
            echo "Continuing to fallback method (if available)"
            return 1;
        fi
    fi

    # Globally assign fuzzy_version to this value
    # Use this value as the return value of this function
    declare -g ${variable_name}="=${fuzzy_version}"
    echo "${variable_name}=${!variable_name}"
}