installer-prep

#!/bin/bash
#
# This script looks at the operating system, architecture, bit type, etc., to determine
# whether or not the system is supported by Mewdeko. Once the system is deemed as
# supported, the main installer will be downloaded and executed.
#
########################################################################################
#### [ Exported and/or Globally Used Variables ]


# Refer to the 'README' note at the beginning of 'linuxAIO' for more information.
current_linuxAIO_revision=4
# Name of the main installer script.
main_installer="mewdeko-main-installer"

# Similar to 'current_linuxAIO_revision', expecpt it's used as a more general tracking
# number. Instead of only being used to represent the relationship between this script
# and 'linuxAIO', it represents major changes to the installer that requires a change in
# behavior, that would otherwise result in conflict with older verisons of the script.
export _REVISION_NUMBER=1

## Modify output text color.
# shellcheck disable=SC2155
{
    export _YELLOW="$(printf '\033[1;33m')"
    export _GREEN="$(printf '\033[0;32m')"
    export _CYAN="$(printf '\033[0;36m')"
    export _RED="$(printf '\033[1;31m')"
    export _NC="$(printf '\033[0m')"
    export _GREY="$(printf '\033[0;90m')"
    export _CLRLN="$(printf '\r\033[K')"
}


#### End of [ Exported and/or Globally Used Variables ]
########################################################################################
#### [ Functions ]


########
# Identify the operating system, version number, architecture, bit type (32 or 64), etc.
#
# Arguments:
#   None
########
detect_sys_info() {
    if [[ -f /etc/os-release ]]; then
        # shellcheck disable=SC1091
        . /etc/os-release
        _DISTRO="$ID"
        _VER="$VERSION_ID"  # Version: x.x.x...
        _SVER=${_VER//.*/}  # Version: x
        pname="$PRETTY_NAME"
    else
        _DISTRO=$(uname -s)
        _VER=$(uname -r)
    fi

    ## Identify bit and architecture type.
    case $(uname -m) in
        x86_64) bits="64"; _ARCH="x64" ;;
        i*86)   bits="32"; _ARCH="x86" ;;
        armv*)  bits="32"; _ARCH="?" ;;
        *)      bits="?";  _ARCH="?" ;;
    esac
}

########
# Download the latest version of 'linuxAIO' if $_LINUXAIO_REVISION and
# $current_linuxAIO_revision aren't of equal value.
#
# Arguments:
#  None
########
linuxAIO_update() {
    echo -n "${_YELLOW}You are using an older version of 'linuxAIO'. "
    read -rp "Press [Enter] to download the latest version.${_NC}"
    echo "Downloading latest version of 'linuxAIO'..."

    ## Only download the newest version of 'linuxAIO', as there are some incompatible
    ## changes to 'linuxAIO' making it difficult or impossible to merge existing
    ## configurations.
    if ((_LINUXAIO_REVISION <= 3)); then
        if [[ -f linuxAIO.sh ]]; then
            echo "Backing up 'linuxAIO.sh' as 'linuxAIO.sh.old'..."
            mv linuxAIO.sh linuxAIO.sh.old
        elif [[ -f linuxAIO ]]; then
            echo "Backing up 'linuxAIO' as 'linuxAIO.old'..."
            mv linuxAIO linuxAIO.old
        fi

        curl -O "$_RAW_URL"/linuxAIO && sudo chmod +x linuxAIO
        echo "${_CYAN}NOT applying existing configurations to 'linuxAIO'"
        echo "${_GREEN}Successfully downloaded the newest version of 'linuxAIO'.${_NC}"
    ## Download the newest version of 'linuxAIO' and apply existing changes to it.
    else
        ## Save the values of the current Configuration Variables specified in
        ## 'linuxAIO', to be set in the new 'linuxAIO'.
        local installer_branch
        local installer_branch_found
        installer_branch=$(grep '^installer_branch=.*' linuxAIO)
        installer_branch_found="$?"
        local bot_install_version
        local bot_install_version_found
        bot_install_version=$(grep '^export _BOT_INSTALL_VERSION=.*' linuxAIO)
        bot_install_version_found="$?"

        curl -O "$_RAW_URL"/linuxAIO && sudo chmod +x linuxAIO

        echo "Applying existing configurations to the new 'linuxAIO'..."

        # Set $installer_branch inside of the new 'linuxAIO'.
        [[ $installer_branch_found = 0 ]] \
            && sed -i "s/^installer_branch=.*/$installer_branch/" linuxAIO

        # Set $bot_install_version inside of the new 'linuxAIO'.
        [[ $bot_install_version_found = 0 ]] \
            && sed -i "s/^export _BOT_INSTALL_VERSION=.*/$bot_install_version/" linuxAIO

        echo "${_GREEN}Successfully downloaded the newest version of 'linuxAIO' and" \
            "applied changes to the newest version of 'linuxAIO'${_NC}"
    fi

    clean_up "0" "Exiting" "true"
}

########
# Provide the end-user with the option to continue, even if their system isn't
# officially supported.
#
# Arguments:
#   None
########
unsupported() {
    echo "${_RED}Your operating system is not OFFICIALLY supported for the" \
        "installation, setup, and/or use of Mewdeko" >&2
    echo "${_YELLOW}WARNING: By continuing, you accept that unexpected behaviors" \
        "may occur. If you run into any errors or problems with the installation and" \
        "use of the Mewdeko, you are on your own.${_NC}"
    read -rp "Would you like to continue anyways? [y/N] " choice

    choice=$(echo "$choice" | tr '[:upper:]' '[:lower:]')
    case "$choice" in
        y|yes) clear -x; execute_main_installer ;;
        *)     clean_up "0" "Exiting" ;;
    esac
}

########
# Cleanly exit the installer by removing files that aren't required unless the installer
# is currently running.
#
# Arguments:
#   $1 - required
#       Exit code.
#   $2 - required
#       Output text.
#   $3 - optional
#       True if 'Cleaning up...' should be printed with two new-line symbols.
########
clean_up() {
    # Files to be removed.
    local installer_files=("installer-prep" "mewdeko-runner" "prereqs-installer"
        "mewdeko-latest-installer" "mewdeko-main-installer")

    if [[ $3 = true ]]; then echo -e "\n\nCleaning up..."
    else                     echo -e "\nCleaning up..."
    fi

    cd "$_WORKING_DIR" || _STDERR "Failed to move to Mewdeko's root directory" "1"
    [[ -d Mewdeko_tmp ]] && rm -rf Mewdeko_tmp

    for file in "${installer_files[@]}"; do
        [[ -f $file ]] && rm "$file"
    done

    echo "$2..."
    exit "$1"
}

########
# Download and execute $main_installer.
#
# Arguments:
#   None
########
execute_main_installer() {
    _DOWNLOAD_SCRIPT "$main_installer" "true"
    ./"$main_installer"
    clean_up "$?" "Exiting"
}

########################################################################################
#### [[ Functions To Be Exported ]]


########
# Download the specified script and modify it's execution permissions.
#
# Arguments:
#   $1 - required
#       Name of the script to download.
#   $2 - optional
#       True if the script should output text indicating $1 is being downloaded.
########
_DOWNLOAD_SCRIPT() {
    [[ $2 = true ]] && printf "Downloading '%s'..." "$1"
    curl -O -s "$_RAW_URL"/"$1"
    sudo chmod +x "$1"
}

########
# Output an error message, and if desired, exit the script.
#
# Arguments:
#   $1 - required
#       Error message.
#   $2 - optional
#       If provided, exit with the provided value.
#   $3 - optional
#       If provided, output an additional message.
########
_STDERR() {
    echo "${_RED}$1${_NC}" >&2
    [[ $3 ]] && echo -e "$3"
    [[ $2 ]] && exit "$2"
}


#### End of [[ Functions To Be Exported ]]
########################################################################################

#### End of [ Functions ]
########################################################################################
#### [ Error Traps ]


trap 'clean_up "130" "Exiting" "true"' SIGINT
trap 'clean_up "143" "Exiting" "true"' SIGTERM
trap 'clean_up "148" "Exiting" "true"' SIGTSTP


#### End of [ Error Traps ]
########################################################################################
#### [ Prepping ]


# If the current 'linuxAIO' revision number is not of equil value of the expected
# revision number...
if [[ $_LINUXAIO_REVISION && $_LINUXAIO_REVISION != "$current_linuxAIO_revision" ]]; then
    linuxAIO_update
    clean_up "0" "Exiting"
fi

# Change the working directory to the location of the executed script.
cd "${0%/*}" || {
    echo "${_RED}Failed to change working directory" >&2
    echo "${_CYAN}Change your working directory to that of the executed script${_NC}"
    clean_up "1" "Exiting"
}

export _WORKING_DIR="$PWD"
export _INSTALLER_PREP="$_WORKING_DIR/installer-prep"


#### End of [ Prepping ]
########################################################################################
#### [ Main ]


clear -x

detect_sys_info
export _DISTRO _SVER _VER _ARCH
export -f _DOWNLOAD_SCRIPT _STDERR

# Use $_DISTRO if $pname is unset or null...
echo "SYSTEM INFO
Bit Type: $bits
Architecture: $_ARCH
Distro: ${pname:=$_DISTRO}
Distro Version: $_VER
"

### Check if the operating system is supported by Mewdeko and the installer.
if [[ $bits = 64 ]]; then
    if [[ $_DISTRO = "ubuntu" ]]; then
        case "$_VER" in
            22.04|20.04|18.04) execute_main_installer ;;
            *)                 unsupported ;;
        esac
    elif [[ $_DISTRO = "debian" ]]; then
        case "$_SVER" in
            11|10) execute_main_installer ;;
            *)     unsupported ;;
        esac
    elif [[ $_DISTRO = "linuxmint" ]]; then
        case "$_SVER" in
            21|20) execute_main_installer ;;
            *)     unsupported ;;
        esac
    else
        unsupported
    fi
else
    unsupported
fi


#### End of [ Main ]
########################################################################################