#!/usr/bin/env bash

#####################
##### DEFAULTS ######
#####################

setDefaults() {

    runDebug "${FUNCNAME[0]}"

    [[ -z $_debug ]] && _debug="true" # Set to true to enable debugging by default
    [[ -z $_builddir ]] && _builddir="$PWD"
    [[ -z $_filesroot ]] && _filesroot="$_builddir/files/"

    # Global default packages for all profiles
    declare -a _packages=("luci" "nano" "htop" "tcpdump" "diffutils")

    # If no profile is specified, use the TP-Link Archer C7 v2
    [[ -z $_profile ]] && _profile="tplink_archer-c7-v2"

    # PROFILES
    # TP-Link Archer C7 v2
    if [[ "$_profile" == "tplink_archer-c7-v2" ]]; then
        [[ -z $_version ]] && _version="19.07.2"
        [[ -z $_target ]] && _target="ath79/generic"
    # Raspberry Pi 4
    elif [[ "$_profile" == "rpi-4" ]]; then
        [[ -z $_version ]] && _version="snapshot"
        [[ -z $_target ]] && _target="bcm27xx/bcm2711"
        packages+=("kmod-usb-net-asix-ax88179" "luci-app-upnp" "luci-app-wireguard" \
        "luci-app-vpn-policy-routing" "-dnsmasq" "dnsmasq-full")
    fi
}

#####################
##### FUNCTIONS #####
#####################
printHelpAndExit () {

    runDebug "${FUNCNAME[0]}"

    cat <<-'EOF'
USAGE:
buildOpenWRT [[OPTION] [VALUE]]...

OPTIONS
    --version, -v OPENWRT_VERSION
    --target, -t TARGET
    --profile, -p PROFILE
    --builddir, -b PATH
    --ssh-backup SSH path
        Example: root@192.168.1.1
    --debug, -d
    --help, -h
EOF
        # Exit using passed exit code
        [[ -z $1 ]] && exit 0 || exit "$1"
}


parseInput () {

    runDebug "${FUNCNAME[0]}"

    if _input=$(getopt -o +v:t:p:b:dh -l version:,target:,profile:,builddir:,ssh-backup:debug,help -- "$@"); then
        eval set -- "$_input"
        while true; do
            case "$1" in
                --version|-v)
                    shift && _version="$1"
                    ;;
                --target|-t)
                    shift && _target="$1"
                    ;;
                --profile|-p)
                    shift && _profile="$1"
                    ;;
                --builddir|-b)
                    shift && _builddir="$1"
                    ;;
                --ssh-backup)
                    shift && _ssh_backup="$1"
                    ;;
                --debug|-d)
                    echo "Debugging on"
                    _debug="true"
                    ;;
                --help|-h)
                    _printHelpAndExit 0
                    ;;
                --)
                    shift
                    break
                    ;;
            esac
            shift
        done
    else
        echo "Incorrect options provided"
        printHelpAndExit 1
    fi
}


runDebug () { [[ "$_debug" == "true" ]] && echo "Running: " "$@" ; }


installPrerequisites () {

    runDebug "${FUNCNAME[0]}"

    getOS () {

        runDebug "${FUNCNAME[0]}"

        if [[ -f /etc/os-release ]]; then
            source /etc/os-release
        else
            echo "Cannot detect OS!"
            exit 1
        fi
    }
    getOS

    if [[ "$ID" == "fedora" ]]; then
        if ! sudo dnf -y install @c-development @development-tools @development-libs zlib-static elfutils-libelf-devel gawk unzip file wget python3 python2 > /dev/null 2>&1; then
            echo "Warning: Problem installing prerequisites"
        fi
    elif [[ "$ID" =~ ^(debian|ubuntu)$ ]]; then
        if ! sudo apt-get -y install build-essential libncurses5-dev libncursesw5-dev zlib1g-dev gawk git gettext libssl-dev xsltproc wget unzip python > /dev/null 2>&1; then
            echo "Warning: Problem installing prerequisites"
        fi
    fi
}


acquireImageBuilder () {

    runDebug "${FUNCNAME[0]}"

    local _url

    if [[ "$_version" == "snapshot" ]]; then
        _filename="openwrt-imagebuilder-${_target//\//-}.Linux-x86_64.tar.xz"
        _url="https://downloads.openwrt.org/snapshots/targets/$_target/$_filename"
    else
        _filename="openwrt-imagebuilder-$_version-${_target//\//-}.Linux-x86_64.tar.xz"
        _url="https://downloads.openwrt.org/releases/$_version/targets/$_target/$_filename"
    fi

    # Make sources directory if it does not exist
    [[ ! -d "$_builddir/sources" ]] && mkdir -p "$_builddir/sources"

    if [[ ! -f "$_builddir/sources/$_filename" ]]; then
            echo "Downloading $_url to $_builddir/sources"
        if ! wget -q -P "$_builddir/sources" "$_url"; then
            echo "Could not download Image Builder"
            exit 1
        fi
    else
        echo "Image builder already exists, skipping download..."
    fi
}


extractImageBuilder () {

    runDebug "${FUNCNAME[0]}"

    if [[ -f "$_builddir/sources/$_filename" ]]; then
        if ! tar -xf "$_builddir/sources/$_filename" -C "$_builddir/sources/"; then
            echo "Extraction failed"
            exit 1
        fi
    fi
}


makeImage () {

    runDebug "${FUNCNAME[0]}"

    # move to extracted source directory
    if ! pushd "$_builddir/sources/${_filename%.tar.xz}" > /dev/null 2>&1; then
        exit 1
    fi

    # Make bin dir
    [[ ! -d "$_builddir/bin" ]] && mkdir -p "$_builddir/bin"

    # build image
    if ! make -j4 image BIN_DIR="$_builddir/bin/$_profile/" PROFILE="$_profile" \
    PACKAGES="${_packages[*]}" FILES="$_filesroot"; then
        echo "Make image failed!"
        exit 1
    fi

    if ! popd > /dev/null 2>&1; then
        exit 1
    fi
}


#sshBackup () {
#
#    runDebug "${FUNCNAME[0]}"
#
#    # Make files directory if it does not exist
#    [[ ! -d "$_filesroot" ]] && mkdir -p "$_filesroot"
#
#    for fd in "${_backedup[@]}"; do
#        _dir="${fd%/*}/"
#        [[ ! -d "$_filesroot$_dir" ]] && mkdir -p "$_filesroot/$_dir"
#        if ! scp -rp "$_ssh_backup:$fd" "$_filesroot/$_dir"; then
#            echo "Did not successfully backup files from --ssh-backup"
#            echo "Exiting now to prevent data loss!"
#            exit 1
#        fi
#    done
#}


# TODO
#flashImage () {
#
#    if ! scp -rp  "$_bin_path" "$_ssh_backup:/tmp/$_bin_name"; then
#        echo "Could not copy update file to device!"
#        exit 1
#    fi
#
#3    # shellcheck disable=SC2029
#    if ! ssh "$_ssh_backup" "sysupgrade -v /tmp/$_bin_name"; then
#3        echo "sysupgrade failed!"
#        exit 1
#    fi
#}


__main () {

    parseInput "$@"
    setDefaults
    getOS
    installPrerequisites
    acquireImageBuilder
    extractImageBuilder
    [[ -n $_ssh_backup ]] && sshBackup
    makeImage
    #flashImage # TODO
    exit 0
}

__main "$@"