#!/usr/bin/env bash
source ./functions.sh

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

setDefaults() {

    debug "${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 -ag _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" "luci-app-ddns")
    fi
}

#####################
##### FUNCTIONS #####
#####################

printHelpAndExit() {

    debug "${FUNCNAME[0]}"

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

OPTIONS
    --version, -v OPENWRT_VERSION
    --target, -t TARGET
    --profile, -p PROFILE
    --builddir, -b PATH
    --ssh-upgrade SSH_PATH
        Example: root@192.168.1.1
    --flash, -f DEVICE
        Example: /dev/sdX
    --debug, -d
    --help, -h
EOF
        # Exit using passed exit code
        [[ -z $1 ]] && exit 0 || exit "$1"
}


parseInput() {

    debug "${FUNCNAME[0]}"

    if _input=$(getopt -o +v:t:p:b:f:dh -l version:,target:,profile:,builddir:,ssh-upgrade:,flash:,debug,help -- "$@"); 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-upgrade)
                    shift && _ssh_upgrade_path="$1"
                    ;;
                --flash|-f)
                    shift && _flash_dev="$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
}


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


setVars() {

    debug "${FUNCNAME[0]}"

    getOS () {

        debug "${FUNCNAME[0]}"

        if [[ -f /etc/os-release ]]; then
            source /etc/os-release
            export ID="$ID"
            echo "Detected platform: $ID"
        else
            echo "Cannot detect OS!"
            exit 1
        fi
    }
    getOS

    export _source_archive="$_builddir/sources/$_profile-$_version.tar.xz"
    export _source_dir="${_source_archive%.tar.xz}"

    export _out_bin_dir="$_builddir/bin/$_profile-$_version/"
    export _out_bin_gz="$_out_bin_dir/openwrt-${_target//\//-}-$_profile-ext4-factory.img.gz"
    export _out_bin="${_out_bin_gz%.gz}"

}


installPrerequisites() {

    debug "${FUNCNAME[0]}"

    local -a _pkg_list
    local _pkg_cmd

    if [[ "$ID" == "fedora" ]]; then
        _pkg_list=("@c-development" "@development-tools" "@development-libs" "zlib-static" "elfutils-libelf-devel" "gawk" "unzip" "file" "wget" "python3" "python2" "axel")
        _pkg_cmd="dnf"
    elif [[ "$ID" =~ ^(debian|ubuntu)$ ]]; then
        _pkg_list=("build-essential" "libncurses5-dev" "libncursesw5-dev" "zlib1g-dev" "gawk" "git" "gettext" "libssl-dev" "xsltproc" "wget" "unzip" "python" "axel")
        _pkg_cmd="apt-get"
    fi

    echo "Installing dependencies"
    debug "sudo $_pkg_cmd -y install ${_pkg_list[*]}"
    if ! sudo "$_pkg_cmd" -y install "${_pkg_list[@]}" > /dev/null 2>&1; then
        echo "Warning: Problem installing prerequisites"
        return 1
    fi
}


acquireImageBuilder() {

    debug "${FUNCNAME[0]}"

    local _url _filename

    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"

    # Remove existing ImageBuilder archives
    [[ -f "$_source_archive" ]] && rm "$_source_archive"

    echo "Downloading image archive"
    debug "axel -o $_source_archive $_url"
    if ! axel -o "$_source_archive" "$_url" > /dev/null 2>&1; then
        echo "Could not download Image Builder"
        exit 1
    fi
}


extractImageBuilder() {

    debug "${FUNCNAME[0]}"

    [[ ! -d "$_source_dir" ]] && mkdir -p "$_source_dir"

    if [[ ! -f "$_source_archive" ]]; then
        echo "Archive missing"
        exit 1
    fi

    echo "Extracting image archive"
    debug "tar -xf $_source_archive -C $_source_dir --strip-components 1"
    if ! tar -xf "$_source_archive" -C "$_source_dir" --strip-components 1; then
        echo "Extraction failed"
        exit 1
    fi
}


makeImage() {

    debug "${FUNCNAME[0]}"

    # move to extracted source directory
    if ! pushd "$_source_dir" > /dev/null 2>&1; then
        exit 1
    fi

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

    # build image
    echo "Running make -j4 image BIN_DIR=$_out_bin_dir PROFILE=$_profile PACKAGES=${_packages[*]} FILES=$_filesroot"
    debug "make -j4 image BIN_DIR=$_out_bin_dir PROFILE=$_profile PACKAGES=${_packages[*]} FILES=$_filesroot > make.log"
    if ! make -j4 image BIN_DIR="$_out_bin_dir" PROFILE="$_profile" \
    PACKAGES="${_packages[*]}" FILES="$_filesroot" > make.log; then
        echo "Make image failed!"
        exit 1
    fi

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


flashImage() {

    debug "${FUNCNAME[0]}"

    extractImage "$_out_bin_gz"

    if [[ ! -d "$_flash_dev" ]]; then
        echo "The device specified by --flash could not be found"
        exit 1
    fi

    echo "Unmounting target device $_flash_dev partitions"
    debug "umount $_flash_dev?*"
    sudo umount "$_flash_dev?*"

    debug "sudo dd if=\"$_out_bin\" of=\"$_flash_dev\" bs=2M conv=fsync"
    if sudo dd if="$_out_bin" of="$_flash_dev" bs=2M conv=fsync; then
        sync
        echo "Image flashed sucessfully!"
    else
        echo "dd failed!"
        exit 1
    fi
}


sshUpgrade() {

    debug "${FUNCNAME[0]}"

    local _out_bin_gz_name="${_out_bin_gz##*/}"

    echo "Copying upgrade image to $_ssh_upgrade_path"
    debug "scp \"$_out_bin_gz\" \"$_ssh_upgrade_path:/tmp/$_out_bin_gz_name\""
    # shellcheck disable=SC2140
    if ! scp "$_out_bin_gz" "$_ssh_upgrade_path":"/tmp/$_out_bin_gz_name"; then
        echo "Could not access the --ssh-upgrade PATH"
        exit 1
    fi

    echo "Executing remote sysupgrade"
    debug "ssh \"$_ssh_upgrade_path\" \"sysupgrade -F /tmp/$_out_bin_gz_name\""
    # shellcheck disable=SC2029
    ssh "$_ssh_upgrade_path" "sysupgrade -F /tmp/$_out_bin_gz_name"
}


__main() {

    parseInput "$@"
    setDefaults
    setVars
    installPrerequisites
    acquireImageBuilder
    extractImageBuilder
    makeImage
    [[ -n $_ssh_upgrade_path ]] && sshUpgrade
    [[ -n $_flash_dev ]] && flashImage
}

__main "$@"
exit $?