#!/usr/bin/env bash
# -*- coding: utf-8 -*-

# region header

# Copyright Torben Sickert (t.sickert["~at~"]gmail.com) 29.10.2015
#           Janosch Dobler (TODO) 29.10.2015

# License
# -------

# This library written by Torben Sickert and Janosch Dobler stand under a
# creative commons naming 3.0 unported license.
# see http://creativecommons.org/licenses/by/3.0/deed.de

# This tool provides a generic way to install systemd based remote linux
# initramfs.

# Examples
# --------

# Start install progress command (Assuming internet is available):
# >>> ./build_initramfs.sh

# Note that you only get very necessary output until you provide "--verbose" as
# commandline options.

# Dependencies
# ------------

# - bash (or any bash like shell)
# - cpio       - Copies files into or out of a cpio or tar archive. The archive
#                can be another file on the disk, a magnetic tape, or a pipe.
# - git        - The stupid content tracker.
# - test       - Check file types and compare values (part of the shell).
# - shift      - Shifts the command line arguments (part of the shell).
# - echo       - Display a line of text (part of coreutils).
# - mktemp     - Create a temporary file or directory (part of coreutils).
# - cat        - Concatenate files and print on the standard output (part of
#                coreutils).
# - rm         - Remove files or directories (part of coreutils).
# - sed        - Stream editor for filtering and transforming text.
# - wget       - The non-interactive network downloader.
# - xz         - Compress or decompress .xz and lzma files.
# - tar        - The GNU version of the tar archiving utility.
# - grep       - Searches the named input files (or standard input if no files
#                are named, or if a single hyphen-minus (-) is given as file
#                name) for lines containing a match to the given PATTERN. By
#                default, grep prints the matching lines.

# Optional dependencies
# ---------------------

# TODO

# TODO

__NAME__='build_initramfs'

# endregion

function build_initramfs() {
    # Provides the main module scope.

    # region properties

    local _SCOPE='local' && \
    if [[ $(echo "\"$@\"" | grep --extended-regexp \
        '(^"| )(-l|--load-environment)("$| )') != '' ]]
    then
        local _SCOPE='export'
    fi
    # NOTE: Only initialize environment if current scope wasn't set yet.
    if [ "$_VERBOSE" == '' ]; then
        "$_SCOPE" _VERBOSE='no'
        "$_SCOPE" _LOAD_ENVIRONMENT='no'
        local dependencies=(bash cpio git test shift echo mktemp cat rm sed \
            wget xz tar grep)
        "$_SCOPE" _DEPENDENCIES="${dependencies[*]}"
        "$_SCOPE" _STANDARD_OUTPUT=/dev/null
        "$_SCOPE" _ERROR_OUTPUT=/dev/null
    fi

    # endregion

    # region functions

    ## region command line interface

    function build_initramfs_print_usage_message() {
        # Prints a description about how to use this program.
    cat << EOF
$__NAME__ This tool provides a generic way to install systemd based remote
linux initramfs.
EOF
    }
    function build_initramfs_print_usage_examples() {
        # Prints a description about how to use this program by providing
        # examples.
        cat << EOF
    # Start install progress:
    # >>> ./build_initramfs.sh
EOF
    }
    function build_initramfs_print_command_line_option_description() {
        # Prints descriptions about each available command line option.
        cat << EOF
    -h --help Shows this help message.

    -v --verbose Tells you what is going on (default: "$_VERBOSE").

    -d --debug Gives you any output from all tools which are used
        (default: "$_DEBUG").

    -l --load-environment Simple load the install arch linux scope without
        doing anything else.
EOF
    }
    function build_initramfs_print_help_message() {
        # Provides a help message for this module.
        echo -e "\nUsage: $0 [options]\n"
        archInstallPrintUsageMessage "$@"
        echo -e '\nExamples:\n'
        archInstallPrintUsageExamples "$@"
        echo -e '\nOption descriptions:\n'
        archInstallPrintCommandLineOptionDescription "$@"
        echo
    }
    function build_initramfs_command_line_interface() {
        # Provides the command line interface and interactive questions.
        while true; do
            case "$1" in
                -h|--help)
                    shift
                    build_initramfs_print_help_message "$0"
                    exit 0
                    ;;
                -v|--verbose)
                    shift
                    _VERBOSE='yes'
                    ;;
                -d|--debug)
                    shift
                    _STANDARD_OUTPUT=/dev/stdout
                    _ERROR_OUTPUT=/dev/stderr
                    ;;
                -l|--load-environment)
                    shift
                    _LOAD_ENVIRONMENT='yes'
                    ;;

                '')
                    shift
                    break
                    ;;
                *)
                    build_initramfs_log 'critical' \
                        "Given argument: \"$1\" is not available." '\n' && \
                    if [[ "$_SCOPE" == 'local' ]]; then
                        build_initramfs_print_help_message "$0"
                    fi
                    return 1
            esac
        done
        if [[ "$UID" != '0' ]]; then
            archInstallLog 'critical' \
                "You have to run this script as \"root\" not as \"${USER}\"."
            exit 2
        fi
        return 0
    }
    function build_initramfs_log() {
        # Handles logging messages. Returns non zero and exit on log level
        # error to support chaining the message into toolchain.
        #
        # Examples:
        #
        # >>> build_initramfs_log
        # info: test
        # >>> build_initramfs_log debug message
        # debug: message
        # >>> build_initramfs_log info message '\n'
        #
        # info: message
        local loggingType='info' && \
        local message="$1" && \
        if [ "$2" ]; then
            loggingType="$1"
            message="$2"
        fi
        if [ "$_VERBOSE" == 'yes' ] || [ "$loggingType" == 'error' ] || \
           [ "$loggingType" == 'critical' ]; then
            if [ "$3" ]; then
                echo -e -n "$3"
            fi
            echo -e "${loggingType}: $message"
        fi
        if [ "$loggingType" == 'error' ]; then
            exit 1
        fi
        return 0
    }

    ## endregion

    # endregion

    # region controller

    if [[ "$0" == *"${__NAME__}.bash" ]]; then
        archInstallPerformDependencyCheck "${_DEPENDENCIES[*]}" || \
            archInstallLog 'error' 'Satisfying main dependencies failed.'
        archInstallCommandLineInterface "$@" || return $?
        _PACKAGES="${_BASIC_PACKAGES[*]} ${_ADDITIONAL_PACKAGES[*]}" && \
        if [ "$_INSTALL_COMMON_ADDITIONAL_PACKAGES" == 'yes' ]; then
            _PACKAGES+=' '${_COMMON_ADDITIONAL_PACKAGES[*]}
        fi
        if [ ! -e "$_OUTPUT_SYSTEM" ]; then
            mkdir --parents "$_OUTPUT_SYSTEM" 1>"$_STANDARD_OUTPUT" \
                2>"$_ERROR_OUTPUT"
        fi
        if [ -d "$_OUTPUT_SYSTEM" ]; then
            _MOUNTPOINT_PATH="$_OUTPUT_SYSTEM" && \
            if [[ ! "$_MOUNTPOINT_PATH" =~ .*/$ ]]; then
                _MOUNTPOINT_PATH+='/'
            fi
        elif [ -b "$_OUTPUT_SYSTEM" ]; then
            _PACKAGES+=' efibootmgr' && \
            archInstallPerformDependencyCheck \
                "${_BLOCK_INTEGRATION_DEPENDENCIES[*]}" || \
            archInstallLog 'error' \
                'Satisfying block device dependencies failed.' && \
            if echo "$_OUTPUT_SYSTEM" | grep --quiet --extended-regexp '[0-9]$'
            then
                archInstallFormatSystemPartition || \
                archInstallLog 'error' 'System partition creation failed.'
            else
                archInstallDetermineAutoPartitioning && \
                archInstallPrepareBlockdevices || \
                archInstallLog 'error' 'Preparing blockdevices failed.'
            fi
        else
            archInstallLog 'error' \
                "Could not install into an existing file \"$_OUTPUT_SYSTEM\"."
        fi
        archInstallPrepareInstallation || \
        archInstallLog 'error' 'Preparing installation failed.'
        if [[ "$UID" == 0 ]] && [[ "$_PREVENT_USING_PACSTRAP" == 'no' ]] && \
            hash pacstrap 1>"$_STANDARD_OUTPUT" 2>/dev/null
        then
            archInstallWithPacstrap || \
            archInstallLog 'error' 'Installation with pacstrap failed.'
        else
            archInstallGenericLinuxSteps || \
            archInstallLog 'error' \
                'Installation via generic linux steps failed.'
        fi
        archInstallTidyUpSystem && \
        archInstallConfigure || \
        archInstallLog 'error' 'Configuring installed system failed.'
        archInstallPrepareNextBoot || \
        archInstallLog 'error' 'Preparing reboot failed.'
        archInstallPackResult || \
        archInstallLog 'error' \
            'Packing system into archiv with files owned by root failed.'
        archInstallLog \
            "Generating operating system into \"$_OUTPUT_SYSTEM\" has successfully finished."
    fi
    return 0

    # endregion


    mkdir dracut
    # download and extract dracut
    curl --location \
        https://www.kernel.org/pub/linux/utils/boot/dracut/dracut-043.tar.gz | \
        tar --extract --gzip --directory dracut --strip-components 1
    cd dracut
    # NOTE: On virtualbox shared folder symlinks are not allowed.
    # make the dracut-install binary (dracut-install resolves dependencies etc.)
    make install/dracut-install
    # copy the binary to current (instead of symlink)
    cp install/dracut-install dracut-install
    ## if symlinks are available
    #make dracut-install

    cd builder/dnbd3-qcow2-rootfs/kernel_modules/nbd/
    make
    cd -

    # TODO build dnbd3.ko, nbd.ko (dnbd3-qcow2-rootfs/kernel_modules/Makefile)
    # TODO add dnbd3-qcow2-rootfs to modules.d

    # build initramfs
    ./dracut.sh --local --verbose --force
}

# region footer

if [[ "$0" == *"${__NAME__}.bash" || $(echo "$@" | grep --extended-regexp \
    '(^| )(-l|--load-environment)($| )') ]]; then
    "$__NAME__" "$@"
fi

# endregion

# region vim modline

# vim: set tabstop=4 shiftwidth=4 expandtab:
# vim: foldmethod=marker foldmarker=region,endregion:

# endregion