#!/bin/bash

# region header

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

    # region dependencies:

# VMware Player      - Runs a virtual machine.
# VMware Workstation - Runs, edits, creates virtual machines for business
#                      usage.
# VirtualBox ver. 4+ - Plays, creates, edits virtual machines.
# bash ver. 4+       - A sh-compatible command line interpreter.
# cat                - Concatenate and prints file contents.
# echo               - Prints chars.
# grep               - Prints lines which matches a given regular expression
#                      pattern.
# sed                - Stream-editor for filtering and transformation text.
# mktemp             - Creates temporary files and folders.
# dirname            - Extracts the last element from a given file path.
# mv                 - moves and renames file objects.
# rm                 - Removes files and folders.
# cp                 - Copies files and folders.
# sleep              - Delays program calls.
# readlink           - Print resolved symbolic links or canonical file names.

    # endregion

# Abbreviation for "createLinkedClone".
__NAME__='vmchooser-clc'

# endregion

# Provides the main module scope.
function vmchooser-clc() {

# region configuration

    # region private properties

        # region command  line arguments

    local _VERBOSE='no'
    # NOTE: You should write upper case first letters to support valid
    # camel case method names to handle given hypervisor.
    local _SUPPORTED_HYPERVISOR=('VMware' 'VirtualBox')
    # NOTE: This value will be determined automatically. If no hypervisor
    # could be detected this value will be used as default.
    # The first value from supported Machines is taken as default.
    local _HYPERVISOR="$_SUPPORTED_HYPERVISOR"
    local _PERSISTENT_SHORT_DESCRIPTION_SUFFIX=' --persistent--'
    local _PERSISTENT_CONFIG_TARGET=''
    local _BASIC_IMAGE_CONFIGURATION_FILE_PATH=''
    local _TARGET_PATH=''
    local _VIRTUAL_BOX_SNAPSHOT_NAME='persistentUserSnapshot'

        # endregion

    local _STANDARD_OUTPUT=/dev/null
    local _ERROR_OUTPUT=/dev/null
    local _VIRTUAL_BOX_SNAPSHOT_UUID_FILE_PATH='/tmp/clcVirtualBoxSnapshotUUID'

    # endregion

# endregion

# region functions

    # region command line interface

    # Prints a description about how to use this program.
    function clcPrintUsageMessage() {
        cat << EOF
    $__NAME__ Generates a linked clone from given machine description file in
    given target location.
EOF
        return $?
    }

    # Prints a description about how to use this program by providing examples.
    function clcPrintUsageExamples() {
        cat << EOF
    # Getting a help message.
    >>> $0 --help

    # Creating a linked clone.
    >>> $0 /path/to/config.xml ~/.persistentLinkedClones/

    # Creating a linked clone configuration file.
    >>> $0 /path/to/config.xml ~/.persistentLinkedClones/ -c

    # Creating a linked clone in verbose mode.
    >>> $0 /path/to/config.xml ~/.persistentLinkedClones/ --verbose

    # Creating a linked clone in verbose mode with debugging output.
    >>> $0 /path/to/config.xml ~/.persistentLinkedClones/ --verbose --debug

    # Creating a linked clone in verbose mode with debugging output.
    >>> $0 /path/to/config.xml ~/.persistentLinkedClones/ -v -d
EOF
        return $?
    }

    # Prints descriptions about each available command line option.
    function clcPrintCommandLineOptionDescriptions() {
        # NOTE; All letters are used for short options.
        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").

    -c --create-persistent-config PERSISTENT_IMAGE_FILE_PATH If set an xml file
        for persistent openslx boot will be created referencing to given
        persistent image path (default: "$_PERSISTENT_CONFIG_TARGET").

    -v --virtualbox-snapshot-name NAME Provide a name for newly created
        snapshots. (default: "$_VIRTUAL_BOX_SNAPSHOT_NAME").

    -u --virtualbox-snapshot-uuid-file-path PATH Provide a file path where to
        save the newly generated snapshot uuid (default: \
        "$_VIRTUAL_BOX_SNAPSHOT_UUID_FILE_PATH").
EOF
        return $?
    }

    # Provides a help message for this module.
    function clcPrintHelpMessage() {
        echo -e \
            "\nUsage: $0 BASIC_IMAGE_CONFIGURATION_FILE_PATH TARGET_PATH [options]\n" && \
        clcPrintUsageMessage "$@" && \
        echo -e '\nExamples:\n' && \
        clcPrintUsageExamples "$@" && \
        echo -e '\nOption descriptions:\n' && \
        clcPrintCommandLineOptionDescriptions "$@" && \
        echo && \
        return $?
    }

    # Provides the command line interface and interactive questions.
    function clcCommandLineInterface() {
        while true; do
            case "$1" in
                -h|--help)
                    shift
                    clcPrintHelpMessage "$0"
                    exit 0
                    ;;
                -v|--verbose)
                    shift
                    _VERBOSE='yes'
                    ;;
                -d|--debug)
                    shift
                    _DEBUG='yes'
                    _STANDARD_OUTPUT=/dev/stdout
                    _ERROR_OUTPUT=/dev/stderr
                    ;;
                -c|--create-persistent-config)
                    shift
                    _PERSISTENT_CONFIG_TARGET="$1"
                    shift
                    ;;
                -v|--virtualbox-snapshot-name)
                    shift
                    _VIRTUAL_BOX_SNAPSHOT_NAME="$1"
                    shift
                    ;;
                -u|--virtualbox-snapshot-uuid-file-path)
                    shift
                    _VIRTUAL_BOX_SNAPSHOT_UUID_FILE_PATH="$1"
                    shift
                    ;;

                '')
                    shift
                    break 2
                    ;;
                *)
                    if [[ ! "$_BASIC_IMAGE_CONFIGURATION_FILE_PATH" ]]; then
                        _BASIC_IMAGE_CONFIGURATION_FILE_PATH="$1"
                    elif [[ ! "$_TARGET_PATH" ]]; then
                        _TARGET_PATH="$1"
                    else
                        clcLog 'critical' \
                            "Given argument: \"$1\" is not available." '\n'
                        clcPrintHelpMessage "$0"
                        return 1
                    fi
                    shift
                    ;;
            esac
        done
        if [[ ! "$_BASIC_IMAGE_CONFIGURATION_FILE_PATH" ]] || \
           [[ ! "$_TARGET_PATH" ]]; then
            clcLog 'critical' \
                "You have to provide a basic image configuration file and a destination path."
            clcPrintHelpMessage "$0"
            return 1
        fi
        local supportedVirtualMachine
        for supportedVirtualMachine in ${_SUPPORTED_HYPERVISOR[*]}; do
            if [[ "$(clcGetXMLValue 'virtualMachine' | \
                  grep --ignore-case "$supportedVirtualMachine")" ]]; then
                _HYPERVISOR="$supportedVirtualMachine"
                clcLog 'debug' "Detected \"$_HYPERVISOR\" as hypervisor."
                break
            fi
        done
        clcLog 'info' "Using \"$_HYPERVISOR\" as hypervisor." && \
        return $?
    }

    # Grabs a value from currently loaded xml file.
    function clcGetXMLValue() {
        grep --ignore-case --only-matching "<$1 param=.*" \
            "$_BASIC_IMAGE_CONFIGURATION_FILE_PATH" | awk -F '"' '{ print $2 }'
        return $?
    }

    # Handles logging messages. Returns non zero and exit on log level error to
    # support chaining the message into toolchain.
    function clcLog() {
        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
    }

    # endregion

    # region tools

    # Returns the minimal vmx vmware configuration file content to create a
    # snapshot.
    function clcGetTemporaryVMXContent() {
        cat << EOF
.encoding = "UTF-8"
config.version = "8"
virtualHW.version = "7"
ide0:0.present = "TRUE"
ide0:0.fileName = "$1"
displayName = ""
EOF
        return $?
    }

    # This functions escapes every special meaning character for a sed
    # replacement.
    #
    # Examples:
    #
    # >>> sed "s/myInputString/$(clcValidateSEDReplacement '\hans/peter&klaus')/g"
    function clcValidateSEDReplacement() {
## bash
##         sed --expression 's/\\/\\\\/g' --expression 's/\//\\\//g' \
##             --expression 's/&/\\\&/g' <<< "$1"
        sed -e 's/\\/\\\\/g' -e 's/\//\\\//g' -e 's/&/\\\&/g' <<< "$1"
##
        return $?
    }

    # endregion

    # region main tasks

    # Creates a snapshot from VMware generated virtual machine.
    function clcCreateVMwareSnapshot() {
        local temporaryConfigurationPath="$(mktemp --directory)/" \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        local temporaryConfigurationFilePath="$(mktemp --suffix '.vmx')" \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        clcLog "Generate a temporary virtual machine configuration file \"$temporaryConfigurationFilePath\"." && \
        clcGetTemporaryVMXContent "$(dirname \
            "$_BASIC_IMAGE_CONFIGURATION_FILE_PATH")/$(clcGetXMLValue \
            'image_name')" 1>"$temporaryConfigurationFilePath" \
            2>"$_ERROR_OUTPUT" && \
        mv "$temporaryConfigurationFilePath" "$temporaryConfigurationPath" \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        clcLog "Needed temporary files generated in \"$temporaryConfigurationPath\" generated." && \
        vmrun snapshot "$temporaryConfigurationPath"*.vmx \
            persistentUserSnapshot 1>"$_STANDARD_OUTPUT" \
            2>"$_ERROR_OUTPUT" && \
        mv "$temporaryConfigurationPath"*.vmdk "$_TARGET_PATH" \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT"
        local result=$?
        if [[ "$_DEBUG" == 'no' ]]; then
## bash             rm --recursive "$temporaryConfigurationPath" \
            rm -r "$temporaryConfigurationPath" \
                1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT"
        fi
        return $result
    }

    # Creates a snapshot from virtualBox generated virtual machine.
    function clcCreateVirtualBoxSnapshot() {
        local temporaryConfigurationPath="$(mktemp --directory)/" \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
## bash
##         (cp --recursive ~/.VirtualBox/ \
##              "${temporaryConfigurationPath}virtualBoxBackup" \
##              1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" || \
##          mkdir --parents \
##              "${temporaryConfigurationPath}virtualBoxBackup" \
##              1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT") && \
        (cp -r ~/.VirtualBox/ \
             "${temporaryConfigurationPath}virtualBoxBackup" \
             1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" || \
         mkdir -p "${temporaryConfigurationPath}virtualBoxBackup" \
             1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT") && \
##
        # VBoxManage version to create snapshots.
        clcLog 'Create a temporary virtual machine.' && \
        # NOTE: Virtualbox needs 5 at leas 5 seconds to register that it has
        # a new configuration directory.
        sleep 5 1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        VBoxManage createvm --name tmp --basefolder \
            "$temporaryConfigurationPath" --register 1>"$_STANDARD_OUTPUT" \
            2>"$_ERROR_OUTPUT" && \
        clcLog 'Create a temporary virtual ide controller.' && \
        VBoxManage storagectl tmp --name tmp --add ide 1>"$_STANDARD_OUTPUT" \
            2>"$_ERROR_OUTPUT" && \
        clcLog 'Attach given virtual disk image to temporary virtual machine.' && \
        VBoxManage storageattach tmp --storagectl tmp --port 0 --device 0 \
            --type hdd --medium  "$(dirname \
                "$_BASIC_IMAGE_CONFIGURATION_FILE_PATH")/$(clcGetXMLValue \
                    'image_name')" \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        clcLog "Needed temporary files generated in \"$temporaryConfigurationPath\" generated." && \
        clcLog "Take a snapshot with name or uuid \"$_VIRTUAL_BOX_SNAPSHOT_NAME\"." && \
        VBoxManage snapshot tmp take "$_VIRTUAL_BOX_SNAPSHOT_NAME" \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
## bash
##         local virtualBoxSnapshotUUID="$(basename \
##             "${temporaryConfigurationPath}tmp/Snapshots/"*.vdi | sed \
##             --regexp-extended 's/\{(.+)\}\..+/\1/g')" \
##             1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        local virtualBoxSnapshotUUID="$(basename \
            "${temporaryConfigurationPath}tmp/Snapshots/"*.vdi | sed \
            -r 's/\{(.+)\}\..+/\1/g')" 1>"$_STANDARD_OUTPUT" \
            2>"$_ERROR_OUTPUT" && \
##
        echo "$virtualBoxSnapshotUUID" \
            1>"$_VIRTUAL_BOX_SNAPSHOT_UUID_FILE_PATH" 2>"$_ERROR_OUTPUT" && \
        clcLog "Created snapshot uuid is \"$virtualBoxSnapshotUUID\" (uuid saved to \"$_VIRTUAL_BOX_SNAPSHOT_UUID_FILE_PATH\")." && \
        clcLog "Copy result to given target path \"$_TARGET_PATH\"." && \
        cp "${temporaryConfigurationPath}tmp/Snapshots/"*.vdi "$_TARGET_PATH" \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        # NOTE: Isn't possible because virtualbox tries to consolidate with
        # readonly basic image.
        #VBoxManage snapshot tmp delete "$_VIRTUAL_BOX_SNAPSHOT_NAME" \
        #    1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        # NOTE: Isn't possible because virtual box has child images registered.
        #VBoxManage closemedium disk "$(dirname \
        #    "$_BASIC_IMAGE_CONFIGURATION_FILE_PATH")/$(clcGetXMLValue \
        #        'image_name')" 1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        clcLog 'Detach given virtual disk image from temporary created virtual machine.' && \
        VBoxManage storageattach tmp --storagectl tmp --port 0 --device 0 \
            --medium none 1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        clcLog 'Remove virtual dummy harddisk.' && \
        VBoxManage storagectl tmp --name tmp --remove \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        clcLog 'Unregister temporary created virtual machine.' && \
        VBoxManage unregistervm tmp 1>"$_STANDARD_OUTPUT" \
            2>"$_ERROR_OUTPUT" && \
        clcLog 'Restore virtualbox home directory.' && \
## bash
##         rm --recursive --force ~/.VirtualBox/ 1>"$_STANDARD_OUTPUT" \
##             2>"$_ERROR_OUTPUT" && \
##         cp --recursive "${temporaryConfigurationPath}virtualBoxBackup/" \
##             ~/.VirtualBox/ 1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
##         rm --recursive --force "$temporaryConfigurationPath" && \
##             1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        rm -rf ~/.VirtualBox/ 1>"$_STANDARD_OUTPUT" \
            2>"$_ERROR_OUTPUT" && \
        cp -r "${temporaryConfigurationPath}virtualBoxBackup/" \
            ~/.VirtualBox/ 1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        rm -rf "$temporaryConfigurationPath" && \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
##
        # NOTE: Virtualbox needs at least 5 seconds to register that it has
        # a new configuration directory.
        sleep 5 1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT"
        local result=$?
        if [[ "$_DEBUG" == 'no' ]]; then
## bash             rm --recursive "$temporaryConfigurationPath" \
            rm -r "$temporaryConfigurationPath" \
                1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" || \
            return $?
        fi
        return $result
    }

    # Creates a persistent version of given configuration file.
    function clcCreatePersistentConfig() {
        clcLog "Create a persistent configuration file version from \"$_BASIC_IMAGE_CONFIGURATION_FILE_PATH\" in \"$_TARGET_PATH\"." && \
        cp "$_BASIC_IMAGE_CONFIGURATION_FILE_PATH" "$_TARGET_PATH" && \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        clcLog 'Edit short description.' && \
## bash         sed --in-place --regexp-extended \
        sed -i -r \
            "s/(< *short_description[^>]*param=\"[^\"]*)(\")/\\1$_PERSISTENT_SHORT_DESCRIPTION_SUFFIX\\2/g" \
            "$_TARGET_PATH" 1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        clcLog 'Append "original_xml_file_path" tag.' && \
## bash
##         sed --in-place --regexp-extended \
##             "s/^([ \\t]*)(< *persistent[^>]+param=\"[^\"]+\"[^>]*>)/\\1\\2\\n\\1<original_xml_file_path param=\"$(clcValidateSEDReplacement \
##                 "$(readlink --canonicalize \
##                 "$_BASIC_IMAGE_CONFIGURATION_FILE_PATH")")\"\/>/g" \
##             "$_TARGET_PATH" 1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        sed -i -r \
            "s/^([ \\t]*)(< *persistent[^>]+param=\"[^\"]+\"[^>]*>)/\\1\\2\\n\\1<original_xml_file_path param=\"$(clcValidateSEDReplacement \
                "$(readlink -f \
                "$_BASIC_IMAGE_CONFIGURATION_FILE_PATH")")\"\/>/g" \
            "$_TARGET_PATH" 1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
##
        clcLog 'Edit image file path.' && \
## bash         sed --in-place --regexp-extended \
        sed -i -r \
            "s/(< *image_name[^>]*param=\")[^\"]*(\")/\\1$(clcValidateSEDReplacement \
            "$_PERSISTENT_CONFIG_TARGET")\\2/g" "$_TARGET_PATH" \
            1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        clcLog 'Convert configuration file from windows style line endings to unix line endings.' && \
## bash
##         sed --in-place --regexp-extended 's/\r//g' "$_TARGET_PATH" \
##             1>"$_STANDARD_OUTPUT" 2>"$_ERROR_OUTPUT" && \
        sed -i -r 's/\r//g' "$_TARGET_PATH" 1>"$_STANDARD_OUTPUT" \
            2>"$_ERROR_OUTPUT" && \
##
        return $?
    }

    # endregion

# endregion

# region controller

    clcCommandLineInterface "$@" || return $?
    if [[ "$_PERSISTENT_CONFIG_TARGET" ]]; then
        clcCreatePersistentConfig || \
            clcLog 'error' 'Creating persistent configuration file failed.'
    else
        "clcCreate${_HYPERVISOR}Snapshot" || \
            clcLog 'error' 'Creating Linked Clone failed.'
    fi
    clcLog 'Program has successfully finished.' && \
    return $?

# endregion

}

# region footer

if [[ "$0" == *"${__NAME__}" ]]; then
    "$__NAME__" "$@"
fi

# endregion