DbusSettingsResources

#!/bin/bash

# DbusSettingsResources for SetupHelper
#
# contains a functions and variables necessary to access dbus Settings parameters
# it should be sourced by scripts setting, creating and removing dbus settings
#
# dbus Settings is not operational during system boot when some setup scripts may
# need to make settings changes
# These functions check to see if the settings system is operational and defer
# the set/create/remove activity so the calling script may continue

# dbus Settings funcitons
# These functions encapsulate an interface to dbus Settings
# NOTE: dbus Settings resources are not always active when it is necessary for
# scripts to make changes or create/remove settings
# it is up to the caller to insure dbus Settings resources are active before callling
# these functions
# a dbus exeption error will be logged if settings are not active yet


# updateDbusStringSetting
# updateDbusIntSetting
# updateDbusRealSetting
#   updates a dbus setting parameter with a new value
#
# if the setting does not exist, it is created
# but max and min values are not set and the default is "", 0 or 0.0 depending on data type
# if these are needed use the dbus command directly
#   this can also be faster if lots of settings must be created at the same time
#
# other data types may exist and would need their own function
#
# $1 is the path to the setting starting with /Settings
# $2 is the new value
#
# if the setting does not yet exist, it is created, then updated to the new value

updateDbusStringSetting ()
{
	# don't do any work if install has already failed
	if $installFailed; then
		return
	fi

    dbus-send --system --print-reply=literal --dest=com.victronenergy.settings "$1"\
            com.victronenergy.BusItem.GetValue &> /dev/null
    if (( $? != 0 )); then
        logMessage "creating dbus Setting $1"
        dbus -y com.victronenergy.settings / AddSettings "%[ {\"path\":\"$1\", \"default\":\"\"} ]" &> /dev/null
    fi

	dbus -y com.victronenergy.settings "$1" SetValue -- "$2" &> /dev/null
}


updateDbusIntSetting ()
{
	# don't do any work if install has already failed
	if $installFailed; then
		return
	fi

    dbus-send --system --print-reply=literal --dest=com.victronenergy.settings "$1"\
            com.victronenergy.BusItem.GetValue &> /dev/null
    if (( $? != 0 )); then
        logMessage "creating dbus Setting $1"
        dbus -y com.victronenergy.settings / AddSettings "%[ {\"path\":\"$1\", \"default\":0} ]" &> /dev/null
    fi

    dbus -y com.victronenergy.settings "$1" SetValue -- "$2" &> /dev/null
}


updateDbusRealSetting ()
{
	# don't do any work if install has already failed
	if $installFailed; then
		return
	fi

    dbus-send --system --print-reply=literal --dest=com.victronenergy.settings "$1"\
            com.victronenergy.BusItem.GetValue &> /dev/null
    if (( $? != 0 )); then
        logMessage "creating dbus Setting $1"
        dbus -y com.victronenergy.settings / AddSettings "%[ {\"path\":\"$1\", \"default\":0.0} ]" &> /dev/null
    fi

    dbus -y com.victronenergy.settings "$1" SetValue -- "$2" &> /dev/null
}



# addAllDbusSettings adds settings from DbusSettingsList in the package directory
# the format of each line is:
# {"path":"/Settings/GuiMods/ShortenTankNames", "default":1, "min":0, "max":1}
# min and max are optional

addAllDbusSettings ()
{
	local settings

	if [ -f "$scriptDir/DbusSettingsList" ]; then
		logMessage "updating dbus Settings"
		while read -r line || [[ -n "$line" ]]; do
			settings+="$line, "
		done < "$scriptDir/DbusSettingsList"

		dbus -y com.victronenergy.settings / AddSettings "%[ $settings  ]" &> /dev/null
	fi
}

# same as above but removes them
# typically settings are retained when removing a package so
# the developer must make this call specifically in the setup script's UNINSTALL section
# if they wish to remove the settings

removeAllDbusSettings ()
{
	local settings

	if [ -f "$scriptDir/DbusSettingsList" ]; then
		logMessage "removing dbus Settings"
		while read -r line || [[ -n "$line" ]]; do
				settings+=$( echo $line | awk -F[:,] '{print $2, ","}' )
		done < "$scriptDir/DbusSettingsList"

		dbus -y com.victronenergy.settings / RemoveSettings "%[ $settings  ]"
	fi
}



# removeDbusSettings removes the setting from dbus Settings
#
# all parameters are each a quoted path to the setting to be removed
# e.g., removeDbusSettings "/Settings/foo" "/Settings/bar"
# (including all settings in one dbus call is much faster)

removeDbusSettings ()
{
    logMessage "removing dbus Settings $@"
    local settings=$(echo "$@" | sed -e s_^_\"_ -e s_\$_\"_ -e s_\ _'", "'_g)
    dbus -y com.victronenergy.settings / RemoveSettings "%[ $settings ]" &> /dev/null
}


# setSetting updates the dbus setting parameter
# the setting must already exist or the update will fail
# (the setting can not be created without knowing the data type(s))
#
# $1 is the new value
# $2 is the setting path

setSetting ()
{
	# don't do any work if install has already failed
	if $installFailed; then
		return
	fi

    dbus -y com.victronenergy.settings $2 SetValue $1 &> /dev/null
}

# move a setting from setup options or from previous dbus Setting
# $1 is the setup options path
# $2 is the old dbus path (has priority over setup option)
# $3 is the new dbus path
# dbus paths start with /Settings
# if specified, the setup option file must include a value
#   that value has priority over the old dbus parameter
#
# setup options can either contain a value or be a flag file
# for flag files, the file will be empty and the state of the option
# depends on the presence of the file (true) or absense of the file (false)
#
# Note: this function does NOT create or remove any old option or Setting
# use other functions or commands to do so

moveSetting ()
{
	# don't do any work if install has already failed
	if $installFailed; then
		return
	fi

    local setupOption="$1"
    local oldDbusPath=$2
    local newDbusPath=$3

    if [ ! -z "$oldDbusPath" ]; then
        oldSetting=$(dbus-send --system --print-reply=literal --dest=com.victronenergy.settings\
            $oldDbusPath com.victronenergy.BusItem.GetValue 2> /dev/null | awk '{print $3}')
    elif [ ! -z $setupOption ]; then
        if [ -f "$setupOption" ]; then
            oldSetting=$(cat "$setupOption")
            # flag file - old setting is true (1)
            if [ -z $oldSetting ]; then
                oldSetting=1
            fi
        # file did not exist - assume a false value for a flag file
        else
            oldSetting=0
        fi
    else
        oldSetting=""
    fi
    if [ ! -z $oldSetting ] && [ ! -z "$newDbusPath" ]; then
        dbus -y com.victronenergy.settings $newDbusPath SetValue $oldSetting &> /dev/null
    fi
}