updater

#!/bin/bash
#AirConnect Updater - Pull latest Update from https://github.com/philippe44/AirConnect
#AirConnect by philippe44 - updater script by FaserF https://github.com/FaserF

#Variables
newversion=0000
currentversion=0000
state=NoLocalInstallationFound
currentdirectory=$PWD
tmpfolder=/tmp/AirConnect
backupfolder=$tmpfolder/backup
downloadfolder=$tmpfolder/download


function checkLocalInstallation() {
	if [ -f "CHANGELOG" ] && [ -f "airupnp.service" ]
	then
		echo "Current installation detected"

		#Remeber current install directory
		currentdirectory=$PWD

		#Set state
		state=LocalInstallationFound
	fi
	if [ -f "$currentdirectory/AirConnect/CHANGELOG" ]  &&  [ -f "$currentdirectory/AirConnect/airupnp.service" ]
	then
		echo "Current installation detected in subfolder AirConnect"
		
		#Remeber current install directory
		currentdirectory=$PWD/AirConnect
		
		#Set state
		state=LocalInstallationFound
	fi
}


function cleanInstall() {
	echo "First installation..."

	#Ask for target installation directory
	read -p "Enter full path where to install: " targetdirectory

	if test -z "targetdirectory"
	then
		# install to current path if nothing is entered
		targetdirectory=$PWD
	fi

	if [ "targetdirectory" = "/" ]
	then
		echo "Error: Can't install at root"
		exit 1
	fi

	#Create target directory
	if [ ! -d "$targetdirectory" ]
	then
		mkdir "$targetdirectory"
	fi

	#Install newest version
	echo "----"
	echo "Installing newest version..."
	echo "----"
	git clone --depth=1 https://github.com/philippe44/AirConnect.git $targetdirectory 2>&1 >/dev/null 
}


function prepareTmpFolder() {
	#Delete previous folder if still exist 
	if [ -d "$tmpfolder" ]
	then
	  rm -rf $tmpfolder
	fi

	#Create new empty tmp folders
	mkdir $tmpfolder
	mkdir $tmpfolder/backup
	mkdir $tmpfolder/download
}


function searchNewVersion() {
	#Checking for new Updates
	echo "----"
	echo "Checking for new updates"
	echo "----"
	
	#Download online changelog
	download https://raw.githubusercontent.com/philippe44/AirConnect/master/CHANGELOG $tmpfolder/CHANGELOG

	#Calculate online version
	newversion=$(head -n 1 $tmpfolder/CHANGELOG)
	newversion=${newversion//[-._]}

	#Delete online changelog
	rm $tmpfolder/CHANGELOG
	
	#Grep current version number
	currentversion=$(head -n 1 $currentdirectory/CHANGELOG)
	currentversion=${currentversion//[-._]}

	if [ "$newversion" -gt "$currentversion" ]
	then
	    echo "Found new version: $newversion"
		state=NewVersionFoundOnGithub
	else
	    echo "No new update found"
	fi
}


function backupCurrentVersion() {
	echo "----"
	echo "Backing up old version..."
	mv $currentdirectory/* $tmpfolder/backup
}


function updateCurrentVersion() {
	#Remove previous version files
	rm -rf $currentdirectory/*

	#Download newest Version
	echo "----"
	echo "Update version..."
	echo "----"
	git clone --depth=1 https://github.com/philippe44/AirConnect.git $downloadfolder 2>&1 >/dev/null

	#Install
	mv $downloadfolder/* $currentdirectory
}


function validateUpdatedVersion() {
	versioncheck=$(head -n 1 $currentdirectory/CHANGELOG)
	versioncheck=${versioncheck//[-._]}

	if [ "$versioncheck" -eq "$newversion" ]
	then
	    echo "----"
	    echo "Update done"
	    echo "----"
	    echo "New Version: $versioncheck"
	else
	    echo "----"
	    echo "Update failed"
	    echo "----"
	    echo "Current Version: $currentversion"	
	fi

	echo "-----"
	echo "Old version backup in: $backupfolder"
}


function download() {
    url=$1
    filename=$2

    if [ -x "$(which wget)" ] ; then
        wget -q $url -O $2
    elif [ -x "$(which curl)" ]; then
        curl -o $2 -sfL $url
    else
        echo "Could not find curl or wget, please install one." >&2
    fi
}


#
# Main
#########################################
#
#

#Check if AirConnect is already installed
checkLocalInstallation

if [ $state = "NoLocalInstallationFound" ]
then
	#Install new version
	cleanInstall
else
	#Create needed folder
	prepareTmpFolder
	
	#Check if a new version is available
	searchNewVersion
	
	if [ $state = "NewVersionFoundOnGithub" ]
	then
		#Backup Current Installation
		backupCurrentVersion
		
		#Update Current Installation
		updateCurrentVersion
		
		#Validate Version
		validateUpdatedVersion
	fi
fi