TronUpdate V3.7

#!/bin/bash
#Automatically downloads new versions of tron script
#This script is designed to update mirrors for tron script. You should probably run it as a cron job.
#
#
#Tron script is located at http://reddit.com/r/tronscript
#
#Written by reddit.com/u/-jimmyrustles
#VERSION 3.7

#CHANGELOG:
#V1.0 Initial release
#V1.1 Forgot double quotes around some variables.
#V2.0 Added file integity check.
#V3.0 Use HTTPS for updating instead of HTTP. Option to purge old versions when updating. Simplified and fixed several things. Added more comments and changed appearance.
#V3.5 Added option to symlink updated file. Fixed "find" searching subdirectories when deleting.
#V3.6 Do not use absolute symbolic links.
#V3.7 Fix symlink getting deleted when updating

#USAGE:
#./tronupdate.sh <directory to download tron in>
#If directory is not specified, the script will default to the current directory


#Change to "true" to purge all previous tron versions when updating.
purgeoldversions="false"

#symlink latest tron version to "latest.exe" when updating
#Change to "true" to enable
symlink="false"


#enable text colours
red=$(tput setaf 1)
green=$(tput setaf 2)
blue=$(tput setaf 4)
reset=$(tput sgr0)
invert=$(tput rev)

# Set repo url
repodir="https://jailhouse.sgc-hosting.com/~bmrforg/repos/tron" #You will most likely want to keep this as it is.
#repodir="http://bmrf.org/repos/tron" #Fallback HTTP mirror

#repodir="http://localhost" #debug (you don't want this)
#repodir="http://localhost/thisdoesnotexist" #debug (you don't want this)

# Set tron repo md5sums.txt file url
md5sumsurl="https://jailhouse.sgc-hosting.com/~bmrforg/repos/tron/md5sums.txt" #You most likely want to keep this as it is.
#md5sumsurl="http://bmrf.org/repos/tron/md5sums.txt" #Fallback HTTP mirror

#set download location (usually your tron mirror directory)
#if directory is not specified on the command line, it will default to the current directory. This can be overwritten.

#change this to change the default directory
defaultdownloaddir="."

if [ "$1" == "" ] #If directory not specified, use default
then
    echo "${red}Download directory not specified, using default (current directory)!${reset}"
    echo
    downloaddir=$defaultdownloaddir #use default directory
else
    downloaddir=$1 #use specified directory
fi

#hash verify function
function verify {
    #Verify downloaded file using "md5sum"
    echo "${green}VERIFYING DOWNLOADED FILE!${reset}"
        #Get "correct" hash from md5sums.txt
        correcthash=$(tail -n 1 "$downloaddir/md5sums.txt" | awk '{ print $1 }')
        #Get hash of downloaded file
        localhash=$(md5sum "$downloaddir/$updatefile" | awk '{ print $1 }')
        #Print hashes
        echo "${green}The hash should be:${red} $correcthash${reset}"
        echo "${green}Your hash is:${red} $localhash${reset}"

        #Check if hashes match.
        if [ "$correcthash" == "$localhash" ]
        then
                verified="true"
        else
        verified="false"

        fi

}

#function that redownloads if not verified, quits if verified
function checkifverified {
        if [ "$verified" == "true" ]
        then
                echo "${green}Hashes Match! $updatefile Verified!${reset}"
                echo "${green}MIRROR UPDATED!${reset}"
        #Purge old versions (if enabled)
        if [ "$purgeoldversions" == "true" ]
        then
                echo "${red}Removing old tron versions!${reset}"
                echo "${blue}"
                #Produce list of old tron files, and use xargs to parse and delete these files.
                find "$downloaddir" -maxdepth 1 | grep 'Tron\|exe' | grep -v "$updatefile" | xargs -n 3 | sed 's/.*/"&"/' | xargs rm -f -v
                echo "${reset}"
                echo "${green}Done!${reset}"
        fi

        #symlink updated tron file to "latest.exe" (if enabled)
        if [ "$symlink" == "true" ]
        then
            echo "${blue}symlinking to \"latest.exe\"${reset}"
            #change dir to download dir.
            cd "$downloaddir"
            #symlink. -s (symbolic) -f (force) -v (verbose)
            ln -s -f -v "$updatefile" "latest.exe"
            echo "${green}Done!${reset}"
        fi
        exit
        else
                echo "${red}Hashes do not match! $updatefile does not match repo file! Will retry!${reset}"
        #cleanup corrupt file
        rm -f -v "$downloaddir/$updatefile"
        #redownload
        echo "${invert}"
        wget -nc -O "$downloaddir/$updatefile" "$repodir/$updatefile"
        echo "${reset}"
        #increment "downloadtries" by 1
        downloadtries=$((downloadtries + 1))
        fi
}


#download md5sums.txt to $downloaddir if repo version is newer
echo "${invert}"
wget -P "$downloaddir" -N "$md5sumsurl"
echo "${reset}"

#get latest version number
latestversion=$(tail -n 1 "$downloaddir/md5sums.txt" | awk '{ print $3 }')

echo "${red}Latest version is:${green} $latestversion ${reset}"

#find latest local version
localversion=$(ls -1 "$downloaddir" | grep 'Tron' | grep 'exe' | tail -n 1 | awk '{ print $2 }')

#if existing mirror does not exist, then fake older version
if [ "$localversion" == "" ]
then
    echo "${red} EXISTING MIRROR NOT FOUND, WILL DOWNLOAD!${reset}"
    localversion="v0.0.0"
fi
echo "${red}Your version:${green} $localversion ${reset}"

#compare local and remote versions
if [ "$latestversion" == "$localversion" ]
then
    echo "MIRROR IS UP TO DATE!"
    exit
fi

if [ "$latestversion" != "$localversion" ]
then
    echo "MIRROR IS OUT OF DATE! UPDATING!"
    #identify version to update to
    updatefile=$(tail -n 1 "$downloaddir/md5sums.txt" | sed 's/*//g' | awk '{ print $2 " " $3 " " $4 }')
    #actually download tron
    echo "${invert}"
    wget -nc -O "$downloaddir/$updatefile" "$repodir/$updatefile"
    echo "${reset}"
    #set download tries to "1"
    downloadtries=1

    #Run while file is not verified
    while [ "$verified" != "true" ]
    do
        #do while download attempts is less than 5
        if (( downloadtries < 5 ))
        then
            verify
            checkifverified
        else
            #fail if still can't verify after 5 downloads
            echo "${red}After $downloadtries downloads $updatefile could still not be verified! Giving Up!${reset}"
            #cleanup corrupt file
            rm -f -v "$downloaddir/$updatefile"
            #exit (obviously) :)
            exit
        fi

    done
fi

#Oops.
echo "${red}The script should never terminate by reaching the end! This should never be executed!${reset}"