#!/bin/sh

### update script for <ab-container> container and utility scripts
# version x.y.z
# script by Asif Bacchus
# usage of this script is subject to the license terms found at:
# https://git.asifbacchus.app/ab-docker/scripts/LICENSE


### pre-requisites

# check if wget is installed
if ! command -v wget > /dev/null 2>&1; then
    printf "\nSorry, this script requires that 'wget' is installed in order to automatically update files.\nExiting.\n\n"
    exit 1
fi

# is user root or in the docker group?
if [ ! "$( id -u )" -eq 0 ]; then
    if ! id -Gn | grep docker > /dev/null; then
        consoleError '1' "You must either be root or in the 'docker' group to pull container updates."
    fi
fi

# zero counters
updatesAvailable=0
downloadFailed=0
downloadSuccess=0
updateFailed=0
updateSuccess=0

# reference constants
containerName=''
containerUpdatePath='docker.asifbacchus.app/...:latest'
server="https://git.asifbacchus.app/ab-docker/scripts/raw/branch/master/$containerName/"
checksumFilename='checksums.sha256'

# files to update
localScriptName='update.sh'
repoScriptName='update.sh'
updateFiles=""


### update container
printf "\n*** Updating %s container and service scripts ***\n\n" "$containerName"

printf "Updating container:\n"
if ! docker pull "$containerUpdatePath"; then
    printf "There was an error updating the container. Try again later.\n\n"
    exit 1
else
    printf "Container updated!\n"
fi


### update scripts
printf "Updating %s service scripts\n" "$containerName"

## download latest checksums
printf "Getting latest checksums from ab-git server... "
if ! wget --quiet --tries=3 --timeout=10 -N "${server}${checksumFilename}"; then
    printf "[ERROR]\n"
    printf "Unable to download checksums from ab-git server. Try again later.\n\n"
    exit 1
else
    printf "[OK]\n"
fi

## check for updates to this script
printf "Checking for updates to this script... "
repoScriptChecksum=$( grep "$repoScriptName" "$checksumFilename" | grep -o '^\S*' )
localScriptChecksum=$( sha256sum "$localScriptName" | grep -o '^\S*' )
if [ "$localScriptChecksum" = "$repoScriptChecksum" ]; then
    printf "[NONE]\n"
else
    # download updated script
    if ! wget --quiet --tries=3 --timeout=10 -O $localScriptName "${server}${repoScriptName}"; then
        printf "[ERROR]\n"
        printf "Unable to download script update. Try again later.\n\n"
        exit 1
    else
        # verify download
        localScriptChecksum=$( sha256sum "$localScriptName" | grep -o '^\S*' )
        if ! [ "$localScriptChecksum" = "$repoScriptChecksum" ]; then
            printf "[ERROR]\n"
            printf "Unable to verify checksum of updated script. Try again later.\n\n"
        else
        printf "[UPDATED]\n\n"
        printf "*** This script has been updated. Please re-run it to load the updated version of this file. ***\n\n"
        exit 0
        fi
    fi
fi

## update files
set -- dummy $updateFiles
shift
for file; do
    updateTarget="$file"
    printf "\nChecking '%s' for updates... " "$updateTarget"
    repoFile=$( grep "$updateTarget" "$checksumFilename" | grep -o '^\S*' )
    if [ -f "$file" ]; then
        localFile=$( sha256sum "$updateTarget" | grep -o '^\S*' )
    else
        localFile=0
    fi

    if ! [ "$localFile" = "$repoFile" ]; then
        printf "[AVAILABLE]\n"
        updatesAvailable=$((updatesAvailable+1))
        # download update
        printf "Downloading updated '%s'... " "$updateTarget"
        # specify a name here instead of using the server name so that wget
        # overwrites the file
        if ! wget --quiet --tries=3 --timeout=10 -O "$updateTarget" "${server}${updateTarget}"; then
            printf "[ERROR]\n"
            downloadFailed=$((downloadFailed+1))
        else
            printf "[OK]\n"
            downloadSuccess=$((downloadSuccess+1))
            # verify download
            printf "Verifying '%s'... " "$updateTarget"
            localFile=$( sha256sum "$updateTarget" | grep -o '^\S*' )
            if ! [ "$localFile" = "$repoFile" ]; then
                printf "[INVALID]\n"
                updateFailed=$((updateFailed+1))
            else
                printf "[OK]\n"
                updateSuccess=$((updateSuccess+1))
            fi
        fi
    else
        printf "[NONE]\n"
    fi
done


### display results
printf "\nResults:\n"
printf "\tUpdates: %s available\n" "$updatesAvailable"
printf "\tDownloads: %s successful, %s failed\n" "$downloadSuccess" "$downloadFailed"
printf "\tUpdates: %s applied, %s failed\n" "$updateSuccess" "$updateFailed"

exit 0