#!/bin/sh

### update script for ab-nginx container and utility scripts
# version 2.0.0
# script by Asif Bacchus
###

### functions
errMsg() {
  printf "\n%s%s%s\n\n" "$err" "$1" "$norm"
  exit 1
}

errNotify() {
  printf "%s[ERROR]%s\n" "$err" "$norm"
}

okMsg() {
  printf "%s%s%s\n\n" "$ok" "$1" "$norm"
}

okNotify() {
  printf "%s[OK]%s\n" "$ok" "$norm"
}

textblock() {
  printf "%s\n" "$1" | fold -w "$width" -s
}

textblockHeader() {
  printf "\n%s***%s***%s\n" "$header" "$1" "$norm"
}

textblockParam() {
  printf "%s%-35s%s%s\n" "$info" "$1" "$2" "$norm"
}

textNewline() {
  printf "\n"
}

### text formatting presets
if command -v tput >/dev/null 2>&1; then
  bold=$(tput bold)
  err=$(tput bold)$(tput setaf 1)
  info=$(tput bold)$(tput setaf 6)
  header=$(tput bold)$(tput setaf 5)
  norm=$(tput sgr0)
  ok=$(tput sgr0)$(tput setaf 2)
  warn=$(tput bold)$(tput setaf 3)
  width=$(tput cols)
else
  bold=''
  err=''
  info=''
  header=''
  norm=''
  ok=''
  warn=''
  width=80
fi

### pre-requisites
# check if wget is installed
if ! command -v wget >/dev/null 2>&1; then
  errMsg "Sorry, this script requires that 'wget' is installed in order to download updates. Exiting."
fi

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

# reference constants
dockerNamespace='nginx'
containerName='ab-nginx'
containerUpdatePath="docker.asifbacchus.app/$dockerNamespace/$containerName:latest"
server="https://asifbacchus.app/updates/docker/$dockerNamespace/$containerName/"
checksumFilename='checksums.sha256'

# operation triggers
doDockerUpdate=1
doScriptUpdate=1

# files to update
localScriptName="$(basename "$0")"
repoScriptName='update.sh'


### process startup parameters
while [ $# -gt 0 ]; do
  case "$1" in
    -h|-\?|--help)
      # display inline help
      # TODO: create script help function
      scriptHelp
      ;;
    -s|--scripts|--scripts-only)
      # update scripts only, skip docker container update
      doDockerUpdate=0
      ;;
    -c|--container|--container-only)
      # update docker container only, skip script update
      doScriptUpdate=0
      ;;
    *)
      printf "%s\nUnknown option: %s\n" "$err" "$1"
      printf "%sUse '--help' for valid options%s\n\n" "$info" "$norm"
      exit 1
      ;;
  esac
shift
done


### update container
if [ "$doDockerUpdate" -eq 1 ]; then
  # check if docker is installed
  if ! command -v docker >/dev/null 2>&1; then
    errMsg "Sorry, it appears that docker is not installed on this machine! Exiting."
  fi

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

  printf "%s\n*** Updating %s container ***\n\n%s" "$info" "$containerName" "$norm"
  if ! docker pull "$containerUpdatePath"; then
    errMsg "There was an error updating the container. Try again later."
  else
    okMsg "Container updated!"
  fi
fi


### update scripts
if [ "$doScriptUpdate" -eq 1 ]; then
  printf "%s*** Updating %s service scripts ***%s\n" "$info" "$containerName" "$norm"

  ## download latest checksums
  printf "Getting latest checksums... "
  if ! wget --quiet --tries=3 --timeout=10 -N "${server}${checksumFilename}"; then
    errNotify
    errMsg "Unable to download checksums. Try again later."
  else
    okNotify
  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" = "$repoScriptChecksum" ]; then
    printf "[NONE]\n"
  else
    printf "[AVAILABLE]\n"
    printf "Getting updated script... "
    # download updated script
    if ! wget --quiet --tries=3 --timeout=10 -O "update.sh.tmp" "${server}${repoScriptName}"; then
      errNotify
      # delete failed download as necessary
      rm -f ./update.sh.tmp 2>/dev/null
      errMsg "Unable to download script update. Try again later."
    else
      # verify download
      dlScriptChecksum=$(sha256sum "update.sh.tmp" | grep -o '^\S*')
      if ! [ "$dlScriptChecksum" = "$repoScriptChecksum" ]; then
        printf "[ERROR]\n"
        # delete corrupt download as necessary
        rm -f ./update.sh.tmp 2>/dev/null
        errMsg "Checksum mismatch! Try again later."
      else
        okNotify
        printf "\n%s*** This script has been updated. Please re-run it to load the updated version of this file. ***%s\n\n" "$warn" "$norm"
        # overwrite this script with updated script
        mv -f ./update.sh.tmp "$localScriptName"
      fi
    fi
  fi

  ## update files
  while IFS='  ' read -r field1 field2; do
    printf "\nChecking '%s' for updates... " "$field2"
    updateFilename="$field2"
    repoFileChecksum="$field1"
    if [ -f "$updateFilename" ]; then
        localFileChecksum=$(sha256sum "$updateFilename" | grep -o '^\S*')
    else
        localFileChecksum=0
    fi

    # update file if necessary
    if ! [ "$localFileChecksum" = "$repoFileChecksum" ]; then
      printf "[AVAILABLE]\n"
      updatesAvailable=$((updatesAvailable + 1))
      # download update
      printf "Downloading updated '%s'... " "$updateFilename"
      if ! wget --quiet --tries=3 --timeout=10 -O "$updateFilename.tmp" "${server}${updateFilename}"; then
        errNotify
        downloadFailed=$((downloadFailed + 1))
        # delete failed download file as necessary
        rm -f "$updateFilename.tmp" 2>&1
      else
        okNotify
        downloadSuccess=$((downloadSuccess + 1))
        # verify download
        printf "Verifying '%s'... " "$updateFilename"
        localFileChecksum=$(sha256sum "$updateFilename.tmp" | grep -o '^\S*')
        if ! [ "$localFileChecksum" = "$repoFileChecksum" ]; then
          errNotify
          updateFailed=$((updateFailed + 1))
          # delete corrupted download file as necessary
          rm -f "$updateFilename.tmp" 2>&1
        else
          okNotify
          updateSuccess=$((updateSuccess + 1))
          # overwrite old version of file
          mv -f "$updateFilename.tmp" "$updateFilename"
        fi
      fi
    else
      printf "[NONE]\n"
    fi
  done <"$checksumFilename"
fi


### display results
printf "\n%s*** Results ***%s\n" "$info" "$norm"
printf "\tUpdates: %s available\n" "$updatesAvailable"
printf "\tDownloads: %s%s successful%s, %s%s failed%s\n" "$ok" "$downloadSuccess" "$norm" "$err" "$downloadFailed" "$norm"
printf "\tUpdates: %s%s applied%s, %s%s failed%s\n" "$ok" "$updateSuccess" "$norm" "$err" "$updateFailed" "$norm"

exit 0