#!/bin/sh

#
# update script for ab-nginx container and utility scripts
#   version 6.0.0
#   script by Asif Bacchus
#

#
# functions
errMsg() {
  printf "\n%s%s%s\n\n" "$err" "$1" "$norm"
  [ -n "$2" ] && exit "$2" || 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"
}

scriptHelp() {
  textNewline
  textBlock "Update ${containerName} container and helper script files"
  textBlock "${bold}Usage: ${localScriptName} [parameters]${norm}"
  textNewline
  textBlock "If run with no parameters, the script will update both the container and the helper script files, including this update script."
  textBlockHeader " parameters "
  textBlockParam "-h | -? | --help" "Display this help screen."
  textBlockParam "-c | --container | --container-only" "Update the docker container only."
  textBlockParam "-s| --scripts |--scripts-only" "Update the helper scripts (including this update script) only."
  textNewline
  exit 0
}

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='ldap'
containerName='ab-openldap'
containerUpdatePath="docker.asifbacchus.dev/$dockerNamespace/$containerName:latest"
server="https://asifbacchus.dev/public/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 "$1" in
  -h | -\? | --help)
    # display inline help
    scriptHelp
    ;;
  -s | --scripts | --scripts-only)
    # update scripts only, skip docker container update
    doDockerUpdate=0
    ;;
  -c | --container | --container-only)
    # update docker container only, skip script update
    doScriptUpdate=0
    ;;
  *)
    printf "%s\nUnknown option: %s\n" "$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." 2
  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." 2
    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." 31
  else
    okMsg "Container updated!"
  fi
fi

#
# update scripts
if [ "$doScriptUpdate" -eq 1 ]; then
  printf "%s*** Updating %s helper scripts ***%s\n" "$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." 41
  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}${repoScriptName}"; then
      errNotify
      # delete failed download as necessary
      rm -f ./update.sh.tmp 2>/dev/null
      errMsg "Unable to download script update. Try again later." 42
    else
      # verify download
      dlScriptChecksum=$(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." 42
      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 "$localScriptName"
        chmod +x "$localScriptName"
        exit 0
      fi
    fi
  fi

  while IFS='  ' read -r field1 field2; do
    if [ "$field2" = "update.sh" ]; then continue; fi
    printf "\nChecking '%s' for updates... " "$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"
          if [ "${updateFilename##*.}" = "sh" ]; then
            # shell file --> make it executable
            chmod +x "$updateFilename"
          fi
        fi
      fi
    else
      printf "[NONE]\n"
    fi
  done <"$checksumFilename"
fi

#
# display results
if [ "$doScriptUpdate" -eq 1 ]; then
  printf "\n%s*** Results ***%s\n" "$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"
fi

#
# exit
if [ "$downloadFailed" -gt 0 ]; then
  exit 43
elif [ "$updateFailed" -gt 0 ]; then
  exit 44
else
  exit 0
fi
# this is a trap for mis-coding... should never get an exit code 99!
exit 99

#
# exit return codes
# 0:        normal exit, no errors
# 1:        missing or invalid parameter
# 2:        docker not found or no docker permissions
# 31:       unable to update docker container
# 4x:       helper files errors
#   40:     unable to make download directories
#   41:     unable to download checksums
#   42:     update script: unable to download or bad checksum
#   43:     update helpers: unable to download
#   44:     update helpers: bad checksum, no update
# 99:       coding mistake trap -- this return code should never happen!

#EOF