#!/usr/bin/env bash
# Pi-hole: A black hole for Internet advertisements
# (c) 2017 Pi-hole, LLC (https://pi-hole.net)
# Network-wide ad blocking via your own hardware.
#
# Show version numbers
#
# This file is copyright under the latest version of the EUPL.
# Please see LICENSE file for your rights under this license.

# Variables
DEFAULT="-1"
COREGITDIR="/etc/.pihole/"
WEBGITDIR="/var/www/html/admin/"

getLocalVersion() {
  # FTL requires a different method
  if [[ "$1" == "FTL" ]]; then
    pihole-FTL version
    return 0
  fi

  # Get the tagged version of the local repository
  local directory="${1}"
  local version

  cd "${directory}" 2> /dev/null || { echo "${DEFAULT}"; return 1; }
  version=$(git describe --tags --always || echo "$DEFAULT")
  if [[ "${version}" =~ ^v ]]; then
    echo "${version}"
  elif [[ "${version}" == "${DEFAULT}" ]]; then
    echo "ERROR"
    return 1
  else
    echo "Untagged"
  fi
  return 0
}

getLocalHash() {
  # Local FTL hash does not exist on filesystem
  if [[ "$1" == "FTL" ]]; then
    echo "N/A"
    return 0
  fi
  
  # Get the short hash of the local repository
  local directory="${1}"
  local hash

  cd "${directory}" 2> /dev/null || { echo "${DEFAULT}"; return 1; }
  hash=$(git rev-parse --short HEAD || echo "$DEFAULT")
  if [[ "${hash}" == "${DEFAULT}" ]]; then
    echo "ERROR"
    return 1
  else
    echo "${hash}"
  fi
  return 0
}

getRemoteHash(){
  # Remote FTL hash is not applicable
  if [[ "$1" == "FTL" ]]; then
    echo "N/A"
    return 0
  fi

  local daemon="${1}"
  local branch="${2}"

  hash=$(git ls-remote --heads "https://github.com/pi-hole/${daemon}" | \
         awk -v bra="$branch" '$0~bra {print substr($0,0,8);exit}')
  if [[ -n "$hash" ]]; then
    echo "$hash"
  else
    echo "ERROR"
    return 1
  fi
  return 0
}

getRemoteVersion(){
  # Get the version from the remote origin
  local daemon="${1}"
  local version

  version=$(curl --silent --fail "https://api.github.com/repos/pi-hole/${daemon}/releases/latest" | \
            awk -F: '$1 ~/tag_name/ { print $2 }' | \
            tr -cd '[[:alnum:]]._-')
  if [[ "${version}" =~ ^v ]]; then
    echo "${version}"
  else
    echo "ERROR"
    return 1
  fi
  return 0
}

versionOutput() {
  [[ "$1" == "pi-hole" ]] && GITDIR=$COREGITDIR
  [[ "$1" == "AdminLTE" ]] && GITDIR=$WEBGITDIR
  [[ "$1" == "FTL" ]] && GITDIR="FTL"
  
  [[ "$2" == "-c" ]] || [[ "$2" == "--current" ]] || [[ -z "$2" ]] && current=$(getLocalVersion $GITDIR)
  [[ "$2" == "-l" ]] || [[ "$2" == "--latest" ]] || [[ -z "$2" ]] && latest=$(getRemoteVersion "$1")
  if [[ "$2" == "-h" ]] || [[ "$2" == "--hash" ]]; then
    [[ "$3" == "-c" ]] || [[ "$3" == "--current" ]] || [[ -z "$3" ]] && curHash=$(getLocalHash "$GITDIR")
    [[ "$3" == "-l" ]] || [[ "$3" == "--latest" ]] || [[ -z "$3" ]] && latHash=$(getRemoteHash "$1" "$(cd "$GITDIR" 2> /dev/null && git rev-parse --abbrev-ref HEAD)")
  fi

  if [[ -n "$current" ]] && [[ -n "$latest" ]]; then
    output="${1^} version is $current (Latest: $latest)"
  elif [[ -n "$current" ]] && [[ -z "$latest" ]]; then
    output="Current ${1^} version is $current"
  elif [[ -z "$current" ]] && [[ -n "$latest" ]]; then
    output="Latest ${1^} version is $latest"
  elif [[ "$curHash" == "N/A" ]] || [[ "$latHash" == "N/A" ]]; then
    output="${1^} hash is not applicable"
  elif [[ -n "$curHash" ]] && [[ -n "$latHash" ]]; then
    output="${1^} hash is $curHash (Latest: $latHash)"
  elif [[ -n "$curHash" ]] && [[ -z "$latHash" ]]; then
    output="Current ${1^} hash is $curHash"
  elif [[ -z "$curHash" ]] && [[ -n "$latHash" ]]; then
    output="Latest ${1^} hash is $latHash"
  else
    errorOutput
  fi

  [[ -n "$output" ]] && echo "  $output"
}

errorOutput() {
  echo "  Invalid Option! Try 'pihole -v --help' for more information."
  exit 1
}
  
defaultOutput() {
  versionOutput "pi-hole" "$@"
  versionOutput "AdminLTE" "$@"
  versionOutput "FTL" "$@"
}

helpFunc() {
  echo "Usage: pihole -v [repo | option] [option]
Example: 'pihole -v -p -l'
Show Pi-hole, Admin Console & FTL versions

Repositories:
  -p, --pihole         Only retrieve info regarding Pi-hole repository
  -a, --admin          Only retrieve info regarding AdminLTE repository
  -f, --ftl            Only retrieve info regarding FTL repository
  
Options:
  -c, --current        Return the current version
  -l, --latest         Return the latest version
  --hash               Return the Github hash from your local repositories
  -h, --help           Show this help dialog"
  exit 0
}

case "${1}" in
  "-p" | "--pihole"    ) shift; versionOutput "pi-hole" "$@";;
  "-a" | "--admin"     ) shift; versionOutput "AdminLTE" "$@";;
  "-f" | "--ftl"       ) shift; versionOutput "FTL" "$@";;
  "-h" | "--help"      ) helpFunc;;
  *                    ) defaultOutput "$@";;
esac