#!/usr/bin/env bash

# The purpose of this script is to clear our custom pacman repository
# i.e. remove old versions of packages
# This script should NOT be run as root.

# Make sure that AWK rules file is present, readable and correctly set in this script's parameters

init() {
  # Only run if the user is not root
  if [[ $USER = 'root' ]] ; then
    echo "You cannot run this script as root!"
    exit 1
  fi
  source variables.conf
  repo_db_file=$repo_name.db.tar
  repo_db_filesfile=$repo_name.files.tar
  awk_rules_file='parser.awk'
  if [ ! -e $repo_directory/$repo_db_file ] ; then
    echo "Could not find db file. Exiting..."
    exit 1
  fi
  echo "ArchRepo clearing script"
}

clearRepo() {
  if [ "$(uname)" = "OpenBSD" ]; then # TODO This could probably be done better (like with actually checking if tar is GNU...)
    gnutar="gtar"
  else
    gnutar="tar"
  fi
  stream=$($gnutar xOf $repo_directory/$repo_db_file --wildcards */desc | awk -f $awk_rules_file)

  OIFS=$IFS
  IFS='|'
  stream="${stream:1}"
  current=""
  for package in $stream
  do
    IFS='
'
    count=0
    for line in $package; do
      if [ $count -eq 0 ]; then
        current="$current $line"
      else
        continue
      fi

      ((count++))
    done

    IFS='|'
  done
  IFS=$OIFS

  cd $repo_directory
  reg="^($repo_name.).+"
  for filename in *; do
    if [[ $filename =~ $reg || $filename = 'sync' || $filename = 'local'  || $filename = 'resources' ]]; then
      continue
    fi
    for package in $current; do
      if [ $filename = $package ]; then
        continue 2
      fi
    done
    echo "Removing $filename..."
    rm $filename
  done
}

run_directory_path=$(pwd)

# Main process

if [ "$1" = "" ]; then
  init
  clearRepo
else
  echo "Please call this script without any arguments."
  exit 1
fi

exit 0