#!/bin/bash

# The purpose of this script is to automate the maintenance of a custom pacman (Arch Linux) repository, whose goal is to
# provide package-ready AUR softs.
# This script should NOT be run as root.

# Dependencies
# Make sure that AWK rules file is present, readable and correctly set in this script's parameters
# Make sure the following packages are installed before running this script:
# package-query aurutils git

# Functions

##################################################################
ascii_frag() {
    expr match "$1" "\([^[:digit:]]*\)"
}

ascii_remainder() {
    expr match "$1" "[^[:digit:]]*\(.*\)"
}

numeric_frag() {
    expr match "$1" "\([[:digit:]]*\)"
}

numeric_remainder() {
    expr match "$1" "[[:digit:]]*\(.*\)"
}

# return 1 for $1 > $2
# return 2 for $1 < $2
# return 0 for equal
vercomp() {
    local WORK1="$1"
    local WORK2="$2"
    local NUM1="", NUM2="", ASCII1="", ASCII2=""
    while true; do
        ASCII1=`ascii_frag "${WORK1}"`
        ASCII2=`ascii_frag "${WORK2}"`
        WORK1=`ascii_remainder "${WORK1}"`
        WORK2=`ascii_remainder "${WORK2}"`

        if [ "${ASCII1}" \> "${ASCII2}" ]; then
            return 1
        elif [ "${ASCII1}" \< "${ASCII2}" ]; then
            return 2
        fi

        NUM1=`numeric_frag "${WORK1}"`
        NUM2=`numeric_frag "${WORK2}"`
        WORK1=`numeric_remainder "${WORK1}"`
        WORK2=`numeric_remainder "${WORK2}"`

        if [ -z "${NUM1}" -a -z "${NUM2}" ]; then
            return 0
        elif [ -z "${NUM1}" -a -n "${NUM2}" ]; then
            return 2
        elif [ -n "${NUM1}" -a -z "${NUM2}" ]; then
            return 1
        fi

        if [ "${NUM1}" -gt "${NUM2}" ]; then
            return 1
        elif [ "${NUM1}" -lt "${NUM2}" ]; then
            return 2
        fi
    done
}
##################################################################

init() {
  # Only run if the user is not root
  if [[ $USER = 'root' ]] ; then
    echo "You cannot run this script as root!"
    exit 1
  fi

  if [ -n "$(ls $run_directory_path)" ] ; then
    echo "The running directory is not empty!"
    exit 1
  fi

  # TODO Check if required packages are installed

  echo "ArchRepo update script"
}

ftpFetch() {
  ftp fetch $remote_repository/$repo_db_file $run_directory_path # TODO use real syntax ^^'
}

checkUpdates() {
  echo "Checking for updates:"
  upgraded_packages=""
  #stream=$(tar xOf $repo_directory/$repo_db_file --wildcards */desc | awk -f $awk_rules_file)
  stream=$(tar xOf $run_directory_path/$repo_db_file --wildcards */desc | awk -f $awk_rules_file)

  OIFS=$IFS
  IFS='|'
  stream="${stream:1}"
  for package in $stream
  do
    IFS='
'
    count=0
    for line in $package; do
      if [ $count -eq 0 ]; then
        filename=$line
      elif [ $count -eq 1 ]; then
        name=$line
      elif [ $count -eq 2 ]; then
        version=$line
      fi

      ((count++))
    done

    reg="(linux-lts).+-((docs)|(headers))"
    if [[ $name =~ $reg ]]; then
      echo -e "\nSkipping $name ($version, default exception)."
      continue 1
    fi

    exlist=""
    if echo $exlist | grep -w $name > /dev/null; then
      echo -e "\nSkipping $name ($version, temporary exception)."
      continue 1
    fi

    echo -e "\nChecking $name ($version)..."
    aur_version=$(package-query -A -f %v $name)

    vercomp $aur_version $version
    result=$?
    if [[ $result -eq 1 ]]; then
      echo "New version for $name: $version -> $aur_version"
      createPackage $name
      addPackageToRepo $name $aur_version
      upgraded_packages="$upgraded_packages $name"
    fi

    IFS='|'
  done
  IFS=$OIFS
  echo "All packages processed."

  if [[ $upgraded_packages != "" ]]; then
    echo "The following packages were upgraded:"
    echo $upgraded_packages
  fi
}

addPackage() {
  createPackage $1
  addPackageToRepo $1
}

createPackage() { # Create package $1
  echo "Fetching $1 from AUR..."
  aur fetch $1 # TODO This could be replaced by a git clone or even a wget+tar thanks to package-query
  echo "Making $1 package..."
  cd $1
  # if linux-lts{414,49} then download kernel source from local repo (saves ~100MB each time)
  # WARNING this onlys works because we already have said sources AND because PKBUILD follow this particular line
  # (not the same in 419 nor 54)
  reg="(linux-lts).+"
  if [[ $1 =~ $reg ]]; then
    sed -i -e "s/\"https:\/\/www.kernel.org\/pub\/linux\/kernel\/v4.x\/\${_srcname}.tar.xz\"/\"https:\/\/archlinux.kto.black\/resources\/\${_srcname}.tar.xz\"/g" ./PKGBUILD
  fi
  makepkg -s --noconfirm --noprogressbar
  cd $run_directory_path
}

ftpSend() {

}

# TODO: try manually: can we update db file before sending to remote repo?
addPackageToRepo() { # Add package $1
  echo "Adding $1 to repository..."
  #cp $run_directory_path/$1/$1-$2*.pkg.tar.xz $repo_directory
  repo-add $repo_db_file $1-$2*.pkg.tar.xz
  ftp send $repo_db_file $repo_db_file.old $remote_repository
  ftp send packages $remote_repository
  reg="(linux-lts).+"
  if [[ $name =~ $reg ]]; then
    echo "Adding $1-headers and $1-docs to repository..."
    cp $run_directory_path/$1/$1-headers-$2*.pkg.tar.xz $run_directory_path/$1/$1-docs-$2*.pkg.tar.xz $repo_directory
    repo-add $repo_directory/$repo_db_file $repo_directory/$1-headers-$2*.pkg.tar.xz $repo_directory/$1-docs-$2*.pkg.tar.xz
  fi
}

clean() {
  echo "Cleaning directory..."
  rm -rf $run_directory_path/*
  echo "Done."
}

clearRepo() {
  stream=$(tar 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)

# Set parameters
repo_directory='/mnt/archrepo'
repo_name='kto'
repo_db_file=$repo_name.db.tar
awk_rules_file='../parser.awk'
#repo_db_file='kto.db.tar' # You can set db name manually here if different

# Main process

if [ "$1" = "" ]; then
  init
  checkUpdates
elif [ "$1" = "add" ]; then
  init
  addPackage $2
elif [ "$1" = "clean" ]; then
  clean
elif [ "$1" = "clear" ]; then
  read -r -p "Are you sure? [y/N] " response
  response=${response,,}    # tolower
  if [[ "$response" =~ ^(yes|y)$ ]]; then
    clearRepo
  else
    echo "Cancelling... Perhaps did you mean 'clean', which empties the local build directory?"
    exit 1
  fi
else
  exit 1
fi

exit 0