#!/bin/bash
# Queries the ABS
# License: GPL3

## TODO
# * Add license text
# * Create symlinks from pkgbase to pkgname[@] for easy package finding

## GOALS
# * Have a searchable database of PKGBUILD metadata
# * Have an interface for source-only builds
# * Possibility to hook up ABS dirs besides ABSROOT (low priority)
# * Tell updates and non available binary packages (working on this)

source /etc/abs.conf
source /etc/libretools.conf

if [ ! -w "$TORUPATH" ]; then
 error "Toru's path isn't writable. Please check $TORUPATH"
 exit 1 
fi

# TODO move to common functions
function in_array {  #  usage : in_array( $needle, $haystack )

    [[ $2 ]] || return 1  # Not found
    local needle=$1; shift
    local item
    for item in "$@"; do
	[[ ${item#@} = $needle ]] && return 0  # Found
    done
    return 1 # Not Found
}

# Stores the lastsync date
lastsync() {
    [ -e ${lastsyncfile} -a ! -w ${lastsyncfile} ] && {
        error "The sync date can't be saved. ${lastsyncfile} isn't writable."
        return 1
    }

    date +%s > ${lastsyncfile}
    touch ${lastsyncfile}
}

# Saves contents on a named cache
# $1 cache name (repo)
# $2+ contents
store_cache() {
  cache=$1; shift

  [ -z "$cache" ] && return 1

  cat $@ > ${TORUPATH}/${cache}.cache

  return $?
}

# Return cache contents
# $1 cache name
read_cache() {
  [ ! -e "$1" ] && return 1

  cat ${TORUPATH}/${1}.cache

  return $?
}

##
#  usage : get_full_version( $epoch, $pkgver, $pkgrel )
# return : full version spec, including epoch (if necessary), pkgver, pkgrel
##
get_full_version() {
   if [[ $1 -eq 0 ]]; then
      # zero epoch case, don't include it in version
       echo $2-$3
   else
       echo $1:$2-$3
   fi
}

# Outputs an ordered package-fullpkgver array
print_package_array() {
   echo "$@" | tr " " "\n" | sort -u
}


# Gets repo.db contents (unordered)
# $1 repo
get_db_contents() {
  [ ! -r /var/lib/pacman/sync/$1.db ] && return 0

  bsdtar -tf /var/lib/pacman/sync/$1.db | cut -d'/' -f1 | sort -u
}


# Get the pkgname
# pkgname from pkgver separator can be either '-' or ' '
extract_pkgname() {
  echo "$@" | tr " " "\n" | sed "s/^\(.\+\)[- ][^-]\+-[^-]\+$/\1/"
}

# Get all the pkgnames from a file
# pkgname from pkgver separator can be either '-' or ' '
extract_pkgname_from_file() {
  sed "s/^\(.\+\)[- ][^-]\+-[^-]\+$/\1/" $1
}

# Split pkgnames from pkgvers
split_pkgname_from_pkgver() {
  sed "s/^\(.\+\)-\([^-]\+-[^-]\+\)$/\1 \2/" $1
}

# Get the fullpkgver 
# pkgname from pkgver separator can be either '-' or ' '
extract_fullpkgver() {
  echo "$@" | tr " " "\n" | sed "s/^.\+[ -]\([^-]\+-[^-]\+\)$/\1/"
}


# Updates the database by finding all PKGBUILDS
# Workflow:
# * Find all PKGBUILDs on the ABS repo specified
# * Get all packages already on package repos
# * Compare them
# Args:
update() {
# The PKGBUILDs found
  local pkgbuilds=()
# The list of pkgname-fullpkgver
  local packages_in_abs=()
  local packages_in_sync=()
  local need_update=()

# Traverse all specified repos
  for _repo in $@; do
    if ! in_array ${_repo} ${REPOS[@]}; then
      warning "You don't have access to this repo (check REPOS at libretools.conf)"
      continue
    fi

# Find all the PKGBUILDs newer than the last update
# Update newer, otherwise everything
    if [[ $force = true || ! -e ${lastsyncfile} ]]; then
      $quiet || warning "Forcing upgrade"
      pkgbuilds=($(find ${_repo} -maxdepth 2 -type f -name 'PKGBUILD'))
    else
      pkgbuilds=($(find ${_repo} -maxdepth 2 -type f -name 'PKGBUILD' -newer ${lastsyncfile}))
      packages_in_abs=($(read_cache ${_repo}))
      $quiet || msg2 "Getting ${#packages_in_abs[@]} packages from cache"
    fi

# Inform how many PKGBUILDS were found and quit immediately if none
    $quiet || msg "Found $((${#pkgbuilds[*]}-1)) PKGBUILDs to update"
    if [ ${#pkgbuilds[*]} -eq 1 ]; then
      $quiet || msg2 "There's nothing to be done. Phew!"
      exit 0
    fi

# Traverse all found PKGBUILDs
    for _pkgbuild in ${pkgbuilds[@]}; do

# The repo name is guessed
# You *must* use repo/pkgbase structure
      _pkgpath=$(dirname "${_pkgbuild}")
      _pkgbase=$(basename "${_pkgpath}")

# Load PKGBUILD's metadata
      source ${_pkgbuild}

# We won't need this
      unset build package url md5sums install pkgdesc backup options
# TODO fill a license list
      unset license
# TODO create source tarballs?
      unset mksource
# TODO solve dependency tree?
      unset depends makedepends

      for _pkg in ${pkgname[@]}; do
# Keep removing unneeded stuff
        unset package_${_pkg} >/dev/null 2>&1
# Fill the list of packages to find
        packages_in_abs+=($_pkg-$(get_full_version ${epoch:-0} $pkgver $pkgrel))
      done # end pkgnames

      unset pkgbase pkgname pkgver pkgrel source epoch
    done # end pkgbuilds

# Get repo database contents
    packages_in_sync=($(get_db_contents ${_repo}))
# Drops arrays into files
    print_package_array "${packages_in_abs[@]}" > ${TMPDIR}/packages_in_abs
    print_package_array "${packages_in_sync[@]}" > ${TMPDIR}/packages_in_sync

    unset packages_in_abs package_in_sync

# Use a different separator for pkgnames and pkvers
# so we can join them by pkgname
    split_pkgname_from_pkgver ${TMPDIR}/packages_in_abs | sort -k1b,1 > ${TMPDIR}/in_abs
    split_pkgname_from_pkgver ${TMPDIR}/packages_in_sync | sort -k1b,1 > ${TMPDIR}/in_sync

    $quiet || msg "This packages are available to update"
# Join both files by pkgname, the end result is:
# pkgname syncver absver
    join ${TMPDIR}/in_sync ${TMPDIR}/in_abs | \
    while read need_line; do
      _pkg=$(echo "${need_line}" | cut -d' ' -f1)
      _syncver=$(echo "${need_line}" | cut -d' ' -f2)
      _absver=$(echo "${need_line}" | cut -d' ' -f3)

# If the versions differ we need an update
      if [ "${_syncver}" != "${_absver}" ]; then
        $quiet || msg2 "$_pkg update from $_syncver to $_absver"
        $quiet && echo "$_pkg"
      fi
    done # end need_line

    unset _pkg _syncver _absver need_line

# Save the cache
    store_cache ${_repo} ${TMPDIR}/packages_in_abs

  done # end repos

  lastsync
}

# Find all the packages that are missing from the repo dbs (aka not built)
missing() {
  true
}



## MAIN
commands=()
repos=()
quiet=false
force=false
while getopts 'hqfum' arg; do
  case $arg in
    h) usage; exit 0 ;;
    q) quiet=true ;;
    f) force=true ;;
    u) commands+=(update);;
    m) commands+=(missing);;
  esac

  shift $((OPTIND-1))
done

# This is the syncfile, stores the last date as content and mtime
lastsyncfile=${TORUPATH}/lastsync

TMPDIR=$(mktemp -d)

[[ -z ${TMPDIR} ]] && exit 1

# TODO this is all for debugging
msg2 "force: $force quiet: $quiet repos: $@ commands: ${commands[@]}"
msg2 "read lastsync: $([ -e $lastsyncfile ])"

${commands[0]} ${@}

#rm -rf ${TMPDIR}

exit $?