#!/bin/bash
# Syncs Arch repos based on info contained in repo.db files
# License: GPLv3

# Principles
# * Get repo.db from an Arch-like repo
# * Generate a list of available packages
# * Create sync whitelist (based on package blacklist)
# * Get packages
# * Check package signatures
# * Check database signatures
# * Sync repo => repo


# eval this
BASEURL="ftp://ftp.archlinux.org/\$repo/os/\$arch/\$file"

# Generates an URL from BASE_URL
# _Params_
# * repo
# * arch
# * file
eval_url() {
  repo="$1"
  arch="$2"
  file="$3"

  eval "${BASE_URL}"
}

# Returns contents of a repo
get_repos() {
  rsync -av --include="*.db*" --exclude="*" rsync://${mirror}/${mirror_path}/ cache/
}

get_repo_content() {
# Return all contents
  bsdtar tf cache/$1/os/$2/$1.db.tar.* | \
    cut -d "/" -f 1 | \
    sort -u
}

# Get the database compression as an extension
get_repo_ext() {
  file "$1" | tr A-Z a-z | sed -e "s/^[^:]\+: *\(.z\).*$/.tar.\1/" -e "s/bz/&2"
}

# Prints blacklisted packages
get_blacklist() {
  cut -d ':' -f 1 "${BLACKLIST_FILE}"
}

# repo
# arch
get_repo_file() {
  [ ! -f "cache/${1}/os/${2}/${1}.db.tar.*" ] && return 1

  echo cache/${1}/os/${2}/${1}.db.tar.*
}

# Process the databases and get the libre packages
init() {
# Fail on every error
  set -E 

  source $(dirname $0)/config
  source $(dirname $0)/local_config
  source $(dirname $0)/libremessages

# Get the blacklisted packages
  blacklist=($(get_blacklist))

# Sync the repos databases
  get_repos

# Traverse all repo-arch pairs
  for _arch in ${ARCHARCHES[@]}; do
    for _repo in ${ARCHREPOS[@]}; do
      msg "Processing ${_repo}-${_arch}"

      repo_file=$(get_repo_file ${_repo} ${_arch})

# Remove blacklisted packages and count them
      msg2 "Removing blacklisted packages: $(
      LC_ALL=C repo-remove ${repo_file} ${blacklist[@]} 2>&1 | \
        grep "\-> Removing" 2>/dev/null| wc -l)"

# Get db contents
      db=($(get_repo ${_repo} ${_arch}))

      msg2 "Process clean db for syncing..."

# Create a whitelist
      echo ${db[@]} | tr ' ' "\n" | sed "s|$|*|g" > /tmp/${_repo}-${_arch}.whitelist

# Sync excluding everything but blacklist
      rsync -av --include-from=/tmp/${_repo}-${_arch}.whitelist --exclude="*"


# Cleanup
      unset db 
    done
  done

# Cleanup
  unset blacklist _arch _repo repo_file
}