#!/bin/sh
# Grabs the bottom 5 packages of needs-build and builds them in a pbuilder
# chroot.

set -e

log() {
   printf "%s %s\n" "$(date +'[%Y/%m/%d %H.%M]')" "$@" >> $log_dir/buildd.log
}

check_restart() {
  if [ -f "$restart_file" ]; then
    log "restart file found; restarting..."
    rm -f "$restart_file"
    cd $buildd_home
    exec $0 $greed
  elif [ -f "$die_file" ]; then
    log "die file found; see you later"
    rm -f "$die_file"
    exit 0
  fi
}

parse_dsc() {
  IFS=" "
  while read str str2; do
    case "$str" in
      Files:*) break ;;
      Architecture:*)
        if [ "$str2" != "$dpkg_arch" ] && [ "$str2" != "any" ]; then
          echo "not-for-us"
          return
        fi
      ;;
    esac
        
    if expr 'Files:' : "$str" >/dev/null; then
      break
    fi
  done
  
  if [ "$1" = dont-download ]; then
    return
  fi
  
  while read md5 size file; do
    if [ "$md5" = -----BEGIN ]; then
      break
    elif [ -z "$md5" ]; then
      continue
    fi
    if ! wget -q -O $file http://incoming.debian.org/$file; then
      case "$file" in
        *.orig.tar.gz) apt-get --tar-only source $package ;;
      esac
    fi
  done 
}

find_dsc_url() {
  package=$1
  version=$2
  IFS="
"
  for line in $(apt-get --print-uris -qq source $1=$2); do
    url=$(echo "$line" | cut -d' ' -f1 | sed "s/'\(.*\)'/\1/")
    filename=$(echo "$line" | cut -d' ' -f2)

    case "$filename" in
      *.dsc) echo $url; return ;;
    esac
  done
}

get_and_build() {
  source=$1

  package=${source%%_*}
  version=${source##*_}
  noe_version="$(echo $version | sed 's/^[0-9]\+://')"

  dsc="${package}_${noe_version}.dsc"
  cd $source_dir
  
  # see if it's already been built
  if [ -f "$completed_dir/${package}_${noe_version}_${dpkg_arch}.changes" ]; then
    log "$dsc is already built (available locally), skipping"
    return
  elif apt-get -qq --print-uris install $package=$version 2>/dev/null; then
    log "$dsc is already built (in archive), skipping"
    return
  fi

  if grep -q "^$source\$" $fail_log; then
    log "skipping previously failed $source"
    return
  fi
  
  log "looking for $dsc in incoming"
  if ! wget -q -O $dsc http://incoming.debian.org/$dsc; then
    log "not found, looking for $source in archive"
    url="$(find_dsc_url $package $version)"
    if [ -n "$url" ] && wget -q -O $dsc $url; then
      verdict="$(parse_dsc dont-download < $dsc)"
      if [ -n "$verdict" ]; then
        log "$dsc is $verdict, skipping for now"
        return
      fi
      if ! apt-get -qq source $package=$version >/dev/null; then
        log "complete source not found, skipping"
        return
      fi
    else
      log "dsc not found, skipping"
    fi
  else
    # must parse the dsc for what packages to download
    verdict="$(parse_dsc < $dsc)"

    if [ -n "$verdict" ]; then
      log "$dsc is $verdict, skipping for now"
      return
    fi
  fi
      
  log "now building $package ($version) with pbuilder"

  logfile="$log_dir/${source}_$(date +%Y%m%d.%H%M).log"
  changes="${binary_dir}${package}_${noe_version}_${dpkg_arch}.changes"
  if sudo pbuilder build --binary-arch --debbuildopts "-B -m\"$maint\"" --buildresult $binary_dir --logfile $logfile $dsc >/dev/null; then
    mail -s "[B] $source completed" $mail_to <<EOF
This is an automated message from quickie-buildd.sh.

The source package $source has built successfully from source
and $changes should be
available for signing and upload. The build log follows.

$(cat $logfile)
EOF
    sed -i "s/^$source\$//g" $fail_log
    log "built $source successfully"
    rm -f $binary_dir/*.gz $binary_dir/*.dsc
    cp $changes $completed_dir
    
  else
    mail -s "[B] $source failed" $mail_to <<EOF
This is an automated message from quickie-buildd.sh.

The source package $source failed to build successfully from
source. It will not be retried until the failure log is cleared.

$(cat $logfile)
EOF
    echo $source >> $fail_log
    log "failed to build $source - added to $fail_log"
  fi

  let "built_something+=1"
}

buildd_home=/home/buildd
dpkg_arch=$(dpkg --print-architecture)
source_dir=$buildd_home/source/
binary_dir=$buildd_home/debs/
log_dir=$buildd_home/logs/
fail_log=$buildd_home/fail
force_log=$buildd_home/force
restart_file=$buildd_home/restart
die_file=$buildd_home/die
mail_to=joshk@triplehelix.org
maint="quickie-buildd.sh at $(hostname -f) <$mail_to>"
completed_dir=$buildd_home/debs/completed
min_greed=5
greed=${1:-$min_greed}

# Clean up
rm -rf $source_dir/*

while true; do
  built_something=0
  log "getting new needs-build (greed $greed)"
  needs_build=$(wget -q -O - http://www.buildd.net/buildd/${dpkg_arch}_needs-build.txt | tail -n $greed)

  if [ $? -ne 0 ]; then
    log "retrieving needs-build failed - sleeping for 10 mins.."
    sleep 600
  else
    IFS="
"
    for src in $needs_build; do
      # Check for an override
      if [ -f "$force_log" ]; then
        while read fsource; do
          get_and_build $fsource
        done < $force_log
        rm -f $force_log
      fi
      check_restart
      
      get_and_build $src
    done

    # be more greedy, or you'll never get anything done
    if [ $built_something -eq 0 ]; then
      let "greed+=5"
    elif [ $built_something -ne $min_greed ]; then
      let "greed-=5"
    fi
  fi
done