#!/bin/bash
#
# Clear Linux -- automatic debuginfo preparation
#
# Copyright 2019 Intel Corporation
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation, version 3 or later of the License.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program. If not, see <http://www.gnu.org/licenses/>.

if [ $# -eq 1 ] || [ $# -gt 2 ]; then
  echo "Usage: $0 [SOURCEDIR] [DESTDIR]"
  echo "Generates automatic debuginfo tarballs in DESTDIR using content from SOURCEDIR."
  echo "The default SOURCEDIR and DESTDIR are /var/www/html/debuginfo.raw and"
  echo "/var/www/html/debuginfo, respectively."
  exit 0
fi >&2

if [ $# -eq 2 ]; then
  if [ ! -d "$1" ]; then
    echo "ERROR: SOURCEDIR argument must be an existing directory"
    exit 1
  fi
fi >&2

export SRC="${1:-/var/www/html/debuginfo.raw}"
export DEST="${2:-/var/www/html/debuginfo}"

srclist=$(mktemp -p .)
destlist=$(mktemp -p .)
trap "rm $srclist $destlist" EXIT

set -o pipefail

# First, scan the state of the SRC tree, containing all content for debuginfo RPMs.
if ! find "$SRC" -mindepth 4 -printf "%p %T@ %y\n" | sed "s|$SRC||" | sort -k 1 > "$srclist"; then
  echo "ERROR: expected content in $SRC"
  exit 1
fi

# Next, scan the state of the DEST tree, containing previously generated
# automatic debuginfo tarballs. Will be empty on first run.
mkdir -p "$DEST"
find "$DEST" -mindepth 2 -name '*.tar' -printf "%p %T@ %y\n" | sed "s|$DEST||;s|\.tar | |" | sort -k 1 > "$destlist"


process_one() {
  srcname="$1"
  destname="$2"
  filetype="$3"
  srcloc="$SRC/$srcname"
  srcdir="$SRC/$(echo "$srcname" | sed -r 's@^(/usr/(lib|share|src)/debug(/src)?).*@\1@')"
  tarcontent="$(echo "$srcname" | sed -r 's@^/usr/(lib|share|src)/debug(/src)?@.@')"
  destdir="$DEST/$(dirname "$destname")"
  dest="$DEST/$destname.tar"

  echo "Creating $destname.tar ..."

  mkdir -p "$destdir"
  if [ "$filetype" = "f" ]; then
    tar --no-recursion -C "$srcdir" --zstd -cf "$dest" "$tarcontent"
  elif [ "$filetype" = "l" ]; then
    # We "unsymlink" non-broken symlinks as an optimization by adding the
    # symlink target to the dest tarball, transforming the name as appropriate.
    if target=$(realpath -e "$srcloc" --relative-to="$srcdir" 2> /dev/null); then
      tar --no-recursion -C "$srcdir" --zstd -cf "$dest" --transform='s|.*|'"$tarcontent"'|' "$target"
    else
      tar --no-recursion -C "$srcdir" --zstd -cf "$dest" "$tarcontent"
    fi
  elif [ "$filetype" = "d" ]; then
    tar --no-recursion -C "$srcdir" --zstd -cf "$dest" "$tarcontent"
  fi
}
export -f process_one


gawk '
BEGIN { OFS = "\t" }
LIST == "src" {
  name = $1
  srcname = name
  ret = sub(/^\/usr\/lib\/debug/, "/lib", name)
  if (ret == 0) {
    ret = sub(/^\/usr\/src\/debug/, "/src", name)
    if (ret == 0) {
      ret = sub(/^\/usr\/share\/debug\/src/, "/src", name)
      if (ret == 0) {
        ret = sub(/^\/usr\/share\/debug/, "/lib", name)
        if (ret == 0) {
          print "Error: unexpected debuginfo file:", name
          exit 1
        }
      }
    }
  }
  src[name]["srcname"] = srcname
  src[name]["time"] = $2
  src[name]["type"] = $3
  src[name]["done"] = 0
}
LIST == "dest" {
  dest_content = 1
  name = $1
  time = $2
  type = $3
  if (name in src) {
    # No need to recreate directory tars if they exist
    if (src[name]["type"] == "d") {
      src[name]["done"] = 1
      next
    } else {
      # Only regenerate content if timestamp is newer
      if (time < src[name]["time"]) {
        print src[name]["srcname"], name, src[name]["type"]
      }
      src[name]["done"] = 1
    }
  }
}
END {
  PROCINFO["sorted_in"] = "@ind_str_asc"
  if (dest_content == 0) {
    for (s in src) {
      print src[s]["srcname"], s, src[s]["type"]
    }
  } else {
    for (s in src) {
      if (src[s]["done"] == 0) {
        print src[s]["srcname"], s, src[s]["type"]
      }
    }
  }
}
' LIST="src" "$srclist" LIST="dest" "$destlist" \
  | parallel --colsep '\t' process_one


# vi: ft=sh et sw=2 sts=2