#!/bin/bash

# A simple script to checkout or update a svn or git repo as source service
#
# (C) 2010 by Adrian Schröter <adrian@suse.de>
#  
# 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; either version 2  
# of the License, or (at your option) any later version.  
# See http://www.gnu.org/licenses/gpl-2.0.html for full license text.  

# defaults
MYSCM=""
MYURL=""
MYVERSION=""
MYPREFIX=""
MYFILENAME=""
MYREVISION=""

while test $# -gt 0; do
  case $1 in
    *-scm)
      MYSCM="$2"
      shift
    ;;
    *-url)
      MYURL="$2"
      shift
    ;;
    *-subdir)
      MYSUBDIR="$2"
      shift
    ;;
    *-revision)
      MYREVISION="$2"
      shift
    ;;
    *-version)
      MYVERSION="$2"
      shift
    ;;
    *-versionprefix)
      MYPREFIX="$2"
      shift
    ;;
    *-exclude)
      EXCLUDES="$EXCLUDES --exclude=\'${2#/}\'"
      shift
    ;;
    *-filename)
      MYFILENAME="${2#/}"
      shift
    ;;
    *-outdir)
      MYOUTDIR="$2"
      shift
    ;;
    *)
      echo Unknown parameter $1.
      echo 'Usage: tar_scm --scm $SCM --url $URL --outdir $OUT'
      exit 1
    ;;
  esac
  shift
done

FILE="$MYFILENAME"
VERSION="$MYVERSION"

if [ -z "$MYSCM" ]; then
  echo "ERROR: no scm is given via --scm parameter (git/svn/hg)!"
  exit 1
fi
if [ -z "$MYURL" ]; then
  echo "ERROR: no checkout URL is given via --url parameter!"
  exit 1
fi
if [ -z "$MYOUTDIR" ]; then
  echo "ERROR: no output directory is given via --outdir parameter!"
  exit 1
fi

cd "$MYOUTDIR"

if [ -z "$FILE" -a "$MYSCM" == "git" ]; then
  FILE="${MYURL%/}"
  FILE="${FILE##*/}"
  FILE="${FILE%.git}"
fi
if [ -z "$FILE" -a "$MYSCM" == "svn" ]; then
  FILE="${MYURL%/}"
  FILE="${FILE##*/}"
fi
if [ -z "$FILE" -a "$MYSCM" == "hg" ]; then
  FILE="${MYURL%/}"
  FILE="${FILE##*/}"
fi

existing_tar=$(echo _service:tar_scm:${FILE}-*.tar*)
if [ -e "$existing_tar" ]; then
  UNCOMPRESS="cat"
  if [ "${existing_tar%.tar.gz}" != "$existing_tar" ]; then
    UNCOMPRESS="gunzip -c"
  elif [ "${existing_tar%.tar.bz2}" != "$existing_tar" ]; then
    UNCOMPRESS="bunzip2 -c"
  elif [ "${existing_tar%.tar.xz}" != "$existing_tar" ]; then
    UNCOMPRESS="xz -dc"
  fi
  if $UNCOMPRESS "$existing_tar" | tar xf -; then
    TAR_DIRECTORY=`find * -maxdepth 0 -a -type d`
  fi
fi

if [ "$MYSCM" == "svn" ]; then
  if [ -z "$SUBDIR" -a -d "$TAR_DIRECTORY" ]; then
    # update existing content for speed/bandwidth reasons
    cd "$TAR_DIRECTORY"
    OLDVERSION=`LC_ALL=C svn info | sed -n 's,^Last Changed Rev: \(.*\),\1,p'`
    if [ -n "$MYREVISION" ]; then
      svn up -r"$MYREVISION" || exit 1
    else
      svn up || exit 1
    fi
    NEWVERSION=`LC_ALL=C svn info | sed -n 's,^Last Changed Rev: \(.*\),\1,p'`
    cd -
    if [ "$OLDVERSION" == "$NEWVERSION" ]; then
      # cleanup and skip
      rm -rf "$TAR_DIRECTORY"
      exit 0
    fi
    mv "$TAR_DIRECTORY" "${FILE}" || exit 1
  else
    # new checkout
    if [ -n "$MYREVISION" ]; then
      svn co -r"$MYREVISION" "$MYURL" "${FILE}" || exit 1
    else
      svn co "$MYURL" "${FILE}" || exit 1
    fi
  fi
  if [ -z "$VERSION" ]; then
    cd "$FILE"
    [ -n "$MYPREFIX" ] && MYPREFIX="$MYPREFIX.rev"
    VERSION="$MYPREFIX"`LC_ALL=C svn info | sed -n 's,^Last Changed Rev: \(.*\),\1,p'`
    cd -
  fi
elif [ "$MYSCM" == "git" ]; then
  if [ -z "$SUBDIR" -a -d "$TAR_DIRECTORY" ]; then
    # update existing content for speed/bandwidth reasons
    cd "$TAR_DIRECTORY"
    OLDVERSION=`git show --pretty=%at  | head -n 1`
    git pull || exit 1
    if [ -n "$MYREVISION" ]; then
      git checkout "$MYREVISION" || exit 1
    fi
    NEWVERSION=`git show --pretty=%at  | head -n 1`
    cd -
    if [ "$OLDVERSION" == "$NEWVERSION" ]; then
      # cleanup and skip
      rm -rf "$TAR_DIRECTORY"
      exit 0
    fi
    mv "$TAR_DIRECTORY" "${FILE}" || exit 1
  else
    # new checkout
    git clone --depth 1 "$MYURL" "${FILE}" || exit 1
    if [ -n "$MYREVISION" ]; then
      cd "$FILE"
      git checkout "$MYREVISION" || exit 1
      cd -
    fi
  fi
  if [ -z "$VERSION" ]; then
    cd "$FILE"
    [ -n "$MYPREFIX" ] && MYPREFIX="$MYPREFIX."
    VERSION="$MYPREFIX"`git show --pretty=%at  | head -n 1`
    cd -
  fi
elif [ "$MYSCM" == "hg" ]; then
  if [ -z "$SUBDIR" -a -d "$TAR_DIRECTORY" ]; then
    # update existing content for speed/bandwidth reasons
    cd "$TAR_DIRECTORY"
    OLDVERSION=`hg tip | head -n 1 | sed -e 's/\s*//g' | awk -F':' '{ print $2 }'`
    hg pull || exit 1
    if [ -n "$MYREVISION" ]; then
      hg checkout "$MYREVISION" || exit 1
    fi
    NEWVERSION=`hg tip | head -n 1 | sed -e 's/\s*//g' | awk -F':' '{ print $2 }'`
    cd -
    if [ "$OLDVERSION" == "$NEWVERSION" ]; then
      # cleanup and skip
      rm -rf "$TAR_DIRECTORY"
      exit 0
    fi
    mv "$TAR_DIRECTORY" "${FILE}" || exit 1
  else
    # new checkout
    hg clone "$MYURL" "${FILE}" || exit 1
    if [ -n "$MYREVISION" ]; then
      cd "$FILE"
      hg checkout "$MYREVISION" || exit 1
      cd -
    fi
  fi
  if [ -z "$VERSION" ]; then
    cd "$FILE"
    [ -n "$MYPREFIX" ] && MYPREFIX="$MYPREFIX."
    VERSION="$MYPREFIX"`hg tip | head -n 1 | sed -e 's/\s*//g' | awk -F':' '{ print $2 }'`
    cd -
  fi
else
  echo "ERROR: unknown scm $MYSCM"
  exit 1
fi

if [ ! -e "$FILE/$SUBDIR" ]; then
  echo "Directory does not exist: $FILE/$SUBDIR"
  exit 1
fi

mv "$FILE/$SUBDIR" "${FILE}-${VERSION}" || exit 1

tar cf "$MYOUTDIR/${FILE}-${VERSION}.tar" $EXCLUDES "${FILE}-${VERSION}" || exit 1
rm -rf "${FILE}-${VERSION}"

exit 0