#!/bin/bash
#
# This script will update all the modules listed below so that
# common points to master in the common module.
#
# If you have many of the GStreamer modules checked out in a particular
# directory, it's best to run this script from that directory.  For
# example, I check everything out in ~/gst, so this file is
# ~/gst/common/update-common.  To do an update, I do
# 'cd ~/gst ; ./common/update-common'.  This will automatically use
# the refs in your existing checkout when cloning the temporary
# checkout.  Alternatively, you can use the reference variable below.
#
# Options:
#
#   --dry-run : pass --dry-run to git push, don't actually push the changes
#   --keep    : keep temporary checkouts around instead of deleting them

# Set this variable to point to any directory containing existing
# git # checkouts, and git will pull objects from there, decreasing
# network usage.
BRANCH=master
reference=~/gst
PUSHURL=ssh://git.freedesktop.org/git/gstreamer
DRY_RUN=
KEEP=no
COMMON_COMMIT=

set -e
set -x

modules="gstreamer gst-plugins-base gst-plugins-good gst-plugins-bad \
	gst-plugins-ugly gst-libav gst-omx \
	gst-rtsp-server gst-editing-services"

topdir=`pwd`
dir=`mktemp -d $topdir/common-update-XXXXXX`

# process command line arguments
set +x
for arg in $@
do
  case $arg in
    --dry-run)
      DRY_RUN="--dry-run";
      ;;
    --keep)
      KEEP="yes";
      ;;
    --commit=*)
      COMMON_COMMIT="${arg#*=}";
      DRY_RUN="--dry-run";
      KEEP="yes";
      ;;
    --help)
      echo
      echo "update-common supported command line options:"
      echo
      echo " --dry-run   Don't actually push changes to the repository, use git push --dry-run"
      echo
      echo " --keep      Don't delete temporary git checkout used for update operation, keep it around"
      echo
      echo " --commit=REF  Update common to commit reference REF (for local testing, implies --dry-run --keep)"
      echo
      exit 0;
      ;;
    *)
      echo "Unknown command line argument $arg"
      echo "Supported: --dry-run, --keep"
      exit 1;
      ;;
  esac
done
set -x

# create temporary checkouts of the modules
for module in $modules
do
  cd $dir
  if test -e $reference/$module/.git ; then
    pushd $reference/$module
    PUSHURL=`git config remote.origin.url | sed 's@\(git/gstreamer\).*@\1@'`
    popd
    git clone --reference $reference/$module/.git --shared ssh://git.freedesktop.org/git/gstreamer/$module
  elif test -e $topdir/$module/.git ; then
    pushd $topdir/$module
    PUSHURL=`git config remote.origin.url | sed 's@\(git/gstreamer\).*@\1@'`
    popd
    git clone --reference $topdir/$module/.git --shared $PUSHURL/$module
  else
    git clone $PUSHURL/$module
  fi
  cd $dir/$module

  # ignore modules that don't have such a branch
  if ! git show-ref origin/$BRANCH >/dev/null; then
    continue;
  fi

  if test $BRANCH = 'master'; then
    git checkout $BRANCH
  else
    git checkout -b $BRANCH origin/$BRANCH
  fi

  git submodule init

  # avoid downloading common submodule by re-using existing common checkout
  if test -e $reference/common/.git ; then
    git submodule update --reference $reference/common -- common
  elif test -e $topdir/common/.git ; then
    git submodule update --reference $topdir/common -- common
  else
    git submodule update
  fi

  # avoid downloading libav submodule by re-using existing checkout
  if test "$module" = "gst-libav"; then
    if test -e $reference/gst-libav/gst-libs/ext/libav/.git ; then
      git submodule update --reference $reference/gst-libav/gst-libs/ext/libav -- gst-libs/ext/gst-libav
    elif test -e $topdir/gst-libav/gst-libs/ext/libav/.git ; then
      git submodule update --reference $topdir/gst-libav/gst-libs/ext/libav/ -- gst-libs/ext/libav
    else
      git submodule update
    fi
  fi

  # for good measure in case there are any other submodules anywhere
  git submodule update

  cd $dir/$module/common
  ref_from=`git log --pretty=format:%h -n 1 HEAD`
  if test $BRANCH = 'master'; then
    git checkout $BRANCH
  else
    git checkout -b $BRANCH origin/$BRANCH
  fi
  git pull origin
  if [ -n "$COMMON_COMMIT" ] ; then
    echo "Forcing common to commit $COMMON_COMMIT";
    git reset --hard $COMMON_COMMIT || {
      echo "Failed to git reset to $COMMON_COMMIT";
      exit 1;
    }
  fi
  ref_to=`git log --pretty=format:%h -n 1 HEAD`
  echo updating common from $ref_from to $ref_to
  if [ "$ref_from" != "$ref_to" ] ; then
    cd $dir/$module
    # update autogen.sh for selected modules
    case $module in
      gstreamer|gst-plugins-base|gst-plugins-good|gst-plugins-ugly|gst-plugins-bad|gst-libav|gst-editing-services|gst-rtsp-server|gst-omx )
        ./common/update-autogen
        git add autogen.sh
        ;;
      *)
        ;;
    esac
    # update README and MAINTAINERS for selected modules
    case $module in
      gstreamer|gst-plugins-base|gst-plugins-good|gst-plugins-ugly|gst-plugins-bad )
        ./common/update-readmes --run-git-add
        ;;
      *)
        ;;
    esac
    # and finally update the common submodule
    git add common
    git commit -m "Automatic update of common submodule

From $ref_from to $ref_to"
  fi
  cd $dir
done

for module in $modules
do
  cd $dir/$module
  if git show-ref origin/$BRANCH >/dev/null; then
    git push $DRY_RUN origin $BRANCH
  fi
done

# delete temporary checkouts again
if test "x$KEEP" != "xyes"; then
  rm -rf $dir
fi