#!/bin/bash

function show_error_msg()
{
  echo "*** ERROR *** $? line $1 $0 did not complete successfully!"
  echo "$ERROR_HELP"
}
ERROR_HELP=""

# Print an Error message if `set -eE` causes the script to exit due to a failed command
trap 'show_error_msg $LINENO' ERR

source dom/media/webrtc/third_party_build/use_config_env.sh
export HGPLAIN=1

if [ "x$ALLOW_RERUN" = "x" ]; then
  ALLOW_RERUN="0"
fi

echo "MOZ_LIBWEBRTC_SRC: $MOZ_LIBWEBRTC_SRC"
echo "MOZ_LIBWEBRTC_BRANCH: $MOZ_LIBWEBRTC_BRANCH"
echo "MOZ_FASTFORWARD_BUG: $MOZ_FASTFORWARD_BUG"
echo "ALLOW_RERUN: $ALLOW_RERUN"

ERROR_HELP=$"
A copy of moz-libwebrtc already exists at $MOZ_LIBWEBRTC_SRC
While this script is not technically idempotent, it will try.
However, the safest way forward is to start fresh by running:
    rm -rf $STATE_DIR && \\
    bash $0

If you are sure you want to reuse the existing directory, run:
    ALLOW_RERUN=1 bash $0
"
if [ -d $MOZ_LIBWEBRTC_SRC ] && [ "x$ALLOW_RERUN" != "x1" ]; then
  echo "$ERROR_HELP"
  exit 1
fi
ERROR_HELP=""

# After this point:
# * eE: All commands should succeed.
# * u: All variables should be defined before use.
# * o pipefail: All stages of all pipes should succeed.
set -eEuo pipefail

# wipe resume_state for new run
rm -f $STATE_DIR/resume_state

# If there is no cache file for the branch-head lookups done in
# update_default_config.sh, go ahead and copy our small pre-warmed
# version.
if [ ! -f $STATE_DIR/milestone.cache ]; then
  cp $SCRIPT_DIR/pre-warmed-milestone.cache $STATE_DIR/milestone.cache
fi

# If there is no .mozconfig file, copy a basic one from default_mozconfig
if [ ! -f .mozconfig ]; then
  cp $SCRIPT_DIR/default_mozconfig .mozconfig
fi

# fetch the github repro
./mach python $SCRIPT_DIR/fetch_github_repo.py \
    --repo-path $MOZ_LIBWEBRTC_SRC \
    --state-path $STATE_DIR

CURRENT_DIR=`pwd`
cd $MOZ_LIBWEBRTC_SRC

# clear any possible previous patches
rm -f *.patch

# create a new work branch and "export" a new patch stack to rebase
# find the common commit between our upstream release branch and trunk
PREVIOUS_RELEASE_BRANCH_BASE=`git merge-base branch-heads/$MOZ_PRIOR_UPSTREAM_BRANCH_HEAD_NUM master`
echo "PREVIOUS_RELEASE_BRANCH_BASE: $PREVIOUS_RELEASE_BRANCH_BASE"

NEXT_RELEASE_BRANCH_BASE=`git merge-base $MOZ_TARGET_UPSTREAM_BRANCH_HEAD master`
echo "NEXT_RELEASE_BRANCH_BASE: $NEXT_RELEASE_BRANCH_BASE"

ERROR_HELP=$"
The previous release branch base ($PREVIOUS_RELEASE_BRANCH_BASE)
and the next release branch base ($NEXT_RELEASE_BRANCH_BASE) are the
same and should not be.  This indicates a problem in the git repo at
$MOZ_LIBWEBRTC_SRC.
At the least it likely means that 'master' is older than the two
release branches.  Investigation is necessary.
"
if [ "x$PREVIOUS_RELEASE_BRANCH_BASE" == "x$NEXT_RELEASE_BRANCH_BASE" ]; then
  echo "$ERROR_HELP"
  exit 1
fi
ERROR_HELP=""

# create a new branch at the common commit and checkout the new branch
ERROR_HELP=$"
Unable to create branch '$MOZ_LIBWEBRTC_BRANCH'.  This probably means
that prep_repo.sh is being called on a repo that already has a patch
stack in progress.  If you're sure you want to do this, the following
commands will allow the process to continue:
  ( cd $MOZ_LIBWEBRTC_SRC && \\
    git checkout $MOZ_LIBWEBRTC_BRANCH && \\
    git checkout -b $MOZ_LIBWEBRTC_BRANCH-old && \\
    git branch -D $MOZ_LIBWEBRTC_BRANCH ) && \\
  ALLOW_RERUN=1 bash $0
"
git branch $MOZ_LIBWEBRTC_BRANCH $PREVIOUS_RELEASE_BRANCH_BASE
ERROR_HELP=""
git checkout $MOZ_LIBWEBRTC_BRANCH

# find the last upstream commit used by the previous update, so we don't
# accidentally grab release branch commits that were added after we started
# the previous update.
LAST_UPSTREAM_COMMIT_SHA=`tail -1 $CURRENT_DIR/third_party/libwebrtc/README.mozilla.last-vendor`
echo "previous update's last commit: $LAST_UPSTREAM_COMMIT_SHA"

# Check that the previous libwebrtc update run actually had release
# branch commits.  If it did, our LAST_UPSTREAM_COMMIT_SHA will be
# different than the PREVIOUS_RELEASE_BRANCH_BASE (which we convert to a
# short sha).  If the two shas are the same, meaning there where no
# fixes on the upstream's release branch, we have no work to do here.
# An example of this if occurance is v136 update.
PREV_REL_BRANCH_SHORT_SHA=`git rev-parse --short $PREVIOUS_RELEASE_BRANCH_BASE`
if [ "x$PREV_REL_BRANCH_SHORT_SHA" != "x$LAST_UPSTREAM_COMMIT_SHA" ]; then
  # make sure we're starting with a clean tmp directory
  rm -f $TMP_DIR/*.patch $TMP_DIR/*.patch.bak

  # grab the patches for all the commits in chrome's release branch for libwebrtc
  git format-patch -o $TMP_DIR -k $PREVIOUS_RELEASE_BRANCH_BASE..$LAST_UPSTREAM_COMMIT_SHA
  # tweak the release branch commit summaries to show they were cherry picked
  sed -i.bak -e "/^Subject: / s/^Subject: /Subject: (cherry-pick-branch-heads\/$MOZ_PRIOR_UPSTREAM_BRANCH_HEAD_NUM) /" $TMP_DIR/*.patch
  git am $TMP_DIR/*.patch # applies to branch mozpatches
  rm $TMP_DIR/*.patch $TMP_DIR/*.patch.bak
fi

# we don't use restore_patch_stack.py here because it would overwrite the patches
# from the previous release branch we just added in the above step.

# grab all the moz patches and apply
git am $CURRENT_DIR/third_party/libwebrtc/moz-patch-stack/*.patch

cd $CURRENT_DIR

# cp all the no-op files to STATE_DIR
NO_OP_FILE_COUNT=`ls third_party/libwebrtc/moz-patch-stack \
    | grep "no-op-cherry-pick-msg" | wc -l | tr -d " " || true`
if [ "x$NO_OP_FILE_COUNT" != "x0" ]; then
  cp $CURRENT_DIR/third_party/libwebrtc/moz-patch-stack/*.no-op-cherry-pick-msg \
     $STATE_DIR
fi

bash $SCRIPT_DIR/verify_vendoring.sh || exit 1