#!/usr/bin/env bash

set -e

DIR="$(realpath "$(dirname $0)")"
REPO_DIR="$(git rev-parse --show-toplevel)"
TOOL="${DIR}/minimerge_tool"
METADATA_FILE="${DIR}/cuttlefish_import_metadata.txt"
CUTTLEFISH_REPO_URL="https://android.googlesource.com/device/google/cuttlefish"

echo "Importing AOSP's device/google/cuttlefish project"

# Do these early to avoid doing unnecessary work when these fail
# Find last imported commit
stat "${METADATA_FILE}" >/dev/null
last_imported_commit="$(grep '^[[:space:]]*last_import[[:space:]]*:' "${METADATA_FILE}" | cut -d: -f2 | grep -o -E '[^[:space:]]+' )"
# Find current commit
pushd "${DIR}" >/dev/null
[[ `git status --porcelain` ]] >/dev/null && (echo "Repository is not in clean state"; exit 1)
current_commit="$(git rev-parse HEAD)"
popd >/dev/null


echo "Compiling minimerge tool..."
pushd ${DIR} >/dev/null
g++ main.cpp -o "${TOOL}" -lgit2 -O2
popd >/dev/null

echo "Cloning cuttlefish repo..."
CUTTLEFISH_DIR="$(mktemp -t -d cuttlefish.XXX)"
trap "rm -rf '${CUTTLEFISH_DIR}'" EXIT
git clone "${CUTTLEFISH_REPO_URL}" "${CUTTLEFISH_DIR}"

# Find commit to import
pushd "${CUTTLEFISH_DIR}" >/dev/null
current_import="$(git rev-parse HEAD)"
popd >/dev/null

if [[ "${last_imported_commit}" == "${current_import}" ]]; then
  echo "Nothing to import"
  exit 0
fi

function import() {
  "${TOOL}" \
    --source="${CUTTLEFISH_DIR}" \
    --destination="${REPO_DIR}" \
    --rev_range="${last_imported_commit}..HEAD" \
    "@${DIR}/cuttlefish_args.txt"
}

import || (git reset --hard "${current_commit}"; exit 1)

pushd "${DIR}" >/dev/null
cat >"${METADATA_FILE}" <<EOF
last_import: ${current_import}
EOF
git commit -a -m "Update import metadata file"
popd >/dev/null