#!/bin/bash

set -o pipefail

if [ ! tools -ef "$(dirname "$0")" ]; then
    echo "This script must be run from the repository's root directory"
    exit 1
fi

if [ $# -ne 1 ]; then
    echo "Usage: $0 PATH"
    echo "PATH is a local clone of WebRTC repository."
    exit 1
fi

SRCREPO="$1"

if [ ! -d "$SRCREPO" ]; then
    echo "$SRCREPO is not a directory"
    exit 1
fi

PATHS=$(grep -e '^[^#]' tools/import-paths) || exit 1

OLDCOMMIT=$(head -n 1 tools/import-commit) || exit 1
NEWCOMMIT=$( cd "$SRCREPO"; git log --format='%H' -1 -- $PATHS ) || exit 1

if [ "$OLDCOMMIT" = "$NEWCOMMIT" ]; then
    echo "Nothing to do, no changes since $OLDCOMMIT."
    exit
fi

echo "Importing changes from $OLDCOMMIT to $NEWCOMMIT...".

(cd "$SRCREPO"; git format-patch -M -B --stdout "$OLDCOMMIT..$NEWCOMMIT" -- $PATHS) | \
    git am --whitespace=fix --directory=import || exit 1

echo "$NEWCOMMIT" > tools/import-commit || exit 1

echo "Done. You should commit the changed tools/import-commit file."