#!/usr/bin/env bash
# Exit immediately on any error.
set -euo pipefail

# Locate the script file.  Cross symlinks if necessary.
loc="$0"
while [ -h "$loc" ]; do
    ls=`ls -ld "$loc"`
    link=`expr "$ls" : '.*-> \(.*\)$'`
    if expr "$link" : '/.*' > /dev/null; then
        loc="$link"  # Absolute link
    else
        loc="`dirname "$loc"`/$link"  # Relative link
    fi
done

# Move to the location of the script
base_dir=`dirname "$loc"`
cd $base_dir

# Save the current branch name.
branch=`git rev-parse --abbrev-ref HEAD`

# Checkout master, update the suprepos and generate source files.
git checkout master
git submodule sync
git submodule update --init
./gradlew cleanGenerateBabelSources generateBabelSources

# Save these source files ia temp directory.
temp_dir="$(mktemp -d -t diff-generated-sources.XXXXXX)"  # Weird usage, but works on Linux and Mac OS
function finish() {
    [[ ! -e "$temp_dir" ]] || rm -r "$temp_dir"
}
trap finish EXIT
cp -r build/generated-sources/ $temp_dir

# Switch back to the original branch, update the suprepos and generate source files.
git checkout $branch
git submodule sync
git submodule update --init
./gradlew cleanGenerateBabelSources generateBabelSources

# Create the diff and open the page to submit to Phabricator.
# The diff command uses its return command to signal whether there was any
# difference, so we disable exiting on non-zero return codes for this command.
set +e
raw_diff=`diff -uNr ${temp_dir}/babel/ build/generated-sources/babel/`
diff_status=$?
set -e
if [ $diff_status -eq 1 ]; then
	echo "$raw_diff" | grep -v "diff -uNr" | pbcopy
	echo "Diff copied to the clipboard."
	open "https://tails.corp.dropbox.com/differential/diff/create/"
elif [ $diff_status -eq 0 ]; then
	>&2 echo "No difference found!"
else
	exit $diff_status
fi