#! /bin/bash
function perform_lint() {
	echo "Performing LINT..."
	if hash clang-format-3.9 2>/dev/null; then
		CLANG_FORMAT=clang-format-3.9
	else
		CLANG_FORMAT=clang-format
	fi
	echo "LINT: Using binary $CLANG_FORMAT"
	CLANG_FORMAT_WHITELIST="util/travis/clang-format-whitelist.txt"

	if [ "$TRAVIS_EVENT_TYPE" = "pull_request" ]; then
		# Get list of every file modified in this pull request
		files_to_lint="$(git diff --name-only --diff-filter=ACMRTUXB $TRAVIS_COMMIT_RANGE | grep '^src/[^.]*[.]\(cpp\|h\)$' | true)"
	else
		# Check everything for branch pushes
		files_to_lint="$(find src/ -name '*.cpp' -or -name '*.h')"
	fi

	local errorcount=0
	local fail=0
	for f in ${files_to_lint}; do
		d=$(diff -u "$f" <(${CLANG_FORMAT} "$f") || true)

		if ! [ -z "$d" ]; then
			whitelisted=$(awk '$1 == "'$f'" { print 1 }' "$CLANG_FORMAT_WHITELIST")

			# If file is not whitelisted, mark a failure
			if [ -z ${whitelisted} ]; then
				errorcount=$((errorcount+1))

				printf "The file %s is not compliant with the coding style" "$f"
				if [ ${errorcount} -gt 50 ]; then
					printf "\nToo many errors encountered previously, this diff is hidden.\n"
				else
					printf ":\n%s\n" "$d"
				fi

				fail=1
			fi
		fi
	done

	if [ "$fail" = 1 ]; then
		echo "LINT reports failure."
		exit 1
	fi

	echo "LINT OK"
}