#!/bin/bash

# Inspired by https://github.com/google/tarpc/blob/master/hooks/pre-commit
#
# Pre-commit hook for the mobilenode repository. To use this hook, copy it or
# add a symlink to it in .git/hooks in your repository root
#
# This precommit checks the following:
# 1. All filenames are ascii
# 2. There is no bad whitespace
# 3. rustfmt is installed
# 4. rustfmt is a noop on files that are in the index
#
# Options:
#
# - SKIP_RUSTFMT, default = 0
#
#   Set this to 1 to skip running rustfmt
#
# Note that these options are most useful for testing the hooks themselves. Use git commit
# --no-verify to skip the pre-commit hook altogether.

BOLD='\033[33;1m'
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'
NC='\033[0m' # No Color

PREFIX="${GREEN}[PRECOMMIT]${NC}"
FAILURE="${RED}FAILED${NC}"
WARNING="${RED}[WARNING]${NC}"
SKIPPED="${YELLOW}SKIPPED${NC}"
SUCCESS="${GREEN}ok${NC}"

GITROOT=$(git rev-parse --show-toplevel)
pushd "$GITROOT" >/dev/null 2>&1

if git rev-parse --verify HEAD &>/dev/null
then
	against=HEAD
else
	# Initial commit: diff against an empty tree object
	against=$(git hash-object -t tree /dev/null)
fi

FAILED=0

printf "${PREFIX} Checking that all filenames are ascii ... "
# Note that the use of brackets around a tr range is ok here, (it's
# even required, for portability to Solaris 10's /usr/bin/tr), since
# the square bracket bytes happen to fall in the designated range.
if test $(git diff --cached --name-only --diff-filter=A -z $against | LC_ALL=C tr -d '[ -~]\0' | wc -c) != 0
then
	FAILED=1
	printf "${FAILURE}\n"
else
	printf "${SUCCESS}\n"
fi

printf "${PREFIX} Checking for bad whitespace ... "
WHITESPACE_OUTPUT=$(git diff-index --color=always --check --cached $against -- 2>&1 | grep -v '^[^a-zA-Z]' | egrep -v '^public/sgx/sgx_(tcrypto|urts|types)' | grep -v '^src/sdk_json_interface/.*\.swift' | grep -v '.*.patch' )
if [[ -n "$WHITESPACE_OUTPUT" ]]; then
	FAILED=1
	printf "${FAILURE}\n"

	echo -e "$WHITESPACE_OUTPUT"
else
	printf "${SUCCESS}\n"
fi

printf "${PREFIX} Checking for rustfmt ... "
cargo fmt --version
if [ $? == 0 ]; then
	printf "${SUCCESS}\n"
else
	printf "${FAILURE}\n"
	popd >/dev/null 2>&1
	exit 1
fi

CARGOFMT="cargo +nightly fmt -- --unstable-features --skip-children"

# Just check that running rustfmt doesn't do anything to the file. I do this instead of
# modifying the file because I don't want to mess with the developer's index, which may
# not only contain discrete files.
printf "${PREFIX} Checking formatting ... "
FMTRESULT=0
diff=""
for file in $(git diff --name-only --cached --diff-filter=d | grep -v '^public/thirdparty/.*' | grep -v '^thirdparty/.*'  | egrep -v '^public/sgx/sgx_(tcrypto|urts|types)');
do
	if [[ ${file: -3} == ".rs" ]]; then
		newdiff=$($CARGOFMT --check $file | grep '^Diff in ' | awk -F' ' '{print $3;}')
		if [[ -n "$newdiff" ]]; then
			for filename in $newdiff; do
				diff="$filename\n$diff"
			done
		fi
	fi
done

if [[ "${SKIP_RUSTFMT}" == 1 ]]; then
	printf "${SKIPPED}\n"$?
elif [[ -n "$diff" ]]; then
	FAILED=1
	printf "${FAILURE}\n"
	echo -e "\033[33;1mFiles Needing Rustfmt:\033[0m"
	echo -e "$diff" | sort -u
	if [[ -n "$(which tty)" ]] && [[ -n "$(tty)" ]]; then
		exec < /dev/tty
		echo "Do you want to fix all these files automatically? (y/N) "
		read YESNO
		if [[ -n "$YESNO" ]] && [[ "$(echo "${YESNO:0:1}" | tr '[[:lower:]]' '[[:upper:]]')" = "Y" ]]; then
			echo -e "$diff" | while read file; do
				$CARGOFMT $file
			done
			echo "You should attempt this commit again to pick up these changes."
		else
			echo -e "Run ${BOLD}$CARGOFMT -- <file>${NC} to format the files you have staged."
		fi
		exec <&-
	else
		echo -e "Run ${BOLD}$CARGOFMT -- <file>${NC} to format the files you have staged."
	fi
else
	printf "${SUCCESS}\n"
fi

popd >/dev/null 2>&1
exit ${FAILED}