#!/usr/bin/env bash

# This script ensures proper POSIX text file formatting and a few other things.

# We need dos2unix and recode.
if [ ! -x "$(command -v dos2unix)" -o ! -x "$(command -v recode)" ]; then
	printf "Install 'dos2unix' and 'recode' to use this script.\n"
fi

set -uo pipefail
IFS=$'\n\t'

# Loops through all text files tracked by Git.
git grep -zIl '' |
while IFS= read -rd '' f; do
	# Exclude some files.
	if [[ "$f" == *"csproj" ]]; then
		continue
	fi
	# Ensure that files are UTF-8 formatted.
	recode UTF-8 "$f" 2> /dev/null
	# Ensure that files have LF line endings and do not contain a BOM.
	dos2unix "$f" 2> /dev/null
	# Remove trailing space characters and ensures that files end
	# with newline characters. -l option handles newlines conveniently.
	perl -i -ple 's/\s*$//g' "$f"
	# Remove the character sequence "== true" if it has a leading space.
	perl -i -pe 's/\x20== true//g' "$f"
	# We don't want to change lines around braces in godot/tscn files.
	if [[ "$f" == *"godot" ]]; then
		continue
	elif [[ "$f" == *"tscn" ]]; then
		continue
	fi
	# Disallow empty lines after the opening brace.
	sed -z -i 's/\x7B\x0A\x0A/\x7B\x0A/g' "$f"
	# Disallow some empty lines before the closing brace.
	sed -z -i 's/\x0A\x0A\x7D/\x0A\x7D/g' "$f"
done

git diff > patch.patch

# If no patch has been generated all is OK, clean up, and exit.
if [ ! -s patch.patch ] ; then
	printf "Files in this commit comply with the formatting rules.\n"
	rm -f patch.patch
	exit 0
fi

# A patch has been created, notify the user, clean up, and exit.
printf "\n*** The following differences were found between the code "
printf "and the formatting rules:\n\n"
cat patch.patch
printf "\n*** Aborting, please fix your commit(s) with 'git commit --amend' or 'git rebase -i <hash>'\n"
rm -f patch.patch
exit 1
