#!/usr/bin/env bash

# This script ensures proper POSIX text file formatting and a few other things.
# This is supplementary to clang_format.sh and black_format.sh, but should be
# run before them.

# 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 types of files.
    if [[ "$f" == *"csproj" ]]; then
        continue
    elif [[ "$f" == *"sln" ]]; then
        continue
    elif [[ "$f" == *"patch" ]]; then
        continue
    elif [[ "$f" == *"pot" ]]; then
        continue
    elif [[ "$f" == *"po" ]]; then
        continue
    elif [[ "$f" == "thirdparty"* ]]; then
        continue
    elif [[ "$f" == "platform/android/java/lib/src/com/google"* ]]; then
        continue
    fi
    # Ensures that files are UTF-8 formatted.
    recode UTF-8 "$f" 2> /dev/null
    # Ensures that files have LF line endings.
    dos2unix "$f" 2> /dev/null
    # Remove trailing space characters.
    # -l option handles newlines conveniently and seems to also get rid of BOMs.
    perl -i -ple 's/\s*$//g' "$f"
    # Remove the character sequence "== true" if it has a leading space.
    perl -i -pe 's/\x20== true//g' "$f"
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