#!/bin/bash
#
# PRE-COMMIT, hook script to verify what is about to be committed
# Copyright (C) 2022 Xavier Delaruelle
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

##########################################################################

# redirect output to stderr.
exec 1>&2

# apply SGR code to message if output channel is attached to terminal
sgr() {
   local code=$1
   local msg=$2
   if [ -t 2 ]; then
      echo "\033[${code}m${msg}\033[0m"
   else
      echo $msg
   fi
}

echo_warning() {
   echo -e "$(sgr 43 WARNING): $1"
}

echo_error() {
   echo -e "$(sgr 41 ERROR): $1"
}

# fail if there are misspellings (check all files)
command -v codespell >/dev/null
if [ $? -eq 0 ]; then
   git diff --cached HEAD | grep '^[+][^+]' | codespell -
   if [ $? -ne 0 ]; then
      exit 1
   fi
else
   echo_warning "codespell command not found"
fi

# interactively check misspellings in doc files
command -v aspell >/dev/null
if [ $? -eq 0 ]; then
   misspell=0
   ASPELL_OPTS='-l en -x --home-dir=. --personal=.aspell.en.pws'
   for docfile in $(git diff --cached --name-only --diff-filter=d | grep -E\
      '(.rst|.md)$'); do
      words=$(git diff --cached $docfile | grep '^[+][^+]' | aspell\
         $ASPELL_OPTS list)
      if [ -n "$words" ]; then
         # interactively edit file to fix misspellings
         aspell $ASPELL_OPTS check $docfile </dev/tty >/dev/tty;
         misspell=1
      fi
   done
   # abort if misspellings were found as commit content should be adapted
   if [ $misspell -eq 1 ]; then
      echo_error "misspelling found, commit should be updated"
      exit 1
   fi
else
   echo_warning "aspell command not found"
fi

# fail if there are whitespace errors
git diff-index --check --cached HEAD --
if [ $? -ne 0 ]; then
   exit 1
fi

exit 0

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