#!/bin/sh
#
# Prepare git commit message:
#   - Add [ci skip] if the changes seem irrelevant for continuous integration

# Add [ci skip] to the commit message unless there are changes to files
# that are relevant for testing such as src/*, test/*, ledger3.texi, ...
add_ci_skip ()
{
  pattern="$1"; shift
  source="$1"

  # Don't add [ci skip] if it's already in the commit message source
  grep '\[ci skip\]' "$source" >/dev/null 2>&1
  [ $? -eq 0 ] && return

  if [ $(git diff --cached --name-only | grep --count "$pattern") -eq 0 ]; then
    tempfile=$(mktemp "${0}.XXXXXX")
    cat - "$1" <<EOF > "$tempfile"

# It seems the changes to be committed are irrelevant for the continuous
# integration, therefore it will be skipped for this commit.
#
# If you still want continuous integration to run for this commit
# comment or remove the next line.
[ci skip]
EOF
    mv "$tempfile" "$source"
  fi
}

## MAIN
file="$1"
source="$2"

# Skip merge commits
[ "$source" = "merge" ] && exit 0
add_ci_skip '\(^src\|^test\|^doc/ledger3.texi\|^\.travis.yml\|CMakeLists.txt\)' "$file"