Bash script to ask Copilot to suggest Git commit messages based on staged changes

coci.sh

#!/usr/bin/env bash
set -eo pipefail

prompt=$(cat <<'EOF'
Suggest 3 one-liner & brief Git commit messages, each formatted EXACTLY as:

MESSAGE:Text of the commit message

Examples:

MESSAGE:First suggestion message
MESSAGE:Second suggestion message
MESSAGE:Third suggestion message

Only suggest commit messages that reflect staged changes. If there are no staged
changes then ask user to stage changes and do not suggest any commit messages.
EOF
)

mapfile suggestions < <(
copilot -p "$prompt" |
  tee >(grep -F MESSAGE: | sed 's/MESSAGE: *//') \
      >(grep -vF MESSAGE: >&2) \
      >/dev/null
)

if [ "${#suggestions[@]}" -ne 3 ]; then
  echo "Expected 3 suggestions, got ${#suggestions[@]}" >&2
  exit 1
fi

n=1
for suggestion in "${suggestions[@]}"; do
    echo -n "$n) $suggestion"
    ((n++))
done
printf 'q) Quit without committing

Select your preference (1/2/3/q): '
read selection

if [[ ! "$selection" =~ ^[1-3q]$ ]]; then
  echo "Invalid selection: $selection" >&2
  exit 1
fi

if [[ "$selection" == "q" ]]; then
  exit 1
fi

selected=${suggestions[$(($selection - 1))]}
git commit -eam "$selected"