#!/bin/bash
set -euo pipefail

usage() {
   printf "Usage: %s [-s|--source <branch>] [-t|--target <branch>] [source target] (target defaults to 'main')\n" "$0"
   exit 2
}

source_branch=""
# default target branch to main
target_branch="main"

# Parse options: -s|--source and -t|--target. Falls back to positional args.
while [[ $# -gt 0 ]]; do
   case "$1" in
      -s|--source)
         source_branch="$2"; shift 2;;
      -t|--target)
         target_branch="$2"; shift 2;;
      -h|--help)
         usage;;
      --)
         shift; break;;
      -*)
         printf "Unknown option: %s\n" "$1"; usage;;
      *)
         if [[ -z "$source_branch" ]]; then
            source_branch="$1"
         elif [[ -z "$target_branch" ]]; then
            target_branch="$1"
         fi
         shift;;
   esac
done

if [[ -z "$source_branch" ]]; then
   printf "no source branch specified, using current HEAD\n"
   source_branch="HEAD"
else
   printf "checking out source branch: %s\n" "$source_branch"
   git checkout "$source_branch"
fi

# Run unit tests
printf "\nUnit test results:\n´´´bash\n"
python3 -m unittest discover
printf "´´´\n"

# Get list of changed files between source and target branches
export CHANGED_FILES=$(git diff --name-only "$source_branch" "$target_branch")
for file in $CHANGED_FILES; do
       if [ -f "${file}" ]; then
          printf "\nHere is the diff between source (%s) version of %s and target (%s):\n\n" "$source_branch" "$file" "$target_branch"
          printf "´´´diff\n"
          git --no-pager diff -U1000 -W "$target_branch" -- "$file"
          printf "´´´\n"
       fi
done


# adjust model context length if needed