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

PROJECT_DIR="${1:-qt5-before/qt5-legacy-migration-benchmark}"
COPILOT_MODEL="${2:-qwen3.5-397b-a17b}"

need_cmd() {
  command -v "$1" >/dev/null 2>&1 || {
    echo "ERROR: '$1' not found in PATH." >&2
    exit 1
  }
}

need_cmd entire
need_cmd copilot
need_cmd git

if ! git rev-parse --show-toplevel >/dev/null 2>&1; then
  echo "ERROR: Dieses Skript muss innerhalb eines bestehenden Git-Repositories gestartet werden." >&2
  echo "Bitte zuerst im Repo-Root 'git init' oder in einem bestehenden Repo arbeiten." >&2
  exit 1
fi

REPO_ROOT="$(git rev-parse --show-toplevel)"
cd "$REPO_ROOT"

if [ ! -d "$PROJECT_DIR" ]; then
  echo "ERROR: project directory '$PROJECT_DIR' not found relative to repo root '$REPO_ROOT'." >&2
  exit 1
fi

echo "Repo root: $REPO_ROOT"
echo "Legacy project: $PROJECT_DIR"
echo "Copilot model: $COPILOT_MODEL"

entire agent add copilot-cli
entire status

git add .
if git diff --cached --quiet; then
  git commit --allow-empty -m "baseline: Qt5/C++11 legacy benchmark before Qt6/C++23 migration"
else
  git commit -m "baseline: Qt5/C++11 legacy benchmark before Qt6/C++23 migration"
fi

echo
echo "== Checkpoints vor der Session =="
entire checkpoint list

envsubst < scripts/migration.prompt | copilot --model "${COPILOT_MODEL}"

echo
echo "== Git status after Copilot session =="
git status --short
git add .

if git diff --cached --quiet; then
  echo "No changes to commit."
else
  git commit -m "migrate: Qt5/C++11 app to Qt6/C++23 with tests and modern Qt APIs"
fi

echo
echo "== Checkpoints nach der Session =="
entire checkpoint list
entire checkpoint explain HEAD || true

read -r -p "Optional Rewind testen? [y/N] " DO_REWIND
if [[ "${DO_REWIND:-N}" =~ ^[Yy]$ ]]; then
  if ! entire checkpoint rewind; then
    echo "WARN: rewind not supported or failed."
  fi
fi

read -r -p "Optional Session-Resume-Hinweis ausgeben? [y/N] " DO_RESUME
if [[ "${DO_RESUME:-N}" =~ ^[Yy]$ ]]; then
  CURRENT_BRANCH="$(git rev-parse --abbrev-ref HEAD)"
  if ! entire session resume "${CURRENT_BRANCH}"; then
    echo "WARN: resume not supported or failed."
  fi
fi