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

if ! git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
  echo "ERROR: Not inside a git repo."
  exit 1
fi

remote="origin"
dev_branch="dev"
main_branch="main"

# If set to YES, bypass the interactive spam prompt.
confirm_env="${RS_CONFIRM_SPAM:-}"

orig_branch="$(git rev-parse --abbrev-ref HEAD)"

echo "== RatedStats: Promote ${dev_branch} -> ${main_branch} (lua/toc only; tag main) =="

if [[ -n "$(git status --porcelain)" ]]; then
  echo "ERROR: Working tree is dirty. Commit/stash first."
  git status --porcelain
  exit 1
fi

next_main_tag() {
  # RatedStats main tag pattern:
  #   v<major>.<build>
  # Examples seen in published artifacts: v1.22, v2.02
  #
  # We intentionally IGNORE beta tags (vX.Y-beta) and anything with extra suffixes.
  local max_major=-1
  local max_build=-1
  local t major build

  while IFS= read -r t; do
    if [[ "$t" =~ ^v([0-9]+)\.([0-9]+)$ ]]; then
      major="${BASH_REMATCH[1]}"
      build="${BASH_REMATCH[2]}"

      if (( major > max_major )); then
        max_major="$major"
        max_build="$build"
      elif (( major == max_major && build > max_build )); then
        max_build="$build"
      fi
    fi
  done < <(git tag --list 'v*' | tr -d '\r')

  if (( max_major < 0 || max_build < 0 )); then
    echo "ERROR: Could not find any existing main tags matching v<major>.<build>"
    echo "       This script refuses to invent a scheme."
    return 1
  fi

  local next_build=$((max_build + 1))
  local candidate="v${max_major}.${next_build}"

  while git rev-parse -q --verify "refs/tags/${candidate}" >/dev/null; do
    next_build=$((next_build + 1))
    candidate="v${max_major}.${next_build}"
  done

  printf '%s\n' "${candidate}"
}

echo "[1/7] Fetching ${remote} (including tags)..."
git fetch --prune --tags "${remote}"

for b in "${dev_branch}" "${main_branch}"; do
  if ! git show-ref --verify --quiet "refs/heads/${b}"; then
    echo "ERROR: Local branch '${b}' not found."
    echo "Fix: git checkout -b ${b} ${remote}/${b}"
    exit 1
  fi
done

echo "[2/7] Fast-forwarding local branches..."
git checkout -q "${dev_branch}"
git pull --ff-only "${remote}" "${dev_branch}"

git checkout -q "${main_branch}"
git pull --ff-only "${remote}" "${main_branch}"

echo "[3/7] Calculating diff ${remote}/${main_branch}..${remote}/${dev_branch}..."
mapfile -t changed < <(git diff --name-only "${remote}/${main_branch}..${remote}/${dev_branch}" | tr -d '\r')
if [[ ${#changed[@]} -eq 0 ]]; then
  echo "Nothing to merge: ${dev_branch} has no changes vs ${main_branch}."
  git checkout -q "${orig_branch}"
  exit 0
fi

echo "Changed files (${#changed[@]}):"
printf ' - %s\n' "${changed[@]}"

allowed=()
disallowed=()
for f in "${changed[@]}"; do
  if [[ "$f" == *.toc ]]; then
    allowed+=("$f")
  elif [[ "$f" == *.lua ]]; then
    allowed+=("$f")
  else
    disallowed+=("$f")
  fi
done

echo
echo "Selective merge policy:"
echo " - Allowed: *.lua and *.toc"
if [[ ${#allowed[@]} -eq 0 ]]; then
  echo "Nothing allowed to merge (only non-Lua/non-TOC changes). Aborting."
  git checkout -q "${orig_branch}"
  exit 0
fi
if [[ ${#disallowed[@]} -gt 0 ]]; then
  echo " - Disallowed (will remain as main's version):"
  printf '   - %s\n' "${disallowed[@]}"
fi

echo
echo "[4/7] Spam scan (prints/chat/event/ticker/onupdate)..."

spam_hits=0

scan_file() {
  local f="$1"
  [[ -f "$f" ]] || return 0

  case "$f" in
    *.lua|*.toc) ;;
    *) return 0 ;;
  esac

  if grep -nE \
    '(^|[^a-zA-Z0-9_])(print|DEFAULT_CHAT_FRAME:AddMessage|ChatFrame[0-9]+:AddMessage|SendChatMessage|BNSendWhisper)\s*\(|RegisterEvent\s*\(|RegisterAllEvents\s*\(|C_Timer\.NewTicker\s*\(|C_Timer\.After\s*\(|SetScript\s*\(\s*["'\'']OnUpdate["'\'']' \
    "$f" >/dev/null 2>&1; then
    echo
    echo "---- ${f} ----"
    grep -nE \
      '(^|[^a-zA-Z0-9_])(print|DEFAULT_CHAT_FRAME:AddMessage|ChatFrame[0-9]+:AddMessage|SendChatMessage|BNSendWhisper)\s*\(|RegisterEvent\s*\(|RegisterAllEvents\s*\(|C_Timer\.NewTicker\s*\(|C_Timer\.After\s*\(|SetScript\s*\(\s*["'\'']OnUpdate["'\'']' \
      "$f" || true
    spam_hits=1
  fi
}

for f in "${allowed[@]}"; do
  scan_file "$f"
done

if [[ "${spam_hits}" -eq 1 ]]; then
  echo
  echo "WARNING: Potentially spammy changes detected above."
  if [[ "${confirm_env}" != "YES" ]]; then
    echo "Type YES to proceed (or Ctrl+C to abort):"
    read -r ans
    if [[ "${ans}" != "YES" ]]; then
      echo "Aborted."
      git checkout -q "${orig_branch}"
      exit 1
    fi
  else
    echo "RS_CONFIRM_SPAM=YES set; proceeding without prompt."
  fi
else
  echo "No spam triggers detected."
fi

echo
echo "[5/7] Promoting allowed files from ${dev_branch} onto ${main_branch}..."
merge_msg="Promote ${dev_branch} -> ${main_branch} (lua/toc only)"
echo "Commit message (enter to accept default): ${merge_msg}"
read -r user_msg || true
if [[ -n "${user_msg}" ]]; then
  merge_msg="${user_msg}"
fi

git checkout -q "${main_branch}"

echo "[5b] Applying allowed files from ${remote}/${dev_branch}..."

# We are NOT merging. We are copying the allowed paths from dev onto main.
for p in "${allowed[@]}"; do
  if git cat-file -e "${remote}/${dev_branch}:${p}" >/dev/null 2>&1; then
    if git restore -h >/dev/null 2>&1; then
      git restore --source "${remote}/${dev_branch}" --staged --worktree -- "${p}"
    else
      git checkout "${remote}/${dev_branch}" -- "${p}"
      git add -- "${p}"
    fi
  else
    # Allowed file was deleted on dev; reflect that on main.
    git rm -f --ignore-unmatch -- "${p}" >/dev/null 2>&1 || true
  fi
done

if git diff --cached --quiet; then
  echo "Nothing staged after promotion. Exiting."
  git checkout -q "${orig_branch}"
  exit 0
fi

echo
echo "[5c] Committing promoted changes..."
git commit -m "${merge_msg}"

echo
echo "[6/7] Tagging main with next version (based on latest main tag)..."
tag="$(next_main_tag)"
echo "Next main tag: ${tag}"

# RatedStats releases commonly use lightweight tags; keep that behavior.
git tag "${tag}"

echo
echo "[7/7] Pushing ${main_branch} + tags to ${remote}..."
git push "${remote}" "${main_branch}"
git push "${remote}" --tags

echo
echo "Merge complete."
git checkout -q "${orig_branch}"
