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

APP_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
CONFIG_PATH="${1:-${APP_DIR}/config.json}"
DOMAIN_FILE="${APP_DIR}/runtime/current_domain.txt"

before=""
if [[ -f "$DOMAIN_FILE" ]]; then
  before="$(tr -d '\r\n' < "$DOMAIN_FILE")"
fi

/usr/bin/python3 "${APP_DIR}/scripts/domain_updater.py" --config "$CONFIG_PATH"

after=""
if [[ -f "$DOMAIN_FILE" ]]; then
  after="$(tr -d '\r\n' < "$DOMAIN_FILE")"
fi

if [[ -z "$after" ]]; then
  echo "[vmess-domain-rotator] empty selected domain, skip git commit"
  exit 0
fi

if [[ "$before" == "$after" ]]; then
  echo "[vmess-domain-rotator] domain unchanged (${after}), skip git commit"
  exit 0
fi

if ! command -v git >/dev/null 2>&1; then
  echo "[vmess-domain-rotator] git not found, skip git commit"
  exit 0
fi

if ! git -C "$APP_DIR" rev-parse --is-inside-work-tree >/dev/null 2>&1; then
  echo "[vmess-domain-rotator] not a git repo, skip git commit"
  exit 0
fi

commit_name="${GIT_COMMIT_NAME:-vmess-domain-rotator}"
commit_email="${GIT_COMMIT_EMAIL:-vmess-domain-rotator@localhost}"
runtime_branch="${GIT_RUNTIME_BRANCH:-runtime-state}"
ts="$(date -u +"%Y-%m-%dT%H:%M:%SZ")"

push_remote="${GIT_PUSH_REMOTE:-origin}"
if ! git -C "$APP_DIR" remote get-url "$push_remote" >/dev/null 2>&1; then
  push_remote=""
  while IFS= read -r r; do
    push_remote="$r"
    break
  done < <(git -C "$APP_DIR" remote)
fi

work_dir=""
cleanup_worktree="0"
current_branch="$(git -C "$APP_DIR" symbolic-ref --quiet --short HEAD 2>/dev/null || true)"

if [[ "$current_branch" == "$runtime_branch" ]]; then
  work_dir="$APP_DIR"
else
  work_dir="$(mktemp -d "${TMPDIR:-/tmp}/vmess-runtime-state.XXXXXX")"
  cleanup_worktree="1"

  if git -C "$APP_DIR" show-ref --verify --quiet "refs/heads/${runtime_branch}"; then
    git -C "$APP_DIR" worktree add --force "$work_dir" "$runtime_branch"
  else
    if [[ -n "$push_remote" ]] && git -C "$APP_DIR" ls-remote --exit-code --heads "$push_remote" "$runtime_branch" >/dev/null 2>&1; then
      git -C "$APP_DIR" fetch "$push_remote" "$runtime_branch:$runtime_branch"
      git -C "$APP_DIR" worktree add --force "$work_dir" "$runtime_branch"
    else
      git -C "$APP_DIR" worktree add --force --detach "$work_dir"
      git -C "$work_dir" checkout --orphan "$runtime_branch"
      git -C "$work_dir" rm -rf . >/dev/null 2>&1 || true
      echo "[vmess-domain-rotator] initialized branch ${runtime_branch}"
    fi
  fi
fi

if [[ "$cleanup_worktree" == "1" ]]; then
  cleanup() {
    git -C "$APP_DIR" worktree remove --force "$work_dir" >/dev/null 2>&1 || rm -rf "$work_dir"
  }
  trap cleanup EXIT
fi

mkdir -p "$work_dir/runtime"
for file in current_domain.txt current_domain.json state.json substore_vars.json; do
  src="$APP_DIR/runtime/$file"
  dst="$work_dir/runtime/$file"
  if [[ -f "$src" ]]; then
    cp "$src" "$dst"
  else
    rm -f "$dst"
  fi
done

git -C "$work_dir" add -A runtime/current_domain.txt runtime/current_domain.json runtime/state.json runtime/substore_vars.json || true

if git -C "$work_dir" diff --cached --quiet; then
  echo "[vmess-domain-rotator] no staged changes for ${runtime_branch}, skip git commit"
  exit 0
fi

git -C "$work_dir" \
  -c user.name="$commit_name" \
  -c user.email="$commit_email" \
  commit -m "chore: rotate preferred domain to ${after} (${ts})"

if [[ -z "$push_remote" ]]; then
  echo "[vmess-domain-rotator] no remote found, skip git push"
else
  if git -C "$work_dir" rev-parse --abbrev-ref --symbolic-full-name "@{u}" >/dev/null 2>&1; then
    if git -C "$work_dir" push "$push_remote" "$runtime_branch:$runtime_branch"; then
      echo "[vmess-domain-rotator] pushed to ${push_remote}/${runtime_branch}"
    else
      echo "[vmess-domain-rotator] git push failed"
    fi
  else
    if git -C "$work_dir" push -u "$push_remote" "$runtime_branch:$runtime_branch"; then
      echo "[vmess-domain-rotator] pushed to ${push_remote}/${runtime_branch} (set upstream)"
    else
      echo "[vmess-domain-rotator] git push failed"
    fi
  fi
fi

echo "[vmess-domain-rotator] committed domain change on ${runtime_branch}: ${before} -> ${after}"