#!/usr/bin/env bash
# GitHub upstream → monorepo submodule 최신 소스 반영 (pull only, push 없음)
#
#   ./git_fetch_all.sh              # 4개 submodule fetch + fast-forward
#   ./git_fetch_all.sh --init       # submodule 미초기화 시 clone 포함
#   ./git_fetch_all.sh --dry-run      # 실행 없이 변경 예상만 출력
#
# 대상 (.gitmodules):
#   chatbotApp-chatbot2.0-agent      → KoreaExpressWayCorp/chatbotApp (chatbot2.0-agent)
#   chatbotApi-chatbot2.0-agent      → KoreaExpressWayCorp/chatbotApi (chatbot2.0-agent)
#   exAiChatBot-chatbot2.0-agent     → KoreaExpressWayCorp/exAiChatBot (chatbot2.0-agent)
#   kakaoChatbotSkill-chatbot2.0-agent → KoreaExpressWayCorp/kakaoChatbotSkill (chatbot2.0-agent)
set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# bare repo 배포 시 상위에서 GIT_DIR 이 export 되면 submodule git 이 깨짐
MONOREPO_GIT_DIR="${MONOREPO_GIT_DIR:-${GIT_DIR:-}}"
unset GIT_DIR GIT_WORK_TREE
INIT=false
DRY_RUN=false

for arg in "$@"; do
  case "$arg" in
    --init)    INIT=true ;;
    --dry-run) DRY_RUN=true ;;
    -h|--help)
      sed -n '2,14p' "$0"
      exit 0
      ;;
    *)
      echo "알 수 없는 옵션: $arg (--help)"
      exit 1
      ;;
  esac
done

log()  { echo "[git_fetch_all] $*"; }
warn() { echo "[git_fetch_all] ⚠️  $*" >&2; }

cd "${ROOT_DIR}"

if [[ ! -f .gitmodules ]]; then
  echo "ERROR: .gitmodules 없음 — submodule 미설정"
  exit 1
fi

SUBMODULE_PATHS=()
while IFS= read -r _path; do
  [[ -n "${_path}" ]] && SUBMODULE_PATHS+=("${_path}")
done < <(git config -f .gitmodules --get-regexp '^submodule\..*\.path$' | awk '{print $2}')

if [[ ${#SUBMODULE_PATHS[@]} -eq 0 ]]; then
  echo "ERROR: .gitmodules 에 submodule 경로 없음"
  exit 1
fi

if $INIT && ! $DRY_RUN; then
  log "submodule init (direct clone)..."
fi

resolve_monorepo_git_dir() {
  if [[ -n "${MONOREPO_GIT_DIR}" && -d "${MONOREPO_GIT_DIR}" ]]; then
    echo "${MONOREPO_GIT_DIR}"
  elif git -C "${ROOT_DIR}" rev-parse --git-dir >/dev/null 2>&1; then
    git -C "${ROOT_DIR}" rev-parse --git-dir
  fi
}

submodule_pinned_sha() {
  local path="$1"
  local git_dir
  git_dir="$(resolve_monorepo_git_dir || true)"
  [[ -n "${git_dir}" ]] || return 0
  git --git-dir="${git_dir}" ls-tree HEAD "${path}" 2>/dev/null | awk '{print $3}'
}

clone_submodule_repo() {
  local path="$1" url="$2" branch="$3"
  local target="${ROOT_DIR}/${path}"
  local sha

  sha="$(submodule_pinned_sha "${path}" || true)"
  log "    clone ${url} → ${path} (branch=${branch})"
  rm -rf "${target}"
  if ! git clone --branch "${branch}" --single-branch "${url}" "${target}"; then
    warn "${path} — clone 실패 (서버 GitHub 미접속 시 sync-submodules-rsync.sh 사용)"
    return 1
  fi
  if [[ -n "${sha}" ]]; then
    git -C "${target}" checkout "${sha}" 2>/dev/null || true
  fi
}

restore_monorepo_overlays() {
  if [[ -f "${ROOT_DIR}/local-dev/docker-compose.rag.local.yml" ]]; then
    cp "${ROOT_DIR}/local-dev/docker-compose.rag.local.yml" \
      "${ROOT_DIR}/exAiChatBot-chatbot2.0-agent/docker-compose.local.yml"
    log "복원: exAiChatBot/docker-compose.local.yml (monorepo overlay)"
  fi
  if [[ -f "${ROOT_DIR}/server-dev/docker-compose.rag.server.yml" ]]; then
    cp "${ROOT_DIR}/server-dev/docker-compose.rag.server.yml" \
      "${ROOT_DIR}/exAiChatBot-chatbot2.0-agent/docker-compose.server.yml"
    log "복원: exAiChatBot/docker-compose.server.yml (monorepo overlay)"
  fi
}

submodule_is_cloned() {
  local path="$1"
  [[ -e "${ROOT_DIR}/${path}/.git" ]]
}

fetch_one() {
  local path="$1"
  local url branch old new dirty

  url="$(git config -f .gitmodules "submodule.${path}.url")"
  branch="$(git config -f .gitmodules "submodule.${path}.branch" || echo main)"
  branch="${branch:-main}"

  log ">>> ${path}"
  log "    url=${url} branch=${branch}"

  if ! submodule_is_cloned "${path}"; then
    if $DRY_RUN; then
      log "    [dry-run] submodule clone 필요 — ./git_fetch_all.sh --init"
      return 0
    fi
    if $INIT; then
      clone_submodule_repo "${path}" "${url}" "${branch}" || return 1
    else
      warn "${path} — submodule 미초기화. --init 옵션 사용"
      return 1
    fi
  fi

  (
    cd "${ROOT_DIR}/${path}"

    if ! git diff --quiet || ! git diff --cached --quiet; then
      dirty=yes
      warn "${path} — 로컬 변경 있음 (fetch는 진행, fast-forward 실패 가능)"
    else
      dirty=no
    fi

    old="$(git rev-parse HEAD 2>/dev/null || echo none)"

    if $DRY_RUN; then
      git fetch origin "${branch}" 2>/dev/null || git fetch origin
      new="$(git rev-parse "origin/${branch}" 2>/dev/null || echo unknown)"
      if [[ "${old}" == "${new}" ]]; then
        log "    [dry-run] 이미 최신: ${old:0:7}"
      else
        log "    [dry-run] ${old:0:7} → ${new:0:7}"
        git log --oneline "${old}..origin/${branch}" 2>/dev/null | sed 's/^/      /' || true
      fi
      exit 0
    fi

    git fetch origin "${branch}"
    git checkout "${branch}" 2>/dev/null || git checkout -B "${branch}" "origin/${branch}"

    if git merge-base --is-ancestor HEAD "origin/${branch}" 2>/dev/null \
      && [[ "$(git rev-parse HEAD)" != "$(git rev-parse "origin/${branch}")" ]]; then
      git merge --ff-only "origin/${branch}"
    elif [[ "$(git rev-parse HEAD)" != "$(git rev-parse "origin/${branch}")" ]]; then
      warn "${path} — fast-forward 불가 (로컬 커밋/변경 존재). 수동 merge 필요"
      git status -sb | sed 's/^/      /'
      exit 1
    fi

    new="$(git rev-parse HEAD)"
    if [[ "${old}" == "${new}" ]]; then
      log "    ✅ 최신 유지 $(git log -1 --oneline)"
    else
      log "    ✅ 갱신 ${old:0:7} → ${new:0:7} $(git log -1 --oneline)"
    fi
  )
}

failures=0
for path in "${SUBMODULE_PATHS[@]}"; do
  if ! fetch_one "${path}"; then
    failures=$((failures + 1))
  fi
  echo ""
done

if ! $DRY_RUN; then
  restore_monorepo_overlays
fi

log "=========================================="
log "submodule 상태:"
git submodule status || true
log "=========================================="

if [[ ${failures} -gt 0 ]]; then
  warn "실패 ${failures}개 — 로그 확인"
  exit 1
fi

log "완료 — GitHub → 로컬 반영 (push 없음)"
log "monorepo 커밋 갱신: git add .gitmodules *-chatbot2.0-agent && git status"