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

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
RUNTIME_DIR="${RUNTIME_DIR:-${ROOT_DIR}/.local}"
LOG_DIR="${RUNTIME_DIR}/logs"
LOG_FILE="${LOG_FILE:-${LOG_DIR}/frontend.log}"
PID_FILE="${PID_FILE:-${RUNTIME_DIR}/frontend.pid}"

BACKEND_URL="${LOCAL_BACKEND_URL:-http://127.0.0.1:9091}"
FRONTEND_PORT="${PORT:-8000}"
NPM_CMD="${NPM_CMD:-npm}"
MAX_CMD="${ROOT_DIR}/node_modules/.bin/max"

info() {
  printf '\033[1;32m%s\033[0m\n' "$*"
}

error() {
  printf '\033[1;31m%s\033[0m\n' "$*" >&2
}

usage() {
  cat <<'EOF'
用法：./local.sh <命令> [参数]

命令：
  install                使用 package-lock.json 安装依赖
  start [--skip-install] 检查本地后端并在后台启动前端
  stop                   停止本脚本启动的前端进程
  restart [--skip-install] 重启前端
  status                 查看前端和本地后端状态
  logs [行数]            查看并持续跟踪日志，默认显示最后 200 行
  help                   显示帮助

可选环境变量：
  LOCAL_BACKEND_URL      本地后端地址，默认 http://127.0.0.1:9091
  PORT                   前端端口，默认 8000
  NPM_CMD                npm 命令，默认 npm
EOF
}

prepare_runtime() {
  mkdir -p "${LOG_DIR}"
}

read_pid() {
  if [[ -f "${PID_FILE}" ]]; then
    tr -d '[:space:]' < "${PID_FILE}"
  fi
}

is_running() {
  local pid
  pid="$(read_pid)"
  [[ -n "${pid}" ]] && kill -0 "${pid}" 2>/dev/null
}

install_dependencies() {
  command -v "${NPM_CMD}" >/dev/null 2>&1 || {
    error "未找到 npm 命令：${NPM_CMD}"
    exit 1
  }

  info "正在根据 package-lock.json 安装依赖..."
  (
    cd "${ROOT_DIR}"
    "${NPM_CMD}" ci
  )
}

check_backend() {
  local status
  command -v curl >/dev/null 2>&1 || {
    error "未找到 curl，无法检查本地后端"
    exit 1
  }

  status="$(curl -s -o /dev/null --max-time 3 -w '%{http_code}' "${BACKEND_URL}/" || true)"
  if [[ -z "${status}" || "${status}" == "000" ]]; then
    error "本地后端不可访问：${BACKEND_URL}"
    error "请先在 shz-backend 中执行：./local.sh start"
    exit 1
  fi
  info "本地后端已连接：${BACKEND_URL}（HTTP ${status}）"
}

start_frontend() {
  local skip_install="${1:-}"

  prepare_runtime
  if is_running; then
    info "前端已在运行，PID：$(read_pid)"
    return 0
  fi
  rm -f "${PID_FILE}"

  check_backend

  if [[ ! -x "${MAX_CMD}" ]]; then
    if [[ "${skip_install}" == "--skip-install" ]]; then
      error "依赖尚未安装，不能跳过安装：${MAX_CMD} 不存在"
      exit 1
    fi
    install_dependencies
  elif [[ -n "${skip_install}" && "${skip_install}" != "--skip-install" ]]; then
    error "未知参数：${skip_install}"
    exit 2
  fi

  export REACT_APP_ENV=dev
  export MOCK=none
  export UMI_ENV=dev
  export LOCAL_BACKEND_URL="${BACKEND_URL}"
  export PORT="${FRONTEND_PORT}"

  info "正在启动前端：http://localhost:${FRONTEND_PORT}"
  info "后端代理目标：${BACKEND_URL}"
  (
    cd "${ROOT_DIR}"
    nohup "${MAX_CMD}" dev >> "${LOG_FILE}" 2>&1 &
    printf '%s\n' "$!" > "${PID_FILE}"
  )

  local frontend_status="000"
  for _ in {1..60}; do
    if ! is_running; then
      break
    fi
    frontend_status="$(curl -s -o /dev/null --max-time 1 -w '%{http_code}' \
      "http://127.0.0.1:${FRONTEND_PORT}/" || true)"
    if [[ -n "${frontend_status}" && "${frontend_status}" != "000" ]]; then
      info "前端已启动，PID：$(read_pid)，HTTP ${frontend_status}"
      info "日志命令：./local.sh logs"
      return 0
    fi
    sleep 1
  done

  rm -f "${PID_FILE}"
  error "前端未能在 60 秒内启动，最近日志如下："
  tail -n 80 "${LOG_FILE}" >&2 || true
  exit 1
}

stop_frontend() {
  local pid
  pid="$(read_pid)"

  if ! is_running; then
    rm -f "${PID_FILE}"
    info "前端未运行"
    return 0
  fi

  info "正在停止前端，PID：${pid}"
  kill "${pid}"
  for _ in {1..15}; do
    if ! kill -0 "${pid}" 2>/dev/null; then
      rm -f "${PID_FILE}"
      info "前端已停止"
      return 0
    fi
    sleep 1
  done

  error "前端未在 15 秒内停止，请检查 PID：${pid}"
  exit 1
}

show_status() {
  local backend_status
  if is_running; then
    info "前端正在运行，PID：$(read_pid)，地址：http://localhost:${FRONTEND_PORT}"
  else
    rm -f "${PID_FILE}"
    info "前端未运行"
  fi

  backend_status="$(curl -s -o /dev/null --max-time 2 -w '%{http_code}' "${BACKEND_URL}/" || true)"
  if [[ -n "${backend_status}" && "${backend_status}" != "000" ]]; then
    info "本地后端可访问：${BACKEND_URL}（HTTP ${backend_status}）"
  else
    error "本地后端不可访问：${BACKEND_URL}"
  fi
  info "日志文件：${LOG_FILE}"
}

show_logs() {
  local lines="${1:-200}"
  if [[ ! "${lines}" =~ ^[0-9]+$ ]]; then
    error "日志行数必须是非负整数：${lines}"
    exit 2
  fi

  prepare_runtime
  touch "${LOG_FILE}"
  info "正在跟踪日志：${LOG_FILE}（Ctrl+C 退出）"
  tail -n "${lines}" -f "${LOG_FILE}"
}

command="${1:-help}"
case "${command}" in
  install)
    install_dependencies
    ;;
  start)
    start_frontend "${2:-}"
    ;;
  stop)
    stop_frontend
    ;;
  restart)
    stop_frontend
    start_frontend "${2:-}"
    ;;
  status)
    show_status
    ;;
  logs)
    show_logs "${2:-200}"
    ;;
  help|-h|--help)
    usage
    ;;
  *)
    error "未知命令：${command}"
    usage >&2
    exit 2
    ;;
esac