#!/usr/bin/env bash

set -Eeuo pipefail
set -m

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
BACKEND_DIR="$ROOT_DIR/backend"
FRONTEND_DIR="$ROOT_DIR/frontend"
BACKEND_VENV="$BACKEND_DIR/.venv"
BACKEND_PYTHON="$BACKEND_VENV/bin/python"

DO_SETUP=false
CHECK_ONLY=false
BACKEND_PID=""
FRONTEND_PID=""
CONFIG_PATH=""
FRONTEND_PORT=""
BACKEND_PORT=""

usage() {
  cat <<'EOF'
用法：
  ./scripts/start-dev.sh           启动前端和后端
  ./scripts/start-dev.sh --setup   同步本地依赖后启动
  ./scripts/start-dev.sh --check   只检查依赖、配置和数据库连接

环境变量：
  PYTHON_BIN           创建虚拟环境时使用的 Python 3.12+ 可执行文件
  BACKEND_CONFIG_FILE 指定其他后端 YAML 配置文件
  FRONTEND_PORT        覆盖 YAML 中的前端端口
  BACKEND_PORT         覆盖 YAML 中的后端端口
EOF
}

fail() {
  echo "❌ $*" >&2
  exit 1
}

process_group_alive() {
  local pid="$1"
  [[ -n "$pid" ]] && kill -0 -- "-$pid" 2>/dev/null
}

stop_process_group() {
  local pid="$1"
  local attempt=0
  [[ -n "$pid" ]] || return 0

  if process_group_alive "$pid"; then
    kill -TERM -- "-$pid" 2>/dev/null || true
    while process_group_alive "$pid" && [[ $attempt -lt 50 ]]; do
      sleep 0.1
      attempt=$((attempt + 1))
    done
    if process_group_alive "$pid"; then
      kill -KILL -- "-$pid" 2>/dev/null || true
    fi
  elif kill -0 "$pid" 2>/dev/null; then
    kill -TERM "$pid" 2>/dev/null || true
  fi
  wait "$pid" 2>/dev/null || true
}

cleanup() {
  trap - EXIT
  stop_process_group "$FRONTEND_PID"
  stop_process_group "$BACKEND_PID"
}

handle_signal() {
  echo
  echo "🛑 正在停止前端和后端……"
  exit 130
}

port_in_use() {
  local port="$1"
  lsof -nP -iTCP:"$port" -sTCP:LISTEN >/dev/null 2>&1
}

select_base_python() {
  if [[ -n "${PYTHON_BIN:-}" ]]; then
    printf '%s\n' "$PYTHON_BIN"
  elif [[ -x /opt/miniconda3/bin/python3 ]]; then
    printf '%s\n' /opt/miniconda3/bin/python3
  else
    command -v python3 || true
  fi
}

setup_dependencies() {
  local base_python
  base_python="$(select_base_python)"
  [[ -n "$base_python" ]] || fail "未找到 Python 3，请通过 PYTHON_BIN 指定 Python 3.12+。"

  "$base_python" -c \
    'import sys; raise SystemExit(0 if sys.version_info >= (3, 12) else 1)' \
    || fail "后端要求 Python 3.12+，当前为 $($base_python --version 2>&1)。"

  if [[ ! -x "$BACKEND_PYTHON" ]]; then
    echo "📦 创建后端虚拟环境……"
    "$base_python" -m venv "$BACKEND_VENV"
  fi

  echo "📦 同步后端依赖……"
  "$BACKEND_PYTHON" -m pip install -r "$BACKEND_DIR/requirements.txt"

  echo "📦 同步前端依赖……"
  (cd "$FRONTEND_DIR" && npm ci)

  if [[ -z "${BACKEND_CONFIG_FILE:-}" && ! -f "$BACKEND_DIR/config.yaml" ]]; then
    cp "$BACKEND_DIR/config.example.yaml" "$BACKEND_DIR/config.yaml"
    echo "📝 已根据 config.example.yaml 创建本地 config.yaml，请填写数据库密码。"
  fi
}

resolve_and_check_config() {
  local port_values

  CONFIG_PATH="$(
    cd "$BACKEND_DIR"
    "$BACKEND_PYTHON" -c \
      'from app.core.config import _resolve_config_path; print(_resolve_config_path()[0])'
  )" || fail "无法解析后端配置文件路径。"

  [[ -f "$CONFIG_PATH" ]] || fail "配置文件不存在：$CONFIG_PATH"
  port_values="$(
    cd "$BACKEND_DIR"
    "$BACKEND_PYTHON" -c \
      'from app.core.config import get_settings; settings = get_settings(); print(settings.frontend_port, settings.backend_port)'
  )" || fail "配置文件无法加载：$CONFIG_PATH"

  read -r FRONTEND_PORT BACKEND_PORT <<< "$port_values"
  [[ -n "$FRONTEND_PORT" && -n "$BACKEND_PORT" ]] \
    || fail "无法从配置文件读取前端和后端端口：$CONFIG_PATH"
}

check_dependencies() {
  command -v node >/dev/null 2>&1 || fail "未找到 Node.js。"
  command -v npm >/dev/null 2>&1 || fail "未找到 npm。"
  command -v curl >/dev/null 2>&1 || fail "未找到 curl。"
  command -v lsof >/dev/null 2>&1 || fail "未找到 lsof。"
  [[ -x "$FRONTEND_DIR/node_modules/.bin/vite" ]] \
    || fail "前端依赖不完整，请先运行 ./scripts/start-dev.sh --setup。"
  [[ -x "$BACKEND_PYTHON" ]] \
    || fail "后端虚拟环境不存在，请先运行 ./scripts/start-dev.sh --setup。"

  "$BACKEND_PYTHON" -c 'import fastapi, psycopg, sqlalchemy, uvicorn, yaml' \
    || fail "后端依赖不完整，请先运行 ./scripts/start-dev.sh --setup。"
  resolve_and_check_config
}

check_database() {
  echo "🔍 检查 PostgreSQL 连接：$CONFIG_PATH"
  (
    cd "$BACKEND_DIR"
    "$BACKEND_PYTHON" -c '
import psycopg
from app.core.config import get_settings

url = get_settings().database_url
prefix = "postgresql+psycopg://"
if url.startswith(prefix):
    url = "postgresql://" + url[len(prefix):]
connection = psycopg.connect(url, connect_timeout=3)
connection.close()
'
  ) || fail "PostgreSQL 无法连接，请检查配置文件中的地址、用户名和密码：$CONFIG_PATH"
}

wait_for_url() {
  local url="$1"
  local service_name="$2"
  local pid="$3"
  local attempt=0
  local max_attempts=30

  while [[ $attempt -lt $max_attempts ]]; do
    if curl -fsS --max-time 1 "$url" >/dev/null 2>&1; then
      return 0
    fi
    if ! kill -0 "$pid" 2>/dev/null; then
      echo "❌ $service_name 进程已提前退出。" >&2
      return 1
    fi
    sleep 1
    attempt=$((attempt + 1))
  done

  echo "❌ 等待 $service_name 就绪超时：$url" >&2
  return 1
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --setup)
      DO_SETUP=true
      ;;
    --check)
      CHECK_ONLY=true
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      usage >&2
      fail "未知参数：$1"
      ;;
  esac
  shift
done

if [[ "$DO_SETUP" == true ]]; then
  setup_dependencies
fi

check_dependencies
check_database

if [[ "$CHECK_ONLY" == true ]]; then
  echo "✅ 前端、后端依赖、配置和 PostgreSQL 连接均正常。"
  exit 0
fi

port_in_use "$BACKEND_PORT" \
  && fail "后端端口 $BACKEND_PORT 已被占用，后端可能已经启动。"
port_in_use "$FRONTEND_PORT" \
  && fail "前端端口 $FRONTEND_PORT 已被占用，前端可能已经启动。"

trap cleanup EXIT
trap handle_signal INT TERM

echo "🚀 启动后端：http://127.0.0.1:$BACKEND_PORT"
(
  cd "$BACKEND_DIR"
  exec "$BACKEND_PYTHON" -m uvicorn app.main:app \
    --host 0.0.0.0 \
    --port "$BACKEND_PORT" \
    --reload
) &
BACKEND_PID=$!

wait_for_url "http://127.0.0.1:$BACKEND_PORT/modelTF/health" "后端" "$BACKEND_PID" \
  || fail "后端启动失败。"

echo "🚀 启动前端：http://127.0.0.1:$FRONTEND_PORT"
(
  cd "$FRONTEND_DIR"
  export FRONTEND_PORT BACKEND_PORT
  exec npm run dev -- --host 0.0.0.0 --port "$FRONTEND_PORT" --strictPort
) &
FRONTEND_PID=$!

wait_for_url "http://127.0.0.1:$FRONTEND_PORT" "前端" "$FRONTEND_PID" \
  || fail "前端启动失败。"

echo "✅ 前端和后端均已就绪，按 Ctrl+C 可同时停止。"

while kill -0 "$BACKEND_PID" 2>/dev/null && kill -0 "$FRONTEND_PID" 2>/dev/null; do
  sleep 1
done

set +e
if ! kill -0 "$BACKEND_PID" 2>/dev/null; then
  wait "$BACKEND_PID"
  EXIT_CODE=$?
  echo "❌ 后端已退出，正在停止前端。" >&2
else
  wait "$FRONTEND_PID"
  EXIT_CODE=$?
  echo "❌ 前端已退出，正在停止后端。" >&2
fi
set -e

exit "$EXIT_CODE"