"""UE5 命令行白模关卡构建脚本。

由 build_level.bat 通过 UE5 的 -ExecutePythonScript 参数调用。
在 UE5 编辑器 Python 环境中运行，无需手动打开编辑器。

用法:
  build_level.bat                              # 默认配置
  build_level.bat --json output/v02.json       # 指定 JSON
  build_level.bat --no-quit                    # 构建后不退出编辑器

环境变量（由 build_level.bat 设置）:
  LB_JSON_PATH    — JSON 数据文件路径（相对于项目根目录）
  LB_MAP_NAME     — 目标关卡资产名
  LB_MAP_PACKAGE  — 关卡包路径（如 /Game/Maps）
  LB_NO_QUIT      — 设为 "1" 不退出编辑器
"""

import json
import os
import sys
import time
from pathlib import Path

# ---- 从环境变量读取配置 ----
json_rel = os.environ.get("LB_JSON_PATH", "tools/level-builder/output/level_v01.json")
map_name = os.environ.get("LB_MAP_NAME", "LVL_SuburbanV01")
map_package = os.environ.get("LB_MAP_PACKAGE", "/Game/Maps")
no_quit = os.environ.get("LB_NO_QUIT", "0") == "1"
map_asset_path = f"{map_package}/{map_name}"

# ---- 检查 unreal 模块 ----
try:
    import unreal
except ImportError:
    print("[LevelBuilder] FATAL: unreal 模块不可用，必须在 UE5 环境中运行")
    sys.exit(1)

# ---- 项目根目录 ----
# UE5 -ExecutePythonScript 模式下 CWD 是引擎目录，不是项目目录
# 所以必须通过环境变量传入项目路径
_project_root_str = os.environ.get("LB_PROJECT_ROOT", "")
if _project_root_str:
    PROJECT_ROOT = Path(_project_root_str)
else:
    # Fallback: 尝试从 .uproject 文件定位
    _cwd = Path(os.getcwd())
    if (_cwd / "ChildHood.uproject").exists():
        PROJECT_ROOT = _cwd
    else:
        # 最后尝试 unreal API
        try:
            PROJECT_ROOT = Path(unreal.Paths.project_dir()).parent
        except Exception:
            PROJECT_ROOT = _cwd

json_path = PROJECT_ROOT / json_rel

print(f"[LevelBuilder] ==========================================")
print(f"[LevelBuilder]   ChildHood Level Builder — Command Line")
print(f"[LevelBuilder] ==========================================")
print(f"[LevelBuilder] Project: {PROJECT_ROOT}")
print(f"[LevelBuilder] JSON:    {json_rel}")
print(f"[LevelBuilder] Map:     {map_asset_path}")
print(f"[LevelBuilder]")


# ---- 等待编辑器子系统就绪 ----
def wait_for_editor(timeout=90):
    """轮询等待 EditorActorSubsystem 可用。"""
    print("[LevelBuilder] 等待编辑器初始化...")
    start = time.time()
    while time.time() - start < timeout:
        try:
            subsys = unreal.get_editor_subsystem(unreal.EditorActorSubsystem)
            if subsys is not None:
                elapsed = time.time() - start
                print(f"[LevelBuilder] 编辑器就绪 ({elapsed:.1f}s)")
                return True
        except Exception:
            pass
        time.sleep(1)
    print(f"[LevelBuilder] FATAL: 编辑器初始化超时 ({timeout}s)")
    return False


if not wait_for_editor():
    sys.exit(1)


# ---- 设置 sys.path ----
lb_dir = str(PROJECT_ROOT / "tools" / "level-builder")
for p in [str(PROJECT_ROOT), lb_dir]:
    if p not in sys.path:
        sys.path.insert(0, p)


# ---- 确保目标关卡存在 ----
def ensure_map(asset_path):
    """创建或加载目标关卡。成功返回 True。"""
    # 已存在 → 加载
    if unreal.EditorAssetLibrary.does_asset_exist(asset_path):
        print(f"[LevelBuilder] 加载已有关卡: {asset_path}")
        unreal.EditorLevelLibrary.load_level(asset_path)
        return True

    print(f"[LevelBuilder] 创建新关卡: {asset_path}")

    # 方法 1: new_level(asset_path) — UE5.7 EditorLevelLibrary 直接创建
    try:
        unreal.EditorLevelLibrary.new_level(asset_path)
        print("[LevelBuilder] ✅ 关卡创建成功 (new_level)")
        return True
    except Exception as e:
        print(f"[LevelBuilder] new_level 失败: {e}")

    # 方法 2: AssetTools + WorldFactory（某些版本可用）
    try:
        asset_tools = unreal.get_editor_subsystem(unreal.AssetToolsSubsystem)
        factory = unreal.WorldFactory()
        new_asset = asset_tools.create_asset(
            asset_name=map_name,
            package_path=map_package,
            asset_class=None,
            factory=factory,
        )
        if new_asset:
            unreal.EditorLevelLibrary.load_level(asset_path)
            print("[LevelBuilder] ✅ 关卡创建成功 (WorldFactory)")
            return True
    except Exception as e:
        print(f"[LevelBuilder] WorldFactory 失败: {e}")

    print("[LevelBuilder] FATAL: 无法创建关卡")
    return False


if not ensure_map(map_asset_path):
    sys.exit(1)


# ---- 验证 JSON ----
if not json_path.exists():
    print(f"[LevelBuilder] FATAL: JSON 文件不存在: {json_path}")
    sys.exit(1)


# ---- 导入并执行构建 ----
from builder.scene_builder import build_level

print(f"[LevelBuilder] 开始构建...")
build_log = build_level(str(json_path), clear_existing=True)


# ---- 保存关卡 ----
print("[LevelBuilder] 保存关卡...")
try:
    unreal.EditorLevelLibrary.save_current_level()
    print(f"[LevelBuilder] ✅ 关卡已保存: {map_asset_path}")
except Exception as e:
    print(f"[LevelBuilder] ⚠️ 保存失败: {e}")


# ---- 构建结果汇总 ----
if build_log:
    ok = sum(1 for b in build_log if b.get("status") == "ok")
    fail = len(build_log) - ok
    print(f"")
    print(f"[LevelBuilder] {'=' * 40}")
    print(f"[LevelBuilder]   SUCCESS: {ok}  |  FAILED: {fail}  |  TOTAL: {len(build_log)}")
    print(f"[LevelBuilder] {'=' * 40}")
    if fail > 0:
        print(f"[LevelBuilder] 失败列表:")
        for b in build_log:
            if b.get("status") != "ok":
                print(f"    ❌ {b.get('name', '?')}: {b.get('reason', '未知')}")


# ---- 退出编辑器 ----
if not no_quit:
    print("[LevelBuilder] 退出编辑器...")
    unreal.SystemLibrary.execute_console_command(None, "quit")

print("[LevelBuilder] Done.")