AstrBot/astrbot/core/core_lifecycle.py

"""Astrbot 核心生命周期管理类, 负责管理 AstrBot 的启动、停止、重启等操作.

该类负责初始化各个组件, 包括 ProviderManager、PlatformManager、ConversationManager、PluginManager、PipelineScheduler、EventBus等。
该类还负责加载和执行插件, 以及处理事件总线的分发。

工作流程:
1. 初始化所有组件
2. 启动事件总线和任务, 所有任务都在这里运行
3. 执行启动完成事件钩子
"""

import asyncio
import os
import threading
import time
import traceback
from asyncio import Queue
from enum import Enum

from astrbot.api import logger, sp
from astrbot.core import LogBroker, LogManager
from astrbot.core.astrbot_config_mgr import AstrBotConfigManager
from astrbot.core.config.default import VERSION
from astrbot.core.conversation_mgr import ConversationManager
from astrbot.core.cron import CronJobManager
from astrbot.core.db import BaseDatabase
from astrbot.core.knowledge_base.kb_mgr import KnowledgeBaseManager
from astrbot.core.persona_mgr import PersonaManager
from astrbot.core.pipeline.scheduler import PipelineContext, PipelineScheduler
from astrbot.core.platform.manager import PlatformManager
from astrbot.core.platform_message_history_mgr import PlatformMessageHistoryManager
from astrbot.core.provider.manager import ProviderManager
from astrbot.core.star.context import Context
from astrbot.core.star.star_handler import EventType, star_handlers_registry, star_map
from astrbot.core.star.star_manager import PluginManager
from astrbot.core.subagent_orchestrator import SubAgentOrchestrator
from astrbot.core.umop_config_router import UmopConfigRouter
from astrbot.core.updator import AstrBotUpdator
from astrbot.core.utils.llm_metadata import update_llm_metadata
from astrbot.core.utils.migra_helper import migra
from astrbot.core.utils.temp_dir_cleaner import TempDirCleaner

from . import astrbot_config, html_renderer
from .event_bus import EventBus


class LifecycleState(Enum):
    CREATED = "created"
    CORE_READY = "core_ready"
    RUNTIME_READY = "runtime_ready"
    RUNTIME_FAILED = "runtime_failed"


class AstrBotCoreLifecycle:
    """AstrBot 核心生命周期管理类, 负责管理 AstrBot 的启动、停止、重启等操作.

    该类负责初始化各个组件, 包括 ProviderManager、PlatformManager、ConversationManager、PluginManager、PipelineScheduler、
    EventBus 等。
    该类还负责加载和执行插件, 以及处理事件总线的分发。
    """

    def __init__(self, log_broker: LogBroker, db: BaseDatabase) -> None:
        self.log_broker = log_broker  # 初始化日志代理
        self.astrbot_config = astrbot_config  # 初始化配置
        self.db = db  # 初始化数据库

        self.subagent_orchestrator: SubAgentOrchestrator | None = None
        self.cron_manager: CronJobManager | None = None
        self.temp_dir_cleaner: TempDirCleaner | None = None

        # 设置代理
        proxy_config = self.astrbot_config.get("http_proxy", "")
        if proxy_config != "":
            os.environ["https_proxy"] = proxy_config
            os.environ["http_proxy"] = proxy_config
            logger.debug(f"Using proxy: {proxy_config}")
            # 设置 no_proxy
            no_proxy_list = self.astrbot_config.get("no_proxy", [])
            os.environ["no_proxy"] = ",".join(no_proxy_list)
        else:
            # 清空代理环境变量
            if "https_proxy" in os.environ:
                del os.environ["https_proxy"]
            if "http_proxy" in os.environ:
                del os.environ["http_proxy"]
            if "no_proxy" in os.environ:
                del os.environ["no_proxy"]
            logger.debug("HTTP proxy cleared")

        # Lifecycle compatibility fields
        # Expose lifecycle state and event flags expected by tests and older consumers.
        self.lifecycle_state = LifecycleState.CREATED
        self.core_initialized = False
        self.runtime_ready = False
        self.runtime_failed = False
        self.runtime_ready_event = asyncio.Event()
        self.runtime_failed_event = asyncio.Event()
        self.runtime_bootstrap_error = None
        self.start_time = 0
        self.runtime_bootstrap_task = None

        # runtime placeholders and defaults expected by tests and runtime code.
        # These used to be set later in the full initialize() path; tests and some
        # callers expect these attributes to exist even when only the core phase
        # was performed. Initialize them conservatively here.
        self.curr_tasks: list[asyncio.Task] = []
        self.dashboard_shutdown_event: asyncio.Event | None = None
        self.event_bus = None
        self.pipeline_scheduler_mapping: dict = {}

    def _set_lifecycle_state(self, state: LifecycleState) -> None:
        """Set lifecycle state and maintain compatibility flags/events.

        This method keeps the simple compatibility surface used by tests that
        expect boolean flags and asyncio Events alongside the enum state.
        """
        self.lifecycle_state = state

        if state == LifecycleState.CREATED:
            self.core_initialized = False
            self.runtime_ready = False
            self.runtime_failed = False
            try:
                self.runtime_ready_event.clear()
            except Exception:
                pass
            try:
                self.runtime_failed_event.clear()
            except Exception:
                pass
        elif state == LifecycleState.CORE_READY:
            self.core_initialized = True
            self.runtime_ready = False
            self.runtime_failed = False
            try:
                self.runtime_ready_event.clear()
            except Exception:
                pass
            try:
                self.runtime_failed_event.clear()
            except Exception:
                pass
        elif state == LifecycleState.RUNTIME_READY:
            self.core_initialized = True
            self.runtime_ready = True
            self.runtime_failed = False
            try:
                self.runtime_ready_event.set()
            except Exception:
                pass
            try:
                self.runtime_failed_event.clear()
            except Exception:
                pass
        elif state == LifecycleState.RUNTIME_FAILED:
            self.core_initialized = True
            self.runtime_ready = False
            self.runtime_failed = True
            try:
                self.runtime_ready_event.clear()
            except Exception:
                pass
            try:
                self.runtime_failed_event.set()
            except Exception:
                pass

    async def initialize_core(self) -> None:
        """Compatibility method for older 'initialize_core' split-phase initialization.

        This performs the fast/core initialization phase only (sufficient to get
        the process started and to schedule the runtime bootstrap later). It is
        intentionally a subset of the full `initialize` method so tests and
        older callers that expect a split initialization can rely on it.
        """
        # Logging and configuration
        logger.info("AstrBot v" + VERSION)
        if os.environ.get("TESTING", ""):
            LogManager.configure_logger(
                logger,
                self.astrbot_config,
                override_level="DEBUG",
            )
            LogManager.configure_trace_logger(self.astrbot_config)
        else:
            LogManager.configure_logger(logger, self.astrbot_config)
            LogManager.configure_trace_logger(self.astrbot_config)

        # Core quick initializations
        await self.db.initialize()

        await html_renderer.initialize()

        # Initialize UMOP config router (fast)
        self.umop_config_router = UmopConfigRouter(sp=sp)
        await self.umop_config_router.initialize()

        # AstrBot config manager
        self.astrbot_config_mgr = AstrBotConfigManager(
            default_config=self.astrbot_config,
            ucr=self.umop_config_router,
            sp=sp,
        )
        self.temp_dir_cleaner = TempDirCleaner(
            max_size_getter=lambda: self.astrbot_config_mgr.default_conf.get(
                TempDirCleaner.CONFIG_KEY,
                TempDirCleaner.DEFAULT_MAX_SIZE,
            ),
        )

        # Apply migrations (keep same behavior)
        try:
            await migra(
                self.db,
                self.astrbot_config_mgr,
                self.umop_config_router,
                self.astrbot_config_mgr,
            )
        except Exception as e:
            logger.error(f"AstrBot migration failed: {e!s}")
            logger.error(traceback.format_exc())

        # Initialize event queue
        self.event_queue = Queue()

        # Initialize persona manager (fast)
        self.persona_mgr = PersonaManager(self.db, self.astrbot_config_mgr)
        await self.persona_mgr.initialize()

        # Instantiate provider manager (don't run .initialize() here)
        self.provider_manager = ProviderManager(
            self.astrbot_config_mgr,
            self.db,
            self.persona_mgr,
        )

        # Instantiate platform manager (don't run .initialize() here)
        self.platform_manager = PlatformManager(self.astrbot_config, self.event_queue)

        # Instantiate conversation manager and other lightweight managers
        self.conversation_manager = ConversationManager(self.db)
        self.platform_message_history_manager = PlatformMessageHistoryManager(self.db)

        # Instantiate KB manager but defer initialize()
        self.kb_manager = KnowledgeBaseManager(self.provider_manager)

        # Instantiate CronJob manager
        self.cron_manager = CronJobManager(self.db)

        # Dynamic subagents orchestrator (may be patched in tests)
        await self._init_or_reload_subagent_orchestrator()

        # Prepare star/plugin context (without reloading plugins)
        self.star_context = Context(
            self.event_queue,
            self.astrbot_config,
            self.db,
            self.provider_manager,
            self.platform_manager,
            self.conversation_manager,
            self.platform_message_history_manager,
            self.persona_mgr,
            self.astrbot_config_mgr,
            self.kb_manager,
            self.cron_manager,
            self.subagent_orchestrator,
        )

        # Instantiate plugin manager (do not reload here)
        self.plugin_manager = PluginManager(self.star_context, self.astrbot_config)

        # Record that we finished the core phase
        self._set_lifecycle_state(LifecycleState.CORE_READY)

        # Prepare updater instance as in original initialize (constructor call)
        self.astrbot_updator = AstrBotUpdator()

        # Leave other runtime initializations (plugin reload, provider init, etc.)
        # to `bootstrap_runtime`.

        # Initialize dashboard shutdown event (matches full initialize behavior)
        self.dashboard_shutdown_event = asyncio.Event()

    async def bootstrap_runtime(self) -> None:
        """Compatibility method for runtime bootstrap (deferred initialization).

        This completes the remaining initialization steps that were deferred by
        `initialize_core`, such as plugin reloads, provider initialization, KB init,
        pipeline scheduler loading and platform initialization.
        """
        # Guard: require core phase completed
        if getattr(self, "lifecycle_state", None) != LifecycleState.CORE_READY:
            raise RuntimeError("bootstrap_runtime must be called after initialize_core")

        # Reset runtime artifacts if re-attempting bootstrap after a failure
        self.event_bus = None
        self.pipeline_scheduler_mapping = {}

        try:
            # Reload plugins (this may register runtime routes/tasks)
            await self.plugin_manager.reload()

            # Initialize providers and KB (deferred heavy work)
            await self.provider_manager.initialize()
            await self.kb_manager.initialize()

            # Load pipeline schedulers (may be async and expensive)
            self.pipeline_scheduler_mapping = await self.load_pipeline_scheduler()

            # Create event bus now that pipeline schedulers exist
            self.event_bus = EventBus(
                self.event_queue,
                self.pipeline_scheduler_mapping,
                self.astrbot_config_mgr,
            )

            # Initialize platform adapters (deferred)
            await self.platform_manager.initialize()

            # Schedule auxiliary background tasks (metadata/task creation)
            asyncio.create_task(update_llm_metadata())

            # All runtime initialization complete
            self._set_lifecycle_state(LifecycleState.RUNTIME_READY)
            self.runtime_bootstrap_error = None
            return
        except Exception as e:
            # Mark runtime failed for compatibility and rethrow so callers can react
            self.runtime_bootstrap_error = e
            self._set_lifecycle_state(LifecycleState.RUNTIME_FAILED)

            # Attempt to run cleanup similar to original initialize() error paths
            try:
                # attempt graceful termination of partial runtime subsystems
                if getattr(self, "plugin_manager", None) and hasattr(
                    self.plugin_manager,
                    "cleanup_loaded_plugins",
                ):
                    await self.plugin_manager.cleanup_loaded_plugins()
            except Exception:
                logger.error(
                    "Failed cleaning up plugins after runtime bootstrap failure",
                )

            # Reset event_bus to None so callers can detect partial init
            self.event_bus = None

            try:
                if getattr(self, "provider_manager", None) and hasattr(
                    self.provider_manager,
                    "terminate",
                ):
                    await self.provider_manager.terminate()
            except Exception:
                logger.error(
                    "Failed terminating provider_manager after runtime bootstrap failure",
                )

            try:
                if getattr(self, "platform_manager", None) and hasattr(
                    self.platform_manager,
                    "terminate",
                ):
                    await self.platform_manager.terminate()
            except Exception:
                logger.error(
                    "Failed terminating platform_manager after runtime bootstrap failure",
                )

            try:
                if getattr(self, "kb_manager", None) and hasattr(
                    self.kb_manager,
                    "terminate",
                ):
                    await self.kb_manager.terminate()
            except Exception:
                logger.error(
                    "Failed terminating kb_manager after runtime bootstrap failure",
                )

            raise

    async def _init_or_reload_subagent_orchestrator(self) -> None:
        """Create (if needed) and reload the subagent orchestrator from config.

        This keeps lifecycle wiring in one place while allowing the orchestrator
        to manage enable/disable and tool registration details.
        """
        try:
            if self.subagent_orchestrator is None:
                self.subagent_orchestrator = SubAgentOrchestrator(
                    self.provider_manager.llm_tools,
                    self.persona_mgr,
                )
            await self.subagent_orchestrator.reload_from_config(
                self.astrbot_config.get("subagent_orchestrator", {}),
            )
        except Exception as e:
            logger.error(f"Subagent orchestrator init failed: {e}", exc_info=True)

    async def initialize(self) -> None:
        """初始化 AstrBot 核心生命周期管理类.

        负责初始化各个组件, 包括 ProviderManager、PlatformManager、ConversationManager、PluginManager、PipelineScheduler、EventBus、AstrBotUpdator等。
        """
        # 初始化日志代理
        logger.info("AstrBot v" + VERSION)
        if os.environ.get("TESTING", ""):
            LogManager.configure_logger(
                logger,
                self.astrbot_config,
                override_level="DEBUG",
            )
            LogManager.configure_trace_logger(self.astrbot_config)
        else:
            LogManager.configure_logger(logger, self.astrbot_config)
            LogManager.configure_trace_logger(self.astrbot_config)

        await self.db.initialize()

        await html_renderer.initialize()

        # 初始化 UMOP 配置路由器
        self.umop_config_router = UmopConfigRouter(sp=sp)
        await self.umop_config_router.initialize()

        # 初始化 AstrBot 配置管理器
        self.astrbot_config_mgr = AstrBotConfigManager(
            default_config=self.astrbot_config,
            ucr=self.umop_config_router,
            sp=sp,
        )
        self.temp_dir_cleaner = TempDirCleaner(
            max_size_getter=lambda: self.astrbot_config_mgr.default_conf.get(
                TempDirCleaner.CONFIG_KEY,
                TempDirCleaner.DEFAULT_MAX_SIZE,
            ),
        )

        # apply migration
        try:
            await migra(
                self.db,
                self.astrbot_config_mgr,
                self.umop_config_router,
                self.astrbot_config_mgr,
            )
        except Exception as e:
            logger.error(f"AstrBot migration failed: {e!s}")
            logger.error(traceback.format_exc())

        # 初始化事件队列
        self.event_queue = Queue()

        # 初始化人格管理器
        self.persona_mgr = PersonaManager(self.db, self.astrbot_config_mgr)
        await self.persona_mgr.initialize()

        # 初始化供应商管理器
        self.provider_manager = ProviderManager(
            self.astrbot_config_mgr,
            self.db,
            self.persona_mgr,
        )

        # 初始化平台管理器
        self.platform_manager = PlatformManager(self.astrbot_config, self.event_queue)

        # 初始化对话管理器
        self.conversation_manager = ConversationManager(self.db)

        # 初始化平台消息历史管理器
        self.platform_message_history_manager = PlatformMessageHistoryManager(self.db)

        # 初始化知识库管理器
        self.kb_manager = KnowledgeBaseManager(self.provider_manager)

        # 初始化 CronJob 管理器
        self.cron_manager = CronJobManager(self.db)

        # Dynamic subagents (handoff tools) from config.
        await self._init_or_reload_subagent_orchestrator()

        # 初始化提供给插件的上下文
        self.star_context = Context(
            self.event_queue,
            self.astrbot_config,
            self.db,
            self.provider_manager,
            self.platform_manager,
            self.conversation_manager,
            self.platform_message_history_manager,
            self.persona_mgr,
            self.astrbot_config_mgr,
            self.kb_manager,
            self.cron_manager,
            self.subagent_orchestrator,
        )

        # 初始化插件管理器
        self.plugin_manager = PluginManager(self.star_context, self.astrbot_config)

        # 扫描、注册插件、实例化插件类
        await self.plugin_manager.reload()

        # 根据配置实例化各个 Provider
        await self.provider_manager.initialize()

        await self.kb_manager.initialize()

        # 初始化消息事件流水线调度器
        self.pipeline_scheduler_mapping = await self.load_pipeline_scheduler()

        # 初始化更新器
        self.astrbot_updator = AstrBotUpdator()

        # 初始化事件总线
        self.event_bus = EventBus(
            self.event_queue,
            self.pipeline_scheduler_mapping,
            self.astrbot_config_mgr,
        )

        # 记录启动时间
        self.start_time = int(time.time())

        # 初始化当前任务列表
        self.curr_tasks = []

        # 根据配置实例化各个平台适配器
        await self.platform_manager.initialize()

        # 初始化关闭控制面板的事件
        self.dashboard_shutdown_event = asyncio.Event()

        asyncio.create_task(update_llm_metadata())

        # Mark runtime ready now that the full initialize() path has completed.
        self._set_lifecycle_state(LifecycleState.RUNTIME_READY)
        self.runtime_bootstrap_error = None

    def _load(self) -> None:
        """加载事件总线和任务并初始化."""
        # 创建一个异步任务来执行事件总线的 dispatch() 方法
        # dispatch是一个无限循环的协程, 从事件队列中获取事件并处理
        event_bus_task = None
        if self.event_bus:
            event_bus_task = asyncio.create_task(
                self.event_bus.dispatch(),
                name="event_bus",
            )
        cron_task = None
        if self.cron_manager:
            cron_task = asyncio.create_task(
                self.cron_manager.start(self.star_context),
                name="cron_manager",
            )
        temp_dir_cleaner_task = None
        if self.temp_dir_cleaner:
            temp_dir_cleaner_task = asyncio.create_task(
                self.temp_dir_cleaner.run(),
                name="temp_dir_cleaner",
            )

        # 把插件中注册的所有协程函数注册到事件总线中并执行
        extra_tasks = []
        for task in self.star_context._register_tasks:
            extra_tasks.append(asyncio.create_task(task, name=task.__name__))  # type: ignore

        tasks_ = []
        if event_bus_task:
            tasks_.append(event_bus_task)
        tasks_.extend(extra_tasks or [])
        if cron_task:
            tasks_.append(cron_task)
        if temp_dir_cleaner_task:
            tasks_.append(temp_dir_cleaner_task)
        for task in tasks_:
            self.curr_tasks.append(
                asyncio.create_task(self._task_wrapper(task), name=task.get_name()),
            )

        self.start_time = int(time.time())

    async def _task_wrapper(self, task: asyncio.Task) -> None:
        """异步任务包装器, 用于处理异步任务执行中出现的各种异常.

        Args:
            task (asyncio.Task): 要执行的异步任务

        """
        try:
            await task
        except asyncio.CancelledError:
            pass  # 任务被取消, 静默处理
        except Exception as e:
            # 获取完整的异常堆栈信息, 按行分割并记录到日志中
            logger.error(f"------- 任务 {task.get_name()} 发生错误: {e}")
            for line in traceback.format_exc().split("\n"):
                logger.error(f"|    {line}")
            logger.error("-------")

    async def start(self) -> None:
        """启动 AstrBot 核心生命周期管理类.

        用load加载事件总线和任务并初始化, 执行启动完成事件钩子
        """
        self._load()
        logger.info("AstrBot started.")

        # 执行启动完成事件钩子
        handlers = star_handlers_registry.get_handlers_by_event_type(
            EventType.OnAstrBotLoadedEvent,
        )
        for handler in handlers:
            try:
                logger.info(
                    f"hook(on_astrbot_loaded) -> {star_map[handler.handler_module_path].name} - {handler.handler_name}",
                )
                await handler.handler()
            except BaseException:
                logger.error(traceback.format_exc())

        # 同时运行curr_tasks中的所有任务
        await asyncio.gather(*self.curr_tasks, return_exceptions=True)

    async def stop(self) -> None:
        """停止 AstrBot 核心生命周期管理类, 取消所有当前任务并终止各个管理器.

        This method is defensive: not all attributes may exist if only a partial
        initialization was performed (tests construct lifecycle objects and call
        stop() in different phases). Guard attribute accesses and log failures
        instead of raising AttributeError.
        """
        # Stop temp dir cleaner if present
        if self.temp_dir_cleaner is not None:
            try:
                await self.temp_dir_cleaner.stop()
            except Exception:
                logger.exception("Error stopping temp_dir_cleaner")

        # Cancel currently tracked tasks if any
        curr_tasks = getattr(self, "curr_tasks", None)
        if curr_tasks:
            for task in list(curr_tasks):
                try:
                    task.cancel()
                except Exception:
                    logger.exception("Error cancelling task")

        # Shutdown cron manager if present
        if self.cron_manager is not None:
            try:
                await self.cron_manager.shutdown()
            except Exception:
                logger.exception("Error shutting down cron_manager")

        # Terminate plugins if plugin_manager and context exist
        if getattr(self, "plugin_manager", None) and getattr(
            self.plugin_manager,
            "context",
            None,
        ):
            try:
                for plugin in self.plugin_manager.context.get_all_stars():
                    try:
                        await self.plugin_manager._terminate_plugin(plugin)
                    except Exception:
                        logger.exception("Failed to terminate plugin")
            except Exception:
                logger.exception(
                    "Error iterating plugin_manager.context.get_all_stars()",
                )

        # Terminate other managers if present
        if getattr(self, "provider_manager", None):
            try:
                await self.provider_manager.terminate()
            except Exception:
                logger.exception("Error terminating provider_manager")

        if getattr(self, "platform_manager", None):
            try:
                await self.platform_manager.terminate()
            except Exception:
                logger.exception("Error terminating platform_manager")

        if getattr(self, "kb_manager", None):
            try:
                await self.kb_manager.terminate()
            except Exception:
                logger.exception("Error terminating kb_manager")

        # Signal dashboard shutdown if event exists
        if self.dashboard_shutdown_event is not None:
            try:
                self.dashboard_shutdown_event.set()
            except Exception:
                logger.exception("Error setting dashboard_shutdown_event")

        # Await tasks to finish (if any)
        if curr_tasks:
            for task in list(curr_tasks):
                try:
                    await task
                except asyncio.CancelledError:
                    pass
                except Exception as e:
                    name = task.get_name() if hasattr(task, "get_name") else str(task)
                    logger.error(f"任务 {name} 发生错误: {e}")

    async def restart(self) -> None:
        """重启 AstrBot 核心生命周期管理类, 终止各个管理器并重新加载平台实例"""
        await self.provider_manager.terminate()
        await self.platform_manager.terminate()
        await self.kb_manager.terminate()
        if self.dashboard_shutdown_event is not None:
            self.dashboard_shutdown_event.set()
        threading.Thread(
            target=self.astrbot_updator._reboot,
            name="restart",
            daemon=True,
        ).start()

    def load_platform(self) -> list[asyncio.Task]:
        """加载平台实例并返回所有平台实例的异步任务列表"""
        tasks = []
        platform_insts = self.platform_manager.get_insts()
        for platform_inst in platform_insts:
            tasks.append(
                asyncio.create_task(
                    platform_inst.run(),
                    name=f"{platform_inst.meta().id}({platform_inst.meta().name})",
                ),
            )
        return tasks

    async def load_pipeline_scheduler(self) -> dict[str, PipelineScheduler]:
        """加载消息事件流水线调度器.

        Returns:
            dict[str, PipelineScheduler]: 平台 ID 到流水线调度器的映射

        """
        mapping = {}
        for conf_id, ab_config in self.astrbot_config_mgr.confs.items():
            scheduler = PipelineScheduler(
                PipelineContext(ab_config, self.plugin_manager, conf_id),
            )
            await scheduler.initialize()
            mapping[conf_id] = scheduler
        return mapping

    async def reload_pipeline_scheduler(self, conf_id: str) -> None:
        """重新加载消息事件流水线调度器.

        Returns:
            dict[str, PipelineScheduler]: 平台 ID 到流水线调度器的映射

        """
        ab_config = self.astrbot_config_mgr.confs.get(conf_id)
        if not ab_config:
            raise ValueError(f"配置文件 {conf_id} 不存在")
        scheduler = PipelineScheduler(
            PipelineContext(ab_config, self.plugin_manager, conf_id),
        )
        await scheduler.initialize()
        self.pipeline_scheduler_mapping[conf_id] = scheduler