# -*- coding: utf-8 -*-
"""
事件数据模型
─────────────────────────────────────────────────────────────────
Event       —— 核心事件对象，贯穿整个生命周期
EventResult —— 处理器返回结果
EventState  —— 事件处理状态机
─────────────────────────────────────────────────────────────────
"""

from __future__ import annotations

import time
import uuid
from dataclasses import dataclass, field
from datetime import datetime
from enum import Enum
from typing import Any, Dict, List, Optional, Union

from uas.event.event_type import EventType, EventPriority, event_registry


# ─────────────────────────────────────────────────────────────────
# 事件状态
# ─────────────────────────────────────────────────────────────────

class EventState(Enum):
    CREATED    = "created"      # 已创建，未提交
    PENDING    = "pending"      # 已提交，等待处理
    PROCESSING = "processing"   # 处理中
    HANDLED    = "handled"      # 已处理完成
    CANCELLED  = "cancelled"    # 已取消
    FAILED     = "failed"       # 处理失败
    IGNORED    = "ignored"      # 无处理器，已忽略


# ─────────────────────────────────────────────────────────────────
# 事件处理结果
# ─────────────────────────────────────────────────────────────────

@dataclass
class EventResult:
    """单个处理器的执行结果"""
    handler_name: str
    success:      bool
    data:         Any          = None
    error:        str          = ""
    elapsed_ms:   float        = 0.0

    def __repr__(self):
        status = "✅" if self.success else "❌"
        return f"EventResult({status} {self.handler_name} {self.elapsed_ms:.1f}ms)"


# ─────────────────────────────────────────────────────────────────
# 核心事件对象
# ─────────────────────────────────────────────────────────────────

@dataclass
class Event:
    """
    核心事件对象
    ─────────────────────────────────────────────────────────────
    字段说明：
      event_type  —— 事件类型（EventType 枚举 或 自定义字符串）
      source      —— 事件来源（设备ID、模块名等）
      params      —— 事件携带参数（任意字典）
      priority    —— 优先级（默认从注册表读取）
      timestamp   —— 发生时间（Unix 时间戳，自动填充）
      event_id    —— 唯一标识（UUID，自动生成）
    ─────────────────────────────────────────────────────────────
    """

    event_type:   Union[EventType, str]
    source:       str                          = "unknown"
    params:       Dict[str, Any]               = field(default_factory=dict)
    priority:     Optional[EventPriority]      = None
    message:      str                          = ""

    # 自动填充字段
    event_id:     str        = field(default_factory=lambda: str(uuid.uuid4()))
    timestamp:    float      = field(default_factory=time.time)
    state:        EventState = field(default=EventState.CREATED)

    # 运行时字段（不参与构造）
    results:      List[EventResult] = field(default_factory=list)
    _cancelled:   bool              = field(default=False, repr=False)
    _submit_time: Optional[float]   = field(default=None,  repr=False)
    _done_time:   Optional[float]   = field(default=None,  repr=False)

    def __post_init__(self):
        # 若未指定优先级，从注册表读取
        if self.priority is None:
            self.priority = event_registry.get_priority(self.type_key)

    # ── 属性 ──────────────────────────────────────────────────────

    @property
    def type_key(self) -> str:
        """统一返回字符串 key"""
        return (self.event_type.value
                if isinstance(self.event_type, EventType)
                else str(self.event_type))

    @property
    def datetime(self) -> datetime:
        return datetime.fromtimestamp(self.timestamp)

    @property
    def datetime_str(self) -> str:
        return self.datetime.strftime("%Y-%m-%d %H:%M:%S.%f")[:-3]

    @property
    def is_cancelled(self) -> bool:
        return self._cancelled

    @property
    def elapsed_ms(self) -> float:
        """从提交到完成的总耗时（ms）"""
        if self._submit_time and self._done_time:
            return (self._done_time - self._submit_time) * 1000
        return 0.0

    @property
    def success_count(self) -> int:
        return sum(1 for r in self.results if r.success)

    @property
    def failed_count(self) -> int:
        return sum(1 for r in self.results if not r.success)

    # ── 状态操作 ──────────────────────────────────────────────────

    def cancel(self) -> bool:
        """取消事件（仅 cancellable 类型可取消）"""
        if event_registry.is_cancellable(self.type_key):
            self._cancelled = True
            self.state      = EventState.CANCELLED
            return True
        return False

    def mark_pending(self):
        self.state        = EventState.PENDING
        self._submit_time = time.time()

    def mark_processing(self):
        self.state = EventState.PROCESSING

    def mark_done(self):
        self._done_time = time.time()
        if self._cancelled:
            self.state = EventState.CANCELLED
        elif any(not r.success for r in self.results):
            self.state = EventState.FAILED
        elif not self.results:
            self.state = EventState.IGNORED
        else:
            self.state = EventState.HANDLED

    def add_result(self, result: EventResult):
        self.results.append(result)

    # ── 序列化 ────────────────────────────────────────────────────

    def to_dict(self) -> dict:
        return {
            "event_id":   self.event_id,
            "event_type": self.type_key,
            "source":     self.source,
            "message":    self.message,
            "params":     self.params,
            "priority":   self.priority.name if self.priority else "NORMAL",
            "timestamp":  self.timestamp,
            "datetime":   self.datetime_str,
            "state":      self.state.value,
            "elapsed_ms": self.elapsed_ms,
            "results":    [str(r) for r in self.results],
        }

    def __repr__(self):
        return (f"Event(id={self.event_id[:8]}, type={self.type_key!r}, "
                f"src={self.source!r}, state={self.state.value}, "
                f"priority={self.priority.name if self.priority else 'N/A'})")


# ─────────────────────────────────────────────────────────────────
# 便捷工厂函数
# ─────────────────────────────────────────────────────────────────

def make_event(
    event_type: Union[EventType, str],
    source:     str = "system",
    message:    str = "",
    **params
) -> Event:
    """
    快速创建事件
    示例：
      e = make_event(EventType.DEVICE_ERROR, source="sensor-01",
                     message="温度传感器异常", code="E001", temp=98.5)
    """
    return Event(
        event_type = event_type,
        source     = source,
        message    = message,
        params     = params,
    )