"""
平台适配器注册机制 - 参照AstrBot @register_platform_adapter 装饰器模式
让新平台接入标准化，通过装饰器注册 + 统一接口
"""
from abc import ABC, abstractmethod
from dataclasses import dataclass, field
from typing import Any, Callable
import logging

logger = logging.getLogger(__name__)

# 全局注册表
platform_registry: dict[str, "PlatformMetadata"] = {}
platform_cls_map: dict[str, type] = {}

@dataclass
class PlatformMetadata:
    """平台元数据"""
    name: str              # 平台标识 wecom/feishu/dingtalk/telegram/slack/whatsapp
    display_name: str      # 显示名称
    description: str       # 描述
    icon: str = ""         # 图标URL或base64
    version: str = "1.0"
    support_streaming: bool = True    # 是否支持流式消息
    support_image: bool = True        # 是否支持图片消息
    support_file: bool = True         # 是否支持文件消息
    support_voice: bool = False       # 是否支持语音消息
    config_schema: dict = field(default_factory=dict)  # JSON Schema for config validation

class BasePlatformAdapter(ABC):
    """平台适配器基类 - 所有平台适配器必须继承此类"""

    def __init__(self, config: dict):
        self.config = config
        self._status = "stopped"  # pending/running/error/stopped

    @abstractmethod
    def get_metadata(self) -> PlatformMetadata:
        """返回平台元数据"""
        ...

    @abstractmethod
    def parse_webhook(self, payload: dict) -> dict:
        """解析webhook payload为统一消息格式
        返回: {
            "content_type": "text"|"image"|"file"|...,
            "content": "文本内容或资源标识",
            "sender_id": "发送者ID",
            "sender_name": "发送者名称",
            "message_id": "平台消息ID",
            "timestamp": 1234567890,
            "group_id": "群聊ID(可选)",
            "group_name": "群聊名称(可选)",
            "raw": raw_payload,
        }
        """
        ...

    @abstractmethod
    def verify_signature(self, payload: dict, signature: str, timestamp: str) -> bool:
        """验证webhook签名"""
        ...

    @abstractmethod
    def build_reply(self, channel_config: dict, content: str, reply_to: str = None) -> dict:
        """构建回复消息格式
        返回: {"api_url": "...", "headers": {...}, "body": {...}}
        """
        ...

    def get_status(self) -> str:
        return self._status

    def start(self):
        self._status = "running"

    def stop(self):
        self._status = "stopped"

def register_platform_adapter(
    name: str,
    display_name: str,
    description: str,
    icon: str = "",
    support_streaming: bool = True,
    support_image: bool = True,
    support_file: bool = True,
    support_voice: bool = False,
    config_schema: dict = None,
):
    """注册平台适配器的装饰器 - 参照AstrBot @register_platform_adapter 模式"""
    def decorator(cls):
        if not issubclass(cls, BasePlatformAdapter):
            raise TypeError(f"{cls.__name__} 必须继承 BasePlatformAdapter")

        metadata = PlatformMetadata(
            name=name,
            display_name=display_name,
            description=description,
            icon=icon,
            support_streaming=support_streaming,
            support_image=support_image,
            support_file=support_file,
            support_voice=support_voice,
            config_schema=config_schema or {},
        )

        if name in platform_cls_map:
            logger.warning(f"平台 {name} 已注册，将被覆盖")

        platform_registry[name] = metadata
        platform_cls_map[name] = cls
        logger.info(f"[Platform] 注册平台适配器: {name} ({display_name})")
        return cls
    return decorator

def get_platform_adapter(name: str, config: dict) -> BasePlatformAdapter:
    """获取平台适配器实例"""
    if name not in platform_cls_map:
        raise ValueError(f"未知平台: {name}. 可用平台: {list(platform_cls_map.keys())}")
    return platform_cls_map[name](config)

def list_platforms() -> list[PlatformMetadata]:
    """列出所有已注册平台"""
    return list(platform_registry.values())