from __future__ import annotations

from typing import Any

from yuxi.channels.base import BaseChannelAdapter
from yuxi.channels.capabilities import ChannelCapabilities
from yuxi.channels.meta import ChannelMeta
from yuxi.channels.registry import _BUILTIN_ADAPTERS


def channel_plugin(
    cls: type[BaseChannelAdapter] | None = None,
    *,
    channel_id: str | None = None,
    capabilities: ChannelCapabilities | None = None,
    meta: ChannelMeta | None = None,
    order: int = 100,
) -> type[BaseChannelAdapter]:
    """渠道插件注册装饰器 — 组合入口, 替代 @register_builtin_adapter

    用法:

        @channel_plugin(
            capabilities=ChannelCapabilities(...),
            meta=ChannelMeta(id="telegram", label="Telegram"),
        )
        class TelegramAdapter(BaseChannelAdapter):
            ...

    当用作无参装饰器时, 从类属性自动推断 channel_id:

        @channel_plugin
        class TelegramAdapter(BaseChannelAdapter):
            channel_id = "telegram"
    """

    def _decorate(_cls: type[BaseChannelAdapter]) -> type[BaseChannelAdapter]:
        cid = channel_id or getattr(_cls, "channel_id", None)
        if not cid:
            raise ValueError(
                f"channel_plugin requires channel_id for {_cls.__name__}. "
                "Set channel_id as a ClassVar or pass it to the decorator."
            )

        if capabilities is not None:
            _cls.capabilities = capabilities  # type: ignore[attr-defined]
        if meta is not None:
            _cls.meta = meta  # type: ignore[attr-defined]

        _BUILTIN_ADAPTERS[cid] = _cls
        return _cls

    if cls is not None:
        return _decorate(cls)

    return _decorate


class ChannelPlugin:
    """渠道插件组合入口 — 聚合协议和能力声明的便利构造器

    为渠道开发者提供声明式 API，在适配器类上组合配置:

        plugin = ChannelPlugin(
            channel_id="telegram",
            channel_type=ChannelType.TELEGRAM,
            capabilities=ChannelCapabilities(
                chat_types=["direct", "group", "thread"],
                polls=True, reactions=True, edit=True,
                supports_streaming=True,
                streaming_modes=["off", "partial", "block", "progress"],
            ),
            meta=ChannelMeta(id="telegram", label="Telegram"),
        )

        @plugin.register
        class TelegramAdapter(BaseChannelAdapter):
            ...
    """

    def __init__(
        self,
        *,
        channel_id: str,
        channel_type: Any = None,
        capabilities: ChannelCapabilities | None = None,
        meta: ChannelMeta | None = None,
        order: int = 100,
        pairing: dict | None = None,
        conversation_bindings: dict | None = None,
        agent_prompt: str | None = None,
        messaging: dict | None = None,
        directory: Any = None,
    ):
        self.channel_id = channel_id
        self.channel_type = channel_type
        self.capabilities = capabilities
        self.meta = meta or ChannelMeta(id=channel_id, label=channel_id)
        self.order = order
        self.pairing = pairing or {}
        self.conversation_bindings = conversation_bindings or {}
        self.agent_prompt = agent_prompt
        self.messaging = messaging or {}
        self.directory = directory

    def register(self, cls: type[BaseChannelAdapter]) -> type[BaseChannelAdapter]:
        if self.capabilities is not None:
            cls.capabilities = self.capabilities  # type: ignore[attr-defined]
        if self.meta is not None:
            cls.meta = self.meta  # type: ignore[attr-defined]

        _BUILTIN_ADAPTERS[self.channel_id] = cls
        return cls