from collections.abc import Mapping
from dataclasses import dataclass
from typing import Any

from app.config import Settings


@dataclass(frozen=True)
class ProviderCapability:
    provider: str
    configured: bool
    strengths: tuple[str, ...]
    model_id: str = ""
    name: str = ""


class ModelRouter:
    def __init__(
        self,
        settings: Settings | Mapping[str, Any],
        tests: Mapping[str, Mapping[str, Any]] | None = None,
    ) -> None:
        self.settings = settings
        self.tests = tests

    def _value(self, key: str, default: Any = "") -> Any:
        if isinstance(self.settings, Mapping):
            return self.settings.get(key, default)
        return getattr(self.settings, key, default)

    @property
    def pool(self) -> list[dict[str, Any]]:
        raw_pool = self._value("model_pool", [])
        return [item for item in raw_pool if isinstance(item, dict) and item.get("enabled", True)]

    def _tested(self, item: Mapping[str, Any]) -> bool:
        if self.tests is None:
            return True
        return bool(self.tests.get(f"model:{item.get('id')}", {}).get("ok"))

    def candidates(self, capability: str) -> list[dict[str, Any]]:
        return [
            item
            for item in self.pool
            if capability in item.get("capabilities", []) and self._tested(item)
        ]

    def orchestrator(self) -> dict[str, Any]:
        selected_id = str(self._value("orchestrator_model_id", ""))
        selected = next(
            (
                item
                for item in self.pool
                if item.get("id") == selected_id
                and item.get("category") == "language"
                and self._tested(item)
            ),
            None,
        )
        if selected:
            return selected
        raise RuntimeError("总调度模型未配置或尚未通过测试。")

    def choose(self, route: str, orchestrator_choice_id: str | None = None) -> dict[str, Any]:
        if route == "spatial":
            mode_key, selected_key, capability = (
                "spatial_routing_mode",
                "spatial_model_id",
                "spatial_understanding",
            )
        elif route == "image":
            mode_key, selected_key, capability = (
                "image_routing_mode",
                "image_model_id",
                "image_generation",
            )
        else:
            raise ValueError(f"未知模型路由：{route}")

        candidates = self.candidates(capability)
        if self._value(mode_key, "auto") == "manual":
            selected_id = str(self._value(selected_key, ""))
            selected = next((item for item in candidates if item.get("id") == selected_id), None)
            if selected:
                return selected
            raise RuntimeError(f"手动选择的{route}模型不可用或尚未通过测试。")
        if orchestrator_choice_id:
            selected = next((item for item in candidates if item.get("id") == orchestrator_choice_id), None)
            if selected:
                return selected
            raise RuntimeError("总调度返回的模型不在已测试候选列表中。")
        if len(candidates) == 1:
            return candidates[0]
        if len(candidates) > 1:
            raise RuntimeError("自动路由存在多个候选，需要总调度返回模型实例 ID。")
        raise RuntimeError(f"没有通过测试且支持{capability}的模型。")

    def capabilities(self) -> list[ProviderCapability]:
        result: list[ProviderCapability] = []
        for item in self.pool:
            strengths: list[str] = []
            if "orchestration" in item.get("capabilities", []):
                strengths.append("总调度")
            if "spatial_understanding" in item.get("capabilities", []):
                strengths.append("空间理解")
            if "image_generation" in item.get("capabilities", []):
                strengths.append("图像生成")
            if "image_editing" in item.get("capabilities", []):
                strengths.append("图像编辑")
            result.append(
                ProviderCapability(
                    provider=str(item.get("provider", "custom")),
                    configured=self._tested(item),
                    strengths=tuple(strengths),
                    model_id=str(item.get("model_id", "")),
                    name=str(item.get("name", "")),
                )
            )
        return result

    def choose_image_provider(self, task: str) -> str:
        return str(self.choose("image").get("provider", "custom"))