from __future__ import annotations

from pathlib import Path
from typing import Any

import yaml
from pydantic import BaseModel

from app.ai_provider.config.models import ModelConfig, ProviderConfig
from app.core.config import settings


class _ModelsFile(BaseModel):
    version: int = 1
    models: list[ModelConfig]


class _ProvidersFile(BaseModel):
    version: int = 1
    providers: dict[str, ProviderConfig]


class _PricingFile(BaseModel):
    """pricing.yaml 顶层结构。"""

    version: int = 1
    pricing: dict[str, dict] = {}


def get_models_config_path() -> Path:
    """返回已解析的 models.yaml 路径（project_root/config/models.yaml）。"""
    return settings.project_root / "config" / "models.yaml"


def get_providers_config_path() -> Path:
    """返回已解析的 providers.yaml 路径（project_root/config/providers.yaml）。"""
    return settings.project_root / "config" / "providers.yaml"


def load_models_config(path: Path | None = None) -> list[ModelConfig]:
    """从 YAML 文件加载模型配置。如果未指定路径，使用配置中的默认路径。"""
    if path is None:
        path = get_models_config_path()
    if not path.exists():
        raise FileNotFoundError(f"Models config not found: {path}")
    raw: dict[str, Any] = yaml.safe_load(path.read_text(encoding="utf-8")) or {}
    parsed = _ModelsFile.model_validate(raw)
    return parsed.models


def load_providers_config(path: Path | None = None) -> dict[str, ProviderConfig]:
    """从 YAML 文件加载提供商配置。如果未指定路径，使用配置中的默认路径。"""
    if path is None:
        path = get_providers_config_path()
    if not path.exists():
        raise FileNotFoundError(f"Providers config not found: {path}")
    raw: dict[str, Any] = yaml.safe_load(path.read_text(encoding="utf-8")) or {}
    # 验证前将字典键注入为 provider 的 name 字段
    providers_raw = raw.get("providers", {})
    for name, cfg in providers_raw.items():
        if isinstance(cfg, dict) and "name" not in cfg:
            cfg["name"] = name
    parsed = _ProvidersFile.model_validate(raw)
    return parsed.providers


def get_pricing_config_path() -> Path:
    """返回 pricing.yaml 路径（project_root/config/pricing.yaml）。"""
    return settings.project_root / "config" / "pricing.yaml"


def load_pricing_config(path: Path | None = None) -> dict[str, dict]:
    """从 YAML 文件加载定价配置。"""
    if path is None:
        path = get_pricing_config_path()
    if not path.exists():
        return {}
    raw: dict[str, Any] = yaml.safe_load(path.read_text(encoding="utf-8")) or {}
    parsed = _PricingFile.model_validate(raw)
    return parsed.pricing