"""LLM provider 工厂。

历史:全站只用一个 LlmClient(单例)指 Agnes。
现在:支持多个 provider,各自独立 base_url / api_key / model / 节流。

- `get_angel_client(setting)` — Agnes 客户端(原 LlmClient 等价)
- `get_meituan_client(setting)` — 美团大模型客户端(OpenAI 兼容,LongCat)

设计:
- 工厂每次返回新实例(无状态;节流靠 client 内部 Semaphore 自带)
- Provider 不可用(api_key 空)= 返回 None
- `get_provider_commentary_defaults()` 暴露 Angel / 美团 的 temperature / max_tokens / system 差异。
"""
from __future__ import annotations

import logging
from typing import Any

from app.models.llm_setting import LlmSetting
from app.services.llm.client import LlmClient

logger = logging.getLogger("news.llm.providers")

# === Provider 名常量(供 enrichment/前端/日志统一引用)===
PROVIDER_ANGEL = "angel"     # Agnes(原 LlmClient 默认端点)
PROVIDER_MEITUAN = "meituan"  # 美团大模型(LongCat,OpenAI 兼容)


def get_angel_client(setting: LlmSetting) -> LlmClient:
    """Agnes(Angel)客户端。

    凭据优先级(高 → 低):
      1. llm_settings.agnes_api_key(DB 里存的 key,UI 可改)
      2. .env AGNES_API_KEY
      3. .env 任意一个都不配 = LlmClient.is_configured() = False

    base_url 优先级:
      1. llm_settings.agnes_base_url_override(DB 里存的)
      2. .env AGNES_BASE_URL
    """
    from app.config import settings as app_settings

    api_key = (getattr(setting, "agnes_api_key", "") or app_settings.agnes_api_key) or ""
    base_url = (
        getattr(setting, "agnes_base_url_override", "") or app_settings.agnes_base_url
    ).rstrip("/")
    return LlmClient(
        base_url=base_url or "https://apihub.agnes-ai.com/v1",
        api_key=api_key,
        chat_model=setting.chat_model or "agnes-2.0-flash",
        image_model=setting.image_model or "agnes-image-2.1-flash",
        interval_sec=setting.interval_sec or 2.0,
    )


def get_meituan_client(setting: LlmSetting) -> LlmClient | None:
    """美团大模型(LongCat)客户端。
    配置来源:llm_settings 表里 meituan_* 字段(API key / base_url / model / interval / enabled)。
    """
    from app.config import settings as app_settings  # 延迟导入,避免循环

    api_key = getattr(setting, "meituan_api_key", "") or app_settings.meituan_api_key
    base_url = (
        getattr(setting, "meituan_base_url", "") or app_settings.meituan_base_url
    )
    model = (
        getattr(setting, "meituan_chat_model", "") or app_settings.meituan_chat_model
    )
    interval = (
        getattr(setting, "meituan_interval_sec", None) or app_settings.meituan_interval_sec
    )
    if not api_key:
        return None
    return LlmClient(
        base_url=base_url or "https://api.longcat.chat/openai/v1",
        api_key=api_key,
        chat_model=model or "LongCat-2.0-Preview",
        interval_sec=float(interval or 2.0),
    )


def get_provider_client(provider: str, setting: LlmSetting) -> LlmClient | None:
    """统一入口:按 provider 名取客户端。不可用时返回 None。"""
    if provider == PROVIDER_ANGEL:
        c = get_angel_client(setting)
        return c if c.is_configured() else None
    if provider == PROVIDER_MEITUAN:
        return get_meituan_client(setting)
    raise ValueError(f"unknown provider: {provider}")


def is_provider_enabled(provider: str, setting: LlmSetting) -> bool:
    """provider 是否启用 + 配置齐全。"""
    if not setting.enabled:
        return False
    if provider == PROVIDER_ANGEL:
        return get_provider_client(PROVIDER_ANGEL, setting) is not None
    if provider == PROVIDER_MEITUAN:
        if not bool(getattr(setting, "meituan_enabled", True)):
            return False
        return get_provider_client(PROVIDER_MEITUAN, setting) is not None
    return False


# === Provider 评论差异(温度 / max_tokens / system)===
# Angel: temperature=0.6, max_tokens=600, system="你是资深新闻评论员。"
# 美团: temperature=0.7, max_tokens=1000, system=None(用户示例无 system 字段)

PROVIDER_COMMENTARY_DEFAULTS: dict[str, dict[str, Any]] = {
    PROVIDER_ANGEL: {
        "temperature": 0.6,
        "max_tokens": 600,
        "system": "你是资深新闻评论员。",
    },
    PROVIDER_MEITUAN: {
        "temperature": 0.7,
        "max_tokens": 1000,
        "system": None,
    },
}