"""
场景配置加载与运行时准备
"""

import copy
import json
import time
import uuid
from pathlib import Path
from typing import Any

from fastapi import Request

from config.custom_scene import (
    CUSTOM_SCENE_ID,
    build_custom_scene_from_env,
    build_llm_settings_from_env,
)
from security.rtc_token import AccessToken, privileges
from utils.validation import assert_scene_value, assert_token_generation_ready

BASE_DIR = Path(__file__).resolve().parent.parent
SCENES_DIR = BASE_DIR / "scenes"


def load_scenes() -> dict:
    scenes = {
        CUSTOM_SCENE_ID: build_custom_scene_from_env(),
    }
    for p in sorted(SCENES_DIR.glob("*.json")):
        if p.stem == CUSTOM_SCENE_ID:
            continue
        with open(p, encoding="utf-8") as f:
            scenes[p.stem] = json.load(f)
    return scenes


def prepare_scene_runtime(scene_name: str, data: dict[str, Any]):
    data = copy.deepcopy(data)
    scene_config = data.get("SceneConfig", {})
    rtc_config = data.get("RTCConfig", {})
    voice_chat = data.get("VoiceChat", {})

    app_id = rtc_config.get("AppId", "")
    assert_scene_value(scene_name, "RTCConfig.AppId", app_id)

    token = rtc_config.get("Token", "")
    user_id = rtc_config.get("UserId", "")
    room_id = rtc_config.get("RoomId", "")
    app_key = rtc_config.get("AppKey", "")

    if app_id and (not token or not user_id or not room_id):
        rtc_config["RoomId"] = voice_chat["RoomId"] = room_id or str(uuid.uuid4())
        rtc_config["UserId"] = user_id = user_id or str(uuid.uuid4())

        agent_config = voice_chat.get("AgentConfig", {})
        target_user_ids = agent_config.get("TargetUserId")
        if target_user_ids:
            target_user_ids[0] = rtc_config["UserId"]

        assert_token_generation_ready(scene_name, app_key)
        key = AccessToken(app_id, app_key, rtc_config["RoomId"], rtc_config["UserId"])
        key.add_privilege(privileges["PrivSubscribeStream"], 0)
        key.add_privilege(privileges["PrivPublishStream"], 0)
        key.expire_time(int(time.time()) + 24 * 3600)
        rtc_config["Token"] = key.serialize()

    return scene_config, rtc_config, voice_chat


def get_custom_llm_callback_settings() -> dict[str, Any]:
    missing: list[str] = []
    settings = build_llm_settings_from_env(missing)
    if missing:
        missing_str = ", ".join(dict.fromkeys(missing))
        raise ValueError(f"Custom 场景缺少以下环境变量: {missing_str}")

    return settings


def ensure_custom_llm_authorized(request: Request, api_key: str):
    if not api_key:
        return

    authorization = request.headers.get("authorization", "")
    expected_value = f"Bearer {api_key}"
    if authorization == expected_value:
        return

    raise PermissionError("自定义 LLM 回调鉴权失败，请检查 CUSTOM_LLM_API_KEY")


try:
    Scenes = load_scenes()
except ValueError as exc:
    raise RuntimeError(f"Custom 场景配置错误：{exc}") from exc