"""
POST /proxy — RTC OpenAPI 代理（含请求签名）
"""

import httpx
from fastapi import APIRouter, Query, Request
from fastapi.responses import JSONResponse
from pydantic import BaseModel, Field

from config.custom_scene import get_rtc_openapi_version
from security.internal_auth import verify_internal_request
from security.signer import Signer
from services.scene_service import Scenes, prepare_scene_runtime
from services.session_store import clear_room_history, get_room_history, load_session
from utils.responses import error_response
from utils.validation import assert_scene_value, assert_value

router = APIRouter(tags=["RTC 代理"])


class ProxyRequest(BaseModel):
    SceneID: str = Field(..., description="场景 ID（从 getScenes 返回的 scene.id 获取）")


@router.post(
    "/proxy",
    summary="开始 / 停止语音对话",
    description=(
        "带 SigV4 签名转发到火山引擎 RTC OpenAPI。\n\n"
        "- `Action=StartVoiceChat`：从 Session 取回 getScenes 分配的 RoomId/TaskId，"
        "自动注入后启动对话。\n"
        "- `Action=StopVoiceChat`：停止对话并清除该房间的历史上下文缓存。\n\n"
        "**鉴权**：需附加内部服务签名 Header（由 java-mock 自动添加）。"
    ),
    responses={
        401: {"description": "内部签名校验失败"},
        400: {"description": "参数缺失或场景配置不存在"},
    },
)
async def proxy(
    request: Request,
    body: ProxyRequest,
    action: str = Query(..., alias="Action", description="操作类型：`StartVoiceChat` 或 `StopVoiceChat`"),
    version: str | None = Query(None, alias="Version", description="火山引擎 OpenAPI 版本，不传时取配置文件默认值"),
):
    if not verify_internal_request(request.headers):
        return JSONResponse({"code": 401, "message": "鉴权失败"}, status_code=401)

    version = version or get_rtc_openapi_version()
    scene_id = body.SceneID

    try:
        assert_value(action, "Action 不能为空")
        assert_value(version, "Version 不能为空")
        assert_value(scene_id, "SceneID 不能为空，SceneID 用于指定场景配置")

        json_data = Scenes.get(scene_id)
        if not json_data:
            raise ValueError(f"{scene_id} 不存在，请先配置对应场景。")

        _, _, voice_chat = prepare_scene_runtime(scene_id, json_data)
        account_config = json_data.get("AccountConfig", {})
        assert_scene_value(
            scene_id, "AccountConfig.accessKeyId", account_config.get("accessKeyId")
        )
        assert_scene_value(
            scene_id, "AccountConfig.secretKey", account_config.get("secretKey")
        )

        if action == "StartVoiceChat":
            # 从 session 取回 getScenes 时分配的 RoomId/UserId/TaskId
            sess = load_session(request, scene_id)
            if sess.get("RoomId"):
                voice_chat["RoomId"] = sess["RoomId"]
            if sess.get("TaskId"):
                voice_chat["TaskId"] = sess["TaskId"]
            if sess.get("UserId"):
                agent_config = voice_chat.get("AgentConfig", {})
                target_user_ids = agent_config.get("TargetUserId", [])
                if target_user_ids:
                    target_user_ids[0] = sess["UserId"]
                else:
                    agent_config["TargetUserId"] = [sess["UserId"]]
            # 将 room_id 追加到 LLM 回调 URL，使 chat_callback 能关联到历史
            room_id = voice_chat.get("RoomId", "")
            if room_id:
                llm_config = voice_chat.get("Config", {}).get("LLMConfig", {})
                llm_url = llm_config.get("Url", "")
                if llm_url:
                    sep = "&" if "?" in llm_url else "?"
                    llm_config["Url"] = f"{llm_url}{sep}room_id={room_id}"
            req_body = voice_chat
        elif action == "StopVoiceChat":
            app_id = voice_chat.get("AppId", "")
            sess = load_session(request, scene_id)
            room_id = sess.get("RoomId") or voice_chat.get("RoomId", "")
            task_id = sess.get("TaskId") or voice_chat.get("TaskId", "")
            assert_scene_value(scene_id, "VoiceChat.AppId", app_id)
            assert_scene_value(scene_id, "VoiceChat.RoomId", room_id)
            assert_scene_value(scene_id, "VoiceChat.TaskId", task_id)
            # 清除该房间的历史上下文
            clear_room_history(room_id)
            req_body = {"AppId": app_id, "RoomId": room_id, "TaskId": task_id}
        else:
            req_body = {}

        request_data = {
            "region": "cn-north-1",
            "method": "POST",
            "params": {"Action": action, "Version": version},
            "headers": {
                "Host": "rtc.volcengineapi.com",
                "Content-type": "application/json",
            },
            "body": req_body,
        }
        signer = Signer(request_data, "rtc")
        signer.add_authorization(account_config)

        async with httpx.AsyncClient() as client:
            resp = await client.post(
                f"https://rtc.volcengineapi.com?Action={action}&Version={version}",
                headers=request_data["headers"],
                json=req_body,
            )
        return JSONResponse(resp.json())

    except ValueError as e:
        return error_response(action, str(e))
    except Exception as e:
        return error_response(action, str(e))