zTools2/app/controllers/whiteboard_controller.py

"""白板接口：REST（访问/管理）+ WebSocket（实时同步）。

路由：
    GET    /whiteboard/{board_id}        公开：访问白板，不存在则新建
    WS     /ws/whiteboard/{board_id}     公开：实时协作 + 心跳
    GET    /api/admin/whiteboards        Basic Auth：管理页列表
    DELETE /api/admin/whiteboards/{id}   Basic Auth：删除白板
"""

from __future__ import annotations

import json
import logging
import uuid

from fastapi import APIRouter, Depends, HTTPException, Query, WebSocket, WebSocketDisconnect
from sqlalchemy.orm import Session

from ..database import get_db
from ..dao.whiteboard_dao import WhiteboardDAO
from ..schemas.whiteboard import WhiteboardListResponse, WhiteboardOut
from ..security import require_docs_auth
from ..services.whiteboard_hub import Connection, get_hub
from ..services.whiteboard_service import WhiteboardService

logger = logging.getLogger("zikai.whiteboard")

router = APIRouter(tags=["whiteboard"])


def _service(db: Session = Depends(get_db)) -> WhiteboardService:
    """REST 路径的 service：注入 hub 以便删除时踢出连接。"""
    return WhiteboardService(WhiteboardDAO(db), hub=get_hub())


# ---------------- 公开 REST ----------------

@router.get(
    "/whiteboard/{board_id}",
    response_model=WhiteboardOut,
    summary="访问白板（不存在则新建）",
    description="任何人凭 board_id 即可访问；不存在时自动创建空板并返回。",
)
def get_whiteboard(board_id: str, service: WhiteboardService = Depends(_service)) -> WhiteboardOut:
    return service.get_or_create(board_id)


# ---------------- 管理 REST（Basic Auth） ----------------

@router.get(
    "/api/admin/whiteboards",
    response_model=WhiteboardListResponse,
    summary="列出所有白板（需鉴权）",
    description="供白板管理页使用：board_id / 创建时间 / 修改次数 / 上次修改时间。",
)
def list_whiteboards(
    limit: int = Query(100, ge=1, le=500),
    offset: int = Query(0, ge=0),
    service: WhiteboardService = Depends(_service),
    _: str = Depends(require_docs_auth),
) -> WhiteboardListResponse:
    total, items = service.list_all(limit=limit, offset=offset)
    return WhiteboardListResponse(total=total, items=items)


@router.delete(
    "/api/admin/whiteboards/{board_id}",
    summary="删除白板（需鉴权）",
    description="删 DB 行，并关闭该 board 的所有在线 WebSocket 连接。",
)
def delete_whiteboard(
    board_id: str,
    service: WhiteboardService = Depends(_service),
    _: str = Depends(require_docs_auth),
) -> dict:
    ok = service.delete(board_id)
    if not ok:
        raise HTTPException(404, "白板不存在")
    return {"deleted": True}


# ---------------- WebSocket（公开，实时同步 + 心跳） ----------------

@router.websocket("/ws/whiteboard/{board_id}")
async def whiteboard_ws(websocket: WebSocket, board_id: str) -> None:
    """白板实时协作端点。

    协议（JSON 文本帧）：
        client -> server:
            {"type":"hello","client_id":"..."}   首帧（可选，未带则服务端生成）
            {"type":"ping"}                      心跳，服务端回 pong 并刷新计时
            {"type":"stroke","stroke":{...}}     新增笔画，持久化并广播给他人
            {"type":"clear"}                     清空，持久化并广播给所有人
        server -> client:
            {"type":"init","strokes":[...],"stroke_count":n}
            {"type":"pong"}
            {"type":"stroke","stroke":{...},"client_id":"..."}
            {"type":"cleared","client_id":"..."}
            {"type":"error","msg":"..."}
    """
    # 路径层只做最基本校验，详细校验交给 service（service 会查表）
    hub = get_hub()
    # 先 accept，便于对非法 board_id 也回一条 error 再关闭
    await websocket.accept()

    # 读取首帧 hello（或任意帧）拿 client_id
    try:
        first = await websocket.receive_text()
    except WebSocketDisconnect:
        return

    client_id = _extract_client_id(first) or uuid.uuid4().hex[:12]

    # 校验 board_id 并加载白板（不存在则新建）
    from ..database import get_session_local
    try:
        board = _with_db(lambda db: WhiteboardService(WhiteboardDAO(db), hub=hub).get_or_create(board_id))
    except HTTPException as exc:
        await _safe_send(websocket, {"type": "error", "msg": exc.detail})
        await _safe_close(websocket)
        return

    # 注册连接并下发 init
    conn = Connection(websocket=websocket, board_id=board_id, client_id=client_id)
    await hub.register(conn)
    await _safe_send(websocket, {
        "type": "init",
        "strokes": board.strokes,
        "stroke_count": board.stroke_count,
    })

    # 主循环：收消息 -> 处理 -> 广播
    try:
        while True:
            raw = await websocket.receive_text()
            msg = _parse(raw)
            if msg is None:
                continue
            mtype = msg.get("type")
            if mtype == "ping":
                conn.touch()
                await _safe_send(websocket, {"type": "pong"})
                continue
            # 任何有效业务帧都视为活性证据
            conn.touch()
            if mtype == "stroke":
                stroke = msg.get("stroke") or {}
                try:
                    _with_db(lambda db: WhiteboardService(WhiteboardDAO(db), hub=hub).append_stroke(board_id, stroke))
                except HTTPException as exc:
                    await _safe_send(websocket, {"type": "error", "msg": exc.detail})
                    continue
                # 广播给他人（发送者本地已画，不回推）
                await hub.broadcast(
                    board_id,
                    {"type": "stroke", "stroke": stroke, "client_id": client_id},
                    exclude=conn,
                )
            elif mtype == "clear":
                try:
                    _with_db(lambda db: WhiteboardService(WhiteboardDAO(db), hub=hub).clear(board_id))
                except HTTPException as exc:
                    await _safe_send(websocket, {"type": "error", "msg": exc.detail})
                    continue
                # clear 广播给所有人（含发送者，用于确认）
                await hub.broadcast(
                    board_id, {"type": "cleared", "client_id": client_id}
                )
            else:
                await _safe_send(websocket, {"type": "error", "msg": f"未知消息类型 {mtype}"})
    except WebSocketDisconnect:
        pass
    except Exception as exc:  # pragma: no cover
        logger.warning("白板 WS 异常 board=%s client=%s: %s", board_id, client_id, exc)
    finally:
        await hub.disconnect(conn)


# ---------------- helpers ----------------

def _with_db(fn):
    """在独立 Session 中执行 fn 并返回结果；用完即关。供 WS 路径每帧独立事务使用。"""
    from ..database import get_session_local
    db = get_session_local()()
    try:
        return fn(db)
    finally:
        db.close()

def _extract_client_id(raw: str) -> str | None:
    try:
        data = json.loads(raw)
    except (json.JSONDecodeError, TypeError):
        return None
    cid = data.get("client_id") if isinstance(data, dict) else None
    if isinstance(cid, str) and cid:
        return cid
    return None


def _parse(raw: str) -> dict | None:
    try:
        data = json.loads(raw)
    except (json.JSONDecodeError, TypeError):
        return None
    return data if isinstance(data, dict) else None


async def _safe_send(ws: WebSocket, msg: dict) -> None:
    try:
        await ws.send_json(msg)
    except Exception:  # pragma: no cover
        pass


async def _safe_close(ws: WebSocket) -> None:
    try:
        await ws.close()
    except Exception:  # pragma: no cover
        pass