feat: add collaborative math board and draw guess mode

2026-08-10 00:47:03 +08:00
parent 40e9462842
commit b8916180a9
16 changed files with 890 additions and 36 deletions
@@ -0,0 +1,147 @@
+import secrets
+from datetime import timedelta
+
+from asgiref.sync import async_to_sync
+from channels.layers import get_channel_layer
+from django.db import transaction
+from django.utils import timezone
+from rest_framework.exceptions import ValidationError
+
+from .models import BoardSession
+
+BOARD_CODE_ALPHABET = "ABCDEFGHJKLMNPQRSTUVWXYZ23456789"
+BOARD_TTL = timedelta(minutes=30)
+DRAW_GUESS_TARGETS = (
+    "抛物线",
+    "三角形",
+    "勾股定理",
+    "质数",
+    "圆",
+    "正弦函数",
+    "分数",
+    "坐标系",
+)
+
+
+def _new_board_code():
+    for _ in range(20):
+        code = "".join(secrets.choice(BOARD_CODE_ALPHABET) for _ in range(6))
+        if not BoardSession.objects.filter(code=code).exists():
+            return code
+    raise ValidationError("暂时无法生成画板联机码，请稍后重试")
+
+
+def broadcast_board(session_id, reason):
+    channel_layer = get_channel_layer()
+    if channel_layer is None:
+        return
+    async_to_sync(channel_layer.group_send)(
+        f"board_{session_id}",
+        {
+            "type": "board.state",
+            "reason": reason,
+        },
+    )
+
+
+def board_payload(session, user):
+    is_host = session.host_id == user.id
+    reveal_target = (
+        session.mode == BoardSession.Mode.DRAW_GUESS
+        and (is_host or session.status == BoardSession.Status.COMPLETED)
+    )
+    return {
+        "session_id": session.id,
+        "code": session.code,
+        "mode": session.mode,
+        "mode_label": session.get_mode_display(),
+        "status": session.status,
+        "role": "host" if is_host else "guest",
+        "target": session.target if reveal_target else None,
+        "host": session.host.nickname,
+        "guest": session.guest.nickname if session.guest else None,
+        "host_score": session.host_score,
+        "guest_score": session.guest_score,
+        "expires_at": session.expires_at,
+        "websocket_path": f"/ws/v1/toolbox/boards/{session.id}/",
+    }
+
+
+@transaction.atomic
+def create_board(user, mode):
+    if mode not in BoardSession.Mode.values:
+        raise ValidationError({"mode": "不支持的画板联机模式"})
+    BoardSession.objects.filter(
+        host=user,
+        status=BoardSession.Status.WAITING,
+    ).update(status=BoardSession.Status.CANCELLED)
+    return BoardSession.objects.create(
+        code=_new_board_code(),
+        mode=mode,
+        host=user,
+        target=(
+            secrets.choice(DRAW_GUESS_TARGETS)
+            if mode == BoardSession.Mode.DRAW_GUESS
+            else ""
+        ),
+        expires_at=timezone.now() + BOARD_TTL,
+    )
+
+
+@transaction.atomic
+def join_board(user, code):
+    normalized = str(code or "").strip().upper()
+    if len(normalized) != 6 or any(
+        character not in BOARD_CODE_ALPHABET for character in normalized
+    ):
+        raise ValidationError({"code": "画板联机码应为 6 位大写字母或数字"})
+    try:
+        session = (
+            BoardSession.objects.select_for_update()
+            .select_related("host", "guest")
+            .get(code=normalized)
+        )
+    except BoardSession.DoesNotExist as exc:
+        raise ValidationError({"code": "画板联机码不存在"}) from exc
+    if session.host_id == user.id:
+        raise ValidationError({"code": "不能加入自己创建的画板"})
+    if session.status != BoardSession.Status.WAITING:
+        raise ValidationError({"code": "画板联机码已失效或已被使用"})
+    if session.expires_at <= timezone.now():
+        session.status = BoardSession.Status.CANCELLED
+        session.save(update_fields=["status"])
+        raise ValidationError({"code": "画板联机码已经过期"})
+    session.guest = user
+    session.status = BoardSession.Status.ACTIVE
+    session.save(update_fields=["guest", "status"])
+    transaction.on_commit(lambda: broadcast_board(session.id, "joined"))
+    return session
+
+
+@transaction.atomic
+def submit_guess(user, session_id, raw_guess):
+    session = (
+        BoardSession.objects.select_for_update()
+        .select_related("host", "guest")
+        .get(id=session_id)
+    )
+    if session.guest_id != user.id:
+        raise ValidationError("只有猜题方可以提交答案")
+    if (
+        session.mode != BoardSession.Mode.DRAW_GUESS
+        or session.status != BoardSession.Status.ACTIVE
+    ):
+        raise ValidationError("当前画板不接受猜题")
+    guess = str(raw_guess or "").strip()
+    if not guess or len(guess) > 40:
+        raise ValidationError({"guess": "请输入不超过 40 个字符的数学对象"})
+    correct = guess.replace(" ", "").lower() == session.target.replace(" ", "").lower()
+    if correct:
+        session.guest_score += 1
+        session.status = BoardSession.Status.COMPLETED
+        session.completed_at = timezone.now()
+        session.save(
+            update_fields=["guest_score", "status", "completed_at"]
+        )
+        transaction.on_commit(lambda: broadcast_board(session.id, "completed"))
+    return session, correct