首个可运行的版本

2026-06-12 23:14:12 +08:00
commit b3d90c65f8
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+"""会话服务"""
+
+import uuid
+from datetime import datetime, timezone
+
+from sqlalchemy import select, and_
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import selectinload
+
+from app.models.conversation import Conversation
+from app.models.conversation_member import ConversationMember
+from app.models.user import User
+
+
+class ConversationService:
+    def __init__(self, db: AsyncSession):
+        self.db = db
+
+    async def get_or_create_private(self, user1_id: str, user2_id: str) -> Conversation:
+        """获取或创建私聊会话"""
+        # 查找已有的私聊
+        result = await self.db.execute(
+            select(Conversation).join(ConversationMember)
+            .where(
+                Conversation.type == "private",
+                ConversationMember.user_id == user1_id,
+            )
+        )
+        for conv in result.scalars().all():
+            member_result = await self.db.execute(
+                select(ConversationMember).where(
+                    ConversationMember.conversation_id == conv.id,
+                    ConversationMember.user_id == user2_id,
+                )
+            )
+            if member_result.scalars().first():
+                return conv
+
+        # 创建新私聊
+        conv = Conversation(id=str(uuid.uuid4()), type="private")
+        self.db.add(conv)
+        await self.db.flush()
+
+        # 添加两个成员
+        self.db.add(ConversationMember(
+            id=str(uuid.uuid4()), conversation_id=conv.id, user_id=user1_id, role="member"
+        ))
+        self.db.add(ConversationMember(
+            id=str(uuid.uuid4()), conversation_id=conv.id, user_id=user2_id, role="member"
+        ))
+        return conv
+
+    async def create_group(self, creator_id: str, name: str, member_ids: list[str],
+                           description: str | None = None) -> Conversation:
+        """创建群聊"""
+        conv = Conversation(
+            id=str(uuid.uuid4()),
+            type="group",
+            name=name,
+            description=description,
+            creator_id=creator_id,
+        )
+        self.db.add(conv)
+        await self.db.flush()
+
+        # 创建者为 owner
+        self.db.add(ConversationMember(
+            id=str(uuid.uuid4()), conversation_id=conv.id,
+            user_id=creator_id, role="owner"
+        ))
+        # 其他成员
+        for mid in member_ids:
+            if mid != creator_id:
+                self.db.add(ConversationMember(
+                    id=str(uuid.uuid4()), conversation_id=conv.id,
+                    user_id=mid, role="member"
+                ))
+        return conv
+
+    async def get_user_conversations(self, user_id: str) -> list[dict]:
+        """获取用户的会话列表"""
+        result = await self.db.execute(
+            select(ConversationMember)
+            .where(ConversationMember.user_id == user_id, ConversationMember.left_at.is_(None))
+            .order_by(ConversationMember.joined_at.desc())
+        )
+        members = result.scalars().all()
+
+        conversations = []
+        for member in members:
+            conv_result = await self.db.execute(
+                select(Conversation).where(Conversation.id == member.conversation_id)
+            )
+            conv = conv_result.scalars().first()
+            if not conv:
+                continue
+
+            # 获取未读数
+            unread = await self._get_unread_count(conv.id, member.last_read_message_id)
+
+            # 获取显示信息
+            display_name = conv.name
+            display_avatar = conv.avatar_url
+
+            if conv.type == "private":
+                other = await self._get_other_member(conv.id, user_id)
+                if other:
+                    display_name = other.username
+                    display_avatar = other.avatar_url
+
+            conversations.append({
+                "id": conv.id,
+                "type": conv.type,
+                "name": display_name,
+                "avatar_url": display_avatar,
+                "description": conv.description,
+                "last_message_preview": conv.last_message_preview,
+                "last_message_at": conv.last_message_at,
+                "unread_count": unread,
+                "created_at": conv.created_at,
+            })
+
+        # 按最后消息时间排序
+        conversations.sort(key=lambda x: x["last_message_at"] or x["created_at"], reverse=True)
+        return conversations
+
+    async def get_conversation_detail(self, conv_id: str, user_id: str) -> dict | None:
+        """获取会话详情"""
+        conv_result = await self.db.execute(
+            select(Conversation).where(Conversation.id == conv_id)
+        )
+        conv = conv_result.scalars().first()
+        if not conv:
+            return None
+
+        # 验证成员身份
+        member_result = await self.db.execute(
+            select(ConversationMember).where(
+                ConversationMember.conversation_id == conv_id,
+                ConversationMember.user_id == user_id,
+                ConversationMember.left_at.is_(None),
+            )
+        )
+        if not member_result.scalars().first():
+            return None
+
+        # 获取所有成员
+        members_result = await self.db.execute(
+            select(ConversationMember).where(
+                ConversationMember.conversation_id == conv_id,
+                ConversationMember.left_at.is_(None),
+            )
+        )
+        members = []
+        for m in members_result.scalars().all():
+            user_result = await self.db.execute(select(User).where(User.id == m.user_id))
+            user = user_result.scalars().first()
+            if user:
+                members.append({
+                    "id": m.id,
+                    "user_id": user.id,
+                    "username": user.username,
+                    "nickname": user.bio,
+                    "avatar_url": user.avatar_url,
+                    "role": m.role,
+                    "joined_at": m.joined_at,
+                })
+
+        return {
+            "id": conv.id,
+            "type": conv.type,
+            "name": conv.name,
+            "avatar_url": conv.avatar_url,
+            "description": conv.description,
+            "last_message_preview": conv.last_message_preview,
+            "last_message_at": conv.last_message_at,
+            "created_at": conv.created_at,
+            "members": members,
+            "unread_count": await self._get_unread_count(conv.id, None),
+        }
+
+    async def _get_other_member(self, conv_id: str, user_id: str) -> User | None:
+        """获取私聊的对方用户"""
+        result = await self.db.execute(
+            select(ConversationMember).where(
+                ConversationMember.conversation_id == conv_id,
+                ConversationMember.user_id != user_id,
+            )
+        )
+        member = result.scalars().first()
+        if member:
+            user_result = await self.db.execute(select(User).where(User.id == member.user_id))
+            return user_result.scalars().first()
+        return None
+
+    async def _get_unread_count(self, conv_id: str, last_read_id: str | None) -> int:
+        """计算未读消息数"""
+        from app.models.message import Message
+        query = select(func := __import__("sqlalchemy").func).count(Message.id).where(
+            Message.conversation_id == conv_id,
+            Message.is_deleted == False,
+        )
+        if last_read_id:
+            # 获取 last_read 消息的时间
+            lr = await self.db.execute(select(Message).where(Message.id == last_read_id))
+            lr_msg = lr.scalars().first()
+            if lr_msg:
+                query = query.where(Message.created_at > lr_msg.created_at)
+        result = await self.db.execute(query)
+        return result.scalar() or 0