Add FastAPI backend with agent system

backend/app/routers/folder.py

@@ -0,0 +1,143 @@
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy import select, and_
+from typing import List
+from app.database import get_db
+from app.models.folder import Folder
+from app.models.user import User
+from app.schemas.folder import FolderCreate, FolderUpdate, FolderOut, FolderTreeOut
+from app.services.auth_service import get_current_user
+
+router = APIRouter(prefix="/api/folders", tags=["文件夹"])
+
+def build_folder_tree(folders: list[Folder], parent_id: str = None) -> List[FolderTreeOut]:
+    """递归构建文件夹树"""
+    tree = []
+    for folder in folders:
+        if folder.parent_id == parent_id:
+            children = build_folder_tree(folders, folder.id)
+            tree.append(FolderTreeOut(
+                id=folder.id,
+                name=folder.name,
+                parent_id=folder.parent_id,
+                children=children
+            ))
+    return tree
+
+@router.get("", response_model=List[FolderTreeOut])
+async def get_folders(
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user)
+):
+    """获取用户的完整文件夹树"""
+    result = await db.execute(
+        select(Folder).where(Folder.user_id == current_user.id)
+    )
+    folders = result.scalars().all()
+    return build_folder_tree(list(folders))
+
+@router.post("", response_model=FolderOut, status_code=status.HTTP_201_CREATED)
+async def create_folder(
+    folder_data: FolderCreate,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user)
+):
+    """创建文件夹"""
+    # 验证父文件夹存在且属于当前用户
+    if folder_data.parent_id:
+        result = await db.execute(
+            select(Folder).where(
+                and_(Folder.id == folder_data.parent_id, Folder.user_id == current_user.id)
+            )
+        )
+        if not result.scalar_one_or_none():
+            raise HTTPException(status_code=404, detail="父文件夹不存在")
+
+    # 检查同名文件夹
+    result = await db.execute(
+        select(Folder).where(
+            and_(
+                Folder.user_id == current_user.id,
+                Folder.parent_id == folder_data.parent_id,
+                Folder.name == folder_data.name
+            )
+        )
+    )
+    if result.scalar_one_or_none():
+        raise HTTPException(status_code=400, detail="同名文件夹已存在")
+
+    folder = Folder(
+        user_id=current_user.id,
+        name=folder_data.name,
+        parent_id=folder_data.parent_id
+    )
+    db.add(folder)
+    await db.commit()
+    await db.refresh(folder)
+    return folder
+
+@router.put("/{folder_id}", response_model=FolderOut)
+async def rename_folder(
+    folder_id: str,
+    folder_data: FolderUpdate,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user)
+):
+    """重命名文件夹"""
+    result = await db.execute(
+        select(Folder).where(
+            and_(Folder.id == folder_id, Folder.user_id == current_user.id)
+        )
+    )
+    folder = result.scalar_one_or_none()
+    if not folder:
+        raise HTTPException(status_code=404, detail="文件夹不存在")
+
+    folder.name = folder_data.name
+    await db.commit()
+    await db.refresh(folder)
+    return folder
+
+@router.delete("/{folder_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_folder(
+    folder_id: str,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user)
+):
+    """删除文件夹（级联删除文档）"""
+    from app.models.document import Document
+    from app.services.knowledge_service import KnowledgeService
+
+    result = await db.execute(
+        select(Folder).where(
+            and_(Folder.id == folder_id, Folder.user_id == current_user.id)
+        )
+    )
+    folder = result.scalar_one_or_none()
+    if not folder:
+        raise HTTPException(status_code=404, detail="文件夹不存在")
+
+    async def delete_recursive(fid: str):
+        # 删除子文件夹（先递归）
+        children = await db.execute(
+            select(Folder).where(Folder.parent_id == fid)
+        )
+        for child in children.scalars():
+            await delete_recursive(child.id)
+
+        # 删除文档
+        docs = await db.execute(
+            select(Document).where(Document.folder_id == fid)
+        )
+        for doc in docs.scalars():
+            knowledge_service = KnowledgeService(db, current_user.id)
+            await knowledge_service.delete_from_vectorstore(current_user.id, doc.id)
+            await db.delete(doc)
+
+        # 删除文件夹本身
+        folder_to_delete = await db.get(Folder, fid)
+        if folder_to_delete:
+            await db.delete(folder_to_delete)
+
+    await delete_recursive(folder_id)
+    await db.commit()