Add FastAPI backend with agent system

backend/app/routers/forum.py

@@ -0,0 +1,111 @@
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy import select, desc
+from app.database import get_db
+from app.models.forum import ForumPost, ForumReply
+from app.models.user import User
+from app.routers.auth import get_current_user
+from app.schemas.forum import ForumPostCreate, ForumPostOut, ForumReplyCreate, ForumReplyOut
+
+router = APIRouter(prefix="/api/forum", tags=["论坛"])
+
+
+@router.get("/posts", response_model=list[ForumPostOut])
+async def list_posts(
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    result = await db.execute(
+        select(ForumPost)
+        .where(ForumPost.user_id == current_user.id)
+        .order_by(desc(ForumPost.created_at))
+    )
+    return result.scalars().all()
+
+
+@router.post("/posts", response_model=ForumPostOut, status_code=201)
+async def create_post(
+    data: ForumPostCreate,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    post = ForumPost(
+        user_id=current_user.id,
+        title=data.title,
+        content=data.content,
+        category=data.category,
+    )
+    db.add(post)
+    await db.commit()
+    await db.refresh(post)
+    return post
+
+
+@router.get("/posts/{post_id}", response_model=ForumPostOut)
+async def get_post(
+    post_id: str,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    result = await db.execute(
+        select(ForumPost).where(ForumPost.id == post_id)
+    )
+    post = result.scalar_one_or_none()
+    if not post:
+        raise HTTPException(status_code=404, detail="帖子不存在")
+    return post
+
+
+@router.delete("/posts/{post_id}", status_code=204)
+async def delete_post(
+    post_id: str,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    result = await db.execute(
+        select(ForumPost).where(
+            ForumPost.id == post_id,
+            ForumPost.user_id == current_user.id,
+        )
+    )
+    post = result.scalar_one_or_none()
+    if not post:
+        raise HTTPException(status_code=404, detail="帖子不存在")
+    await db.delete(post)
+    await db.commit()
+
+
+@router.get("/posts/{post_id}/replies", response_model=list[ForumReplyOut])
+async def list_replies(
+    post_id: str,
+    db: AsyncSession = Depends(get_db),
+):
+    result = await db.execute(
+        select(ForumReply)
+        .where(ForumReply.post_id == post_id)
+        .order_by(ForumReply.created_at)
+    )
+    return result.scalars().all()
+
+
+@router.post("/posts/{post_id}/replies", response_model=ForumReplyOut, status_code=201)
+async def create_reply(
+    post_id: str,
+    data: ForumReplyCreate,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    reply = ForumReply(
+        post_id=post_id,
+        user_id=current_user.id,
+        content=data.content,
+    )
+    db.add(reply)
+    # 更新帖子回复数
+    result = await db.execute(select(ForumPost).where(ForumPost.id == post_id))
+    post = result.scalar_one_or_none()
+    if post:
+        post.reply_count += 1
+    await db.commit()
+    await db.refresh(reply)
+    return reply