refactor(stage-4): partition monolithic main.py into modular APIRouters

app/routers/tasks.py

@@ -0,0 +1,117 @@
+import asyncio
+from typing import Optional
+from fastapi import APIRouter, Depends, HTTPException, Query
+from pydantic import BaseModel, Field
+
+from app.auth import require_user
+from app.database import get_db
+from app.tasks import (
+    create_task,
+    get_task_status,
+    get_active_task,
+    cancel_task,
+)
+from app.miner import run_mining_task_background
+
+router = APIRouter(tags=["Background Tasks"])
+
+
+class MineBooksRequest(BaseModel):
+    book_id: Optional[int] = None
+    level: str = "A1"
+    count: int = Field(15, ge=1, le=50)
+
+
+@router.post("/api/tasks/mine-books")
+async def api_tasks_mine_books(
+    req: MineBooksRequest,
+    user: dict = Depends(require_user),
+):
+    """
+    Starts an asynchronous background task to mine CEFR Cloze Tap questions
+    from user's uploaded books (EPUB, TXT, PDF).
+    """
+    level = req.level.upper().strip()
+    if level not in ["A1", "A2", "B1", "B2", "ALL"]:
+        raise HTTPException(status_code=400, detail="Invalid CEFR level")
+
+    count = max(1, min(req.count, 50))
+
+    with get_db() as conn:
+        active = get_active_task(conn, user["id"], task_type="mine_books")
+        if active:
+            return {
+                "status": "already_running",
+                "message": "Сборка уже выполняется в фоне",
+                "task": active,
+            }
+
+        task_id = create_task(
+            conn,
+            user_id=user["id"],
+            task_type="mine_books",
+            params={
+                "book_id": req.book_id,
+                "level": level,
+                "count": count,
+            },
+            total=count,
+        )
+
+    # Launch background asyncio task
+    asyncio.create_task(
+        run_mining_task_background(
+            task_id=task_id,
+            user_id=user["id"],
+            book_id=req.book_id,
+            target_level=level,
+            target_count=count,
+        )
+    )
+
+    return {
+        "status": "ok",
+        "task_id": task_id,
+        "message": f"Запущена фоновая сборка тестов ({level})",
+    }
+
+
+@router.get("/api/tasks/active")
+async def api_tasks_active(
+    task_type: Optional[str] = Query(None),
+    user: dict = Depends(require_user),
+):
+    """
+    Returns current user's active background task (if any).
+    """
+    with get_db() as conn:
+        task = get_active_task(conn, user["id"], task_type=task_type)
+        return {"task": task}
+
+
+@router.get("/api/tasks/{task_id}")
+async def api_tasks_status(
+    task_id: int,
+    user: dict = Depends(require_user),
+):
+    """
+    Returns status and progress of a background task.
+    """
+    with get_db() as conn:
+        task = get_task_status(conn, task_id, user_id=user["id"])
+        if not task:
+            raise HTTPException(status_code=404, detail="Task not found")
+        return {"task": task}
+
+
+@router.post("/api/tasks/{task_id}/cancel")
+async def api_tasks_cancel(
+    task_id: int,
+    user: dict = Depends(require_user),
+):
+    """
+    Cancels a running background task.
+    """
+    with get_db() as conn:
+        cancelled = cancel_task(conn, task_id, user_id=user["id"])
+        return {"status": "ok" if cancelled else "not_found", "cancelled": cancelled}