from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy import select, desc
from sqlalchemy.orm import selectinload
from sqlalchemy.ext.asyncio import AsyncSession

from app.dependencies import get_current_user, get_db
from app.models.task import Task
from app.models.user import User
from app.plugins.registry import action_registry
from app.schemas.task import ActionInfo, TaskCreate, TaskDetail, TaskRead
from app.services import task as task_service

router = APIRouter(prefix="/api/v1/tasks", tags=["tasks"])


@router.get("/actions", response_model=list[ActionInfo])
async def list_actions(_: User = Depends(get_current_user)):
    return [
        ActionInfo(
            name=a.name,
            display_name=a.display_name,
            compatible_categories=a.compatible_categories,
            params_schema=a.params_schema,
        )
        for a in action_registry.all()
    ]


@router.post("", response_model=TaskRead, status_code=status.HTTP_202_ACCEPTED)
async def create_task(
    body: TaskCreate,
    current_user: User = Depends(get_current_user),
):
    try:
        task = await task_service.create_task(
            action_type=body.type,
            target_scope=body.target_scope,
            params=body.params,
            user_id=current_user.id,
        )
    except ValueError as e:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(e))
    return task


@router.get("", response_model=list[TaskRead])
async def list_tasks(
    limit: int = 50,
    offset: int = 0,
    db: AsyncSession = Depends(get_db),
    _: User = Depends(get_current_user),
):
    result = await db.execute(
        select(Task).order_by(desc(Task.created_at)).offset(offset).limit(limit)
    )
    return result.scalars().all()


@router.get("/{task_id}", response_model=TaskDetail)
async def get_task(
    task_id: str,
    db: AsyncSession = Depends(get_db),
    _: User = Depends(get_current_user),
):
    result = await db.execute(
        select(Task)
        .options(selectinload(Task.events), selectinload(Task.device_results))
        .where(Task.id == task_id)
    )
    task = result.scalar_one_or_none()
    if task is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Task not found")
    return task