"""
Task Management API routes
"""
from fastapi import APIRouter, HTTPException, Depends, Query
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, desc

from app.database import get_db
from app.models.db import Task
from app.services.task_service import task_service

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


@router.get("")
async def list_tasks(
    limit: int = Query(20, ge=1, le=100),
    offset: int = Query(0, ge=0),
    db: AsyncSession = Depends(get_db)
):
    """
    List background tasks

    Args:
        limit: Maximum number of tasks to return (1-100, default 20)
        offset: Number of tasks to skip (default 0)
    """
    result = await db.execute(
        select(Task).order_by(desc(Task.created_at)).limit(limit).offset(offset)
    )
    tasks = result.scalars().all()
    return tasks


@router.get("/{task_id}")
async def get_task_status(
    task_id: int,
    db: AsyncSession = Depends(get_db)
):
    """
    Get task status and progress

    Returns merged data from Redis (real-time progress) and database (persistent record)
    """
    # Check Redis first for real-time progress
    redis_data = await task_service.get_task_progress_from_redis(task_id)

    # Get DB record
    task = await task_service.get_task(db, task_id)
    if not task:
        raise HTTPException(status_code=404, detail="Task not found")

    # Merge Redis data if available (Redis has fresher progress)
    response = {
        "id": task.id,
        "task_type": task.task_type,
        "status": task.status,
        "progress": task.progress,
        "description": task.description,
        "created_at": task.created_at,
        "started_at": task.started_at,
        "completed_at": task.completed_at,
        "error_message": task.error_message,
        "result": task.result
    }

    if redis_data:
        response["status"] = redis_data.get("status", task.status)
        response["progress"] = redis_data.get("progress", task.progress)
        if "error" in redis_data:
            response["error_message"] = redis_data["error"]

    return response