import logging
from typing import Optional

from fastapi import APIRouter, HTTPException, Query
from fastapi.responses import FileResponse

from app.schemas.common import TaskDetail, TaskListResponse, TaskStatus
from app.services import task_tracker
from app.services.file_manager import get_result_path

logger = logging.getLogger(__name__)

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


@router.get('', response_model=TaskListResponse)
async def list_tasks(
    status: Optional[TaskStatus] = Query(None),
    limit: int = Query(20, ge=1, le=100),
    offset: int = Query(0, ge=0),
):
    tasks, total = task_tracker.list_tasks(status=status, limit=limit, offset=offset)
    return TaskListResponse(
        tasks=[_to_detail(t) for t in tasks],
        total=total,
    )


@router.get('/{task_id}', response_model=TaskDetail)
async def get_task(task_id: str):
    task = task_tracker.get_task(task_id)
    if not task:
        raise HTTPException(status_code=404, detail='Task not found')
    return _to_detail(task)


@router.get('/{task_id}/result')
async def get_task_result(task_id: str):
    task = task_tracker.get_task(task_id)
    if not task:
        raise HTTPException(status_code=404, detail='Task not found')
    if task['status'] != TaskStatus.completed:
        raise HTTPException(status_code=409, detail=f'Task status is {task["status"].value}')

    path = task.get('local_path') or get_result_path(task_id)
    if not path:
        # Fall back to redirect if we have a remote URL
        if task.get('result_url'):
            from fastapi.responses import RedirectResponse
            return RedirectResponse(url=task['result_url'])
        raise HTTPException(status_code=404, detail='Result file not found')

    return FileResponse(path)


@router.delete('/{task_id}')
async def delete_task(task_id: str):
    if not task_tracker.delete_task(task_id):
        raise HTTPException(status_code=404, detail='Task not found')
    return {'status': 'deleted', 'task_id': task_id}


def _to_detail(task: dict) -> TaskDetail:
    result_url = None
    if task['status'] == TaskStatus.completed:
        result_url = f'/api/v1/tasks/{task["task_id"]}/result'
    return TaskDetail(
        task_id=task['task_id'],
        status=task['status'],
        created_at=task['created_at'],
        updated_at=task['updated_at'],
        progress=task.get('progress'),
        result_url=result_url,
        error=task.get('error'),
    )