"""get_activity MCP tool implementation."""

from xer_mcp.db.queries import get_activity_by_id
from xer_mcp.server import is_file_loaded


async def get_activity(activity_id: str) -> dict:
    """Get detailed information for a specific activity by ID.

    Args:
        activity_id: The task_id of the activity

    Returns:
        Dictionary with complete activity details or error
    """
    if not is_file_loaded():
        return {
            "error": {
                "code": "NO_FILE_LOADED",
                "message": "No XER file is loaded. Use the load_xer tool first.",
            }
        }

    activity = get_activity_by_id(activity_id)

    if activity is None:
        return {
            "error": {
                "code": "ACTIVITY_NOT_FOUND",
                "message": f"Activity not found: {activity_id}",
            }
        }

    return activity