import csv
from io import StringIO
import logging

logger = logging.getLogger(__name__)

async def get_data_as_csv(cfg: dict, id_recv: int, unit: str, tool: str, matlab_timestamp: float, pool: object) -> str:
    """
    Retrieves elaborated data from the database and formats it as a CSV string.

    The query selects data from the `ElabDataView` based on `UnitName`, `ToolNameID`,
    and a `updated_at` timestamp, then orders it. The first row of the CSV will be
    the column headers.

    Args:
        cfg (dict): Configuration dictionary (not directly used in the query but passed for consistency).
        id (int): The ID of the record being processed (used for logging).
        pool (object): The database connection pool.
        unit (str): The name of the unit to filter the data.
        tool (str): The ID of the tool to filter the data.
        matlab_timestamp (float): A timestamp used to filter data updated after this time.

    Returns:
        str: A string containing the elaborated data in CSV format.
    """
    query = """
    select * from (
        select 'ToolNameID', 'EventDate', 'EventTime', 'NodeNum', 'NodeType', 'NodeDepth',
        'XShift', 'YShift', 'ZShift' , 'X', 'Y', 'Z', 'HShift', 'HShiftDir', 'HShift_local',
        'speed', 'speed_local', 'acceleration', 'acceleration_local', 'T_node', 'water_level', 'pressure', 'load_value', 'AlfaX', 'AlfaY', 'CalcErr'
        union all
        select ToolNameID, EventDate, EventTime, NodeNum, NodeType, NodeDepth,
        XShift, YShift, ZShift , X, Y, Z, HShift, HShiftDir, HShift_local,
        speed, speed_local, acceleration, acceleration_local, T_node, water_level, pressure, load_value, AlfaX, AlfaY, calcerr
        from ElabDataView
        where UnitName = %s and ToolNameID = %s and updated_at > %s
        order by ToolNameID DESC, concat(EventDate, EventTime), convert(`NodeNum`, UNSIGNED INTEGER) DESC
    ) resulting_set
    """
    async with pool.acquire() as conn:
        async with conn.cursor() as cur:
            try:
                await cur.execute(query, (unit, tool, matlab_timestamp))
                results = await cur.fetchall()
                logger.info(f"id {id_recv} - {unit} - {tool}: estratti i dati per invio CSV")
                logger.info(f"Numero di righe estratte: {len(results)}")

                # Creare CSV in memoria
                output = StringIO()
                writer = csv.writer(output, delimiter=",", lineterminator="\n", quoting=csv.QUOTE_MINIMAL)
                for row in results:
                    writer.writerow(row)
                csv_data = output.getvalue()
                output.close()

                return csv_data

            except Exception as e:
                logger.error(f"id {id_recv} - {unit} - {tool} - errore nel query creazione csv: {e}")
                return None