"""
Helper functions for the Snowflake connector client.
"""

from csv import DictWriter, QUOTE_ALL
from io import StringIO
from typing import Sequence, Iterable

import msgpack

from ...typings import ColName


def _zip_cols_rows(col_names: Sequence[str], data: list[tuple]) -> Iterable[dict]:
    """Zip column names and data rows into a generator of dictionaries."""
    return (dict(zip(col_names, row)) for row in data)


def data_to_json(col_names: Sequence[str], data: list[tuple]) -> list[dict]:
    """
    Convert a list of tuples into a list of dictionaries (JSON).

    Args:
        col_names: Column names.
        data: Rows of data as tuples.

    Returns:
        A list of dictionaries representing each row.
    """
    return list(_zip_cols_rows(col_names, data))


def data_to_csv_string(col_names: Sequence[ColName], data: list[tuple]) -> str:
    """Convert a list of tuples into a CSV string.

    Args:
        col_names: Column names.
        data: Data to convert to CSV.

    Returns:
        CSV string with the data, including the header and with all fields quoted.
    """
    buffer = StringIO()
    csv_writer = DictWriter(
        buffer, fieldnames=col_names, quoting=QUOTE_ALL, lineterminator="\n"
    )
    csv_writer.writeheader()
    csv_writer.writerows(_zip_cols_rows(col_names, data))
    return buffer.getvalue()


def data_to_msgpack(col_names: Sequence[ColName], data: list[tuple]) -> bytes:
    """Convert a list of tuples into a msgpack binary string.

    Args:
        col_names: Column names.
        data: Data to convert to msgpack.

    Returns:
        Msgpack binary string with the data.
    """
    return msgpack.packb(data_to_json(col_names, data))