# User account export job for the analytics platform.

import csv

import os

from datetime import date

from typing import List

# Type alias for a user record dict.

User = dict  # keys: user_id (str), email (str), created_at (date), is_active (bool)

# Parameters: date_from, date_to — start and end dates for the export window.

# Returns: None. Raises ValueError when date_from is after date_to.

def _validate_date_range(date_from: date, date_to: date) -> None:

    if date_from > date_to:

        raise ValueError(

            f"date_from ({date_from}) must not be after date_to ({date_to})"

        )

def export_users(

    users: List[User],

    path: str,

    date_from: date,

    date_to: date,

) -> int:

    """Export active users created within [date_from, date_to] to a CSV file.

    Both date_from and date_to are inclusive. Only active users are exported.

    Parameters

    ----------

    users : list of User

        Full list of user records to filter.

    path : str

        Destination file path; parent directories are created if needed.

    date_from : date

        Earliest creation date to include (inclusive).

    date_to : date

        Latest creation date to include (inclusive).

    Returns

    -------

    int

        Number of rows written, excluding the header.

    """

    _validate_date_range(date_from, date_to)

    filtered = [

        u for u in users

        if date_from <= u["created_at"] < date_to

    ]

    os.makedirs(os.path.dirname(os.path.abspath(path)), exist_ok=True)

    with open(path, "w", newline="") as fh:

        writer = csv.DictWriter(

            fh,

            fieldnames=["user_id", "email", "created_at"],

            extrasaction="ignore",

        )

        writer.writeheader()

        writer.writerows(filtered)

    return len(filtered)