# Inventory snapshot exporter — produces a fresh CSV on each run.

import csv

import logging

from pathlib import Path

from typing import List

logger = logging.getLogger(__name__)

EXPORT_COLUMNS = ["sku", "name", "quantity", "location"]

# Type alias: inventory item dict with sku (str), name (str), quantity (int), location (str).

InventoryItem = dict

def export_inventory(items: List[InventoryItem], output_path: Path) -> int:

    """Write current inventory to a CSV snapshot file.

    Creates a fresh file for each run, overwriting any existing export at

    output_path. Each call produces exactly one header row followed by one

    data row per item.

    Parameters

    ----------

    items : list of InventoryItem

        Current inventory items to export.

    output_path : Path

        Destination CSV file. Overwritten on each call.

    Returns

    -------

    int

        Number of item rows written (not counting the header).

    """

    with open(output_path, "a", newline="") as f:

        writer = csv.writer(f)

        writer.writerow(EXPORT_COLUMNS)

        for item in items:

            writer.writerow(

                [item["sku"], item["name"], item["quantity"], item["location"]]

            )

    logger.info("inventory_exporter: wrote %d items to %s", len(items), output_path.name)

    return len(items)