from fastapi.testclient import TestClient

from app.db import update_product_inventory

from app.main import app
from app.parser import read_file
from app.read_settings import read_settings

client = TestClient(app)


def get_inventory_amount(inventories, product_variation_id: str) -> int:
    """Helper function to get the inventory amount of the given product
    with specified product_id
    """
    for inventory in inventories:
        if inventory.product_variation_id == product_variation_id:
            return inventory.amount


def test_update_product_inventory():
    """Test the function to update the inventory list of a product. The
    function receives a list of strings after the Stripe or
    NOWPayments checkout, and update each purchased product's
    inventory, by decreasing the inventory amount for each option with
    the amount of copies bought of each product.
    """
    settings = read_settings("settings.toml")

    product_list = {
        "product_variation_id": "prod_RZBk650b1Tx95N__s",
        "product_name": "a-tshirt-01",
        "update_amount": 3,
    }

    tree = "products"

    # -- store current inventory amount pre-update
    pre_product = read_file(
        settings.git_repo,
        product_list["product_name"],
        settings.document_match,
        settings.block_types,
        tree,
    )

    pre_inventory_amount = get_inventory_amount(
        pre_product.meta.inventory,
        product_list["product_variation_id"],
    )

    # -- update inventory
    update_product_inventory(
        product_list["product_name"],
        product_list["update_amount"],
        product_list["product_variation_id"],
        settings,
    )

    # -- store updated inventory amount post-update
    post_product = read_file(
        settings.git_repo,
        product_list["product_name"],
        settings.document_match,
        settings.block_types,
        tree,
    )

    post_inventory_amount = get_inventory_amount(
        post_product.meta.inventory,
        product_list["product_variation_id"]
    )

    # -- if pre_inventory_amount is already 0 make sure it
    # stays like that also after the update else do subtraction

    if pre_inventory_amount > 0:
        assert (
            pre_inventory_amount - product_list["update_amount"]
        ) == post_inventory_amount
    else:
        assert pre_inventory_amount == post_inventory_amount

    # Restore the amount to original after the test
    update_product_inventory(
        product_list["product_name"],
        -pre_inventory_amount,
        product_list["product_variation_id"],
        settings,
    )