import qrcode from "qrcode";
import invariant from "tiny-invariant";
import db from "../db.server";

export async function getQRCode(id, graphql) {
    const qrCode = await db.qRCode.findFirst({ where: { id } });

    if (!qrCode) {
        return null;
    }

    return supplementQRCode(qrCode, graphql);
}

export async function getQRCodes(shop, graphql) {
    const qrCodes = await db.qRCode.findMany({
        where: { shop },
        orderBy: { id: "desc" },
    });

    if (qrCodes.length === 0) return [];

    return Promise.all(
        qrCodes.map((qrCode) => supplementQRCode(qrCode, graphql))
    );
}

export function getQRCodeImage(id) {
    const url = new URL(`/qrcodes/${id}/scan`, process.env.SHOPIFY_APP_URL);
    return qrcode.toDataURL(url.href);
}

export function getDestinationUrl(qrCode) {
    if (qrCode.destination === "product") {
        return `https://${qrCode.shop}/products/${qrCode.productHandle}`;
    }

    const match = /gid:\/\/shopify\/ProductVariant\/([0-9]+)/.exec(qrCode.productVariantId);
    invariant(match, "Unrecognized product variant ID");

    return `https://${qrCode.shop}/cart/${match[1]}:1`;
}

async function supplementQRCode(qrCode, graphql) {
    const qrCodeImagePromise = getQRCodeImage(qrCode.id);

    const response = await graphql(
        `
      query supplementQRCode($id: ID!) {
        product(id: $id) {
          title
          media(first: 1) {
            nodes {
              preview {
                image {
                  altText
                  url
                }
              }
            }
          }
        }
      }
    `,
        {
            variables: {
                id: qrCode.productId,
            },
        }
    );

    const {
        data: { product },
    } = await response.json();

    return {
        ...qrCode,
        productDeleted: !product?.title,
        productTitle: product?.title,
        productImage: product?.media?.nodes[0]?.preview?.image?.url,
        productAlt: product?.media?.nodes[0]?.preview?.image?.altText,
        destinationUrl: getDestinationUrl(qrCode),
        image: await qrCodeImagePromise,
    };
}

export function validateQRCode(data) {
    const errors = {};

    if (!data.title) {
        errors.title = "Title is required";
    }

    if (!data.productId) {
        errors.productId = "Product is required";
    }

    if (!data.destination) {
        errors.destination = "Destination is required";
    }

    if (Object.keys(errors).length) {
        return errors;
    }
}