// Offer image upload: staged upload -> Shopify Files (write_files). Returns the CDN url once processed.
import type { ActionFunctionArgs } from "react-router";
import { authenticate } from "../shopify.server";
import { gql } from "../lib/shop.server";

const STAGE = `#graphql
  mutation BundleOffersStage($input: [StagedUploadInput!]!) {
    stagedUploadsCreate(input: $input) {
      stagedTargets { url resourceUrl parameters { name value } }
      userErrors { field message }
    }
  }`;

const CREATE = `#graphql
  mutation BundleOffersFile($files: [FileCreateInput!]!) {
    fileCreate(files: $files) {
      files { id fileStatus ... on MediaImage { image { url } } }
      userErrors { field message }
    }
  }`;

const STATUS = `#graphql
  query BundleOffersFileStatus($id: ID!) {
    node(id: $id) { ... on MediaImage { fileStatus image { url } } }
  }`;

const MAX_BYTES = 10 * 1024 * 1024;

export const action = async ({ request }: ActionFunctionArgs) => {
  const { admin } = await authenticate.admin(request);
  const form = await request.formData();
  const file = form.get("file");
  if (!(file instanceof File) || !file.size) return { error: "Choose an image." };
  if (!file.type.startsWith("image/")) return { error: "Use a JPG, PNG, GIF or WebP image." };
  if (file.size > MAX_BYTES) return { error: "Images must be 10 MB or smaller." };

  const staged = await gql(admin, STAGE, {
    input: [{ filename: file.name, mimeType: file.type, resource: "IMAGE", httpMethod: "POST", fileSize: String(file.size) }],
  });
  const target = staged.stagedUploadsCreate.stagedTargets?.[0];
  if (!target) return { error: staged.stagedUploadsCreate.userErrors?.[0]?.message || "Upload failed." };

  const body = new FormData();
  for (const p of target.parameters) body.append(p.name, p.value);
  body.append("file", file);
  const up = await fetch(target.url, { method: "POST", body });
  if (!up.ok) return { error: `Upload failed (${up.status}).` };

  const created = await gql(admin, CREATE, { files: [{ originalSource: target.resourceUrl, contentType: "IMAGE", alt: "Bundle offer image" }] });
  const f = created.fileCreate.files?.[0];
  if (!f) return { error: created.fileCreate.userErrors?.[0]?.message || "Could not save the image." };
  if (f.image?.url) return { url: f.image.url };

  // processing is asynchronous: poll for a few seconds
  for (let i = 0; i < 10; i += 1) {
    await new Promise((r) => setTimeout(r, 1000));
    const s = await gql(admin, STATUS, { id: f.id });
    if (s.node?.image?.url) return { url: s.node.image.url as string };
    if (s.node?.fileStatus === "FAILED") return { error: "Shopify could not process this image." };
  }
  return { error: "The image is still processing. Try saving again in a minute." };
};