import { json } from "@remix-run/node";
import { useLoaderData } from "@remix-run/react";
import {
  Page,
  Layout,
  Card,
  Thumbnail,
  TextContainer,
  Spinner,
  Button,
  Text,
  TextField,
} from "@shopify/polaris";
import { useState } from "react";
import { authenticate } from "../shopify.server";

export const loader = async ({ request }) => {
  const { admin } = await authenticate.admin(request);
  const { getTurn14AccessTokenFromMetafield } = await import("../utils/turn14Token.server");
  const accessToken = await getTurn14AccessTokenFromMetafield(request);

  const res = await admin.graphql(`
    {
      shop {
        metafield(namespace: "turn14", key: "selected_brands") {
          value
        }
      }
    }
  `);

  const data = await res.json();
  const rawValue = data?.data?.shop?.metafield?.value;

  let brands = [];
  try {
    brands = JSON.parse(rawValue);
  } catch (err) {
    console.error("❌ Failed to parse metafield value:", err);
  }

  return json({ brands, accessToken });
};

export default function ManageBrandProducts() {
  const { brands, accessToken } = useLoaderData();
  const [expandedBrand, setExpandedBrand] = useState(null);
  const [itemsMap, setItemsMap] = useState({});
  const [loadingMap, setLoadingMap] = useState({});
  const [productCount, setProductCount] = useState("10");
  const [adding, setAdding] = useState(false);

  const toggleBrandItems = async (brandId) => {
    const isExpanded = expandedBrand === brandId;
    if (isExpanded) {
      setExpandedBrand(null);
    } else {
      setExpandedBrand(brandId);
      if (!itemsMap[brandId]) {
        setLoadingMap((prev) => ({ ...prev, [brandId]: true }));
        try {
          const res = await fetch(`https://turn14.data4autos.com/v1/items/brand/${brandId}?page=1`, {
            headers: {
              Authorization: `Bearer ${accessToken}`,
              "Content-Type": "application/json",
            },
          });
          const data = await res.json();
          setItemsMap((prev) => ({ ...prev, [brandId]: data }));
        } catch (err) {
          console.error("Error fetching items:", err);
        }
        setLoadingMap((prev) => ({ ...prev, [brandId]: false }));
      }
    }
  };

  const handleAddProducts = async (brandId) => {
    const count = parseInt(productCount || "10");
    const items = (itemsMap[brandId] || []).slice(0, count);
    if (!items.length) return alert("No products to add.");
    setAdding(true);

    for (const item of items) {
      const attr = item.attributes;

      // Step 1: Create Product (only allowed fields)
      const productInput = {
        title: attr.product_name,
        descriptionHtml: `<p>${attr.part_description}</p>`,
        vendor: attr.brand,
        productType: attr.category,
        tags: [attr.subcategory, attr.brand].filter(Boolean).join(", "),
      };

      const createProductRes = await fetch("/admin/api/2023-04/graphql.json", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          "X-Shopify-Access-Token": accessToken,
        },
        body: JSON.stringify({
          query: `
            mutation productCreate($input: ProductInput!) {
              productCreate(input: $input) {
                product {
                  id
                  title
                }
                userErrors {
                  field
                  message
                }
              }
            }`,
          variables: { input: productInput },
        }),
      });

      const createProductResult = await createProductRes.json();
      const product = createProductResult?.data?.productCreate?.product;
      const productErrors = createProductResult?.data?.productCreate?.userErrors;

      if (productErrors?.length || !product?.id) {
        console.error("❌ Product create error:", productErrors);
        continue;
      }

      const productId = product.id;

      // Step 2: Create Variant
      const variantInput = {
        productId,
        sku: attr.part_number,
        barcode: attr.barcode || undefined,
        price: "0.00",
        weight: attr.dimensions?.[0]?.weight || 0,
        weightUnit: "KILOGRAMS",
        inventoryManagement: "SHOPIFY",
      };

      await fetch("/admin/api/2023-04/graphql.json", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          "X-Shopify-Access-Token": accessToken,
        },
        body: JSON.stringify({
          query: `
            mutation productVariantCreate($input: ProductVariantInput!) {
              productVariantCreate(input: $input) {
                productVariant {
                  id
                }
                userErrors {
                  field
                  message
                }
              }
            }`,
          variables: { input: variantInput },
        }),
      });

      // Step 3: Add Image
      if (attr.thumbnail) {
        await fetch("/admin/api/2023-04/graphql.json", {
          method: "POST",
          headers: {
            "Content-Type": "application/json",
            "X-Shopify-Access-Token": accessToken,
          },
          body: JSON.stringify({
            query: `
              mutation productImageCreate($productId: ID!, $image: ImageInput!) {
                productImageCreate(productId: $productId, image: $image) {
                  image {
                    id
                    src
                  }
                  userErrors {
                    field
                    message
                  }
                }
              }`,
            variables: {
              productId,
              image: {
                src: attr.thumbnail,
              },
            },
          }),
        });
      }

      console.log("✅ Added:", attr.product_name);
    }

    setAdding(false);
    alert(`${items.length} products added.`);
  };

  return (
    <Page title="Manage Brand Products">
      <Layout>
        {brands.length === 0 && (
          <Layout.Section>
            <Card sectioned>
              <p>No brands selected yet.</p>
            </Card>
          </Layout.Section>
        )}

        {brands.map((brand) => (
          <div key={brand.id}>
            <Layout.Section oneThird>
              <Card title={brand.name} sectioned>
                <Thumbnail
                  source={brand.logo || "https://cdn.shopify.com/s/files/1/0757/9955/files/no-image_280x@2x.png"}
                  alt={brand.name}
                  size="large"
                />
                <TextContainer spacing="tight">
                  <p><strong>Brand:</strong> {brand.name}</p>
                  <p><strong>ID:</strong> {brand.id}</p>
                </TextContainer>
                <div style={{ marginTop: "1rem" }}>
                  <Button onClick={() => toggleBrandItems(brand.id)} fullWidth>
                    {expandedBrand === brand.id ? "Hide Products" : "Show Products"}
                  </Button>
                </div>
              </Card>
            </Layout.Section>

            {expandedBrand === brand.id && (
              <Layout.Section fullWidth>
                <Card sectioned>
                  <TextField
                    label="Number of products to add"
                    type="number"
                    value={productCount}
                    onChange={setProductCount}
                    autoComplete="off"
                  />
                  <div style={{ marginTop: "1rem" }}>
                    <Button
                      onClick={() => handleAddProducts(brand.id)}
                      loading={adding}
                      disabled={adding}
                      primary
                    >
                      Add First {productCount} Products to Store
                    </Button>
                  </div>
                </Card>

                <Card title={`Items from ${brand.name}`} sectioned>
                  {loadingMap[brand.id] ? (
                    <Spinner accessibilityLabel="Loading items" size="small" />
                  ) : (
                    <div style={{ paddingTop: "1rem" }}>
                      {(itemsMap[brand.id] || []).map(item => (
                        <Card key={item.id} title={item.attributes.product_name} sectioned>
                          <Layout>
                            <Layout.Section oneThird>
                              <Thumbnail
                                source={
                                  item.attributes.thumbnail ||
                                  "https://cdn.shopify.com/s/files/1/0757/9955/files/no-image_280x@2x.png"
                                }
                                alt={item.attributes.product_name}
                                size="large"
                              />
                            </Layout.Section>
                            <Layout.Section>
                              <TextContainer spacing="tight">
                                <p><strong>Part Number:</strong> {item.attributes.part_number}</p>
                                <p><strong>Brand:</strong> {item.attributes.brand}</p>
                                <p><strong>Category:</strong> {item.attributes.category} > {item.attributes.subcategory}</p>
                                <p><strong>Dimensions:</strong> {item.attributes.dimensions?.[0]?.length} x {item.attributes.dimensions?.[0]?.width} x {item.attributes.dimensions?.[0]?.height} in</p>
                              </TextContainer>
                            </Layout.Section>
                          </Layout>
                        </Card>
                      ))}
                    </div>
                  )}
                </Card>
              </Layout.Section>
            )}
          </div>
        ))}
      </Layout>
    </Page>
  );
}