import type { Core, UID } from "@strapi/strapi";

/**
 * Generate preview pathname based on content type and document
 * @param {string} uid - Content type identifier (e.g., 'api::article.article')
 * @param {object} options - Options containing locale and document data
 * @returns {string|null} - The preview pathname or null if no preview available
 */
const getPreviewPathname = (uid, { locale, document }) => {
  const { slug } = document || {};

  switch (uid) {
    // Global single type - preview on homepage
    case "api::global.global":
      return "/";

    // Generic pages with slugs
    case "api::page.page":
      if (!slug) {
        return null; // No slug, no preview
      }
      return `/${slug}`;

    // Articles/blog posts
    case "api::article.article":
      if (!slug) {
        return "/articles"; // Could redirect to articles index
      }
      return `/articles/${slug}`;

    // Products (example)
    case "api::product.product":
      if (!slug) {
        return "/products";
      }
      return `/products/${slug}`;

    // Add more content types as needed
    default:
      // Return null for content types that shouldn't have previews
      // (e.g., configuration, metadata, components)
      return null;
  }
};

const config = ({
  env,
}: Core.Config.Shared.ConfigParams): Core.Config.Admin => {
  const clientUrl = env("CLIENT_URL");
  const previewSecret = env("PREVIEW_SECRET");

  return {
    auth: {
      secret: env("ADMIN_JWT_SECRET"),
    },
    apiToken: {
      salt: env("API_TOKEN_SALT"),
    },
    transfer: {
      token: {
        salt: env("TRANSFER_TOKEN_SALT"),
      },
    },
    secrets: {
      encryptionKey: env("ENCRYPTION_KEY"),
    },
    flags: {
      nps: env.bool("FLAG_NPS", true),
      promoteEE: env.bool("FLAG_PROMOTE_EE", true),
    },
    // Preview
    preview: {
      enabled: true,
      config: {
        // Allow preview iframe to load from your frontend domain
        allowedOrigins: [clientUrl],

        /**
         * Preview handler - generates preview URLs for content
         * @param {string} uid - Content type UID
         * @param {object} context - Preview context
         * @param {string} context.documentId - Document ID being previewed
         * @param {string} context.locale - Document locale
         * @param {string} context.status - Document status ('draft' or 'published')
         * @returns {string|null} - Preview URL or null to disable preview
         */
        async handler(uid, { documentId, locale, status }) {
          try {
            // Fetch the complete document from Strapi
            const document = await strapi
              .documents(uid as UID.ContentType)
              .findOne({
                documentId,
                // Ensure we get the correct version based on status
                ...(status === "draft" && { status: "draft" }),
              });

            // Generate the preview pathname
            const pathname = getPreviewPathname(uid, { locale, document });

            // If no pathname is generated, disable preview for this content type
            if (!pathname) {
              return null;
            }

            // Build preview URL with all necessary parameters
            const urlSearchParams = new URLSearchParams({
              path: pathname,
              secret: previewSecret,
              status: status || "draft",
              documentId,
              uid,
              ...(locale && { locale }),
            });

            // Return the complete preview URL pointing to your Vike app's preview API
            return `${clientUrl}/api/preview?${urlSearchParams}`;
          } catch (error) {
            console.error("Preview handler error:", error);
            return null;
          }
        },
      },
    },
  };
};

export default config;