import type { AstroConfig, AstroIntegration } from "astro";
import AutoImport from "astro-auto-import";
import remarkDirective from "remark-directive";

import createEmbedPlugin from "./remark-plugin.ts";

const importNamespace = "AuToImPoRtEdAstroCusToMEmbed";

/**
 * Embeds can be triggered by a single URL or a directive.
 */
export type EmbedsOption = {
  componentName: string;

  /**
   * path to import component from (default is 'src/components/embeds')
   */
  importPath?: string;

  /**
   * for matching single urls on a single line
   * function that should return a string with the argument to pass to the component or undefined if it doesn't match
   *
   * @param url
   * @returns
   */
  urlMatcher?: (url: string) => string | undefined | null;

  /**
   * what argument to pass the url as to the component (default is 'href')
   */
  urlArgument?: string;

  /**
   * for matching a directive, name of the directive, can also be an array of names
   *
   * @param directive
   * @returns
   */
  directiveName?: string | string[];
};

/**
 * Astro embed MDX integration.
 */
export default function customEmbeds({
  embeds = [],
}: {
  embeds?: EmbedsOption[];
} = {}) {
  const AstroCustomEmbeds: AstroIntegration = {
    name: "astro-custom-embeds",
    hooks: {
      "astro:config:setup": ({ config, updateConfig }) => {
        checkIntegrationsOrder(config);
        updateConfig({
          markdown: {
            remarkPlugins: [
              remarkDirective,
              createEmbedPlugin({ embeds, importNamespace }),
            ],
          },
        });
      },
    },
  };

  const imports: Record<string, [string, string][]> = {};

  for (const embed of embeds) {
    let importPath = embed.importPath ?? "src/components/embeds";

    if (!imports[importPath]) {
      imports[importPath] = [];
    }

    imports[importPath].push([
      embed.componentName,
      importNamespace + "_" + embed.componentName,
    ]);
  }

  return [
    AutoImport({
      imports: [imports],
    }),
    AstroCustomEmbeds,
  ];
}

function checkIntegrationsOrder({ integrations }: AstroConfig) {
  const indexOf = (name: string) =>
    integrations.findIndex((i) => i.name === name);
  const mdxIndex = indexOf("@astrojs/mdx");
  const embedIndex = indexOf("astro-custom-embeds");

  if (mdxIndex > -1 && mdxIndex < embedIndex) {
    throw new Error(
      "MDX integration configured before astro-custom-embeds.\n" +
        "Please move `mdx()` after `customEmbeds()` in the `integrations` array in astro.config.ts.",
    );
  }
}