import HtmlWebpackPlugin from "html-webpack-plugin";
import path from "path";
import type { TGetHTMLPluginInstancesOptions } from "../../types/webpack";
import { getDir } from "../node/getDir";
import { getFilesWithFS } from "../node/getFilesWithFS";

interface IFileNameParams {
  file: string;
  outputPath: string;
  filePath: string;
}

interface IDirConfig {
  filePath?: string;
  inject?: boolean;
  outputPath: string;
}

const defaults: Required<TGetHTMLPluginInstancesOptions> = {
  options: {},
  dirs: [],
  extensions: [ ".tsx", ".jsx" ],
  loaders: [],
  getFilterFn: (idPage: string) => true,
};

/**
 * Возвращает массив экземпляров `HtmlWebpackPlugin` с настроенными параметрами.
 * @param params{TGetHTMLPluginInstancesOptions} параметры конфигурации.
 * @returns Promise<HtmlWebpackPlugin[]> массив экземпляров `HtmlWebpackPlugin`.
 * @example
 * import { getHTMLPluginInstances } from "@delement/ui/utils/webpack";
 *
 * const instances = await getHTMLPluginInstances({
 *   dirs: [{ filePath: "./src/pages", outputPath: "./" }],
 * });
 */
export const getHTMLPluginInstances = async (
  params: TGetHTMLPluginInstancesOptions = {}
): Promise<HtmlWebpackPlugin[]> => {

  const {
    getFilterFn,
    options,
    dirs,
    extensions,
    loaders,
  } = {
    ...defaults,
    ...params,
  };

  const customLoaders = loaders.length > 0
    ? loaders
      .map((loaderName) => loaderName.trim())
      .filter((loaderName) => !!loaderName)
      .map((loaderName) => loaderName.replace(/^!+|!+$/g, ""))
      .join("!")
    : "";

  const getFileName = ({ file, outputPath, filePath }: IFileNameParams): string => {

    const parsedPath = path.parse(file);
    const basePath = path.resolve(getDir(import.meta.url), filePath);

    return path.join(
      outputPath, path.format({
        ...parsedPath,
        base: "",
        ext: ".html",
      }).replace(basePath, "")
    );

  };

  const isRightExtension = (filePath: string): boolean =>
    extensions.some((ext) => filePath.endsWith(ext));

  const processDirectory = async ({ filePath, inject, outputPath }: IDirConfig): Promise<HtmlWebpackPlugin[]> => {

    if (!filePath) {
      return [];
    }

    console.debug(`[getHTMLPluginInstances] Reading dir "${filePath}"`);

    const files = await getFilesWithFS(filePath)
      .catch((err: Error) => {
        console.error(`[getHTMLPluginInstances] Error while processing directory "${filePath}":`, err);
        return [] as string[];
      });

    return files
      .filter((file) => {
        const baseName = path.basename(file, path.extname(file));
        return isRightExtension(file) && getFilterFn(baseName);
      })
      .map((file) => {
        const template = customLoaders ? `${customLoaders}!${file}` : file;
        const id = path.basename(file, path.extname(file));
        return new HtmlWebpackPlugin({
          cache: true,
          minify: false,
          filename: getFileName({ file, outputPath, filePath }),
          template,
          id,
          ...options,
          ...(typeof inject === "undefined" ? {} : { inject }),
        });
      });
  };

  const instances = await Promise.all(
    dirs.map(processDirectory)
  );

  return instances.flat();

};