const path = require("path");

const nodeExternalModules = ["better-sqlite3"];

const commonConfig = {
  externals: nodeExternalModules,
  resolve: {
    fallback: {
      fs: false,
      path: false,
      util: false,
    },
  },
};

const configs = {
  cjs: {
    output: {
      path: path.resolve(__dirname, "dist"),
      filename: "windychen-utils.cjs.js",
      libraryTarget: "commonjs2",
    },
  },
  esm: {
    experiments: { outputModule: true },
    output: {
      path: path.resolve(__dirname, "dist"),
      filename: "windychen-utils.esm.js",
      libraryTarget: "module",
    },
  },
  umd: {
    output: {
      path: path.resolve(__dirname, "dist"),
      filename: "windychen-utils.js",
      library: { name: "WindychenUtils", type: "umd", export: "default" },
    },
  },
};

module.exports = (env = {}) => {
  const format = env.format;

  if (!format || format === "all") {
    return Object.keys(configs).map((key) => ({
      name: key,
      entry: "./index.js",
      ...commonConfig,
      ...configs[key],
    }));
  }

  if (!configs[format]) {
    throw new Error(`不支持的格式: ${format}，可选值: cjs, esm, umd`);
  }

  return { entry: "./index.js", ...commonConfig, ...configs[format] };
};