import fs from "fs";
import path from "path";
import typescript from "@rollup/plugin-typescript";
import babel from "@rollup/plugin-babel";
import resolve from "@rollup/plugin-node-resolve";
import commonjs from "@rollup/plugin-commonjs";
import { terser } from "rollup-plugin-terser";

const pkgPath = path.resolve("package.json");
const pkg = JSON.parse(fs.readFileSync(pkgPath, "utf8"));

const external = [
  ...Object.keys(pkg.dependencies || {}),
  ...Object.keys(pkg.peerDependencies || {}),
  /@babel\/runtime/,
];

const rollupConfig = {
  input: "src/index.ts",
  output: {
    dir: "dist",
    format: "esm",
    sourcemap: false,
    preserveModules: true,
    preserveModulesRoot: "src",
  },
  external,
  plugins: [
    resolve(),
    commonjs(),
    typescript({
      tsconfig: "./tsconfig.json",
      declaration: true,
      noEmitOnError: true,
      importHelpers: true,
    }),
    babel({
      extensions: [".js", ".ts"],
      babelHelpers: "runtime",
      include: ["src/**/*"],
      plugins: ["@babel/plugin-transform-runtime"],
    }),
    terser(),
  ],
};

export default rollupConfig;