const fs = require("fs");
const path = require("path");
const { execSync } = require("child_process");
import commonjs from "@rollup/plugin-commonjs";
import resolve from "@rollup/plugin-node-resolve";
import moment from "moment/moment";
import css from "rollup-plugin-css-only";
import livereload from "rollup-plugin-livereload";
import svelte from "rollup-plugin-svelte";
import svg from "rollup-plugin-svg";
import { terser } from "rollup-plugin-terser";
import sveltePreprocess from "svelte-preprocess";

const production = !process.env.ROLLUP_WATCH;

let buildVersion;
if (production) {
  buildVersion = process.env.GIT_REV; // latest commit hash
} else {
  buildVersion = execSync("git rev-parse --short HEAD").toString();
}
fs.writeFileSync(
  "build-info.js",
  "export default " +
    JSON.stringify({
      buildDate: moment().format("MMMM Do YYYY, h:mm:ss a"),
      buildVersion,
    })
);

function serve() {
  let server;

  function toExit() {
    if (server) server.kill(0);
  }

  return {
    writeBundle() {
      if (server) return;
      server = require("child_process").spawn(
        "npm",
        ["run", "start", "--", "--dev"],
        {
          stdio: ["ignore", "inherit", "inherit"],
          shell: true,
        }
      );

      process.on("SIGTERM", toExit);
      process.on("exit", toExit);
    },
  };
}

export default [
  {
    input: "src/main.js",
    output: {
      sourcemap: true,
      format: "iife",
      name: "app",
      file: "public/build/bundle.js",
    },
    plugins: [
      svelte({
        preprocess: sveltePreprocess({ sourceMap: !production }),
        compilerOptions: {
          // enable run-time checks when not in production
          dev: !production,
        },
      }),
      // we'll extract any component CSS out into
      // a separate file - better for performance
      css({ output: "bundle.css" }),

      svg(),

      // If you have external dependencies installed from
      // npm, you'll most likely need these plugins. In
      // some cases you'll need additional configuration -
      // consult the documentation for details:
      // https://github.com/rollup/plugins/tree/master/packages/commonjs
      resolve({
        browser: true,
        dedupe: ["svelte"],
      }),
      commonjs(),

      // In dev mode, call `npm run start` once
      // the bundle has been generated
      !production && serve(),

      // Watch the `public` directory and refresh the
      // browser on changes when not in production
      !production && livereload("public"),

      // If we're building for production (npm run build
      // instead of npm run dev), minify
      production && terser(),

      {
        name: "copy-comlink",
        generateBundle() {
          const buildDir = "./public/build";
          if (!fs.existsSync(buildDir)) {
            fs.mkdirSync(buildDir);
          }

          fs.copyFileSync(
            path.resolve("./node_modules/comlink/dist/umd/comlink.min.js"),
            path.resolve("./public/build/comlink.min.js")
          );
        },
      },
    ],
    watch: {
      clearScreen: false,
    },
  },

  {
    input: "src/workers/stats-worker.js",
    output: {
      sourcemap: true,
      format: "iife",
      name: "app",
      file: "public/build/stats-worker.js",
    },
    plugins: [
      // If you have external dependencies installed from
      // npm, you'll most likely need these plugins. In
      // some cases you'll need additional configuration -
      // consult the documentation for details:
      // https://github.com/rollup/plugins/tree/master/packages/commonjs
      resolve({
        browser: true,
        dedupe: ["svelte"],
      }),
      commonjs(),

      // If we're building for production (npm run build
      // instead of npm run dev), minify
      production && terser(),
      {
        name: "copy-test-worker",
        load() {
          this.addWatchFile(path.resolve("./src/workers/stats-worker.js"));
        },
        generateBundle() {
          const buildDir = "./public/build";
          if (!fs.existsSync(buildDir)) {
            fs.mkdirSync(buildDir);
          }

          fs.copyFileSync(
            path.resolve("./src/workers/stats-worker.js"),
            path.resolve("./public/build/stats-worker.js")
          );
        },
      },
    ],
  },
];