import fs from "fs";

import svelte from "rollup-plugin-svelte";
import commonjs from "@rollup/plugin-commonjs";
import resolve from "@rollup/plugin-node-resolve";
import livereload from "rollup-plugin-livereload";
import { terser } from "rollup-plugin-terser";
import sveltePreprocess from "svelte-preprocess";
import typescript from "@rollup/plugin-typescript";
import css from "rollup-plugin-css-only";
import dev from "rollup-plugin-dev";
import replace from "@rollup/plugin-replace";
import json from "@rollup/plugin-json";

const production = !process.env.ROLLUP_WATCH;
const envVariables = fs.readFileSync("build.env", "utf-8")
	.split("\n")
	.filter(l => l.length > 0)
	.map(l => l.trim().split("="))
	.reduce((p, [key, value]) => ({...p, [key]: value}), {});

export default {
	input: "src/main.ts",
	output: {
		sourcemap: true,
		format: "iife",
		name: "app",
		file: "public/build/bundle.js"
	},
	plugins: [
		svelte({
			preprocess: sveltePreprocess(),
			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" }),

		// 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,
      preferBuiltins: false,
			dedupe: ["svelte"],
		}),
    json(),
		commonjs({
			include: 'node_modules/**',
		}),
		typescript({
			sourceMap: !production,
			inlineSources: !production
		}),

		replace({
      // 2 level deep object should be stringify
      "process.env": JSON.stringify({
				NODE_ENV: production ? "production" : "development",
				...envVariables,
      }),
    }),

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

		// Add dev server in development.
		!production && dev({
			dirs: ["public"],
			spa: "public/index.html", 
			port: 5000, 
			proxy: { 
				"/api/*": process.env.API_PROXY_TARGET || "localhost:8000",
			},
		}),

		// If we're building for production (npm run build
		// instead of npm run dev), minify
		production && terser({
			output: { comments: false },
		})
	],
	watch: {
		clearScreen: false
	},
	onwarn: function(warning) {
    // Skip certain warnings
    if ( warning.code === "THIS_IS_UNDEFINED" ) { return; }

    // console.warn everything else
    console.warn( warning.message );
	}
};