import { plugin as analysis } from 'rollup-plugin-analyzer';
import babel from 'rollup-plugin-babel';
import commonjs from 'rollup-plugin-commonjs';
import filesize from 'rollup-plugin-filesize';
import nodeExternal from 'rollup-node-externals';
import nodeResolve from 'rollup-plugin-node-resolve';
import replace from 'rollup-plugin-replace';

const sharedConfig = {
  external: nodeExternal({
    whitelist: [
      '@skatejs/renderer-lit-html',
      '@skatejs/renderer-preact',
      '@skatejs/renderer-react',
      '@skatejs/renderer-snabbdom',
      'hyperhtml',
      'lit-html',
      'preact',
      'react',
      'react-dom',
      'skatejs',
      'snabbdom',
      'snabbdom-pragma',
      'snabbdom/es/modules/attributes',
      'snabbdom/es/modules/eventlisteners',
      'snabbdom/es/modules/class',
      'snabbdom/es/modules/props',
      'snabbdom/es/modules/style',
      'snabbdom/es/modules/dataset',
      'snabbdom/vnode'
    ]
  }),
  input: 'index.js',
  plugins: [
    nodeResolve({
      // TODO: esnext isn't actually supported, so I temporarily added it
      esnext: true,
      jsnext: true,
      main: true,
      module: true,
      browser: false
    }),
    babel({
      babelrc: false,
      include: '**/*.js',
      plugins: [
        // TODO: later
        // 'transform-custom-element-classes',
        [
          '@babel/plugin-transform-runtime',
          {
            regenerator: false,
            useESModules: true
          }
        ]
      ],
      presets: [
        ['@babel/preset-react'],
        [
          '@babel/preset-env',
          {
            targets: {
              // TODO: temporary, more later
              chrome: '70'
            }
          }
        ]
      ],
      runtimeHelpers: true
    }),
    replace({
      'process.env.NODE_ENV': JSON.stringify('production')
    }),
    commonjs({
      namedExports: {
        'react-dom': ['render', 'unmountComponentAtNode']
      }
    }),
    filesize()
  ]
};

const getBaseConfig = function(options = {}) {
  // npx rollup -c --config-analysis
  if (options['config-analysis']) {
    sharedConfig.plugins.push(analysis());
  }
  return sharedConfig;
};

const umdOutput = function(options) {
  const baseConfig = getBaseConfig(options);
  return Object.assign({}, baseConfig, {
    output: {
      file: 'dist/index.umd.js',
      format: 'umd',
      name: 'skateJsDemo'
    }
  });
};

export default function(options) {
  return [
    // TODO: esModuleOutput(options),
    umdOutput(options)
  ];
}