import { existsSync } from 'fs'
import { basename, extname, join } from 'path';
import { ModuleFormat, RollupOptions, Plugin } from 'rollup';
import url from '@rollup/plugin-url';
import json from '@rollup/plugin-json';
import replace from '@rollup/plugin-replace';
import commonjs from '@rollup/plugin-commonjs';
import nodeResolve from '@rollup/plugin-node-resolve';
import inject, { RollupInjectOptions } from '@rollup/plugin-inject';
import babel, { RollupBabelInputPluginOptions } from '@rollup/plugin-babel';
import { createFilter } from '@rollup/pluginutils';
import postcss from 'rollup-plugin-postcss';
import { terser } from 'rollup-plugin-terser';
import typescript2 from 'rollup-plugin-typescript2';
import { camelCase } from 'lodash';
import tempDir from 'temp-dir';
import autoprefixer from 'autoprefixer';
import NpmImport from 'less-plugin-npm-import';
import svgr from '@svgr/rollup';
import getBabelConfig from './getBabelConfig';
import { getPkgPath, shouldTransform } from './es5ImcompatibleVersions';
import { IBundleOptions } from './types';

interface IGetRollupConfigOpts {
  cwd: string;
  rootPath: string;
  entry: string;
  type: ModuleFormat;
  importLibToEs?: boolean;
  bundleOpts: IBundleOptions;
}

interface IPkg {
  dependencies?: Object;
  peerDependencies?: Object;
  name?: string;
}

export default function(opts: IGetRollupConfigOpts): RollupOptions[] {
  const { type, entry, cwd, rootPath, importLibToEs, bundleOpts } = opts;
  const {
    umd,
    esm,
    cjs,
    file,
    target = 'browser',
    extractCSS = false,
    injectCSS = true,
    cssModules: modules,
    extraPostCSSPlugins = [],
    extraBabelPresets = [],
    extraBabelPlugins = [],
    extraRollupPlugins = [],
    autoprefixer: autoprefixerOpts,
    include = /node_modules/,
    runtimeHelpers: runtimeHelpersOpts,
    replace: replaceOpts,
    inject: injectOpts,
    extraExternals = [],
    externalsExclude = [],
    nodeVersion,
    typescriptOpts,
    nodeResolveOpts = {},
    disableTypeCheck,
    lessInRollupMode = {},
    sassInRollupMode = {},
  } = bundleOpts;
  const entryExt = extname(entry);
  const name = file || basename(entry, entryExt);
  const isTypeScript = entryExt === '.ts' || entryExt === '.tsx';
  const extensions = ['.js', '.jsx', '.ts', '.tsx', '.es6', '.es', '.mjs'];

  let pkg = {} as IPkg;
  try {
    pkg = require(join(cwd, 'package.json')); // eslint-disable-line
  } catch (e) {}

  // cjs 不给浏览器用，所以无需 runtimeHelpers
  const runtimeHelpers = type === 'cjs' ? false : runtimeHelpersOpts;
  const babelOpts = {
    ...(getBabelConfig({
      type,
      target: type === 'esm' ? 'browser' : target,
      // watch 模式下有几率走的 babel？原因未知。
      // ref: https://github.com/umijs/father/issues/158
      typescript: true,
      runtimeHelpers,
      nodeVersion,
    }).opts),
    // ref: https://github.com/rollup/plugins/tree/master/packages/babel#babelhelpers
    babelHelpers: (runtimeHelpers ? 'runtime' : 'bundled') as RollupBabelInputPluginOptions['babelHelpers'],
    // exclude: /\/node_modules\//,
    filter: (filePath: string) => {
      const rollupFilter = createFilter(null, /\/node_modules\//);
      // 默认过滤 node_modules
      if (!rollupFilter(filePath)) {
        const pkgPath = getPkgPath(filePath);
        return shouldTransform(pkgPath);
      }
      return true;
    },
    babelrc: false,
    // ref: https://github.com/rollup/rollup-plugin-babel#usage
    extensions,
  };
  if (importLibToEs && type === 'esm') {
    babelOpts.plugins.push(require.resolve('../lib/importLibToEs'));
  }
  babelOpts.presets.push(...extraBabelPresets);
  babelOpts.plugins.push(...extraBabelPlugins);

  // rollup configs
  const input = join(cwd, entry);
  const format = type;

  // ref: https://rollupjs.org/guide/en#external
  // 潜在问题：引用包的子文件时会报 warning，比如 @babel/runtime/helpers/esm/createClass
  // 解决方案：可以用 function 处理
  const external = [
    ...Object.keys(pkg.dependencies || {}),
    ...Object.keys(pkg.peerDependencies || {}),
    ...extraExternals,
  ];
  // umd 只要 external peerDependencies
  const externalPeerDeps = [
    ...Object.keys(pkg.peerDependencies || {}),
    ...extraExternals,
  ];

  function getPkgNameByid(id) {
    const splitted = id.split('/');
    // @ 和 @tmp 是为了兼容 umi 的逻辑
    if (id.charAt(0) === '@' && splitted[0] !== '@' && splitted[0] !== '@tmp') {
      return splitted
        .slice(0, 2)
        .join('/');
    } else {
      return id.split('/')[0];
    }
  }

  function testExternal(pkgs, excludes, id) {
    if (excludes.includes(id)) {
      return false;
    }
    return pkgs.includes(getPkgNameByid(id));
  }

  const terserOpts = {
    compress: {
      pure_getters: true,
      unsafe: true,
      unsafe_comps: true,
      warnings: false,
    },
  };

  // https://github.com/umijs/father/issues/164
  function mergePlugins(defaultRollupPlugins: Array<Plugin> = [], extraRollupPlugins: Array<Plugin> = []) {
    const pluginsMap: Record<string, Plugin> = Object.assign(
      defaultRollupPlugins.reduce((r, plugin) => ({ ...r, [plugin.name]: plugin }), {}),
      extraRollupPlugins.reduce((r, plugin) => ({ ...r, [plugin.name]: plugin }), {}),
    );
    return Object.values(pluginsMap);
  }

  function getPlugins(opts = {} as { minCSS: boolean; }) {
    const { minCSS } = opts;
    const defaultRollupPlugins = [
      url(),
      svgr(),
      postcss({
        extract: extractCSS,
        inject: injectCSS,
        modules,
        // modules => all .less will convert into css modules
        ...(modules ? { autoModules: false } : {}),
        minimize: !!minCSS,
        use: {
          less: {
            plugins: [new NpmImport({ prefix: '~' })],
              javascriptEnabled: true,
              ...lessInRollupMode
          },
          sass: {
            ...sassInRollupMode,
          },
          stylus: false,
        },
        plugins: [autoprefixer({
          // https://github.com/postcss/autoprefixer/issues/776
          remove: false,
          ...autoprefixerOpts,
        }), ...extraPostCSSPlugins],
      }),
      ...(injectOpts ? [inject(injectOpts as RollupInjectOptions)] : []),
      ...(replaceOpts && Object.keys(replaceOpts || {}).length ? [replace(replaceOpts)] : []),
      nodeResolve({
        mainFields: ['module', 'jsnext:main', 'main'],
        extensions,
        ...nodeResolveOpts,
      }),
      ...(isTypeScript
        ? [
          typescript2({
            cwd,
            // @see https://github.com/umijs/father/issues/61#issuecomment-544822774
            clean: true,
            cacheRoot: `${tempDir}/.rollup_plugin_typescript2_cache`,
            // 支持往上找 tsconfig.json
            // 比如 lerna 的场景不需要每个 package 有个 tsconfig.json
            tsconfig: [join(cwd, 'tsconfig.json'), join(rootPath, 'tsconfig.json')].find(existsSync),
            tsconfigDefaults: {
              compilerOptions: {
                // Generate declaration files by default
                declaration: true,
              },
            },
            tsconfigOverride: {
              compilerOptions: {
                // Support dynamic import
                target: 'esnext',
              },
            },
            check: !disableTypeCheck,
            ...(typescriptOpts || {}),
          }),
        ]
        : []),
      babel(babelOpts),
      json(),
    ];
    return mergePlugins(defaultRollupPlugins, extraRollupPlugins || []);
  }

  switch (type) {
    case 'esm':
      const output: Record<string, any> = {
        dir: join(cwd, `${esm && (esm as any).dir || 'dist'}`),
        entryFileNames: `${(esm && (esm as any).file) || `${name}.esm`}.js`,
      }
    
      return [
        {
          input,
          output: {
            format,
            ...output,
          },
          plugins: [...getPlugins(), ...(esm && (esm as any).minify ? [terser(terserOpts)] : [])],
          external: testExternal.bind(null, external, externalsExclude),
        },
        ...(esm && (esm as any).mjs
          ? [
              {
                input,
                output: {
                  format,
                  file: join(cwd, `dist/${(esm && (esm as any).file) || `${name}`}.mjs`),
                },
                plugins: [
                  ...getPlugins(),
                  replace({
                    'process.env.NODE_ENV': JSON.stringify('production'),
                  }),
                  terser(terserOpts),
                ],
                external: testExternal.bind(null, externalPeerDeps, externalsExclude),
              },
            ]
          : []),
      ];

    case 'cjs':
      return [
        {
          input,
          output: {
            format,
            file: join(cwd, `dist/${(cjs && (cjs as any).file) || name}.js`),
          },
          plugins: [...getPlugins(), ...(cjs && (cjs as any).minify ? [terser(terserOpts)] : [])],
          external: testExternal.bind(null, external, externalsExclude),
        },
      ];

    case 'umd':
      // Add umd related plugins
      const extraUmdPlugins = [
        commonjs({
          include,
          // namedExports options has been remove from https://github.com/rollup/plugins/pull/149
        }),
      ];

      return [
        {
          input,
          output: {
            format,
            sourcemap: umd && umd.sourcemap,
            file: join(cwd, `dist/${(umd && umd.file) || `${name}.umd`}.js`),
            globals: umd && umd.globals,
            name: (umd && umd.name) || (pkg.name && camelCase(basename(pkg.name))),
          },
          plugins: [
            ...extraUmdPlugins,
            ...getPlugins(),
            replace({
              'process.env.NODE_ENV': JSON.stringify('development'),
            }),
          ],
          external: testExternal.bind(null, externalPeerDeps, externalsExclude),
        },
        ...(umd && umd.minFile === false
          ? []
          : [
              {
                input,
                output: {
                  format,
                  sourcemap: umd && umd.sourcemap,
                  file: join(cwd, `dist/${(umd && umd.file) || `${name}.umd`}.min.js`),
                  globals: umd && umd.globals,
                  name: (umd && umd.name) || (pkg.name && camelCase(basename(pkg.name))),
                },
                plugins: [
                  ...extraUmdPlugins,
                  ...getPlugins({ minCSS: true }),
                  replace({
                    'process.env.NODE_ENV': JSON.stringify('production'),
                  }),
                  terser(terserOpts),
                ],
                external: testExternal.bind(null, externalPeerDeps, externalsExclude),
              },
            ]),
      ];

    default:
      throw new Error(`Unsupported type ${type}`);
  }
}