const { nodeResolve: rollupResolve } = require('@rollup/plugin-node-resolve');
const { babel: rollupBabelPlugin } = require('@rollup/plugin-babel');
const { terser: rollupTerser } = require('rollup-plugin-terser');
const rollupInject = require('@rollup/plugin-inject');
const rollupCommonjs = require('@rollup/plugin-commonjs');
const rollupTypescript = require('rollup-plugin-typescript2');
const rollupPrettier = require('rollup-plugin-prettier');
const del = require('del');
const fs = require('fs');
const path = require('path');
const resolve = require('./resolve.config.json');

const isTestEnv = process.env.NODE_ENV === 'test';

const rollupConfigDefaults = {
  input: './src/index',
  src: './src',
  dist: './dist',
  types: './types',
  tests: './tests',
  cache: [],
  minVersions: true,
  sourcemap: true,
  esmBuild: true,
  exports: 'auto',
  pipeline: ['typescript', 'resolve', 'inject', 'commonjs', 'babel'],
};

const legacyBabelConfig = {
  exclude: isTestEnv ? [/\/core-js\//] : [],
  presets: [
    [
      '@babel/preset-env',
      {
        ...(isTestEnv ? { useBuiltIns: 'usage', corejs: { version: 3, proposals: true } } : {}),
        loose: true,
        targets: {
          ie: '11',
        },
      },
    ],
  ],
};

const esmBabelConfig = {
  presets: [
    [
      '@babel/preset-env',
      {
        loose: true,
        bugfixes: true,
        targets: {
          esmodules: true,
        },
      },
    ],
  ],
};

const normalizePath = (pathName) => (pathName ? pathName.split(path.sep).join(path.posix.sep) : pathName);

const appendExtension = (file) => {
  if (path.extname(file) === '') {
    return file + resolve.extensions.find((ext) => fs.existsSync(path.resolve(`${file}${ext}`)));
  }
  return file;
};

const resolvePath = (basePath, pathToResolve, appendExt) => {
  const result = pathToResolve ? (path.isAbsolute(pathToResolve) ? pathToResolve : path.resolve(basePath, pathToResolve)) : null;
  return result && appendExt ? appendExtension(result) : result;
};

const resolveConfig = (config, userConfig) => {
  if (typeof config === 'function') {
    return (
      config({
        defaultConfig: rollupConfigDefaults,
        legacyBabelConfig,
        esmBabelConfig,
        userConfig,
      }) || {}
    );
  }
  return config;
};

const rollupConfig = (config = {}, { project = process.cwd(), overwrite = {}, silent, fast } = {}) => {
  const projectPath = resolvePath(__dirname, project);
  const relativeBackPath = path.relative(projectPath, __dirname);
  const projectName = path.basename(project);

  const packageJSONPath = resolvePath(projectPath, 'package.json');
  const tsconfigJSONPath = resolvePath(projectPath, 'tsconfig.json');

  const isTypeScriptProject = fs.existsSync(tsconfigJSONPath);
  const userConfig = resolveConfig(config);
  const overwriteConfig = resolveConfig(overwrite, userConfig);
  const buildConfig = {
    ...rollupConfigDefaults,
    ...{ name: projectName, file: projectName },
    ...userConfig,
    ...overwriteConfig,
  };

  const {
    input,
    src,
    dist,
    types,
    tests,
    file,
    cache,
    minVersions,
    sourcemap,
    esmBuild,
    name,
    exports,
    globals,
    external,
    pipeline,
    inject,
  } = buildConfig;
  const { devDependencies = {}, peerDependencies = {} } = require(packageJSONPath);

  const srcPath = resolvePath(projectPath, src);
  const distPath = resolvePath(projectPath, dist);
  const typesPath = resolvePath(projectPath, types);
  const testsPath = resolvePath(projectPath, tests);
  const inputPath = resolvePath(projectPath, input, true);

  const prependBackPath = (value) => normalizePath(`${relativeBackPath}${path.sep}`) + value;
  const genOutputConfig = (esm) => ({
    format: esm ? 'esm' : 'umd',
    file: path.resolve(distPath, `${file}${esm ? '.esm' : ''}.js`),
    sourcemap,
    ...(!esm && {
      name,
      globals,
      exports,
    }),
    plugins: [
      ...(fast
        ? []
        : [
            rollupPrettier({
              sourcemap: sourcemap && 'silent',
            }),
          ]),
    ],
  });

  const genConfig = ({ esm, typeDeclaration }) => {
    const pipelineMap = {
      typescript: isTypeScriptProject
        ? rollupTypescript({
            check: !fast,
            clean: true,
            useTsconfigDeclarationDir: true,
            tsconfig: tsconfigJSONPath,
            tsconfigOverride: {
              compilerOptions: {
                target: 'ESNext',
                sourceMap: sourcemap,
                declaration: typeDeclaration && types !== null,
                declarationDir: typesPath,
              },
              exclude: (require(tsconfigJSONPath).exclude || []).concat(testsPath),
            },
            include: ['*.ts+(|x)', '**/*.ts+(|x)'].map(prependBackPath),
            exclude: ['*.d.ts', '**/*.d.ts'].map(prependBackPath),
          })
        : {},
      resolve: rollupResolve({
        mainFields: ['browser', 'umd:main', 'module', 'main'],
        extensions: resolve.extensions,
        rootDir: srcPath,
        customResolveOptions: {
          moduleDirectory: [...resolve.directories.map((dir) => path.resolve(projectPath, dir)), path.resolve(__dirname, 'node_modules')],
        },
      }),
      inject: rollupInject({
        ...(typeof inject === 'object' ? inject : {}),
      }),
      commonjs: rollupCommonjs({
        sourceMap: sourcemap,
        extensions: resolve.extensions,
      }),
      babel: rollupBabelPlugin({
        ...(esm ? esmBabelConfig : legacyBabelConfig),
        babelHelpers: 'runtime',
        extensions: resolve.extensions,
        caller: {
          name: 'babel-rollup-build',
        },
      }),
    };

    const output = genOutputConfig(esm);
    return {
      input: inputPath,
      output: [output].concat(
        minVersions
          ? {
              ...output,
              compact: true,
              file: output.file.replace('.js', '.min.js'),
              sourcemap: false,
              plugins: [
                ...(output.plugins || []),
                rollupTerser({
                  ecma: 8,
                  safari10: true,
                  mangle: {
                    safari10: true,
                    properties: {
                      regex: /^_/,
                    },
                  },
                }),
              ],
            }
          : []
      ),
      external: [...Object.keys(devDependencies), ...Object.keys(peerDependencies), ...((Array.isArray(external) && external) || [])],
      plugins: pipeline.map((item) => (typeof item === 'string' ? pipelineMap[item] : item)),
    };
  };

  if (!silent) {
    console.log('');
    console.log('PROJECT : ', project);
    console.log('CONFIG  : ', buildConfig);
  }

  const legacy = genConfig({ esm: false, typeDeclaration: true });
  const esm = esmBuild ? genConfig({ esm: true, typeDeclaration: false }) : null;

  const builds = [legacy, esm]
    .filter((build) => build !== null)
    .map((build, index, buildsArr) => {
      const isFirst = index === 0;
      const isLast = index === buildsArr.length - 1;

      if (isFirst) {
        build.plugins.unshift({
          name: 'deleteGeneratedDirs',
          options() {
            const deletedDirs = del.sync([distPath, typesPath].filter((curr) => curr !== null));
            if (deletedDirs.length > 0 && !silent) {
              console.log('Deleted directories:\n', deletedDirs.join('\n'));
            }
          },
        });
      }
      if (isLast) {
        build.plugins.push({
          name: 'deleteCacheDirs',
          moduleParsed(moduleInfo) {
            //if (filename.includes('index.browser')) {
            console.log('moduleInfo', moduleInfo);
            //console.log('importer', filename);
            //}
          },
          writeBundle() {
            const cacheDirs = cache.map((dir) => path.resolve(projectPath, dir));
            const deletedDirs = del.sync(cacheDirs);
            if (deletedDirs.length > 0 && !silent) {
              console.log('Deleted cache:\n', deletedDirs.join('\n'));
            }
          },
        });
      }

      return build;
    });

  return builds;
};

module.exports = rollupConfig;