/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

// Rollup configuration
// GENERATED BY Bazel

const buildOptimizer = require(
    'npm/node_modules/@angular-devkit/build-optimizer/src/build-optimizer/rollup-plugin.js');
const nodeResolve = require('rollup-plugin-node-resolve');
const sourcemaps = require('rollup-plugin-sourcemaps');
const commonjs = require('rollup-plugin-commonjs');
const path = require('path');
const fs = require('fs');

function log_verbose(...m) {
  // This is a template file so we use __filename to output the actual filename
  if (!!process.env['VERBOSE_LOGS']) console.error(`[${path.basename(__filename)}]`, ...m);
}

const workspaceName = 'TMPL_workspace_name';
const useBuildOptimzier = TMPL_build_optimizer;
const rootDir = 'TMPL_root_dir';
const bannerFile = TMPL_banner_file;
const stampData = TMPL_stamp_data;
const moduleMappings = TMPL_module_mappings;
const nodeModulesRoot = 'TMPL_node_modules_root';
const ivyEnabled = TMPL_ivy_enabled;

log_verbose(`running with
  cwd: ${process.cwd()}
  workspaceName: ${workspaceName}
  useBuildOptimzier: ${useBuildOptimzier}
  rootDir: ${rootDir}
  bannerFile: ${bannerFile}
  stampData: ${stampData}
  moduleMappings: ${JSON.stringify(moduleMappings)}
  nodeModulesRoot: ${nodeModulesRoot}
  ivyEnabled: ${ivyEnabled}
`);

function fileExists(filePath) {
  try {
    return fs.statSync(filePath).isFile();
  } catch (e) {
    return false;
  }
}

// This resolver mimics the TypeScript Path Mapping feature, which lets us resolve
// modules based on a mapping of short names to paths.
function resolveBazel(
    importee, importer, baseDir = process.cwd(), resolve = require.resolve, root = rootDir) {
  log_verbose(`resolving '${importee}' from ${importer}`);

  function resolveInRootDir(importee) {
    function tryImportee(importee) {
      var candidate = path.join(baseDir, root, importee);
      log_verbose(`try to resolve '${importee}' at '${candidate}'`);
      try {
        var result = resolve(candidate);
        return result;
      } catch (e) {
        return undefined;
      }
    }
    // Attempt in the following order {importee}.mjs, {importee}/index.mjs,
    // {importee}, {importee}.js, {importee}/index.js. If an .mjs file is
    // available it should be resolved as rollup cannot handle the .js files
    // generated by ts_library as they are not esm. When rolling up esm5 files
    // these are re-rooted so it is not an issue.
    // TODO(gregmagolan): clean this up in the future as the .mjs es2015 outputs
    // along side the .js es5 outputs from ts_library creates this unusual situation for
    // which we can't rely on standard node module resolution to do the right thing.
    // In the future ts_library (or equivalent) should only produce a single flavor of
    // output and ng_rollup_bundle should also just use the use the vanilla rollup_bundle
    // rule without the need for a custom bazel resolver.
    return tryImportee(`${importee}.mjs`) || tryImportee(`${importee}/index.mjs`) ||
        tryImportee(importee) || tryImportee(`${importee}.js`) ||
        tryImportee(`${importee}/index.js`);
  }

  // Since mappings are always in POSIX paths, when comparing the importee to mappings
  // we should normalize the importee.
  // Having it normalized is also useful to determine relative paths.
  const normalizedImportee = importee.replace(/\\/g, '/');

  // If import is fully qualified then resolve it directly
  if (fileExists(importee)) {
    log_verbose(`resolved fully qualified '${importee}'`);
    return importee;
  }

  var resolved;
  if (normalizedImportee.startsWith('./') || normalizedImportee.startsWith('../')) {
    // relative import
    if (importer) {
      let importerRootRelative = path.dirname(importer);
      const relative = path.relative(path.join(baseDir, root), importerRootRelative);
      if (!relative.startsWith('.')) {
        importerRootRelative = relative;
      }
      resolved = path.join(importerRootRelative, importee);
    } else {
      throw new Error('cannot resolve relative paths without an importer');
    }
    if (resolved) resolved = resolveInRootDir(resolved);
  }

  if (!resolved) {
    // possible workspace import or external import if importee matches a module
    // mapping
    for (const k in moduleMappings) {
      if (normalizedImportee == k || normalizedImportee.startsWith(k + '/')) {
        // replace the root module name on a mappings match
        // note that the module_root attribute is intended to be used for type-checking
        // so it uses eg. "index.d.ts". At runtime, we have only index.js, so we strip the
        // .d.ts suffix and let node require.resolve do its thing.
        var v = moduleMappings[k].replace(/\.d\.ts$/, '');
        const mappedImportee = path.join(v, normalizedImportee.slice(k.length + 1));
        log_verbose(`module mapped '${importee}' to '${mappedImportee}'`);
        resolved = resolveInRootDir(mappedImportee);
        if (resolved) break;
      }
    }
  }

  if (!resolved) {
    // workspace import
    const userWorkspacePath = path.relative(workspaceName, importee);
    resolved = resolveInRootDir(userWorkspacePath.startsWith('..') ? importee : userWorkspacePath);
  }

  if (resolved) {
    log_verbose(`resolved to ${resolved}`);
  } else {
    log_verbose(`allowing rollup to resolve '${importee}' with node module resolution`);
  }

  return resolved;
}

// We make mainFields match what was the default for plugin-node-resolve <4.2.0
// when mainFields was introduced. Resolving to 'browser' or 'es2015' first breaks
// some of the benchmarks such as `//modules/benchmarks/src/expanding_rows:perf_chromium-local`.
// See https://app.circleci.com/jobs/github/angular/angular/507444 &&
// https://app.circleci.com/jobs/github/angular/angular/507442 for affected tests.
const mainFields = ['module', 'main'];
const ngccMainFields = mainFields.map(f => `${f}_ivy_ngcc`);

let plugins = [
  {
    name: 'resolveBazel',
    resolveId: resolveBazel,
  },
  nodeResolve({
    // If Ivy is enabled, we need to make sure that the module resolution prioritizes ngcc
    // processed entry-point fields. Ngcc adds special fields to `package.json` files of
    // modules that have been processed. Prioritizing these fields matches the Angular CLIs
    // behavior for supporting Ivy. We need to support ngcc because `ng_rollup_bundle` rule is
    // shared with other repositories that consume Angular from NPM (w/ ngcc).
    // https://github.com/angular/angular-cli/blob/1a1ceb609b9a87c4021cce3a6f0fc6d167cd09d2/packages/ngtools/webpack/src/angular_compiler_plugin.ts#L918-L920
    mainFields: ivyEnabled ? [...ngccMainFields, ...mainFields] : mainFields,
    jail: process.cwd(),
    customResolveOptions: {moduleDirectory: nodeModulesRoot}
  }),
  commonjs({ignoreGlobal: true}),
  sourcemaps(),
];

if (useBuildOptimzier) {
  plugins = [
    buildOptimizer.default({
      sideEffectFreeModules: [
        '.esm5/packages/core/src',
        '.esm5/packages/common/src',
        '.esm5/packages/compiler/src',
        '.esm5/packages/platform-browser/src',
      ]
    }),
  ].concat(plugins);
}

let banner = '';
if (bannerFile) {
  banner = fs.readFileSync(bannerFile, {encoding: 'utf-8'});
  if (stampData) {
    const versionTag = fs.readFileSync(stampData, {encoding: 'utf-8'})
                           .split('\n')
                           .find(s => s.startsWith('BUILD_SCM_VERSION'));
    // Don't assume BUILD_SCM_VERSION exists
    if (versionTag) {
      const version = versionTag.split(' ')[1].trim();
      banner = banner.replace(/0.0.0-PLACEHOLDER/, version);
    }
  }
}

const config = {
  plugins,
  external: [TMPL_external],
  output: {
    globals: {TMPL_globals},
    banner,
  }
};

module.exports = config;