/**
 * @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
 */

import { JsonObject } from '@angular-devkit/core';
import { execSync } from 'child_process';
import * as fs from 'fs';
import * as path from 'path';
import * as ts from 'typescript';

const distRoot = path.join(__dirname, '../dist');
const { packages: monorepoPackages } = require('../.monorepo.json');

export interface PackageInfo {
  name: string;
  root: string;
  bin: { [name: string]: string };
  relative: string;
  main: string;
  dist: string;
  build: string;
  tar: string;
  private: boolean;
  experimental: boolean;
  packageJson: JsonObject;
  dependencies: string[];
  reverseDependencies: string[];

  snapshot: boolean;
  snapshotRepo: string;
  snapshotHash: string;

  version: string;
}
export type PackageMap = { [name: string]: PackageInfo };

export function loadRootPackageJson() {
  return require('../package.json');
}

function loadPackageJson(p: string) {
  const root = loadRootPackageJson();
  const pkg = require(p);

  for (const key of Object.keys(root)) {
    switch (key) {
      // Keep the following keys from the package.json of the package itself.
      case 'bin':
      case 'description':
      case 'dependencies':
      case 'name':
      case 'main':
      case 'peerDependencies':
      case 'optionalDependencies':
      case 'typings':
      case 'version':
      case 'private':
      case 'workspaces':
      case 'resolutions':
      case 'scripts':
        continue;

      // Remove the following keys from the package.json.
      case 'devDependencies':
        delete pkg[key];
        continue;

      // Merge the following keys with the root package.json.
      case 'keywords':
        const a = pkg[key] || [];
        const b = Object.keys(
          root[key].concat(a).reduce((acc: { [k: string]: boolean }, curr: string) => {
            acc[curr] = true;

            return acc;
          }, {}),
        );
        pkg[key] = b;
        break;

      // Overwrite engines to a common default.
      case 'engines':
        pkg['engines'] = {
          'node': '^12.20.0 || ^14.15.0 || >=16.10.0',
          'npm': '^6.11.0 || ^7.5.6',
          'yarn': '>= 1.13.0',
        };
        break;

      // Overwrite the package's key with to root one.
      default:
        pkg[key] = root[key];
    }
  }

  return pkg;
}

function* _findPrimaryPackageJsonFiles(dir: string, exclude: RegExp): Iterable<string> {
  const subdirectories = [];
  for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
    const p = path.join(dir, entry.name);

    if (exclude.test(p)) {
      continue;
    }

    if (entry.isDirectory() && entry.name !== 'node_modules') {
      subdirectories.push(p);
      continue;
    }

    if (entry.name === 'package.json') {
      yield p;

      // First package.json found will be the package's root package.json
      // Secondary entrypoint package.json files should not be found here
      return;
    }
  }

  for (const directory of subdirectories) {
    yield* _findPrimaryPackageJsonFiles(directory, exclude);
  }
}

const tsConfigPath = path.join(__dirname, '../tsconfig.json');
const tsConfig = ts.readConfigFile(tsConfigPath, ts.sys.readFile);
const pattern =
  '^(' +
  (tsConfig.config.exclude as string[])
    .map((ex) => path.join(path.dirname(tsConfigPath), ex))
    .map(
      (ex) =>
        '(' +
        ex
          .replace(/[-[\]{}()+?./\\^$|]/g, '\\$&')
          .replace(/(\\\\|\\\/)\*\*/g, '((/|\\\\).+?)?')
          .replace(/\*/g, '[^/\\\\]*') +
        ')',
    )
    .join('|') +
  ')($|/|\\\\)';
const excludeRe = new RegExp(pattern);

// Find all the package.json that aren't excluded from tsconfig.
const packageJsonPaths = [
  ..._findPrimaryPackageJsonFiles(path.join(__dirname, '..', 'packages'), excludeRe),
];

function _exec(cmd: string) {
  return execSync(cmd).toString().trim();
}

let gitShaCache: string;
function _getSnapshotHash(_pkg: PackageInfo): string {
  if (!gitShaCache) {
    gitShaCache = _exec('git log --format=%h -n1');
  }

  return gitShaCache;
}

const stableVersion = loadRootPackageJson().version;
const experimentalVersion = stableToExperimentalVersion(stableVersion);

/**
 * Convert a stable version to its experimental equivalent. For example,
 *   stable = 10.2.3, experimental = 0.1002.3
 * @param stable Must begin with d+.d+ where d is a 0-9 digit.
 */
export function stableToExperimentalVersion(stable: string): string {
  return `0.${stable.replace(/^(\d+)\.(\d+)/, (_, major, minor) => {
    return '' + (parseInt(major, 10) * 100 + parseInt(minor, 10));
  })}`;
}

// All the supported packages. Go through the packages directory and create a map of
// name => PackageInfo. This map is partial as it lacks some information that requires the
// map itself to finish building.
export const packages: PackageMap = packageJsonPaths
  .map((pkgPath) => ({ root: path.dirname(pkgPath) }))
  .reduce((packages: PackageMap, pkg) => {
    const pkgRoot = pkg.root;
    const packageJson = loadPackageJson(path.join(pkgRoot, 'package.json'));
    const name = packageJson['name'];
    if (!name) {
      // Only build the entry if there's a package name.
      return packages;
    }
    if (!(name in monorepoPackages)) {
      throw new Error(
        `Package ${name} found in ${JSON.stringify(pkg.root)}, not found in .monorepo.json.`,
      );
    }

    const bin: { [name: string]: string } = {};
    Object.keys(packageJson['bin'] || {}).forEach((binName) => {
      let p = path.resolve(pkg.root, packageJson['bin'][binName]);
      if (!fs.existsSync(p)) {
        p = p.replace(/\.js$/, '.ts');
      }
      bin[binName] = p;
    });

    const experimental = !!packageJson.private || !!packageJson.experimental;

    packages[name] = {
      build: path.join(distRoot, pkgRoot.substr(path.dirname(__dirname).length)),
      dist: path.join(distRoot, name),
      root: pkgRoot,
      relative: path.relative(path.dirname(__dirname), pkgRoot),
      main: path.resolve(pkgRoot, 'src/index.ts'),
      private: !!packageJson.private,
      experimental,
      // yarn doesn't take kindly to @ in tgz filenames
      // https://github.com/yarnpkg/yarn/issues/6339
      tar: path.join(distRoot, name.replace(/\/|@/g, '_') + '.tgz'),
      bin,
      name,
      packageJson,

      snapshot: !!monorepoPackages[name].snapshotRepo,
      snapshotRepo: monorepoPackages[name].snapshotRepo,
      get snapshotHash() {
        return _getSnapshotHash(this);
      },

      dependencies: [],
      reverseDependencies: [],
      version: experimental ? experimentalVersion : stableVersion,
    };

    return packages;
  }, {});

// Update with dependencies.
for (const pkgName of Object.keys(packages)) {
  const pkg = packages[pkgName];
  const pkgJson = require(path.join(pkg.root, 'package.json'));
  pkg.dependencies = Object.keys(packages).filter((name) => {
    return name in (pkgJson.dependencies || {}) || name in (pkgJson.devDependencies || {});
  });
  pkg.dependencies.forEach((depName) => packages[depName].reverseDependencies.push(pkgName));
}

/** The set of packages which are built and released. */
export const releasePackages = Object.fromEntries(
  Object.entries(packages).filter(([_, pkg]) => !pkg.private),
);