nycJSorg/angular-presentation

import { Injectable } from '@angular/core';
import { FileConfig } from '../../../../../apps/codelab/src/app/shared/interfaces/file-config';
import { simpleVisitor } from './visitor';
import { getTypeScript } from '@codelab/utils/src/lib/loaders/loaders';

const ts = getTypeScript();

@Injectable({
  providedIn: 'root'
})
export class DepsService {
  constructor() {}

  // TODO(kirjs): Retire this
  /**
   * Takes a file path, and another path relative to the first one.
   * Returns the fulle
   */
  static normalizePathRelativeToFile(path: string, file: string) {
    // TODO: Simplify
    let fullPath = '/' + path.substr(0, path.lastIndexOf('/')) + '/' + file;
    while (fullPath.match(/\/[^/]*\/\.\./)) {
      fullPath = fullPath.replace(/\/[^/]*\/\.\./, '');
    }
    fullPath = fullPath.replace(/\/.\//, '/');
    return fullPath.replace(/^\//, '').replace(/^\//, '');
  }

  static isLocalDep(string) {
    return !string.match(/\/code\b/) && !!string.match(/^\./);
  }

  order(files: Array<FileConfig>) {
    let deps: { [key: string]: string } = files.reduce((result, file) => {
      result[file.path] = { file, deps: [] };
      const source = ts.createSourceFile(
        file.path,
        file.code,
        ts.ScriptTarget.ES5
      );
      simpleVisitor(
        source,
        node => node.kind === ts.SyntaxKind.ImportDeclaration,
        (node: any) => {
          if (DepsService.isLocalDep(node.moduleSpecifier.text)) {
            result[file.path].deps.push(
              DepsService.normalizePathRelativeToFile(
                file.path,
                node.moduleSpecifier.text + '.ts'
              )
            );
          }
        }
      );
      return result;
    }, {});

    let orderedFiles = [];

    while (Object.keys(deps).length > 0) {
      const keys = Object.keys(deps);
      const depLen = keys.length;

      // Iterate over deps, grab each file with no dependencies, and add it to the list. Repeat.
      [deps, orderedFiles] = keys.reduce(
        (
          [result, orderedFiles_]: any,
          key
        ): [{ [key: string]: string }, Array<FileConfig>] => {
          if (result[key].deps.length === 0) {
            orderedFiles_.push(result[key].file);

            Object.keys(result).forEach(key_ => {
              result[key_].deps = result[key_].deps.filter(dep => dep !== key);
            });

            delete deps[key];
          }

          return [result, orderedFiles_];
        },
        [deps, orderedFiles]
      );

      if (depLen === Object.keys(deps).length) {
        throw new Error('cyclic dependencies found, or missing dependencies');
      }
    }

    return orderedFiles;
  }
}