/**
 * @license
 * Copyright Google Inc. 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 {join} from 'path';
import * as ts from 'typescript/lib/tsserverlibrary';

const logger: ts.server.Logger = {
  close(): void{},
  hasLevel(level: ts.server.LogLevel): boolean {
    return false;
  },
  loggingEnabled(): boolean {
    return false;
  },
  perftrc(s: string): void{},
  info(s: string): void{},
  startGroup(): void{},
  endGroup(): void{},
  msg(s: string, type?: ts.server.Msg): void{},
  getLogFileName(): string |
      undefined {
        return;
      },
};

export const TEST_SRCDIR = process.env.TEST_SRCDIR!;
export const PROJECT_DIR =
    join(TEST_SRCDIR, 'angular', 'packages', 'language-service', 'test', 'project');
export const TSCONFIG = join(PROJECT_DIR, 'tsconfig.json');
export const APP_COMPONENT = join(PROJECT_DIR, 'app', 'app.component.ts');
export const APP_MAIN = join(PROJECT_DIR, 'app', 'main.ts');
export const PARSING_CASES = join(PROJECT_DIR, 'app', 'parsing-cases.ts');

export const host: ts.server.ServerHost = {
  ...ts.sys,
  readFile(absPath: string, encoding?: string): string |
      undefined {
        // TODO: Need to remove all annotations in templates like we do in
        // MockTypescriptHost
        return ts.sys.readFile(absPath, encoding);
      },
  // TODO: Need to cast as never because this is not a proper ServerHost interface.
  // ts.sys lacks methods like watchFile() and watchDirectory(), but these are not
  // needed for now.
} as never;

/**
 * Create a ConfiguredProject and an actual program for the test project located
 * in packages/language-service/test/project. Project creation exercises the
 * actual code path, but a mock host is used for the filesystem to intercept
 * and modify test files.
 */
export function setup() {
  const projectService = new ts.server.ProjectService({
    host,
    logger,
    cancellationToken: ts.server.nullCancellationToken,
    useSingleInferredProject: true,
    useInferredProjectPerProjectRoot: true,
    typingsInstaller: ts.server.nullTypingsInstaller,
  });
  // Opening APP_COMPONENT forces a new ConfiguredProject to be created based
  // on the tsconfig.json in the test project.
  projectService.openClientFile(APP_COMPONENT);
  const project = projectService.findProject(TSCONFIG);
  if (!project) {
    throw new Error(`Failed to create project for ${TSCONFIG}`);
  }
  // The following operation forces a ts.Program to be created.
  const tsLS = project.getLanguageService();
  return {projectService, project, tsLS};
}