/*
 * Copyright 2017 The Kythe Authors. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// This program runs the Kythe verifier on test cases in the testdata/
// directory.  It's written in TypeScript (rather than a plain shell
// script) so it can reuse TypeScript data structures across test cases,
// speeding up the test.
//
// If run with no arguments, runs all tests found in testdata/.
// Otherwise run any files through the verifier by passing them:
//   node test.js path/to/test1.ts testdata/test2.ts

import * as assert from 'assert';
import * as child_process from 'child_process';
import * as fs from 'fs';
import * as path from 'path';
import * as ts from 'typescript';

import * as indexer from './indexer';

const KYTHE_PATH = process.env['KYTHE'] || '/opt/kythe';
const RUNFILES = process.env['RUNFILES_DIR'];

const ENTRYSTREAM = RUNFILES ?
    path.resolve('kythe/go/platform/tools/entrystream/entrystream') :
    path.resolve(KYTHE_PATH, 'tools/entrystream');
const VERIFIER = RUNFILES ? path.resolve('kythe/cxx/verifier/verifier') :
                            path.resolve(KYTHE_PATH, 'tools/verifier');

/**
 * createTestCompilerHost creates a ts.CompilerHost that caches its default
 * library.  This prevents re-parsing the (big) TypeScript standard library
 * across each test.
 */
function createTestCompilerHost(options: ts.CompilerOptions): ts.CompilerHost {
  const compilerHost = ts.createCompilerHost(options);

  const libPath = compilerHost.getDefaultLibFileName(options);
  const libSource =
      compilerHost.getSourceFile(libPath, ts.ScriptTarget.ES2015)!;

  const hostGetSourceFile = compilerHost.getSourceFile;
  compilerHost.getSourceFile =
      (fileName: string, languageVersion: ts.ScriptTarget,
       onError?: (message: string) => void): ts.SourceFile|undefined => {
        if (fileName === libPath) return libSource;
        return hostGetSourceFile(fileName, languageVersion, onError);
      };
  return compilerHost;
}

/**
 * verify runs the indexer against a test case and passes it through the
 * Kythe verifier.  It returns a Promise because the node subprocess API must
 * be run async; if there's an error, it will reject the promise.
 */
function verify(
    host: ts.CompilerHost, options: ts.CompilerOptions, test: string,
    plugins?: indexer.Plugin[]): Promise<void> {
  const compilationUnit: indexer.VName = {
    corpus: 'testcorpus',
    root: '',
    path: '',
    signature: '',
    language: '',
  };
  const program = ts.createProgram([test], options, host);

  const verifier = child_process.spawn(
      `${ENTRYSTREAM} --read_format=json | ${VERIFIER} ${test}`, [], {
        stdio: ['pipe', process.stdout, process.stderr],
        shell: true,
      });

  indexer.index(compilationUnit, new Map(), [test], program, (obj: {}) => {
    verifier.stdin.write(JSON.stringify(obj) + '\n');
  }, plugins);
  verifier.stdin.end();

  return new Promise<void>((resolve, reject) => {
    verifier.on('close', (exitCode) => {
      if (exitCode === 0) {
        resolve();
      } else {
        reject(`process exited with code ${exitCode}`);
      }
    });
  });
}

function testLoadTsConfig() {
  const config =
      indexer.loadTsConfig('testdata/tsconfig-files.json', 'testdata');
  // We expect the paths that were loaded to be absolute.
  assert.deepEqual(config.fileNames, [path.resolve('testdata/alt.ts')]);
}

async function testIndexer(args: string[], plugins?: indexer.Plugin[]) {
  const config = indexer.loadTsConfig('testdata/tsconfig.json', 'testdata');
  let testPaths = args.map(arg => path.resolve(arg));
  if (args.length === 0) {
    // If no tests were passed on the command line, run all the .ts files found
    // by the tsconfig.json, which covers all the tests in testdata/.
    testPaths = config.fileNames;
  }

  const host = createTestCompilerHost(config.options);
  for (const test of testPaths) {
    const testName = path.relative(config.options.rootDir!, test);
    const start = new Date().valueOf();
    process.stdout.write(`${testName}: `);
    try {
      await verify(host, config.options, test, plugins);
    } catch (e) {
      console.log('FAIL');
      throw e;
    }
    const time = new Date().valueOf() - start;
    console.log('PASS', time + 'ms');
  }
  return 0;
}

async function testPlugin() {
  const plugin: indexer.Plugin = {
    name: 'TestPlugin',
    index(
        pathToVName: (path: string) => indexer.VName, paths: string[],
        program: ts.Program, emit?: (obj: {}) => void) {
      for (const testPath of paths) {
        const relPath = path.relative(
                                program.getCompilerOptions().rootDir!,
                                program.getSourceFile(testPath)!.fileName)
                            .replace(/\.(d\.)?ts$/, '');

        const pluginMod = {
          ...pathToVName(relPath),
          signature: 'plugin-module',
          language: 'plugin-language',
        };
        emit!({
          source: pluginMod,
          fact_name: '/kythe/node/pluginKind',
          fact_value: Buffer.from('pluginRecord').toString('base64'),
        });
      }
    },
  };
  return testIndexer(['testdata/plugin.ts'], [plugin]);
}

async function testMain(args: string[]) {
  if (RUNFILES) {
    process.chdir('kythe/typescript');
  }
  testLoadTsConfig();
  await testIndexer(args);
  await testPlugin();
}

testMain(process.argv.slice(2))
    .then(() => {
      process.exitCode = 0;
    })
    .catch((e) => {
      console.error(e);
      process.exitCode = 1;
    });