/**
 * Copyright 2019 Google Inc. All rights reserved.
 * Modifications copyright (c) Microsoft Corporation.
 *
 * 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.
 */

/* eslint-disable no-console */
import rimraf from 'rimraf';
import * as fs from 'fs';
import * as path from 'path';
import { promisify } from 'util';
import { Dispatcher } from './dispatcher';
import { createMatcher, FilePatternFilter, monotonicTime, raceAgainstDeadline } from './util';
import { TestCase, Suite } from './test';
import { Loader } from './loader';
import { Reporter } from '../../types/testReporter';
import { Multiplexer } from './reporters/multiplexer';
import DotReporter from './reporters/dot';
import LineReporter from './reporters/line';
import ListReporter from './reporters/list';
import JSONReporter from './reporters/json';
import JUnitReporter from './reporters/junit';
import EmptyReporter from './reporters/empty';
import { ProjectImpl } from './project';
import { Minimatch } from 'minimatch';
import { Config, FullConfig } from './types';
import { LaunchServers } from './launchServer';

const removeFolderAsync = promisify(rimraf);
const readDirAsync = promisify(fs.readdir);
const readFileAsync = promisify(fs.readFile);

type RunResultStatus = 'passed' | 'failed' | 'sigint' | 'forbid-only' | 'clashing-test-titles' | 'no-tests' | 'timedout';

type RunResult = {
  status: Exclude<RunResultStatus, 'forbid-only' | 'clashing-test-titles'>;
} | {
  status: 'forbid-only',
  locations: string[]
} | {
  status: 'clashing-test-titles',
  clashingTests: Map<string, TestCase[]>
};

export class Runner {
  private _loader: Loader;
  private _reporter!: Reporter;
  private _didBegin = false;

  constructor(defaultConfig: Config, configOverrides: Config) {
    this._loader = new Loader(defaultConfig, configOverrides);
  }

  private async _createReporter(list: boolean) {
    const reporters: Reporter[] = [];
    const defaultReporters: {[key in BuiltInReporter]: new(arg: any) => Reporter} = {
      dot: list ? ListModeReporter : DotReporter,
      line: list ? ListModeReporter : LineReporter,
      list: list ? ListModeReporter : ListReporter,
      json: JSONReporter,
      junit: JUnitReporter,
      null: EmptyReporter,
    };
    for (const r of this._loader.fullConfig().reporter) {
      const [name, arg] = r;
      if (name in defaultReporters) {
        reporters.push(new defaultReporters[name as keyof typeof defaultReporters](arg));
      } else {
        const reporterConstructor = await this._loader.loadReporter(name);
        reporters.push(new reporterConstructor(arg));
      }
    }
    return new Multiplexer(reporters);
  }

  loadConfigFile(file: string): Promise<Config> {
    return this._loader.loadConfigFile(file);
  }

  loadEmptyConfig(rootDir: string) {
    this._loader.loadEmptyConfig(rootDir);
  }

  async run(list: boolean, filePatternFilters: FilePatternFilter[], projectName?: string): Promise<RunResultStatus> {
    this._reporter = await this._createReporter(list);
    const config = this._loader.fullConfig();
    const globalDeadline = config.globalTimeout ? config.globalTimeout + monotonicTime() : undefined;
    const { result, timedOut } = await raceAgainstDeadline(this._run(list, filePatternFilters, projectName), globalDeadline);
    if (timedOut) {
      if (!this._didBegin)
        this._reporter.onBegin?.(config, new Suite(''));
      await this._reporter.onEnd?.({ status: 'timedout' });
      await this._flushOutput();
      return 'failed';
    }
    if (result?.status === 'forbid-only') {
      console.error('=====================================');
      console.error(' --forbid-only found a focused test.');
      for (const location of result?.locations)
        console.error(` - ${location}`);
      console.error('=====================================');
    } else if (result!.status === 'no-tests') {
      console.error('=================');
      console.error(' no tests found.');
      console.error('=================');
    } else if (result?.status === 'clashing-test-titles') {
      console.error('=================');
      console.error(' duplicate test titles are not allowed.');
      for (const [title, tests] of result?.clashingTests.entries()) {
        console.error(` - title: ${title}`);
        for (const test of tests)
          console.error(`   - ${buildItemLocation(config.rootDir, test)}`);
        console.error('=================');
      }
    }
    await this._flushOutput();
    return result!.status!;
  }

  async _flushOutput() {
    // Calling process.exit() might truncate large stdout/stderr output.
    // See https://github.com/nodejs/node/issues/6456.
    // See https://github.com/nodejs/node/issues/12921
    await new Promise<void>(resolve => process.stdout.write('', () => resolve()));
    await new Promise<void>(resolve => process.stderr.write('', () => resolve()));
  }

  async _run(list: boolean, testFileReFilters: FilePatternFilter[], projectName?: string): Promise<RunResult> {
    const testFileFilter = testFileReFilters.length ? createMatcher(testFileReFilters.map(e => e.re)) : () => true;
    const config = this._loader.fullConfig();

    const projects = this._loader.projects().filter(project => {
      return !projectName || project.config.name.toLocaleLowerCase() === projectName.toLocaleLowerCase();
    });
    if (projectName && !projects.length) {
      const names = this._loader.projects().map(p => p.config.name).filter(name => !!name);
      if (!names.length)
        throw new Error(`No named projects are specified in the configuration file`);
      throw new Error(`Project "${projectName}" not found. Available named projects: ${names.map(name => `"${name}"`).join(', ')}`);
    }

    const files = new Map<ProjectImpl, string[]>();
    const allTestFiles = new Set<string>();
    for (const project of projects) {
      const testDir = project.config.testDir;
      if (!fs.existsSync(testDir))
        throw new Error(`${testDir} does not exist`);
      if (!fs.statSync(testDir).isDirectory())
        throw new Error(`${testDir} is not a directory`);
      const allFiles = await collectFiles(project.config.testDir);
      const testMatch = createMatcher(project.config.testMatch);
      const testIgnore = createMatcher(project.config.testIgnore);
      const testFileExtension = (file: string) => ['.js', '.ts', '.mjs'].includes(path.extname(file));
      const testFiles = allFiles.filter(file => !testIgnore(file) && testMatch(file) && testFileFilter(file) && testFileExtension(file));
      files.set(project, testFiles);
      testFiles.forEach(file => allTestFiles.add(file));
    }

    const launchServers = await LaunchServers.create(config.launch);
    let globalSetupResult: any;
    if (config.globalSetup)
      globalSetupResult = await (await this._loader.loadGlobalHook(config.globalSetup, 'globalSetup'))(this._loader.fullConfig());
    try {
      for (const file of allTestFiles)
        await this._loader.loadTestFile(file);

      const preprocessRoot = new Suite('');
      for (const fileSuite of this._loader.fileSuites().values())
        preprocessRoot._addSuite(fileSuite);
      if (config.forbidOnly) {
        const onlyTestsAndSuites = preprocessRoot._getOnlyItems();
        if (onlyTestsAndSuites.length > 0) {
          const locations = onlyTestsAndSuites.map(testOrSuite => {
            // Skip root and file.
            const title = testOrSuite.titlePath().slice(2).join(' ');
            return `${buildItemLocation(config.rootDir, testOrSuite)} > ${title}`;
          });
          return { status: 'forbid-only', locations };
        }
      }
      const clashingTests = getClashingTestsPerSuite(preprocessRoot);
      if (clashingTests.size > 0)
        return { status: 'clashing-test-titles', clashingTests: clashingTests };
      filterOnly(preprocessRoot);
      filterByFocusedLine(preprocessRoot, testFileReFilters);

      const fileSuites = new Map<string, Suite>();
      for (const fileSuite of preprocessRoot.suites)
        fileSuites.set(fileSuite._requireFile, fileSuite);

      const outputDirs = new Set<string>();
      const grepMatcher = createMatcher(config.grep);
      const grepInvertMatcher = config.grepInvert ? createMatcher(config.grepInvert) : null;
      const rootSuite = new Suite('');
      for (const project of projects) {
        const projectSuite = new Suite(project.config.name);
        rootSuite._addSuite(projectSuite);
        for (const file of files.get(project)!) {
          const fileSuite = fileSuites.get(file);
          if (!fileSuite)
            continue;
          for (let repeatEachIndex = 0; repeatEachIndex < project.config.repeatEach; repeatEachIndex++) {
            const cloned = project.cloneFileSuite(fileSuite, repeatEachIndex, test => {
              const grepTitle = test.titlePath().join(' ');
              if (grepInvertMatcher?.(grepTitle))
                return false;
              return grepMatcher(grepTitle);
            });
            if (cloned)
              projectSuite._addSuite(cloned);
          }
        }
        outputDirs.add(project.config.outputDir);
      }

      const total = rootSuite.allTests().length;
      if (!total)
        return { status: 'no-tests' };

      await Promise.all(Array.from(outputDirs).map(outputDir => removeFolderAsync(outputDir).catch(e => {})));

      let sigint = false;
      let sigintCallback: () => void;
      const sigIntPromise = new Promise<void>(f => sigintCallback = f);
      const sigintHandler = () => {
        // We remove handler so that double Ctrl+C immediately kills the runner,
        // for the case where our shutdown takes a lot of time or is buggy.
        // Removing the handler synchronously sometimes triggers the default handler
        // that exits the process, so we remove asynchronously.
        setTimeout(() => process.off('SIGINT', sigintHandler), 0);
        sigint = true;
        sigintCallback();
      };
      process.on('SIGINT', sigintHandler);

      if (process.stdout.isTTY) {
        const workers = new Set();
        rootSuite.allTests().forEach(test => {
          workers.add(test._requireFile + test._workerHash);
        });
        console.log();
        const jobs = Math.min(config.workers, workers.size);
        const shard = config.shard;
        const shardDetails = shard ? `, shard ${shard.current + 1} of ${shard.total}` : '';
        console.log(`Running ${total} test${total > 1 ? 's' : ''} using ${jobs} worker${jobs > 1 ? 's' : ''}${shardDetails}`);
      }

      this._reporter.onBegin?.(config, rootSuite);
      this._didBegin = true;
      let hasWorkerErrors = false;
      if (!list) {
        const dispatcher = new Dispatcher(this._loader, rootSuite, this._reporter);
        await Promise.race([dispatcher.run(), sigIntPromise]);
        await dispatcher.stop();
        hasWorkerErrors = dispatcher.hasWorkerErrors();
      }

      if (sigint) {
        await this._reporter.onEnd?.({ status: 'interrupted' });
        return { status: 'sigint' };
      }

      const failed = hasWorkerErrors || rootSuite.allTests().some(test => !test.ok());
      await this._reporter.onEnd?.({ status: failed ? 'failed' : 'passed' });
      return { status: failed ? 'failed' : 'passed' };
    } finally {
      if (globalSetupResult && typeof globalSetupResult === 'function')
        await globalSetupResult(this._loader.fullConfig());
      if (config.globalTeardown)
        await (await this._loader.loadGlobalHook(config.globalTeardown, 'globalTeardown'))(this._loader.fullConfig());
      await launchServers.killAll();
    }
  }
}

function filterOnly(suite: Suite) {
  const suiteFilter = (suite: Suite) => suite._only;
  const testFilter = (test: TestCase) => test._only;
  return filterSuite(suite, suiteFilter, testFilter);
}

function filterByFocusedLine(suite: Suite, focusedTestFileLines: FilePatternFilter[]) {
  const testFileLineMatches = (testFileName: string, testLine: number) => focusedTestFileLines.some(({re, line}) => {
    re.lastIndex = 0;
    return re.test(testFileName) && (line === testLine || line === null);
  });
  const suiteFilter = (suite: Suite) => !!suite.location && testFileLineMatches(suite.location.file, suite.location.line);
  const testFilter = (test: TestCase) => testFileLineMatches(test.location.file, test.location.line);
  return filterSuite(suite, suiteFilter, testFilter);
}

function filterSuite(suite: Suite, suiteFilter: (suites: Suite) => boolean, testFilter: (test: TestCase) => boolean) {
  const onlySuites = suite.suites.filter(child => filterSuite(child, suiteFilter, testFilter) || suiteFilter(child));
  const onlyTests = suite.tests.filter(testFilter);
  const onlyEntries = new Set([...onlySuites, ...onlyTests]);
  if (onlyEntries.size) {
    suite.suites = onlySuites;
    suite.tests = onlyTests;
    suite._entries = suite._entries.filter(e => onlyEntries.has(e)); // Preserve the order.
    return true;
  }
  return false;
}

async function collectFiles(testDir: string): Promise<string[]> {
  type Rule = {
    dir: string;
    negate: boolean;
    match: (s: string, partial?: boolean) => boolean
  };
  type IgnoreStatus = 'ignored' | 'included' | 'ignored-but-recurse';

  const checkIgnores = (entryPath: string, rules: Rule[], isDirectory: boolean, parentStatus: IgnoreStatus) => {
    let status = parentStatus;
    for (const rule of rules) {
      const ruleIncludes = rule.negate;
      if ((status === 'included') === ruleIncludes)
        continue;
      const relative = path.relative(rule.dir, entryPath);
      if (rule.match('/' + relative) || rule.match(relative)) {
        // Matches "/dir/file" or "dir/file"
        status = ruleIncludes ? 'included' : 'ignored';
      } else if (isDirectory && (rule.match('/' + relative + '/') || rule.match(relative + '/'))) {
        // Matches "/dir/subdir/" or "dir/subdir/" for directories.
        status = ruleIncludes ? 'included' : 'ignored';
      } else if (isDirectory && ruleIncludes && (rule.match('/' + relative, true) || rule.match(relative, true))) {
        // Matches "/dir/donotskip/" when "/dir" is excluded, but "!/dir/donotskip/file" is included.
        status = 'ignored-but-recurse';
      }
    }
    return status;
  };

  const files: string[] = [];

  const visit = async (dir: string, rules: Rule[], status: IgnoreStatus) => {
    const entries = await readDirAsync(dir, { withFileTypes: true });
    entries.sort((a, b) => a.name.localeCompare(b.name));

    const gitignore = entries.find(e => e.isFile() && e.name === '.gitignore');
    if (gitignore) {
      const content = await readFileAsync(path.join(dir, gitignore.name), 'utf8');
      const newRules: Rule[] = content.split(/\r?\n/).map(s => {
        s = s.trim();
        if (!s)
          return;
        // Use flipNegate, because we handle negation ourselves.
        const rule = new Minimatch(s, { matchBase: true, dot: true, flipNegate: true }) as any;
        if (rule.comment)
          return;
        rule.dir = dir;
        return rule;
      }).filter(rule => !!rule);
      rules = [...rules, ...newRules];
    }

    for (const entry of entries) {
      if (entry === gitignore || entry.name === '.' || entry.name === '..')
        continue;
      if (entry.isDirectory() && entry.name === 'node_modules')
        continue;
      const entryPath = path.join(dir, entry.name);
      const entryStatus = checkIgnores(entryPath, rules, entry.isDirectory(), status);
      if (entry.isDirectory() && entryStatus !== 'ignored')
        await visit(entryPath, rules, entryStatus);
      else if (entry.isFile() && entryStatus === 'included')
        files.push(entryPath);
    }
  };
  await visit(testDir, [], 'included');
  return files;
}

function getClashingTestsPerSuite(rootSuite: Suite): Map<string, TestCase[]> {
  function visit(suite: Suite, clashingTests: Map<string, TestCase[]>) {
    for (const childSuite of suite.suites)
      visit(childSuite, clashingTests);
    for (const test of suite.tests) {
      const fullTitle = test.titlePath().slice(2).join(' ');
      if (!clashingTests.has(fullTitle))
        clashingTests.set(fullTitle, []);
      clashingTests.set(fullTitle, clashingTests.get(fullTitle)!.concat(test));
    }
  }
  const out = new Map<string, TestCase[]>();
  for (const fileSuite of rootSuite.suites) {
    const clashingTests = new Map<string, TestCase[]>();
    visit(fileSuite, clashingTests);
    for (const [title, tests] of clashingTests.entries()) {
      if (tests.length > 1)
        out.set(title, tests);
    }
  }
  return out;
}

function buildItemLocation(rootDir: string, testOrSuite: Suite | TestCase) {
  if (!testOrSuite.location)
    return '';
  return `${path.relative(rootDir, testOrSuite.location.file)}:${testOrSuite.location.line}`;
}

class ListModeReporter implements Reporter {
  onBegin(config: FullConfig, suite: Suite): void {
    console.log(`Listing tests:`);
    const tests = suite.allTests();
    const files = new Set<string>();
    for (const test of tests) {
      // root, project, file, ...describes, test
      const [, projectName, , ...titles] = test.titlePath();
      const location = `${path.relative(config.rootDir, test.location.file)}:${test.location.line}:${test.location.column}`;
      const projectTitle = projectName ? `[${projectName}] › ` : '';
      console.log(`  ${projectTitle}${location} › ${titles.join(' ')}`);
      files.add(test.location.file);
    }
    console.log(`Total: ${tests.length} ${tests.length === 1 ? 'test' : 'tests'} in ${files.size} ${files.size === 1 ? 'file' : 'files'}`);
  }
}

export const builtInReporters = ['list', 'line', 'dot', 'json', 'junit', 'null'] as const;
export type BuiltInReporter = typeof builtInReporters[number];