<?php

/**
 * Very basic unit test engine which runs libphutil tests.
 */
final class PhutilUnitTestEngine extends ArcanistUnitTestEngine {

  protected function supportsRunAllTests() {
    return true;
  }

  public function run() {
    if ($this->getRunAllTests()) {
      $run_tests = $this->getAllTests();
    } else {
      $run_tests = $this->getTestsForPaths();
    }

    if (!$run_tests) {
      throw new ArcanistNoEffectException('No tests to run.');
    }

    $enable_coverage = $this->getEnableCoverage();
    if ($enable_coverage !== false) {
      if (!function_exists('xdebug_start_code_coverage')) {
        if ($enable_coverage === true) {
          throw new ArcanistUsageException(
            pht(
              'You specified %s but xdebug is not available, so '.
              'coverage can not be enabled for %s.',
              '--coverage',
              __CLASS__));
        }
      } else {
        $enable_coverage = true;
      }
    }

    $project_root = $this->getWorkingCopy()->getProjectRoot();

    $test_cases = array();
    foreach ($run_tests as $test_class) {
      $test_case = newv($test_class, array());
      $test_case->setEnableCoverage($enable_coverage);
      $test_case->setWorkingCopy($this->getWorkingCopy());

      if ($this->getPaths()) {
        $test_case->setPaths($this->getPaths());
      }
      if ($this->renderer) {
        $test_case->setRenderer($this->renderer);
      }
      $test_cases[] = $test_case;
    }

    foreach ($test_cases as $test_case) {
      $test_case->willRunTestCases($test_cases);
    }

    $results = array();
    foreach ($test_cases as $test_case) {
      $results[] = $test_case->run();
    }
    $results = array_mergev($results);

    foreach ($test_cases as $test_case) {
      $test_case->didRunTestCases($test_cases);
    }

    return $results;
  }

  private function getAllTests() {
    $project_root = $this->getWorkingCopy()->getProjectRoot();

    $symbols = id(new PhutilSymbolLoader())
      ->setType('class')
      ->setAncestorClass('PhutilTestCase')
      ->setConcreteOnly(true)
      ->selectSymbolsWithoutLoading();

    $in_working_copy = array();

    $run_tests = array();
    foreach ($symbols as $symbol) {
      if (!preg_match('@(?:^|/)__tests__/@', $symbol['where'])) {
        continue;
      }

      $library = $symbol['library'];

      if (!isset($in_working_copy[$library])) {
        $library_root = phutil_get_library_root($library);
        $in_working_copy[$library] = Filesystem::isDescendant(
          $library_root,
          $project_root);
      }

      if ($in_working_copy[$library]) {
        $run_tests[] = $symbol['name'];
      }
    }

    return $run_tests;
  }

  private function getTestsForPaths() {
    $project_root = $this->getWorkingCopy()->getProjectRoot();

    $look_here = array();

    foreach ($this->getPaths() as $path) {
      $library_root = phutil_get_library_root_for_path($path);
      if (!$library_root) {
        continue;
      }
      $library_name = phutil_get_library_name_for_root($library_root);

      if (!$library_name) {
        throw new Exception(
          sprintf(
            "%s\n\n    %s\n\n%s\n\n    - %s\n    - %s\n",
            pht(
              'Attempting to run unit tests on a libphutil library '.
              'which has not been loaded, at:'),
            $library_root,
            pht('This probably means one of two things:'),
            pht(
              'You may need to add this library to %s.',
              '.arcconfig.'),
            pht(
              'You may be running tests on a copy of libphutil or '.
              'arcanist using a different copy of libphutil or arcanist. '.
              'This operation is not supported.')));
      }

      $path = Filesystem::resolvePath($path, $project_root);

      if (!is_dir($path)) {
        $path = dirname($path);
      }

      if ($path == $library_root) {
        $look_here[$library_name.':.'] = array(
          'library' => $library_name,
          'path'    => '',
        );
      } else if (!Filesystem::isDescendant($path, $library_root)) {
        // We have encountered some kind of symlink maze -- for instance, $path
        // is some symlink living outside the library that links into some file
        // inside the library. Just ignore these cases, since the affected file
        // does not actually lie within the library.
        continue;
      } else {
        $library_path = Filesystem::readablePath($path, $library_root);
        do {
          $look_here[$library_name.':'.$library_path] = array(
            'library' => $library_name,
            'path'    => $library_path,
          );
          $library_path = dirname($library_path);
        } while ($library_path != '.');
      }
    }

    // Look for any class that extends PhutilTestCase inside a `__tests__`
    // directory in any parent directory of every affected file.
    //
    // The idea is that "infrastructure/__tests__/" tests defines general tests
    // for all of "infrastructure/", and those tests run for any change in
    // "infrastructure/". However, "infrastructure/concrete/rebar/__tests__/"
    // defines more specific tests that run only when rebar/ (or some
    // subdirectory) changes.

    $run_tests = array();
    foreach ($look_here as $path_info) {
      $library = $path_info['library'];
      $path    = $path_info['path'];

      $symbols = id(new PhutilSymbolLoader())
        ->setType('class')
        ->setLibrary($library)
        ->setPathPrefix(($path ? $path.'/' : '').'__tests__/')
        ->setAncestorClass('PhutilTestCase')
        ->setConcreteOnly(true)
        ->selectAndLoadSymbols();

      foreach ($symbols as $symbol) {
        $run_tests[$symbol['name']] = true;
      }
    }
    $run_tests = array_keys($run_tests);

    return $run_tests;
  }

  public function shouldEchoTestResults() {
    return !$this->renderer;
  }

}