// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef ZXTEST_BASE_RUNNER_H_
#define ZXTEST_BASE_RUNNER_H_

#include <lib/stdcompat/span.h>
#include <lib/stdcompat/string_view.h>

#include <atomic>
#include <cstdio>

#include <fbl/string.h>
#include <fbl/vector.h>
#include <zxtest/base/assertion.h>
#include <zxtest/base/environment.h>
#include <zxtest/base/event-broadcaster.h>
#include <zxtest/base/log-sink.h>
#include <zxtest/base/observer.h>
#include <zxtest/base/parameterized-value.h>
#include <zxtest/base/reporter.h>
#include <zxtest/base/test-case.h>
#include <zxtest/base/test-driver.h>
#include <zxtest/base/test-info.h>

namespace zxtest {

// Prefix used to prevent a test from executing, without explicitly requesting disabled test to run.
static constexpr cpp17::string_view kDisabledTestPrefix = "DISABLED_";

namespace internal {

// Test Driver implementation for the runner. Observes lifecycle events to
// reset the test state correctly.
class TestDriverImpl final : public TestDriver, public LifecycleObserver {
 public:
  TestDriverImpl();
  ~TestDriverImpl() final;

  // Called when a test is skipped.
  void Skip() final;

  // Return true if the test has been skipped.
  bool IsSkipped() const { return status_ == TestStatus::kSkipped; }

  // Return true if the is allowed to continue execution.
  bool Continue() const final;

  // Returns the status of the current test.
  TestStatus Status() const final { return status_; }

  // Reports before every test starts.
  void OnTestStart(const TestCase& test_case, const TestInfo& test) final;

  // Reports when current test assert condition fails. May be called
  // concurrently from multiple threads.
  void OnAssertion(const Assertion& assertion) final;

  // Reports after a test execution was skipped.
  void OnTestSkip(const TestCase& test_case, const TestInfo& test) final;

  // Reports after test execution completed with failures.
  void OnTestFailure(const TestCase& test_case, const TestInfo& test) final;

  // Reports after test execution completed with no failures.
  void OnTestSuccess(const TestCase& test_case, const TestInfo& test) final;

  // Resets the states for running new tests.
  void Reset();

  // Returns whether the current test has any failures so far. May be
  // called concurrently from multiple threads.
  bool CurrentTestHasAnyFailures() const { return current_test_has_any_failures_; }

  // Returns whether any test driven by this instance had any test failure.
  // This is not cleared on |TestDriverImpl::Reset|.
  bool HadAnyFailures() const { return had_any_failures_; }

  // Control whether calls to OnAssertion do anything.
  void EnableAsserts() { asserts_enabled_ = true; }
  void DisableAsserts() { asserts_enabled_ = false; }

 private:
  std::atomic<TestStatus> status_ = TestStatus::kFailed;

  std::atomic<bool> current_test_has_any_failures_ = false;
  std::atomic<bool> current_test_has_fatal_failures_ = false;

  std::atomic<bool> had_any_failures_ = false;

  bool asserts_enabled_ = true;
};
}  // namespace internal

// Struct used to safely reference a registered test. This is not affected
// by vector growth.
struct TestRef {
  size_t test_case_index = 0;
  size_t test_index = 0;
};

// Returns the amount of registered and active test and testcases.
struct RunnerSummary {
  // Number of iterations to run.
  size_t total_iterations = 1;
  // Number of registered tests that match a filter.
  size_t active_test_count = 0;
  // Number of registered test cases that match a filter.
  size_t active_test_case_count = 0;
  // Number of registered tests.
  size_t registered_test_count = 0;
  // Number of registered test cases.
  size_t registered_test_case_count = 0;
};

// Holds the pattern used for filtering.
struct FilterOp {
  // Returns true if the test_case and test matches |pattern|.
  bool operator()(const fbl::String& test_case, const fbl::String& test) const;

  fbl::String pattern;
  bool run_disabled = false;
};

// This class is the entry point for test and constructs registration.
class Runner {
 public:
  struct Options {
    // Parses the contents of argv into |Options|.
    static Options FromArgs(int argc, char** argv, fbl::Vector<fbl::String>* errors);

    // Prints the usage message into the |stream|.
    static void Usage(char* bin, LogSink* sink);

    // Pattern for filtering tests. Empty pattern matches all.
    fbl::String filter;

    // Seed used for random decisions.
    int seed = 0;

    // Number of iterations to run.
    int repeat = 1;

    // When set test order within a test case are randomized.
    bool shuffle = true;

    // When set prints the help message.
    bool help = false;

    // When set list all registered tests.
    bool list = false;

    // When set, disabled tests will be executed.
    bool run_disabled = false;

    // Whether the test suite should stop running upon encountering the first fatal failure.
    bool break_on_failure = false;
  };

  // Default Runner options.
  static const Options kDefaultOptions;

  // Returns process shared |Runner| instance.
  static Runner* GetInstance();

  Runner() = delete;
  explicit Runner(Reporter&& reporter);
  Runner(const Runner&) = delete;
  Runner(Runner&&) = delete;
  virtual ~Runner();

  Runner& operator=(const Runner&) = delete;
  Runner& operator=(Runner&&) = delete;

  // Register a test for execution with the default factory.
  template <typename TestBase, typename TestImpl>
  TestRef RegisterTest(const fbl::String& test_case_name, const fbl::String& test_name,
                       const char* filename, int line) {
    return RegisterTest<TestBase, TestImpl>(test_case_name, test_name, filename, line,
                                            &Test::Create<TestImpl>);
  }

  // Register a test for execution with a customized factory.
  template <typename TestBase, typename TestImpl>
  TestRef RegisterTest(const fbl::String& test_case_name, const fbl::String& test_name,
                       const char* filename, int line, internal::TestFactory factory) {
    static_assert(std::is_base_of<Test, TestImpl>::value, "Must inherit from Test");
    SourceLocation location = {.filename = filename, .line_number = line};
    return RegisterTest(test_case_name, test_name, location, std::move(factory),
                        internal::Accessor<TestBase>::SetUpTestSuite(),
                        internal::Accessor<TestBase>::TearDownTestSuite());
  }

  template <typename SuiteClass>
  bool AddParameterizedTest(std::unique_ptr<internal::AddTestDelegate> delegate,
                            const fbl::String& suite_name, const fbl::String& test_name,
                            const SourceLocation& location) {
    std::unique_ptr<internal::ParameterizedTestCaseInfo> new_suite =
        delegate->CreateSuite(suite_name);
    auto target_suite = new_suite.get();

    auto fixture_id = internal::TypeIdProvider<SuiteClass>::Get();
    for (auto& test_info : parameterized_test_info_) {
      if (test_info->GetFixtureId() == fixture_id) {
        // found existing entry
        target_suite = test_info.get();
      }
    }
    ZX_ASSERT_MSG(delegate->AddTest(target_suite, test_name, location), "Failed to add a test");
    if (target_suite == new_suite.get()) {
      parameterized_test_info_.push_back(std::move(new_suite));
    }
    return true;
  }

  template <typename SuiteClass, typename ParamType>
  bool AddInstantiation(std::unique_ptr<internal::AddInstantiationDelegate<ParamType>> delegate,
                        const fbl::String& instantiation_name, const SourceLocation& location,
                        zxtest::internal::ValueProvider<ParamType>& provider,
                        std::function<std::string(zxtest::TestParamInfo<ParamType>)> name_fn) {
    auto fixture_id = internal::TypeIdProvider<SuiteClass>::Get();
    bool found_match = false;
    for (auto& test_info : parameterized_test_info_) {
      if (test_info->GetFixtureId() == fixture_id) {
        // found existing entry
        auto* suite = test_info.get();
        found_match = true;
        ZX_ASSERT_MSG(
            delegate->AddInstantiation(suite, instantiation_name, location, provider, name_fn),
            "Failed to add instantiation.");
      }
    }
    ZX_ASSERT_MSG(found_match, "Failed to find a test suite to add an instantiation.");
    return true;
  }

  // Runs the registered tests with the specified |options|.
  int Run(const Options& options);

  // List tests according to options.
  void List(const Options& options);

  const RunnerSummary& summary() const { return summary_; }

  const TestInfo& GetTestInfo(const TestRef& test_ref) {
    return test_cases_[test_ref.test_case_index].GetTestInfo(test_ref.test_index);
  }

  // Adds an environment to be set up and tear down for each iteration.
  void AddGlobalTestEnvironment(std::unique_ptr<Environment> environment) {
    environments_.push_back(std::move(environment));
  }

  // Provides an entry point for assertions. The runner will propagate the assertion to the
  // interested parties. This is needed in a global scope, because helper methods do not have
  // access to a |Test| instance and legacy tests are not part of a Fixture, but wrapped by one.
  // If this is called without any test running, it will have no effect.
  void NotifyAssertion(const Assertion& assertion);

  // Tells the runner to skip the current test.  The runner will propagate the message to
  // interested parties.  See NotifyAssertion above for more explanation as to why this is in
  // global scope.
  void SkipCurrent(const Message& message);

  // Returns true if the current test is skipped.
  bool IsSkipped() const { return test_driver_.IsSkipped(); }

  // Returns true if the current test should be aborted. This happens as a result of a fatal
  // failure.
  bool CurrentTestHasFatalFailures() const { return !test_driver_.Continue(); }

  // Returns whether the current test has experienced any type of failure.
  bool CurrentTestHasFailures() const { return test_driver_.CurrentTestHasAnyFailures(); }

  int random_seed() const { return options_ ? options_->seed : kDefaultOptions.seed; }

  void AddObserver(LifecycleObserver* observer) { event_broadcaster_.Subscribe(observer); }

  // Set of options currently in use. By default |Runner::kDefaultOptions| will be returned.
  const Options& options() const { return options_ ? *options_ : kDefaultOptions; }

  // Notify the runner that the test is in a bad state, and should attempt to exit. This means
  // end test execution.
  void NotifyFatalError() { fatal_error_ = true; }

  // Returns a pointer to the |LogSink| where the |reporter_| is running to.
  Reporter* mutable_reporter() { return &reporter_; }

  // Returns true if the runner is currently executing tests.
  bool IsRunning() const { return is_running_; }

  void EnableAsserts() { return test_driver_.EnableAsserts(); }
  void DisableAsserts() { return test_driver_.DisableAsserts(); }

  void PushTrace(zxtest::Message* trace) { scoped_traces_.push_back(trace); }

  void PopTrace() { scoped_traces_.pop_back(); }

  cpp20::span<zxtest::Message*> GetScopedTraces() { return scoped_traces_; }

 private:
  friend class RunnerTestPeer;

  TestRef RegisterTest(const fbl::String& test_case_name, const fbl::String& test_name,
                       const SourceLocation& location, internal::TestFactory factory,
                       internal::SetUpTestCaseFn set_up, internal::TearDownTestCaseFn tear_down);

  virtual void RegisterParameterizedTests() final {
    if (should_register_parameterized_tests) {
      for (auto& test : parameterized_test_info_) {
        test->RegisterTest(this);
      }
      should_register_parameterized_tests = false;
    }
  }

  void EnforceOptions(const Runner::Options& options);

  // List of registered environments.
  fbl::Vector<std::unique_ptr<Environment>> environments_;

  // List of registered test cases.
  fbl::Vector<TestCase> test_cases_;

  // Store the traces coming from the SCOPED_TRACE() macro.
  std::vector<zxtest::Message*> scoped_traces_;

  // Serves as a |LifecycleObserver| list where events are sent to all subscribed observers.
  internal::EventBroadcaster event_broadcaster_;

  // Driver owned by the |Runner| instance, which drives tests registered for execution
  // with the given instance. We need at the |Runner| level, to reduce the amount of piping
  // and exposure of the internal classes, so we can propagate errors in Helper methods
  // or those that are not within a Fixture scope.
  internal::TestDriverImpl test_driver_;

  // Provides human readable output.
  Reporter reporter_;

  // Runner information.
  RunnerSummary summary_;

  // Sets of options to use for |Runner::Run| or |Runner::List|.
  const Options* options_ = nullptr;

  bool fatal_error_ = false;

  fbl::Vector<std::unique_ptr<zxtest::internal::ParameterizedTestCaseInfo>>
      parameterized_test_info_;

  bool should_register_parameterized_tests = true;

  bool is_running_ = false;
};

// Entry point for C++
int RunAllTests(int argc, char** argv);

}  // namespace zxtest

#endif  // ZXTEST_BASE_RUNNER_H_