// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "extensions/renderer/module_system_test.h"

#include <map>
#include <string>

#include "base/callback.h"
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/lazy_instance.h"
#include "base/memory/scoped_ptr.h"
#include "base/path_service.h"
#include "base/strings/string_piece.h"
#include "extensions/common/extension_paths.h"
#include "extensions/renderer/logging_native_handler.h"
#include "extensions/renderer/object_backed_native_handler.h"
#include "extensions/renderer/safe_builtins.h"
#include "extensions/renderer/utils_native_handler.h"
#include "ui/base/resource/resource_bundle.h"

namespace extensions {
namespace {

class FailsOnException : public ModuleSystem::ExceptionHandler {
 public:
  FailsOnException() : ModuleSystem::ExceptionHandler(nullptr) {}
  void HandleUncaughtException(const v8::TryCatch& try_catch) override {
    FAIL() << "Uncaught exception: " << CreateExceptionString(try_catch);
  }
};

class V8ExtensionConfigurator {
 public:
  V8ExtensionConfigurator()
      : safe_builtins_(SafeBuiltins::CreateV8Extension()),
        names_(1, safe_builtins_->name()),
        configuration_(
            new v8::ExtensionConfiguration(static_cast<int>(names_.size()),
                                           names_.data())) {
    v8::RegisterExtension(safe_builtins_.get());
  }

  v8::ExtensionConfiguration* GetConfiguration() {
    return configuration_.get();
  }

 private:
  scoped_ptr<v8::Extension> safe_builtins_;
  std::vector<const char*> names_;
  scoped_ptr<v8::ExtensionConfiguration> configuration_;
};

base::LazyInstance<V8ExtensionConfigurator>::Leaky g_v8_extension_configurator =
    LAZY_INSTANCE_INITIALIZER;

}  // namespace

// Native JS functions for doing asserts.
class ModuleSystemTestEnvironment::AssertNatives
    : public ObjectBackedNativeHandler {
 public:
  explicit AssertNatives(ScriptContext* context)
      : ObjectBackedNativeHandler(context),
        assertion_made_(false),
        failed_(false) {
    RouteFunction(
        "AssertTrue",
        base::Bind(&AssertNatives::AssertTrue, base::Unretained(this)));
    RouteFunction(
        "AssertFalse",
        base::Bind(&AssertNatives::AssertFalse, base::Unretained(this)));
  }

  bool assertion_made() { return assertion_made_; }
  bool failed() { return failed_; }

  void AssertTrue(const v8::FunctionCallbackInfo<v8::Value>& args) {
    CHECK_EQ(1, args.Length());
    assertion_made_ = true;
    failed_ = failed_ || !args[0]->ToBoolean(args.GetIsolate())->Value();
  }

  void AssertFalse(const v8::FunctionCallbackInfo<v8::Value>& args) {
    CHECK_EQ(1, args.Length());
    assertion_made_ = true;
    failed_ = failed_ || args[0]->ToBoolean(args.GetIsolate())->Value();
  }

 private:
  bool assertion_made_;
  bool failed_;
};

// Source map that operates on std::strings.
class ModuleSystemTestEnvironment::StringSourceMap
    : public ModuleSystem::SourceMap {
 public:
  StringSourceMap() {}
  ~StringSourceMap() override {}

  v8::Local<v8::Value> GetSource(v8::Isolate* isolate,
                                 const std::string& name) override {
    if (source_map_.count(name) == 0)
      return v8::Undefined(isolate);
    return v8::String::NewFromUtf8(isolate, source_map_[name].c_str());
  }

  bool Contains(const std::string& name) override {
    return source_map_.count(name);
  }

  void RegisterModule(const std::string& name, const std::string& source) {
    CHECK_EQ(0u, source_map_.count(name)) << "Module " << name << " not found";
    source_map_[name] = source;
  }

 private:
  std::map<std::string, std::string> source_map_;
};

ModuleSystemTestEnvironment::ModuleSystemTestEnvironment(v8::Isolate* isolate)
    : isolate_(isolate),
      context_holder_(new gin::ContextHolder(isolate_)),
      handle_scope_(isolate_),
      source_map_(new StringSourceMap()) {
  context_holder_->SetContext(v8::Context::New(
      isolate, g_v8_extension_configurator.Get().GetConfiguration()));
  context_.reset(new ScriptContext(context_holder_->context(),
                                   nullptr,  // WebFrame
                                   nullptr,  // Extension
                                   Feature::BLESSED_EXTENSION_CONTEXT,
                                   nullptr,  // Effective Extension
                                   Feature::BLESSED_EXTENSION_CONTEXT));
  context_->v8_context()->Enter();
  assert_natives_ = new AssertNatives(context_.get());

  {
    scoped_ptr<ModuleSystem> module_system(
        new ModuleSystem(context_.get(), source_map_.get()));
    context_->set_module_system(module_system.Pass());
  }
  ModuleSystem* module_system = context_->module_system();
  module_system->RegisterNativeHandler(
      "assert", scoped_ptr<NativeHandler>(assert_natives_));
  module_system->RegisterNativeHandler(
      "logging",
      scoped_ptr<NativeHandler>(new LoggingNativeHandler(context_.get())));
  module_system->RegisterNativeHandler(
      "utils",
      scoped_ptr<NativeHandler>(new UtilsNativeHandler(context_.get())));
  module_system->SetExceptionHandlerForTest(
      scoped_ptr<ModuleSystem::ExceptionHandler>(new FailsOnException));
}

ModuleSystemTestEnvironment::~ModuleSystemTestEnvironment() {
  if (context_->is_valid())
    ShutdownModuleSystem();
}

void ModuleSystemTestEnvironment::RegisterModule(const std::string& name,
                                                 const std::string& code) {
  source_map_->RegisterModule(name, code);
}

void ModuleSystemTestEnvironment::RegisterModule(const std::string& name,
                                                 int resource_id) {
  const std::string& code = ResourceBundle::GetSharedInstance()
                                .GetRawDataResource(resource_id)
                                .as_string();
  source_map_->RegisterModule(name, code);
}

void ModuleSystemTestEnvironment::OverrideNativeHandler(
    const std::string& name,
    const std::string& code) {
  RegisterModule(name, code);
  context_->module_system()->OverrideNativeHandlerForTest(name);
}

void ModuleSystemTestEnvironment::RegisterTestFile(
    const std::string& module_name,
    const std::string& file_name) {
  base::FilePath test_js_file_path;
  ASSERT_TRUE(PathService::Get(DIR_TEST_DATA, &test_js_file_path));
  test_js_file_path = test_js_file_path.AppendASCII(file_name);
  std::string test_js;
  ASSERT_TRUE(base::ReadFileToString(test_js_file_path, &test_js));
  source_map_->RegisterModule(module_name, test_js);
}

void ModuleSystemTestEnvironment::ShutdownGin() {
  context_holder_.reset();
}

void ModuleSystemTestEnvironment::ShutdownModuleSystem() {
  CHECK(context_->is_valid());
  context_->v8_context()->Exit();
  context_->Invalidate();
}

v8::Local<v8::Object> ModuleSystemTestEnvironment::CreateGlobal(
    const std::string& name) {
  v8::EscapableHandleScope handle_scope(isolate_);
  v8::Local<v8::Object> object = v8::Object::New(isolate_);
  isolate_->GetCurrentContext()->Global()->Set(
      v8::String::NewFromUtf8(isolate_, name.c_str()), object);
  return handle_scope.Escape(object);
}

ModuleSystemTest::ModuleSystemTest()
    : isolate_(v8::Isolate::GetCurrent()),
      should_assertions_be_made_(true) {
}

ModuleSystemTest::~ModuleSystemTest() {
}

void ModuleSystemTest::SetUp() {
  env_ = CreateEnvironment();
}

void ModuleSystemTest::TearDown() {
  // All tests must assert at least once unless otherwise specified.
  EXPECT_EQ(should_assertions_be_made_,
            env_->assert_natives()->assertion_made());
  EXPECT_FALSE(env_->assert_natives()->failed());
  env_.reset();
  v8::HeapStatistics stats;
  isolate_->GetHeapStatistics(&stats);
  size_t old_heap_size = 0;
  // Run the GC until the heap size reaches a steady state to ensure that
  // all the garbage is collected.
  while (stats.used_heap_size() != old_heap_size) {
    old_heap_size = stats.used_heap_size();
    isolate_->RequestGarbageCollectionForTesting(
        v8::Isolate::kFullGarbageCollection);
    isolate_->GetHeapStatistics(&stats);
  }
}

scoped_ptr<ModuleSystemTestEnvironment> ModuleSystemTest::CreateEnvironment() {
  return make_scoped_ptr(new ModuleSystemTestEnvironment(isolate_));
}

void ModuleSystemTest::ExpectNoAssertionsMade() {
  should_assertions_be_made_ = false;
}

void ModuleSystemTest::RunResolvedPromises() {
  isolate_->RunMicrotasks();
}

}  // namespace extensions