// 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 <stddef.h>
#include <utility>

#include "base/macros.h"
#include "base/message_loop/message_loop.h"
#include "base/run_loop.h"
#include "chromeos/geolocation/geoposition.h"
#include "chromeos/timezone/timezone_provider.h"
#include "chromeos/timezone/timezone_resolver.h"
#include "net/http/http_response_headers.h"
#include "net/http/http_status_code.h"
#include "net/url_request/test_url_fetcher_factory.h"
#include "net/url_request/url_fetcher_impl.h"
#include "net/url_request/url_request_status.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace {

const int kRequestRetryIntervalMilliSeconds = 200;

// This should be different from default to prevent TimeZoneRequest
// from modifying it.
const char kTestTimeZoneProviderUrl[] =
    "https://localhost/maps/api/timezone/json?";

const char kSimpleResponseBody[] =
    "{\n"
    "    \"dstOffset\" : 0.0,\n"
    "    \"rawOffset\" : -28800.0,\n"
    "    \"status\" : \"OK\",\n"
    "    \"timeZoneId\" : \"America/Los_Angeles\",\n"
    "    \"timeZoneName\" : \"Pacific Standard Time\"\n"
    "}";

struct SimpleRequest {
  SimpleRequest()
      : url("https://localhost/maps/api/timezone/"
            "json?location=39.603481,-119.682251&timestamp=1331161200&sensor="
            "false"),
        http_response(kSimpleResponseBody) {
    position.latitude = 39.6034810;
    position.longitude = -119.6822510;
    position.accuracy = 1;
    position.error_code = 0;
    position.timestamp = base::Time::FromTimeT(1331161200);
    position.status = chromeos::Geoposition::STATUS_NONE;
    EXPECT_EQ(
        "latitude=39.603481, longitude=-119.682251, accuracy=1.000000, "
        "error_code=0, error_message='', status=0 (NONE)",
        position.ToString());

    timezone.dstOffset = 0;
    timezone.rawOffset = -28800;
    timezone.timeZoneId = "America/Los_Angeles";
    timezone.timeZoneName = "Pacific Standard Time";
    timezone.error_message.erase();
    timezone.status = chromeos::TimeZoneResponseData::OK;
    EXPECT_EQ(
        "dstOffset=0.000000, rawOffset=-28800.000000, "
        "timeZoneId='America/Los_Angeles', timeZoneName='Pacific Standard "
        "Time', error_message='', status=0 (OK)",
        timezone.ToStringForDebug());
  }

  GURL url;
  chromeos::Geoposition position;
  std::string http_response;
  chromeos::TimeZoneResponseData timezone;
};

}  // anonymous namespace

namespace chromeos {

// This is helper class for net::FakeURLFetcherFactory.
class TestTimeZoneAPIURLFetcherCallback {
 public:
  TestTimeZoneAPIURLFetcherCallback(const GURL& url,
                                    const size_t require_retries,
                                    const std::string& response,
                                    TimeZoneProvider* provider)
      : url_(url),
        require_retries_(require_retries),
        response_(response),
        factory_(NULL),
        attempts_(0),
        provider_(provider) {}

  std::unique_ptr<net::FakeURLFetcher> CreateURLFetcher(
      const GURL& url,
      net::URLFetcherDelegate* delegate,
      const std::string& response_data,
      net::HttpStatusCode response_code,
      net::URLRequestStatus::Status status) {
    EXPECT_EQ(provider_->requests_.size(), 1U);

    TimeZoneRequest* timezone_request = provider_->requests_[0].get();

    const base::TimeDelta base_retry_interval =
        base::TimeDelta::FromMilliseconds(kRequestRetryIntervalMilliSeconds);
    timezone_request->set_retry_sleep_on_server_error_for_testing(
        base_retry_interval);
    timezone_request->set_retry_sleep_on_bad_response_for_testing(
        base_retry_interval);

    ++attempts_;
    if (attempts_ > require_retries_) {
      response_code = net::HTTP_OK;
      status = net::URLRequestStatus::SUCCESS;
      factory_->SetFakeResponse(url, response_, response_code, status);
    }
    std::unique_ptr<net::FakeURLFetcher> fetcher(new net::FakeURLFetcher(
        url, delegate, response_, response_code, status));
    scoped_refptr<net::HttpResponseHeaders> download_headers =
        new net::HttpResponseHeaders(std::string());
    download_headers->AddHeader("Content-Type: application/json");
    fetcher->set_response_headers(download_headers);
    return fetcher;
  }

  void Initialize(net::FakeURLFetcherFactory* factory) {
    factory_ = factory;
    factory_->SetFakeResponse(url_,
                              std::string(),
                              net::HTTP_INTERNAL_SERVER_ERROR,
                              net::URLRequestStatus::FAILED);
  }

  size_t attempts() const { return attempts_; }

 private:
  const GURL url_;
  // Respond with OK on required retry attempt.
  const size_t require_retries_;
  std::string response_;
  net::FakeURLFetcherFactory* factory_;
  size_t attempts_;
  TimeZoneProvider* provider_;

  DISALLOW_COPY_AND_ASSIGN(TestTimeZoneAPIURLFetcherCallback);
};

// This implements fake TimeZone API remote endpoint.
// Response data is served to TimeZoneProvider via
// net::FakeURLFetcher.
class TimeZoneAPIFetcherFactory {
 public:
  TimeZoneAPIFetcherFactory(const GURL& url,
                            const std::string& response,
                            const size_t require_retries,
                            TimeZoneProvider* provider) {
    url_callback_.reset(new TestTimeZoneAPIURLFetcherCallback(
        url, require_retries, response, provider));
    net::URLFetcherImpl::set_factory(NULL);
    fetcher_factory_.reset(new net::FakeURLFetcherFactory(
        NULL,
        base::Bind(&TestTimeZoneAPIURLFetcherCallback::CreateURLFetcher,
                   base::Unretained(url_callback_.get()))));
    url_callback_->Initialize(fetcher_factory_.get());
  }

  size_t attempts() const { return url_callback_->attempts(); }

 private:
  std::unique_ptr<TestTimeZoneAPIURLFetcherCallback> url_callback_;
  std::unique_ptr<net::FakeURLFetcherFactory> fetcher_factory_;

  DISALLOW_COPY_AND_ASSIGN(TimeZoneAPIFetcherFactory);
};

class TimeZoneReceiver {
 public:
  TimeZoneReceiver() : server_error_(false) {}

  void OnRequestDone(std::unique_ptr<TimeZoneResponseData> timezone,
                     bool server_error) {
    timezone_ = std::move(timezone);
    server_error_ = server_error;

    message_loop_runner_->Quit();
  }

  void WaitUntilRequestDone() {
    message_loop_runner_.reset(new base::RunLoop);
    message_loop_runner_->Run();
  }

  const TimeZoneResponseData* timezone() const { return timezone_.get(); }
  bool server_error() const { return server_error_; }

 private:
  std::unique_ptr<TimeZoneResponseData> timezone_;
  bool server_error_;
  std::unique_ptr<base::RunLoop> message_loop_runner_;
};

class TimeZoneTest : public testing::Test {
 private:
  base::MessageLoop message_loop_;
};

TEST_F(TimeZoneTest, ResponseOK) {
  TimeZoneProvider provider(NULL, GURL(kTestTimeZoneProviderUrl));
  const SimpleRequest simple_request;

  TimeZoneAPIFetcherFactory url_factory(simple_request.url,
                                        simple_request.http_response,
                                        0 /* require_retries */,
                                        &provider);

  TimeZoneReceiver receiver;

  provider.RequestTimezone(simple_request.position,
                           base::TimeDelta::FromSeconds(1),
                           base::Bind(&TimeZoneReceiver::OnRequestDone,
                                      base::Unretained(&receiver)));
  receiver.WaitUntilRequestDone();

  EXPECT_EQ(simple_request.timezone.ToStringForDebug(),
            receiver.timezone()->ToStringForDebug());
  EXPECT_FALSE(receiver.server_error());
  EXPECT_EQ(1U, url_factory.attempts());
}

TEST_F(TimeZoneTest, ResponseOKWithRetries) {
  TimeZoneProvider provider(NULL, GURL(kTestTimeZoneProviderUrl));
  const SimpleRequest simple_request;

  TimeZoneAPIFetcherFactory url_factory(simple_request.url,
                                        simple_request.http_response,
                                        3 /* require_retries */,
                                        &provider);

  TimeZoneReceiver receiver;

  provider.RequestTimezone(simple_request.position,
                           base::TimeDelta::FromSeconds(1),
                           base::Bind(&TimeZoneReceiver::OnRequestDone,
                                      base::Unretained(&receiver)));
  receiver.WaitUntilRequestDone();
  EXPECT_EQ(simple_request.timezone.ToStringForDebug(),
            receiver.timezone()->ToStringForDebug());
  EXPECT_FALSE(receiver.server_error());
  EXPECT_EQ(4U, url_factory.attempts());
}

TEST_F(TimeZoneTest, InvalidResponse) {
  TimeZoneProvider provider(NULL, GURL(kTestTimeZoneProviderUrl));
  const SimpleRequest simple_request;

  TimeZoneAPIFetcherFactory url_factory(simple_request.url,
                                        "invalid JSON string",
                                        0 /* require_retries */,
                                        &provider);

  TimeZoneReceiver receiver;

  const int timeout_seconds = 1;
  size_t expected_retries = static_cast<size_t>(
      timeout_seconds * 1000 / kRequestRetryIntervalMilliSeconds);
  ASSERT_GE(expected_retries, 2U);

  provider.RequestTimezone(simple_request.position,
                           base::TimeDelta::FromSeconds(timeout_seconds),
                           base::Bind(&TimeZoneReceiver::OnRequestDone,
                                      base::Unretained(&receiver)));
  receiver.WaitUntilRequestDone();
  EXPECT_EQ(
      "dstOffset=0.000000, rawOffset=0.000000, timeZoneId='', timeZoneName='', "
      "error_message='TimeZone provider at 'https://localhost/' : JSONReader "
      "failed: Line: 1, column: 1, Unexpected token..', status=6 "
      "(REQUEST_ERROR)",
      receiver.timezone()->ToStringForDebug());
  EXPECT_FALSE(receiver.server_error());
  EXPECT_GE(url_factory.attempts(), 2U);
  if (url_factory.attempts() > expected_retries + 1) {
    LOG(WARNING) << "TimeZoneTest::InvalidResponse: Too many attempts ("
                 << url_factory.attempts() << "), no more than "
                 << expected_retries + 1 << " expected.";
  }
  if (url_factory.attempts() < expected_retries - 1) {
    LOG(WARNING) << "TimeZoneTest::InvalidResponse: Too less attempts ("
                 << url_factory.attempts() << "), greater than "
                 << expected_retries - 1 << " expected.";
  }
}

TEST(TimeZoneResolverTest, CheckIntervals) {
  for (int requests_count = 1; requests_count < 10; ++requests_count) {
    EXPECT_EQ(requests_count,
              TimeZoneResolver::MaxRequestsCountForIntervalForTesting(
                  TimeZoneResolver::IntervalForNextRequestForTesting(
                      requests_count)));
  }
}

}  // namespace chromeos