/*
 *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include <memory>
#include <string>
#include <vector>

#include "webrtc/p2p/base/p2pconstants.h"
#include "webrtc/p2p/base/transportdescription.h"
#include "webrtc/p2p/base/transportdescriptionfactory.h"
#include "webrtc/base/fakesslidentity.h"
#include "webrtc/base/gunit.h"
#include "webrtc/base/ssladapter.h"

using cricket::TransportDescriptionFactory;
using cricket::TransportDescription;
using cricket::TransportOptions;

class TransportDescriptionFactoryTest : public testing::Test {
 public:
  TransportDescriptionFactoryTest()
      : cert1_(rtc::RTCCertificate::Create(std::unique_ptr<rtc::SSLIdentity>(
            new rtc::FakeSSLIdentity("User1")))),
        cert2_(rtc::RTCCertificate::Create(std::unique_ptr<rtc::SSLIdentity>(
            new rtc::FakeSSLIdentity("User2")))) {}

  void CheckDesc(const TransportDescription* desc,
                 const std::string& opt, const std::string& ice_ufrag,
                 const std::string& ice_pwd, const std::string& dtls_alg) {
    ASSERT_TRUE(desc != NULL);
    EXPECT_EQ(!opt.empty(), desc->HasOption(opt));
    if (ice_ufrag.empty() && ice_pwd.empty()) {
      EXPECT_EQ(static_cast<size_t>(cricket::ICE_UFRAG_LENGTH),
                desc->ice_ufrag.size());
      EXPECT_EQ(static_cast<size_t>(cricket::ICE_PWD_LENGTH),
                desc->ice_pwd.size());
    } else {
      EXPECT_EQ(ice_ufrag, desc->ice_ufrag);
      EXPECT_EQ(ice_pwd, desc->ice_pwd);
    }
    if (dtls_alg.empty()) {
      EXPECT_TRUE(desc->identity_fingerprint.get() == NULL);
    } else {
      ASSERT_TRUE(desc->identity_fingerprint.get() != NULL);
      EXPECT_EQ(desc->identity_fingerprint->algorithm, dtls_alg);
      EXPECT_GT(desc->identity_fingerprint->digest.size(), 0U);
    }
  }

  // This test ice restart by doing two offer answer exchanges. On the second
  // exchange ice is restarted. The test verifies that the ufrag and password
  // in the offer and answer is changed.
  // If |dtls| is true, the test verifies that the finger print is not changed.
  void TestIceRestart(bool dtls) {
    if (dtls) {
      f1_.set_secure(cricket::SEC_ENABLED);
      f2_.set_secure(cricket::SEC_ENABLED);
      f1_.set_certificate(cert1_);
      f2_.set_certificate(cert2_);
    } else {
      f1_.set_secure(cricket::SEC_DISABLED);
      f2_.set_secure(cricket::SEC_DISABLED);
    }

    cricket::TransportOptions options;
    // The initial offer / answer exchange.
    std::unique_ptr<TransportDescription> offer(f1_.CreateOffer(options, NULL));
    std::unique_ptr<TransportDescription> answer(
        f2_.CreateAnswer(offer.get(), options, NULL));

    // Create an updated offer where we restart ice.
    options.ice_restart = true;
    std::unique_ptr<TransportDescription> restart_offer(
        f1_.CreateOffer(options, offer.get()));

    VerifyUfragAndPasswordChanged(dtls, offer.get(), restart_offer.get());

    // Create a new answer. The transport ufrag and password is changed since
    // |options.ice_restart == true|
    std::unique_ptr<TransportDescription> restart_answer(
        f2_.CreateAnswer(restart_offer.get(), options, answer.get()));
    ASSERT_TRUE(restart_answer.get() != NULL);

    VerifyUfragAndPasswordChanged(dtls, answer.get(), restart_answer.get());
  }

  void VerifyUfragAndPasswordChanged(bool dtls,
                                     const TransportDescription* org_desc,
                                     const TransportDescription* restart_desc) {
    EXPECT_NE(org_desc->ice_pwd, restart_desc->ice_pwd);
    EXPECT_NE(org_desc->ice_ufrag, restart_desc->ice_ufrag);
    EXPECT_EQ(static_cast<size_t>(cricket::ICE_UFRAG_LENGTH),
              restart_desc->ice_ufrag.size());
    EXPECT_EQ(static_cast<size_t>(cricket::ICE_PWD_LENGTH),
              restart_desc->ice_pwd.size());
    // If DTLS is enabled, make sure the finger print is unchanged.
    if (dtls) {
      EXPECT_FALSE(
          org_desc->identity_fingerprint->GetRfc4572Fingerprint().empty());
      EXPECT_EQ(org_desc->identity_fingerprint->GetRfc4572Fingerprint(),
                restart_desc->identity_fingerprint->GetRfc4572Fingerprint());
    }
  }

 protected:
  TransportDescriptionFactory f1_;
  TransportDescriptionFactory f2_;

  rtc::scoped_refptr<rtc::RTCCertificate> cert1_;
  rtc::scoped_refptr<rtc::RTCCertificate> cert2_;
};

TEST_F(TransportDescriptionFactoryTest, TestOfferDefault) {
  std::unique_ptr<TransportDescription> desc(
      f1_.CreateOffer(TransportOptions(), NULL));
  CheckDesc(desc.get(), "", "", "", "");
}

TEST_F(TransportDescriptionFactoryTest, TestOfferDtls) {
  f1_.set_secure(cricket::SEC_ENABLED);
  f1_.set_certificate(cert1_);
  std::string digest_alg;
  ASSERT_TRUE(cert1_->ssl_certificate().GetSignatureDigestAlgorithm(
      &digest_alg));
  std::unique_ptr<TransportDescription> desc(
      f1_.CreateOffer(TransportOptions(), NULL));
  CheckDesc(desc.get(), "", "", "", digest_alg);
  // Ensure it also works with SEC_REQUIRED.
  f1_.set_secure(cricket::SEC_REQUIRED);
  desc.reset(f1_.CreateOffer(TransportOptions(), NULL));
  CheckDesc(desc.get(), "", "", "", digest_alg);
}

// Test generating an offer with DTLS fails with no identity.
TEST_F(TransportDescriptionFactoryTest, TestOfferDtlsWithNoIdentity) {
  f1_.set_secure(cricket::SEC_ENABLED);
  std::unique_ptr<TransportDescription> desc(
      f1_.CreateOffer(TransportOptions(), NULL));
  ASSERT_TRUE(desc.get() == NULL);
}

// Test updating an offer with DTLS to pick ICE.
// The ICE credentials should stay the same in the new offer.
TEST_F(TransportDescriptionFactoryTest, TestOfferDtlsReofferDtls) {
  f1_.set_secure(cricket::SEC_ENABLED);
  f1_.set_certificate(cert1_);
  std::string digest_alg;
  ASSERT_TRUE(cert1_->ssl_certificate().GetSignatureDigestAlgorithm(
      &digest_alg));
  std::unique_ptr<TransportDescription> old_desc(
      f1_.CreateOffer(TransportOptions(), NULL));
  ASSERT_TRUE(old_desc.get() != NULL);
  std::unique_ptr<TransportDescription> desc(
      f1_.CreateOffer(TransportOptions(), old_desc.get()));
  CheckDesc(desc.get(), "",
            old_desc->ice_ufrag, old_desc->ice_pwd, digest_alg);
}

TEST_F(TransportDescriptionFactoryTest, TestAnswerDefault) {
  std::unique_ptr<TransportDescription> offer(
      f1_.CreateOffer(TransportOptions(), NULL));
  ASSERT_TRUE(offer.get() != NULL);
  std::unique_ptr<TransportDescription> desc(
      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
  CheckDesc(desc.get(), "", "", "", "");
  desc.reset(f2_.CreateAnswer(offer.get(), TransportOptions(),
                              NULL));
  CheckDesc(desc.get(), "", "", "", "");
}

// Test that we can update an answer properly; ICE credentials shouldn't change.
TEST_F(TransportDescriptionFactoryTest, TestReanswer) {
  std::unique_ptr<TransportDescription> offer(
      f1_.CreateOffer(TransportOptions(), NULL));
  ASSERT_TRUE(offer.get() != NULL);
  std::unique_ptr<TransportDescription> old_desc(
      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
  ASSERT_TRUE(old_desc.get() != NULL);
  std::unique_ptr<TransportDescription> desc(
      f2_.CreateAnswer(offer.get(), TransportOptions(), old_desc.get()));
  ASSERT_TRUE(desc.get() != NULL);
  CheckDesc(desc.get(), "",
            old_desc->ice_ufrag, old_desc->ice_pwd, "");
}

// Test that we handle answering an offer with DTLS with no DTLS.
TEST_F(TransportDescriptionFactoryTest, TestAnswerDtlsToNoDtls) {
  f1_.set_secure(cricket::SEC_ENABLED);
  f1_.set_certificate(cert1_);
  std::unique_ptr<TransportDescription> offer(
      f1_.CreateOffer(TransportOptions(), NULL));
  ASSERT_TRUE(offer.get() != NULL);
  std::unique_ptr<TransportDescription> desc(
      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
  CheckDesc(desc.get(), "", "", "", "");
}

// Test that we handle answering an offer without DTLS if we have DTLS enabled,
// but fail if we require DTLS.
TEST_F(TransportDescriptionFactoryTest, TestAnswerNoDtlsToDtls) {
  f2_.set_secure(cricket::SEC_ENABLED);
  f2_.set_certificate(cert2_);
  std::unique_ptr<TransportDescription> offer(
      f1_.CreateOffer(TransportOptions(), NULL));
  ASSERT_TRUE(offer.get() != NULL);
  std::unique_ptr<TransportDescription> desc(
      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
  CheckDesc(desc.get(), "", "", "", "");
  f2_.set_secure(cricket::SEC_REQUIRED);
  desc.reset(f2_.CreateAnswer(offer.get(), TransportOptions(),
                              NULL));
  ASSERT_TRUE(desc.get() == NULL);
}

// Test that we handle answering an DTLS offer with DTLS, both if we have
// DTLS enabled and required.
TEST_F(TransportDescriptionFactoryTest, TestAnswerDtlsToDtls) {
  f1_.set_secure(cricket::SEC_ENABLED);
  f1_.set_certificate(cert1_);

  f2_.set_secure(cricket::SEC_ENABLED);
  f2_.set_certificate(cert2_);
  // f2_ produces the answer that is being checked in this test, so the
  // answer must contain fingerprint lines with cert2_'s digest algorithm.
  std::string digest_alg2;
  ASSERT_TRUE(cert2_->ssl_certificate().GetSignatureDigestAlgorithm(
      &digest_alg2));

  std::unique_ptr<TransportDescription> offer(
      f1_.CreateOffer(TransportOptions(), NULL));
  ASSERT_TRUE(offer.get() != NULL);
  std::unique_ptr<TransportDescription> desc(
      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
  CheckDesc(desc.get(), "", "", "", digest_alg2);
  f2_.set_secure(cricket::SEC_REQUIRED);
  desc.reset(f2_.CreateAnswer(offer.get(), TransportOptions(),
                              NULL));
  CheckDesc(desc.get(), "", "", "", digest_alg2);
}

// Test that ice ufrag and password is changed in an updated offer and answer
// if |TransportDescriptionOptions::ice_restart| is true.
TEST_F(TransportDescriptionFactoryTest, TestIceRestart) {
  TestIceRestart(false);
}

// Test that ice ufrag and password is changed in an updated offer and answer
// if |TransportDescriptionOptions::ice_restart| is true and DTLS is enabled.
TEST_F(TransportDescriptionFactoryTest, TestIceRestartWithDtls) {
  TestIceRestart(true);
}