// Copyright 2020 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 "services/network/trust_tokens/trust_token_request_helper_factory.h"

#include <memory>
#include <utility>

#include "base/callback_forward.h"
#include "base/metrics/histogram_functions.h"
#include "base/strings/strcat.h"
#include "net/base/isolation_info.h"
#include "net/log/net_log_event_type.h"
#include "net/log/net_log_with_source.h"
#include "net/url_request/url_request.h"
#include "services/network/public/cpp/resource_request.h"
#include "services/network/public/cpp/trust_token_parameterization.h"
#include "services/network/public/mojom/trust_tokens.mojom-shared.h"
#include "services/network/trust_tokens/boringssl_trust_token_issuance_cryptographer.h"
#include "services/network/trust_tokens/boringssl_trust_token_redemption_cryptographer.h"
#include "services/network/trust_tokens/ed25519_key_pair_generator.h"
#include "services/network/trust_tokens/ed25519_trust_token_request_signer.h"
#include "services/network/trust_tokens/suitable_trust_token_origin.h"
#include "services/network/trust_tokens/trust_token_http_headers.h"
#include "services/network/trust_tokens/trust_token_key_commitment_controller.h"
#include "services/network/trust_tokens/trust_token_parameterization.h"
#include "services/network/trust_tokens/trust_token_request_canonicalizer.h"
#include "services/network/trust_tokens/trust_token_request_issuance_helper.h"
#include "services/network/trust_tokens/trust_token_request_redemption_helper.h"
#include "services/network/trust_tokens/trust_token_request_signing_helper.h"
#include "services/network/trust_tokens/types.h"

namespace network {

namespace {

using Outcome = internal::TrustTokenRequestHelperFactoryOutcome;

base::StringPiece OutcomeToString(Outcome outcome) {
  switch (outcome) {
    case Outcome::kSuccessfullyCreatedAnIssuanceHelper:
      return "Successfully created an issuance helper";
    case Outcome::kSuccessfullyCreatedARedemptionHelper:
      return "Successfully created a redemption helper";
    case Outcome::kSuccessfullyCreatedASigningHelper:
      return "Successfully created a signing helper";
    case Outcome::kEmptyIssuersParameter:
      return "Empty 'issuers' parameter";
    case Outcome::kUnsuitableIssuerInIssuersParameter:
      return "Unsuitable issuer in 'issuers' parameter";
    case Outcome::kUnsuitableTopFrameOrigin:
      return "Unsuitable top frame origin";
    case Outcome::kRequestRejectedDueToBearingAnInternalTrustTokensHeader:
      return "Request rejected due to bearing an internal Trust Tokens header";
    case Outcome::kRejectedByAuthorizer:
      return "Rejected by authorizer (check cookie settings?)";
  }
}

void LogOutcome(const net::NetLogWithSource& log,
                mojom::TrustTokenOperationType type,
                Outcome outcome) {
  base::UmaHistogramEnumeration(
      base::StrCat({"Net.TrustTokens.RequestHelperFactoryOutcome.",
                    internal::TrustTokenOperationTypeToString(type)}),
      outcome);
  log.EndEvent(net::NetLogEventType::TRUST_TOKEN_OPERATION_REQUESTED,
               [outcome]() {
                 base::Value ret(base::Value::Type::DICTIONARY);
                 ret.SetStringKey("outcome", OutcomeToString(outcome));
                 return ret;
               });
}

}  // namespace

TrustTokenRequestHelperFactory::TrustTokenRequestHelperFactory(
    PendingTrustTokenStore* store,
    const TrustTokenKeyCommitmentGetter* key_commitment_getter,
    base::RepeatingCallback<bool(void)> authorizer)
    : store_(store),
      key_commitment_getter_(key_commitment_getter),
      authorizer_(std::move(authorizer)) {}
TrustTokenRequestHelperFactory::~TrustTokenRequestHelperFactory() = default;

void TrustTokenRequestHelperFactory::CreateTrustTokenHelperForRequest(
    const net::URLRequest& request,
    const mojom::TrustTokenParams& params,
    base::OnceCallback<void(TrustTokenStatusOrRequestHelper)> done) {
  request.net_log().BeginEventWithIntParams(
      net::NetLogEventType::TRUST_TOKEN_OPERATION_REQUESTED,
      "Operation type (mojom.TrustTokenOperationType)",
      static_cast<int>(params.type));

  if (!authorizer_.Run()) {
    LogOutcome(request.net_log(), params.type, Outcome::kRejectedByAuthorizer);
    std::move(done).Run(mojom::TrustTokenOperationStatus::kUnavailable);
    return;
  }

  for (base::StringPiece header : TrustTokensRequestHeaders()) {
    if (request.extra_request_headers().HasHeader(header)) {
      LogOutcome(
          request.net_log(), params.type,
          Outcome::kRequestRejectedDueToBearingAnInternalTrustTokensHeader);
      std::move(done).Run(mojom::TrustTokenOperationStatus::kInvalidArgument);
      return;
    }
  }

  base::Optional<SuitableTrustTokenOrigin> maybe_top_frame_origin;
  if (request.isolation_info().top_frame_origin()) {
    maybe_top_frame_origin = SuitableTrustTokenOrigin::Create(
        *request.isolation_info().top_frame_origin());
  }
  if (!maybe_top_frame_origin) {
    LogOutcome(request.net_log(), params.type,
               Outcome::kUnsuitableTopFrameOrigin);
    std::move(done).Run(mojom::TrustTokenOperationStatus::kFailedPrecondition);
    return;
  }

  store_->ExecuteOrEnqueue(base::BindOnce(
      &TrustTokenRequestHelperFactory::ConstructHelperUsingStore,
      weak_factory_.GetWeakPtr(), *maybe_top_frame_origin,
      base::Passed(params.Clone()), request.net_log(), std::move(done)));
}

void TrustTokenRequestHelperFactory::ConstructHelperUsingStore(
    SuitableTrustTokenOrigin top_frame_origin,
    mojom::TrustTokenParamsPtr params,
    net::NetLogWithSource net_log,
    base::OnceCallback<void(TrustTokenStatusOrRequestHelper)> done,
    TrustTokenStore* store) {
  DCHECK(params);

  switch (params->type) {
    case mojom::TrustTokenOperationType::kIssuance: {
      LogOutcome(net_log, params->type,
                 Outcome::kSuccessfullyCreatedAnIssuanceHelper);
      std::move(done).Run(std::unique_ptr<TrustTokenRequestHelper>(
          new TrustTokenRequestIssuanceHelper(
              std::move(top_frame_origin), store, key_commitment_getter_,
              std::make_unique<BoringsslTrustTokenIssuanceCryptographer>(),
              std::move(net_log))));
      return;
    }

    case mojom::TrustTokenOperationType::kRedemption: {
      LogOutcome(net_log, params->type,
                 Outcome::kSuccessfullyCreatedARedemptionHelper);
      std::move(done).Run(std::unique_ptr<TrustTokenRequestHelper>(
          new TrustTokenRequestRedemptionHelper(
              std::move(top_frame_origin), params->refresh_policy, store,
              key_commitment_getter_,
              std::make_unique<Ed25519KeyPairGenerator>(),
              std::make_unique<BoringsslTrustTokenRedemptionCryptographer>(),
              std::move(net_log))));
      return;
    }

    case mojom::TrustTokenOperationType::kSigning: {
      if (params->issuers.empty()) {
        LogOutcome(net_log, params->type, Outcome::kEmptyIssuersParameter);
        std::move(done).Run(mojom::TrustTokenOperationStatus::kInvalidArgument);
        return;
      }

      std::vector<SuitableTrustTokenOrigin> issuers;
      for (url::Origin& potentially_unsuitable_issuer : params->issuers) {
        base::Optional<SuitableTrustTokenOrigin> maybe_issuer =
            SuitableTrustTokenOrigin::Create(
                std::move(potentially_unsuitable_issuer));
        if (!maybe_issuer) {
          LogOutcome(net_log, params->type,
                     Outcome::kUnsuitableIssuerInIssuersParameter);
          std::move(done).Run(
              mojom::TrustTokenOperationStatus::kInvalidArgument);
          return;
        }

        issuers.emplace_back(std::move(*maybe_issuer));
      }

      TrustTokenRequestSigningHelper::Params signing_params(
          std::move(issuers), top_frame_origin,
          std::move(params->additional_signed_headers),
          params->include_timestamp_header, params->sign_request_data,
          params->possibly_unsafe_additional_signing_data);

      LogOutcome(net_log, params->type,
                 Outcome::kSuccessfullyCreatedASigningHelper);
      std::move(done).Run(std::unique_ptr<TrustTokenRequestHelper>(
          new TrustTokenRequestSigningHelper(
              store, std::move(signing_params),
              std::make_unique<Ed25519TrustTokenRequestSigner>(),
              std::make_unique<TrustTokenRequestCanonicalizer>(),
              std::move(net_log))));
      return;
    }
  }
}

TrustTokenStatusOrRequestHelper::TrustTokenStatusOrRequestHelper() = default;

TrustTokenStatusOrRequestHelper::TrustTokenStatusOrRequestHelper(
    mojom::TrustTokenOperationStatus status)
    : status_(status) {
  DCHECK_NE(status_, mojom::TrustTokenOperationStatus::kOk);
}
TrustTokenStatusOrRequestHelper::TrustTokenStatusOrRequestHelper(
    std::unique_ptr<TrustTokenRequestHelper> helper)
    : status_(mojom::TrustTokenOperationStatus::kOk),
      helper_(std::move(helper)) {
  DCHECK(helper_);
}

TrustTokenStatusOrRequestHelper::~TrustTokenStatusOrRequestHelper() = default;

TrustTokenStatusOrRequestHelper::TrustTokenStatusOrRequestHelper(
    TrustTokenStatusOrRequestHelper&&) = default;
TrustTokenStatusOrRequestHelper& TrustTokenStatusOrRequestHelper::operator=(
    TrustTokenStatusOrRequestHelper&&) = default;

}  // namespace network