// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/policy/messaging_layer/upload/server_uploader.h"

#include <algorithm>
#include <memory>
#include <utility>
#include <vector>

#include "base/memory/ptr_util.h"
#include "base/task/bind_post_task.h"
#include "base/task/sequenced_task_runner.h"
#include "base/task/task_runner.h"
#include "base/types/expected.h"
#include "chrome/browser/policy/messaging_layer/util/upload_declarations.h"
#include "components/policy/core/common/cloud/user_cloud_policy_manager.h"
#include "components/reporting/proto/synced/record.pb.h"
#include "components/reporting/proto/synced/record_constants.pb.h"
#include "components/reporting/resources/resource_manager.h"
#include "components/reporting/util/status.h"
#include "components/reporting/util/status_macros.h"
#include "components/reporting/util/statusor.h"
#include "components/reporting/util/task_runner_context.h"
#include "content/public/browser/browser_task_traits.h"
#include "content/public/browser/browser_thread.h"

namespace reporting {

ServerUploader::ServerUploader(
    bool need_encryption_key,
    int config_file_version,
    std::vector<EncryptedRecord> records,
    ScopedReservation scoped_reservation,
    std::unique_ptr<RecordHandler> handler,
    UploadEnqueuedCallback enqueued_cb,
    ReportSuccessfulUploadCallback report_success_upload_cb,
    EncryptionKeyAttachedCallback encryption_key_attached_cb,
    ConfigFileAttachedCallback config_file_attached_cb,
    CompletionCallback completion_cb,
    scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner)
    : TaskRunnerContext<CompletionResponse>(std::move(completion_cb),
                                            sequenced_task_runner),
      need_encryption_key_(need_encryption_key),
      config_file_version_(config_file_version),
      encrypted_records_(std::move(records)),
      scoped_reservation_(std::move(scoped_reservation)),
      enqueued_cb_(std::move(enqueued_cb)),
      report_success_upload_cb_(std::move(report_success_upload_cb)),
      encryption_key_attached_cb_(std::move(encryption_key_attached_cb)),
      config_file_attached_cb_(std::move(config_file_attached_cb)),
      handler_(std::move(handler)) {
  DETACH_FROM_SEQUENCE(sequence_checker_);
}

ServerUploader::~ServerUploader() = default;

void ServerUploader::OnStart() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!handler_) {
    Finalize(
        base::unexpected(Status(error::INVALID_ARGUMENT, "handler was null")));
    return;
  }
  // Early exit if we don't have any records and do not need encryption key.
  if (encrypted_records_.empty() && !need_encryption_key_) {
    Finalize(base::unexpected(
        Status(error::INVALID_ARGUMENT, "No records received for upload.")));
    return;
  }

  if (!encrypted_records_.empty()) {
    const auto process_status = ProcessRecords();
    if (!process_status.ok()) {
      Finalize(base::unexpected(process_status));
      return;
    }
  }

  HandleRecords();
}

Status ServerUploader::ProcessRecords() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  Status process_status;

  const int64_t expected_generation_id =
      encrypted_records_.front().sequence_information().generation_id();
  int64_t expected_sequencing_id =
      encrypted_records_.front().sequence_information().sequencing_id();

  // Will stop processing records on the first record that fails to pass.
  size_t records_added = 0;
  for (const auto& encrypted_record : encrypted_records_) {
    process_status = IsRecordValid(encrypted_record, expected_generation_id,
                                   expected_sequencing_id);
    if (!process_status.ok()) {
      LOG(ERROR) << "Record was invalid or received out of order";
      break;
    }
    ++records_added;
    ++expected_sequencing_id;
  }

  if (records_added == 0) {
    // No valid records found, report failure.
    return process_status;
  }

  // Some records are valid, discard the rest and continue.
  encrypted_records_.resize(records_added);
  return Status::StatusOK();
}

void ServerUploader::HandleRecords() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  handler_->HandleRecords(
      need_encryption_key_, config_file_version_, std::move(encrypted_records_),
      std::move(scoped_reservation_), std::move(enqueued_cb_),
      base::BindPostTaskToCurrentDefault(
          base::BindOnce(&ServerUploader::Finalize, base::Unretained(this))),
      std::move(encryption_key_attached_cb_),
      std::move(config_file_attached_cb_));
}

void ServerUploader::Finalize(CompletionResponse upload_result) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (enqueued_cb_) {
    // Finalized before upload has been enqueued - make a call now.
    std::move(enqueued_cb_)
        .Run(base::unexpected(
            Status(error::NOT_FOUND, "Upload failed to enqueue")));
  }

  if (upload_result.has_value()) {
    std::move(report_success_upload_cb_)
        .Run(upload_result.value().sequence_information,
             upload_result.value().force_confirm);
  } else {
    // Log any error except those listed below:
    static constexpr std::array<error::Code, 2> kIgnoredCodes = {
        // a transient state for managed device and an uninteresting one for
        // unmanaged ones
        error::NOT_FOUND,
        // too many upload requests, tripped rate limiting and rejecting the
        // upload (it will be resent later, so it does not cause any loss of
        // data)
        error::OUT_OF_RANGE,
    };
    LOG_IF(WARNING,
           !std::ranges::contains(kIgnoredCodes, upload_result.error().code()))
        << upload_result.error();
  }
  Response(upload_result);
}

Status ServerUploader::IsRecordValid(
    const EncryptedRecord& encrypted_record,
    const int64_t expected_generation_id,
    const int64_t expected_sequencing_id) const {
  // Test to ensure all records are in the same generation.
  if (encrypted_record.sequence_information().generation_id() !=
      expected_generation_id) {
    return Status(error::INVALID_ARGUMENT,
                  "Record does not have the correct generation");
  }

  if (encrypted_record.sequence_information().sequencing_id() !=
      expected_sequencing_id) {
    return Status(error::INVALID_ARGUMENT, "Out of order sequencing_id");
  }

  return Status::StatusOK();
}
}  // namespace reporting