// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/download/internal/background_service/logger_impl.h"

#include <memory>

#include "base/i18n/time_formatting.h"
#include "base/observer_list.h"
#include "base/values.h"
#include "components/download/internal/background_service/driver_entry.h"
#include "components/download/internal/background_service/entry.h"
#include "components/download/internal/background_service/log_source.h"
#include "components/download/public/background_service/clients.h"
#include "components/download/public/background_service/download_params.h"

namespace download {
namespace {

std::string ControllerStateToString(Controller::State state) {
  switch (state) {
    case Controller::State::CREATED:
      return "CREATED";
    case Controller::State::INITIALIZING:
      return "INITIALIZING";
    case Controller::State::READY:
      return "READY";
    case Controller::State::RECOVERING:
      return "RECOVERING";
    case Controller::State::UNAVAILABLE:  // Intentional fallthrough.
    default:
      return "UNAVAILABLE";
  }
}

std::string OptBoolToString(std::optional<bool> value) {
  if (value.has_value())
    return value.value() ? "OK" : "BAD";

  return "UNKNOWN";
}

std::string EntryStateToString(Entry::State state) {
  switch (state) {
    case Entry::State::NEW:
      return "NEW";
    case Entry::State::AVAILABLE:
      return "AVAILABLE";
    case Entry::State::ACTIVE:
      return "ACTIVE";
    case Entry::State::PAUSED:
      return "PAUSED";
    case Entry::State::COMPLETE:
      return "COMPLETE";
    default:
      NOTREACHED();
  }
}

std::string DriverEntryStateToString(DriverEntry::State state) {
  switch (state) {
    case DriverEntry::State::IN_PROGRESS:
      return "IN_PROGRESS";
    case DriverEntry::State::COMPLETE:
      return "COMPLETE";
    case DriverEntry::State::CANCELLED:
      return "CANCELLED";
    case DriverEntry::State::INTERRUPTED:
      return "INTERRUPTED";
    default:
      NOTREACHED();
  }
}

std::string CompletionTypeToString(CompletionType type) {
  switch (type) {
    case CompletionType::SUCCEED:
      return "SUCCEED";
    case CompletionType::FAIL:
      return "FAIL";
    case CompletionType::ABORT:
      return "ABORT";
    case CompletionType::TIMEOUT:
      return "TIMEOUT";
    case CompletionType::UNKNOWN:
      return "UNKNOWN";
    case CompletionType::CANCEL:
      return "CANCEL";
    case CompletionType::OUT_OF_RETRIES:
      return "OUT_OF_RETRIES";
    case CompletionType::OUT_OF_RESUMPTIONS:
      return "OUT_OF_RESUMPTIONS";
    default:
      NOTREACHED();
  }
}

std::string StartResultToString(DownloadParams::StartResult result) {
  switch (result) {
    case DownloadParams::StartResult::ACCEPTED:
      return "ACCEPTED";
    case DownloadParams::StartResult::BACKOFF:
      return "BACKOFF";
    case DownloadParams::StartResult::UNEXPECTED_CLIENT:
      return "UNEXPECTED_CLIENT";
    case DownloadParams::StartResult::UNEXPECTED_GUID:
      return "UNEXPECTED_GUID";
    case DownloadParams::StartResult::CLIENT_CANCELLED:
      return "CLIENT_CANCELLED";
    case DownloadParams::StartResult::INTERNAL_ERROR:
      return "INTERNAL_ERROR";
    default:
      NOTREACHED();
  }
}

base::Value::Dict DriverEntryToValue(const DriverEntry& entry) {
  base::Value::Dict serialized_entry;
  serialized_entry.Set("state", DriverEntryStateToString(entry.state));
  serialized_entry.Set("paused", entry.paused);
  serialized_entry.Set("done", entry.done);
  return serialized_entry;
}

base::Value::Dict EntryToValue(
    const Entry& entry,
    const std::optional<DriverEntry>& driver,
    const std::optional<CompletionType>& completion_type) {
  base::Value::Dict serialized_entry;
  serialized_entry.Set("client",
                       BackgroundDownloadClientToString(entry.client));
  serialized_entry.Set("state", EntryStateToString(entry.state));
  serialized_entry.Set("guid", entry.guid);

  // Convert the URL to a proper logging format.
  GURL::Replacements replacements;
  replacements.ClearQuery();

  serialized_entry.Set(
      "url", entry.request_params.url.ReplaceComponents(replacements).spec());
  serialized_entry.Set("file_path", entry.target_file_path.MaybeAsASCII());

  if (driver.has_value()) {
    serialized_entry.Set("bytes_downloaded",
                         static_cast<double>(driver->bytes_downloaded));
    serialized_entry.Set("driver", DriverEntryToValue(driver.value()));
    serialized_entry.Set("time_downloaded",
                         base::TimeFormatHTTP(driver->completion_time));
  } else {
    serialized_entry.Set("bytes_downloaded",
                         static_cast<double>(entry.bytes_downloaded));
    serialized_entry.Set("time_downloaded",
                         base::TimeFormatHTTP(entry.completion_time));
  }

  if (completion_type.has_value()) {
    serialized_entry.Set("result",
                         CompletionTypeToString(completion_type.value()));
  } else if (entry.state == Entry::State::COMPLETE) {
    serialized_entry.Set("result",
                         CompletionTypeToString(CompletionType::SUCCEED));
  }
  return serialized_entry;
}

}  // namespace

LoggerImpl::LoggerImpl() : log_source_(nullptr) {}
LoggerImpl::~LoggerImpl() = default;

void LoggerImpl::SetLogSource(LogSource* log_source) {
  log_source_ = log_source;
}

void LoggerImpl::AddObserver(Observer* observer) {
  DCHECK(!observers_.HasObserver(observer));
  observers_.AddObserver(observer);
}

void LoggerImpl::RemoveObserver(Observer* observer) {
  DCHECK(observers_.HasObserver(observer));
  observers_.RemoveObserver(observer);
}

base::Value::Dict LoggerImpl::GetServiceStatus() {
  base::Value::Dict service_status;

  if (!log_source_)
    return service_status;

  Controller::State state = log_source_->GetControllerState();
  const StartupStatus& status = log_source_->GetStartupStatus();

  service_status.Set("serviceState", ControllerStateToString(state));
  service_status.Set("modelStatus", OptBoolToString(status.model_ok));
  service_status.Set("driverStatus", OptBoolToString(status.driver_ok));
  service_status.Set("fileMonitorStatus",
                     OptBoolToString(status.file_monitor_ok));

  return service_status;
}

base::Value::List LoggerImpl::GetServiceDownloads() {
  base::Value::List serialized_entries;

  if (!log_source_)
    return serialized_entries;

  auto entries = log_source_->GetServiceDownloads();
  for (auto& entry : entries) {
    serialized_entries.Append(
        EntryToValue(*entry.first, entry.second, std::nullopt));
  }

  return serialized_entries;
}

void LoggerImpl::OnServiceStatusChanged() {
  if (observers_.empty())
    return;

  base::Value::Dict service_status = GetServiceStatus();

  for (auto& observer : observers_)
    observer.OnServiceStatusChanged(service_status);
}

void LoggerImpl::OnServiceDownloadsAvailable() {
  if (observers_.empty())
    return;

  base::Value::List service_downloads = GetServiceDownloads();
  for (auto& observer : observers_)
    observer.OnServiceDownloadsAvailable(service_downloads);
}

void LoggerImpl::OnServiceDownloadChanged(const std::string& guid) {
  if (observers_.empty())
    return;

  auto entry_details = log_source_->GetServiceDownload(guid);
  if (!entry_details.has_value())
    return;

  auto entry = EntryToValue(*(entry_details->first), entry_details->second,
                            std::nullopt);

  for (auto& observer : observers_)
    observer.OnServiceDownloadChanged(entry);
}

void LoggerImpl::OnServiceDownloadFailed(CompletionType completion_type,
                                         const Entry& entry) {
  DCHECK_NE(CompletionType::SUCCEED, completion_type);

  if (observers_.empty())
    return;

  auto serialized_entry = EntryToValue(entry, std::nullopt, completion_type);
  for (auto& observer : observers_)
    observer.OnServiceDownloadFailed(serialized_entry);
}

void LoggerImpl::OnServiceRequestMade(
    DownloadClient client,
    const std::string& guid,
    DownloadParams::StartResult start_result) {
  if (observers_.empty())
    return;

  base::Value::Dict serialized_request;
  serialized_request.Set("client", BackgroundDownloadClientToString(client));
  serialized_request.Set("guid", guid);
  serialized_request.Set("result", StartResultToString(start_result));
  for (auto& observer : observers_)
    observer.OnServiceRequestMade(serialized_request);
}

}  // namespace download