// Copyright 2020 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/query_tiles/internal/tile_config.h"

#include "base/command_line.h"
#include "base/metrics/field_trial_params.h"
#include "base/strings/string_util.h"
#include "components/query_tiles/switches.h"

namespace query_tiles {

// Default URL string for GetQueryTiles RPC.
constexpr char kDefaultGetQueryTilePath[] = "/v1/querytiles";

// Finch parameter key for experiment tag to be passed to the server.
constexpr char kExperimentTagKey[] = "experiment_tag";

// Finch parameter key for base server URL to retrieve the tiles.
constexpr char kBaseURLKey[] = "base_url";

// Finch parameter key for expire duration in seconds.
constexpr char kExpireDurationKey[] = "expire_duration";

// Finch parameter key for expire duration in seconds.
constexpr char kIsUnmeteredNetworkRequiredKey[] =
    "is_unmetered_network_required";

// Finch parameter key for schedule interval.
constexpr char kScheduleIntervalKey[] =
    "tile_background_task_schedule_interval";

// Finch parameter key for random window.
constexpr char kMaxRandomWindowKey[] = "tile_background_task_random_window";

// Finch parameter key for oneoff task window.
constexpr char kOneoffTaskWindowKey[] =
    "tile_background_task_oneoff_task_window";

const char kImagePrefetchModeKey[] = "image_prefetch_mode";

// Finch parameter key for Backoff policy initial delay in ms.
constexpr char kBackoffInitDelayInMsKey[] = "backoff_policy_init_delay_in_ms";

// Finch parameter key for Backoff policy maximum delay in ms.
constexpr char kBackoffMaxDelayInMsKey[] = "backoff_policy_max_delay_in_ms";

constexpr char kTileScoreDecayLambdaKey[] = "tile_score_decay_lambda";

constexpr char kMinimumScoreForNewFrontTilesKey[] =
    "min_score_for_new_front_tiles";

constexpr char kNumTrendingTilesKey[] = "num_trending_tiles_to_display";

constexpr char kMaxTrendingTileImpressionsKey[] =
    "max_trending_tile_impressions";

constexpr char kTileShufflePositionKey[] = "tile_shuffle_position";

// Finch parameter key for resetting tile scores after a number of days without
// interaction.
constexpr char kNumDaysToResetTileScoreKey[] = "num_days_to_reset_tile_score";

// Default expire duration.
constexpr int kDefaultExpireDurationInSeconds = 48 * 60 * 60;  // 2 days.

// Default periodic interval of background task.
constexpr int kDefaultScheduleInterval = 12 * 3600 * 1000;  // 12 hours.

// Default length of random window added to the interval.
constexpr int kDefaultRandomWindow = 4 * 3600 * 1000;  // 4 hours.

// Default delta value from start window time to end window time in one-off
// background task.
constexpr int kDefaultOneoffTaskWindow = 2 * 3600 * 1000;  // 2 hours.

// Default initial delay in backoff policy.
constexpr int kDefaultBackoffInitDelayInMs = 30 * 1000;  // 30 seconds.

// Default maximum delay in backoff policy, also used for suspend duration.
constexpr int kDefaultBackoffMaxDelayInMs = 24 * 3600 * 1000;  // 1 day.

// Default lambda value used for calculating tile score decay over time.
constexpr double kDefaultTileScoreDecayLambda = -0.099;

// Default minimum score for new tiles in front of others. 0.9 is chosen so
// that new tiles will have a higher score than tiles that have not been
// clicked for 2 days.
constexpr double kDefaultMinimumTileScoreForNewFrontTiles = 0.9;

// Default number of trending tiles to be displayed at the same time.
constexpr int kDefaultNumTrendingTilesToDisplay = 2;

// Default number of impressions a trending tile to be displayed .
constexpr int kDefaultMaxTrendingTileImpressions = 1;

// Default position to start shuffling unclicked tile.
constexpr int kDefaultTileShufflePosition = 2;

// Default number of non-interacted days to reset tile score.
constexpr int kDefauktNumDaysToResetTileScore = 28;

namespace {

// For testing. Json string for single tier experiment tag.
const char kQueryTilesSingleTierExperimentTag[] = "\"maxLevels\": \"1\"";

// Json Experiment tag for enabling trending queries.
const char kQueryTilesEnableTrendingExperimentTag[] =
    "\"enableTrending\": \"true\"";

// Json Experiment tag for ranking tiles on server based on client context.
const char kQueryTilesRankTilesExperimentTag[] = "\"rankTiles\": \"true\"";

// Default Json experiment tag for IN and NG.
constexpr char kDefaultExperimentTagForINAndNG[] =
    "{maxLevels : 1, enableTrending : true, maxTrendingQueries : 8}";

// Default Json experiment tag for JP.
constexpr char kDefaultExperimentTagForJP[] =
    "{maxLevels : 1, rankTiles : true, enableTrending : true, "
    "maxTrendingQueries : 8, disableEntityTranslation: true}";

const GURL BuildGetQueryTileURL(const GURL& base_url, const char* path) {
  GURL::Replacements replacements;
  replacements.SetPathStr(path);
  return base_url.ReplaceComponents(replacements);
}

}  // namespace

// static
GURL TileConfig::GetQueryTilesServerUrl(
    const std::string& base_url,
    bool override_field_trial_param_value_if_empty) {
  std::string url = base_url;
  if (!override_field_trial_param_value_if_empty) {
    std::string field_trial_server_url = base::GetFieldTrialParamValueByFeature(
        features::kQueryTiles, kBaseURLKey);
    if (!field_trial_server_url.empty())
      url = field_trial_server_url;
  }

  if (url.empty())
    return GURL();

  return BuildGetQueryTileURL(GURL(url), kDefaultGetQueryTilePath);
}

// static
bool TileConfig::GetIsUnMeteredNetworkRequired() {
  return base::GetFieldTrialParamByFeatureAsBool(
      features::kQueryTiles, kIsUnmeteredNetworkRequiredKey, false);
}

// static
std::string TileConfig::GetExperimentTag(const std::string& country_code) {
  std::vector<std::string> experiment_tag;
  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kQueryTilesSingleTier)) {
    experiment_tag.emplace_back(kQueryTilesSingleTierExperimentTag);
  }

  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kQueryTilesEnableTrending)) {
    experiment_tag.emplace_back(kQueryTilesEnableTrendingExperimentTag);
  }

  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kQueryTilesRankTiles)) {
    experiment_tag.emplace_back(kQueryTilesRankTilesExperimentTag);
  }

  if (!experiment_tag.empty()) {
    return "{" + base::JoinString(experiment_tag, ",") + "}";
  }

  std::string tag = base::GetFieldTrialParamValueByFeature(
      features::kQueryTiles, kExperimentTagKey);
  if (tag.empty() &&
      !base::FeatureList::IsEnabled(
          query_tiles::features::kQueryTilesDisableCountryOverride) &&
      features::IsQueryTilesEnabledForCountry(country_code)) {
    if (base::EqualsCaseInsensitiveASCII(country_code, "IN") ||
        base::EqualsCaseInsensitiveASCII(country_code, "NG")) {
      return kDefaultExperimentTagForINAndNG;
    } else if (base::EqualsCaseInsensitiveASCII(country_code, "JP")) {
      return kDefaultExperimentTagForJP;
    }
  }
  return tag;
}

// static
base::TimeDelta TileConfig::GetExpireDuration() {
  int time_in_seconds = base::GetFieldTrialParamByFeatureAsInt(
      features::kQueryTiles, kExpireDurationKey,
      kDefaultExpireDurationInSeconds);
  return base::Seconds(time_in_seconds);
}

// static
ImagePrefetchMode TileConfig::GetImagePrefetchMode() {
  std::string image_prefetch_mode = base::GetFieldTrialParamValueByFeature(
      features::kQueryTiles, kImagePrefetchModeKey);
  if (image_prefetch_mode == "none")
    return ImagePrefetchMode::kNone;
  if (image_prefetch_mode == "top")
    return ImagePrefetchMode::kTopLevel;
  if (image_prefetch_mode == "all")
    return ImagePrefetchMode::kAll;

  return ImagePrefetchMode::kTopLevel;
}

// static
int TileConfig::GetScheduleIntervalInMs() {
  return base::GetFieldTrialParamByFeatureAsInt(
      features::kQueryTiles, kScheduleIntervalKey, kDefaultScheduleInterval);
}

// static
int TileConfig::GetMaxRandomWindowInMs() {
  return base::GetFieldTrialParamByFeatureAsInt(
      features::kQueryTiles, kMaxRandomWindowKey, kDefaultRandomWindow);
}

// static
int TileConfig::GetOneoffTaskWindowInMs() {
  return base::GetFieldTrialParamByFeatureAsInt(
      features::kQueryTiles, kOneoffTaskWindowKey, kDefaultOneoffTaskWindow);
}

// static
int TileConfig::GetBackoffPolicyArgsInitDelayInMs() {
  return base::GetFieldTrialParamByFeatureAsInt(features::kQueryTiles,
                                                kBackoffInitDelayInMsKey,
                                                kDefaultBackoffInitDelayInMs);
}

// static
int TileConfig::GetBackoffPolicyArgsMaxDelayInMs() {
  return base::GetFieldTrialParamByFeatureAsInt(features::kQueryTiles,
                                                kBackoffMaxDelayInMsKey,
                                                kDefaultBackoffMaxDelayInMs);
}

// static
double TileConfig::GetTileScoreDecayLambda() {
  return base::GetFieldTrialParamByFeatureAsDouble(
      features::kQueryTiles, kTileScoreDecayLambdaKey,
      kDefaultTileScoreDecayLambda);
}

// static
double TileConfig::GetMinimumScoreForNewFrontTiles() {
  return base::GetFieldTrialParamByFeatureAsDouble(
      features::kQueryTiles, kMinimumScoreForNewFrontTilesKey,
      kDefaultMinimumTileScoreForNewFrontTiles);
}

// static
int TileConfig::GetNumTrendingTilesToDisplay() {
  return base::GetFieldTrialParamByFeatureAsInt(
      features::kQueryTiles, kNumTrendingTilesKey,
      kDefaultNumTrendingTilesToDisplay);
}

// static
int TileConfig::GetMaxTrendingTileImpressions() {
  return base::GetFieldTrialParamByFeatureAsInt(
      features::kQueryTiles, kMaxTrendingTileImpressionsKey,
      kDefaultMaxTrendingTileImpressions);
}

// static
int TileConfig::GetTileShufflePosition() {
  return base::GetFieldTrialParamByFeatureAsInt(features::kQueryTiles,
                                                kTileShufflePositionKey,
                                                kDefaultTileShufflePosition);
}

// static
int TileConfig::GetNumDaysToResetTileScore() {
  return base::GetFieldTrialParamByFeatureAsInt(
      features::kQueryTiles, kNumDaysToResetTileScoreKey,
      kDefauktNumDaysToResetTileScore);
}

}  // namespace query_tiles