// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/btm/btm_database.h"

#include <cstddef>
#include <limits>
#include <optional>
#include <set>
#include <string>
#include <string_view>
#include <vector>

#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/logging.h"
#include "base/metrics/histogram_functions.h"
#include "base/metrics/histogram_macros.h"
#include "base/strings/strcat.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/threading/thread_restrictions.h"
#include "base/time/time.h"
#include "content/browser/btm/btm_database_migrator.h"
#include "content/browser/btm/btm_utils.h"
#include "content/public/common/content_features.h"
#include "sql/database.h"
#include "sql/error_delegate_util.h"
#include "sql/init_status.h"
#include "sql/meta_table.h"
#include "sql/statement.h"
#include "sql/transaction.h"
#include "third_party/abseil-cpp/absl/strings/str_format.h"

namespace content {

namespace {

// NOTE: This is flag is intended for local testing and debugging only.
BASE_FEATURE(kDisableExclusiveLockingOnDipsDatabase,
             base::FEATURE_DISABLED_BY_DEFAULT);

constexpr char kTimerLastFiredKey[] = "timer_last_fired";

std::optional<base::Time> ColumnOptionalTime(sql::Statement& statement,
                                             int column_index) {
  if (statement.GetColumnType(column_index) == sql::ColumnType::kNull) {
    return std::nullopt;
  }
  return statement.ColumnTime(column_index);
}

TimestampRange RangeFromColumns(sql::Statement& statement,
                                int start_column_idx,
                                int end_column_idx,
                                std::vector<BtmErrorCode>& errors) {
  std::optional<base::Time> first_time =
      ColumnOptionalTime(statement, start_column_idx);
  std::optional<base::Time> last_time =
      ColumnOptionalTime(statement, end_column_idx);

  if (!first_time.has_value() && !last_time.has_value()) {
    return std::nullopt;
  }

  if (!first_time.has_value()) {
    errors.push_back(BtmErrorCode::kRead_OpenEndedRange_NullStart);
    return std::nullopt;
  }

  if (!last_time.has_value()) {
    errors.push_back(BtmErrorCode::kRead_OpenEndedRange_NullEnd);
    return std::nullopt;
  }

  return std::make_pair(first_time.value(), last_time.value());
}

// Binds either the start/ends of `range` or NULL at
// `start_param_idx`/`end_param_idx` in `statement` if time is provided.
void BindTimesOrNull(sql::Statement& statement,
                     TimestampRange time,
                     int start_param_idx,
                     int end_param_idx) {
  if (time.has_value()) {
    statement.BindTime(start_param_idx, time->first);
    statement.BindTime(end_param_idx, time->second);
  } else {
    statement.BindNull(start_param_idx);
    statement.BindNull(end_param_idx);
  }
}

}  // namespace

BtmDatabase::BtmDatabase(const std::optional<base::FilePath>& db_path)
    : db_path_(db_path.value_or(base::FilePath())) {
  DCHECK(base::FeatureList::IsEnabled(features::kBtm));

  sql::DatabaseOptions db_options =
      sql::DatabaseOptions()
          .set_wal_mode(true)
          .set_cache_size(32)
          .set_exclusive_locking(!base::FeatureList::IsEnabled(
              kDisableExclusiveLockingOnDipsDatabase));

  db_ = std::make_unique<sql::Database>(db_options, sql::Database::Tag("DIPS"));

  base::AssertLongCPUWorkAllowed();
  if (db_path.has_value()) {
    DCHECK(!db_path->empty())
        << "To create an in-memory BtmDatabase, explicitly pass an "
           "std::nullopt `db_path`.";
    if (base::PathExists(db_path.value())) {
      if (!base::PathIsReadable(db_path.value())) {
        DLOG(ERROR) << "The BTM SQLite database is not readable.";
        return;
      }
      if (!base::PathIsWritable(db_path.value())) {
        DLOG(ERROR) << "The BTM SQLite database is not writable.";
        return;
      }
    }
  }

  if (Init() != sql::INIT_OK) {
    LOG(WARNING) << "Failed to initialize the DIPS SQLite database.";
  }
}

BtmDatabase::~BtmDatabase() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
}

// Invoked on a db error.
void BtmDatabase::DatabaseErrorCallback(int extended_error,
                                        sql::Statement* stmt) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  sql::UmaHistogramSqliteResult("Privacy.DIPS.DatabaseErrors", extended_error);

  if (sql::IsErrorCatastrophic(extended_error) && db_->is_open()) {
    // Normally this will poison the database, causing any subsequent operations
    // to silently fail without any side effects. However, if RazeAndPoison() is
    // called from the error callback in response to an error raised from within
    // sql::Database::Open, opening the now-razed database will be retried.
    db_->RazeAndPoison();
    return;
  }

  // The default handling is to assert on debug and to ignore on release.
  if (!sql::Database::IsExpectedSqliteError(extended_error)) {
    DLOG(FATAL) << db_->GetErrorMessage();
  }
}

sql::InitStatus BtmDatabase::OpenDatabase() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  DCHECK(db_);

  // If this is not the first call to `OpenDatabase()` which can happen when
  // retrying the DB's initialization, then the error callback would've
  // previously been set.
  db_->reset_error_callback();

  db_->set_error_callback(base::BindRepeating(
      &BtmDatabase::DatabaseErrorCallback, base::Unretained(this)));

  if (in_memory()) {
    if (!db_->OpenInMemory()) {
      return sql::INIT_FAILURE;
    }
  } else {
    if (!db_->Open(db_path_)) {
      return sql::INIT_FAILURE;
    }
  }
  return sql::INIT_OK;
}

bool BtmDatabase::InitTables() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  static constexpr char kBouncesSql[] =  // clang-format off
    "CREATE TABLE bounces("
      "site TEXT PRIMARY KEY NOT NULL,"
      "first_user_activation_time INTEGER,"
      "last_user_activation_time INTEGER,"
      "first_bounce_time INTEGER,"
      "last_bounce_time INTEGER,"
      "first_web_authn_assertion_time INTEGER,"
      "last_web_authn_assertion_time INTEGER"
    ")";
  // clang-format on
  DCHECK(db_->IsSQLValid(kBouncesSql));

  static constexpr char kPopupsSql[] =  // clang-format off
    "CREATE TABLE popups("
      "opener_site TEXT NOT NULL,"
      "popup_site TEXT NOT NULL,"
      "access_id INT64,"
      "last_popup_time INTEGER,"
      "is_current_interaction BOOLEAN,"
      "is_authentication_interaction BOOLEAN,"
      "PRIMARY KEY (`opener_site`,`popup_site`)"
    ")";
  // clang-format on
  DCHECK(db_->IsSQLValid(kPopupsSql));

  static constexpr char kConfigSql[] =  // clang-format off
    "CREATE TABLE config("
      "key TEXT NOT NULL,"
      "int_value INTEGER,"
      "PRIMARY KEY (`key`)"
    ")";
  // clang-format on
  DCHECK(db_->IsSQLValid(kConfigSql));

  if (!db_->Execute(kConfigSql)) {
    return false;
  }

  return db_->Execute(kBouncesSql) && db_->Execute(kPopupsSql);
}

sql::InitStatus BtmDatabase::InitImpl() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);

  SCOPED_UMA_HISTOGRAM_TIMER("Privacy.DIPS.Database.Operation.InitTime");

  sql::InitStatus status = OpenDatabase();
  if (status != sql::INIT_OK) {
    return status;
  }
  DCHECK(db_->is_open());

  if (sql::MetaTable::RazeIfIncompatible(
          db_.get(), sql::MetaTable::kNoLowestSupportedVersion,
          kLatestSchemaVersion) == sql::RazeIfIncompatibleResult::kFailed) {
    return sql::INIT_FAILURE;
  }

  // Scope initialization in a transaction so we can't be partially initialized.
  sql::Transaction transaction(db_.get());
  if (!transaction.Begin()) {
    return sql::INIT_FAILURE;
  }

  // Check if the table already exists to update schema if needed.
  bool table_already_exists = sql::MetaTable::DoesTableExist(db_.get());
  // Create the tables.
  if (!meta_table_.Init(db_.get(), kLatestSchemaVersion,
                        kMinCompatibleSchemaVersion)) {
    db_->Close();
    return sql::INIT_FAILURE;
  }

  if (table_already_exists
          ? !MigrateBtmSchemaToLatestVersion(*(db_.get()), meta_table_)
          : !InitTables()) {
    return sql::INIT_FAILURE;
  }

  // Initialization is complete.
  if (!transaction.Commit()) {
    return sql::INIT_FAILURE;
  }

  return sql::INIT_OK;
}

sql::InitStatus BtmDatabase::Init() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);

  sql::InitStatus status = InitImpl();
  int attempts = 1;

  if (status != sql::INIT_OK) {
    db_->Close();

    // Try to initialize the database once more in case it failed once and was
    // razed.
    status = InitImpl();
    attempts++;

    if (status != sql::INIT_OK) {
      attempts = 0;
    }
  }

  db_init_ = (status == sql::INIT_OK);
  base::UmaHistogramExactLinear("Privacy.DIPS.DatabaseInit", attempts, 3);

  last_health_metrics_time_ = clock_->Now();
  LogDatabaseMetrics();

  return status;
}

void BtmDatabase::LogDatabaseMetrics() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  base::TimeTicks start_time = base::TimeTicks::Now();

  std::optional<int64_t> db_size = base::GetFileSize(db_path_);
  if (db_size.has_value()) {
    base::UmaHistogramMemoryKB("Privacy.DIPS.DatabaseSize",
                               db_size.value() / 1024);
  }

  base::UmaHistogramCounts10000("Privacy.DIPS.DatabaseEntryCount",
                                GetEntryCount(BtmDatabaseTable::kBounces));

  base::UmaHistogramTimes("Privacy.DIPS.DatabaseHealthMetricsTime",
                          base::TimeTicks::Now() - start_time);
}

bool BtmDatabase::CheckDBInit() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!db_ || !db_->is_open() || !db_init_) {
    return false;
  }

  // Computing these metrics may be costly, so we only do it every
  // |kMetricsInterval|.
  base::Time now = clock_->Now();
  if (now > last_health_metrics_time_ + kMetricsInterval) {
    last_health_metrics_time_ = now;
    LogDatabaseMetrics();
  }

  return true;
}

bool BtmDatabase::ExecuteSqlForTesting(const base::cstring_view sql) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return false;
  }
  return db_->ExecuteScriptForTesting(sql);  // IN-TEST
}

bool BtmDatabase::Write(const std::string& site,
                        const TimestampRange& user_activation_times,
                        const TimestampRange& bounce_times,
                        const TimestampRange& web_authn_assertion_times) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return false;
  }

  if (site.empty()) {
    base::UmaHistogramEnumeration("Privacy.DIPS.DIPSErrorCodes",
                                  BtmErrorCode::kWrite_EmptySite);
    return false;
  }

  static constexpr char kWriteSql[] =  // clang-format off
    "INSERT OR REPLACE INTO bounces("
      "site,"
      "first_user_activation_time,"
      "last_user_activation_time,"
      "first_bounce_time,"
      "last_bounce_time,"
      "first_web_authn_assertion_time,"
      "last_web_authn_assertion_time"
    ") VALUES(?,?,?,?,?,?,?)";
  // clang-format on
  DCHECK(db_->IsSQLValid(kWriteSql));

  SCOPED_UMA_HISTOGRAM_TIMER("Privacy.DIPS.Database.Operation.WriteTime");

  sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE, kWriteSql));
  statement.BindString(0, site);
  BindTimesOrNull(statement, user_activation_times, 1, 2);
  BindTimesOrNull(statement, bounce_times, 3, 4);
  BindTimesOrNull(statement, web_authn_assertion_times, 5, 6);

  if (!statement.Run()) {
    return false;
  }

  base::UmaHistogramEnumeration("Privacy.DIPS.DIPSErrorCodes",
                                BtmErrorCode::kWrite_None);
  return true;
}

bool BtmDatabase::WritePopup(const std::string& opener_site,
                             const std::string& popup_site,
                             const uint64_t access_id,
                             const base::Time& popup_time,
                             bool is_current_interaction,
                             bool is_authentication_interaction) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return false;
  }

  static constexpr char kWriteSql[] =  // clang-format off
    "INSERT OR REPLACE INTO popups("
      "opener_site,"
      "popup_site,"
      "access_id,"
      "last_popup_time,"
      "is_current_interaction,"
      "is_authentication_interaction"
    ") VALUES(?,?,?,?,?,?)";
  // clang-format on
  DCHECK(db_->IsSQLValid(kWriteSql));

  SCOPED_UMA_HISTOGRAM_TIMER("Privacy.DIPS.Database.Operation.WritePopupTime");

  sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE, kWriteSql));
  statement.BindString(0, opener_site);
  statement.BindString(1, popup_site);
  statement.BindInt64(2, access_id);
  statement.BindTime(3, popup_time);
  statement.BindBool(4, is_current_interaction);
  statement.BindBool(5, is_authentication_interaction);

  return statement.Run();
}

std::optional<StateValue> BtmDatabase::Read(const std::string& site) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return std::nullopt;
  }

  static constexpr char kReadSql[] = R"SQL(
    SELECT
      site,
      first_user_activation_time,
      last_user_activation_time,
      first_bounce_time,
      last_bounce_time,
      first_web_authn_assertion_time,
      last_web_authn_assertion_time
    FROM bounces
    WHERE site=?
  )SQL";
  DCHECK(db_->IsSQLValid(kReadSql));

  SCOPED_UMA_HISTOGRAM_TIMER("Privacy.DIPS.Database.Operation.ReadTime");

  sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE, kReadSql));
  statement.BindString(0, site);

  if (!statement.Step()) {
    if (statement.Succeeded() && site.empty()) {
      base::UmaHistogramEnumeration("Privacy.DIPS.DIPSErrorCodes",
                                    BtmErrorCode::kRead_EmptySite_NotInDb);
    }
    return std::nullopt;
  }

  std::optional<base::Time> last_user_activation_time =
      ColumnOptionalTime(statement, 2);
  std::optional<base::Time> last_web_authn_assertion_time =
      ColumnOptionalTime(statement, 6);
  // If the last user activation and last web authn assertion have expired,
  // treat this entry as not in the database so that callers rewrite the entry
  // for `site` as if it were deleted.
  if ((last_user_activation_time.has_value() ||
       last_web_authn_assertion_time.has_value()) &&
      IsNullOrExpired(last_user_activation_time) &&
      IsNullOrExpired(last_web_authn_assertion_time)) {
    return std::nullopt;
  }

  std::vector<BtmErrorCode> errors;
  TimestampRange user_activation_times =
      RangeFromColumns(statement, 1, 2, errors);
  TimestampRange bounce_times = RangeFromColumns(statement, 3, 4, errors);
  TimestampRange web_authn_assertion_times =
      RangeFromColumns(statement, 5, 6, errors);

  if (site.empty()) {
    errors.push_back(BtmErrorCode::kRead_EmptySite_InDb);
  }

  if (errors.empty()) {
    errors.push_back(BtmErrorCode::kRead_None);
  }
  for (const BtmErrorCode& error : errors) {
    base::UmaHistogramEnumeration("Privacy.DIPS.DIPSErrorCodes", error);
  }

  // If `site` is an empty string, treat the entry as not in the database and
  // remove it. See crbug.com/1447035 for context.
  if (site.empty()) {
    RemoveRow(BtmDatabaseTable::kBounces, site);
    return std::nullopt;
  }

  return StateValue{user_activation_times, bounce_times,
                    web_authn_assertion_times};
}

std::optional<PopupsStateValue> BtmDatabase::ReadPopup(
    const std::string& opener_site,
    const std::string& popup_site) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return std::nullopt;
  }

  static constexpr char kReadSql[] =  // clang-format off
      "SELECT opener_site,"
        "popup_site,"
        "access_id,"
        "last_popup_time, "
        "is_current_interaction, "
        "is_authentication_interaction "
        "FROM popups "
        "WHERE opener_site=? AND popup_site=?";
  // clang-format on
  DCHECK(db_->IsSQLValid(kReadSql));

  SCOPED_UMA_HISTOGRAM_TIMER("Privacy.DIPS.Database.Operation.ReadPopupTime");

  sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE, kReadSql));
  statement.BindString(0, opener_site);
  statement.BindString(1, popup_site);

  if (!statement.Step()) {
    return std::nullopt;
  }

  uint64_t access_id = statement.ColumnInt64(2);
  std::optional<base::Time> popup_time = ColumnOptionalTime(statement, 3);
  if (!popup_time.has_value()) {
    return std::nullopt;
  }
  bool is_current_interaction = statement.ColumnBool(4);

  bool is_authentication_interaction = statement.ColumnBool(5);

  return PopupsStateValue{access_id, popup_time.value(), is_current_interaction,
                          is_authentication_interaction};
}

std::vector<PopupWithTime> BtmDatabase::ReadRecentPopupsWithInteraction(
    const base::TimeDelta& lookback) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return std::vector<PopupWithTime>();
  }

  static constexpr char kReadSql[] =  // clang-format off
      "SELECT opener_site,popup_site,last_popup_time "
      "FROM popups "
      "WHERE "
        "is_current_interaction "
        "AND last_popup_time>?";
  // clang-format on
  DCHECK(db_->IsSQLValid(kReadSql));

  SCOPED_UMA_HISTOGRAM_TIMER(
      "Privacy.DIPS.Database.Operation.ReadRecentPopupsWithInteractionTime");

  sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE, kReadSql));
  statement.BindTime(0, clock_->Now() - lookback);

  std::vector<PopupWithTime> popups;
  while (statement.Step()) {
    popups.push_back(PopupWithTime{.opener_site = statement.ColumnString(0),
                                   .popup_site = statement.ColumnString(1),
                                   .last_popup_time = statement.ColumnTime(2)});
  }
  return popups;
}

std::vector<std::string> BtmDatabase::GetAllSitesForTesting(
    BtmDatabaseTable table) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return {};
  }

  std::vector<std::string> sites;

  if (table == BtmDatabaseTable::kBounces) {
    static constexpr char kReadBounceTableSqlStr[] = "SELECT site FROM bounces";
    DCHECK(db_->IsSQLValid(kReadBounceTableSqlStr));
    sql::Statement s_bounces(
        db_->GetCachedStatement(SQL_FROM_HERE, kReadBounceTableSqlStr));
    while (s_bounces.Step()) {
      sites.push_back(s_bounces.ColumnString(0));
    }
  } else if (table == BtmDatabaseTable::kPopups) {
    static constexpr char kReadPopupTableSqlStr[] =
        "SELECT opener_site,popup_site FROM popups";
    DCHECK(db_->IsSQLValid(kReadPopupTableSqlStr));
    sql::Statement s_popups(
        db_->GetCachedStatement(SQL_FROM_HERE, kReadPopupTableSqlStr));
    while (s_popups.Step()) {
      sites.push_back(s_popups.ColumnString(0));
      sites.push_back(s_popups.ColumnString(1));
    }
  }

  return sites;
}

std::vector<std::string> BtmDatabase::GetSitesThatBounced(
    base::TimeDelta grace_period) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return {};
  }

  SCOPED_UMA_HISTOGRAM_TIMER(
      "Privacy.DIPS.Database.Operation.GetSitesThatBouncedTime");

  ClearExpiredRows();

  static constexpr char kBounceSql[] =  // clang-format off
    "SELECT site FROM bounces "
    "WHERE "
      "first_bounce_time<? "
      "AND last_user_activation_time IS NULL "
      "AND last_web_authn_assertion_time IS NULL "
    "ORDER BY site";
  // clang-format on
  DCHECK(db_->IsSQLValid(kBounceSql));
  sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE, kBounceSql));
  statement.BindTime(0, clock_->Now() - grace_period);

  std::vector<std::string> sites;
  while (statement.Step()) {
    sites.push_back(statement.ColumnString(0));
  }
  return sites;
}

std::set<std::string> BtmDatabase::FilterSites(
    const std::set<std::string>& sites,
    BounceFilterType filter) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return {};
  }

  static constexpr char kReadSqlFmt[] = R"SQL(
    SELECT
      site,
      last_user_activation_time,
      last_web_authn_assertion_time
    FROM bounces
    WHERE site IN (%s)
  )SQL";

  // Interpolate unnamed parameters (i.e. the "?") into the SQL query for each
  // site in the list.
  const std::string kReadSql = absl::StrFormat(
      kReadSqlFmt,
      base::JoinString(std::vector<std::string_view>(sites.size(), "?"), ","));
  DCHECK(db_->IsSQLValid(kReadSql));

  std::string histogram_name;
  switch (filter) {
    case BounceFilterType::kProtectiveEvent:
      histogram_name =
          "Privacy.DIPS.Database.Operation.FilterSitesWithProtectiveEventTime";
      break;
    case BounceFilterType::kUserActivation:
      histogram_name =
          "Privacy.DIPS.Database.Operation.FilterSitesWithUserActivationTime";
      break;
    case BounceFilterType::kWebAuthnAssertion:
      histogram_name =
          "Privacy.DIPS.Database.Operation."
          "FilterSitesWithWebAuthnAssertionTime";
      break;
  }
  base::ScopedUmaHistogramTimer histogram_timer(histogram_name);

  ClearExpiredRows();

  sql::Statement statement(db_->GetUniqueStatement(kReadSql));
  int param_index = 0;
  for (std::string site : sites) {
    statement.BindString(param_index++, site);
  }

  std::set<std::string> filtered_sites;
  while (statement.Step()) {
    std::optional<base::Time> last_user_activation_time =
        ColumnOptionalTime(statement, 1);
    std::optional<base::Time> last_web_authn_assertion_time =
        ColumnOptionalTime(statement, 2);

    bool should_pass_filter = false;
    switch (filter) {
      case BounceFilterType::kProtectiveEvent:
        should_pass_filter = last_user_activation_time.has_value() ||
                             last_web_authn_assertion_time.has_value();
        break;
      case BounceFilterType::kUserActivation:
        should_pass_filter = last_user_activation_time.has_value();
        break;
      case BounceFilterType::kWebAuthnAssertion:
        should_pass_filter = last_web_authn_assertion_time.has_value();
        break;
    }
    if (should_pass_filter) {
      filtered_sites.insert(statement.ColumnString(0));
    }
  }

  return filtered_sites;
}

size_t BtmDatabase::ClearExpiredRows() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  DCHECK(clock_);
  if (!CheckDBInit()) {
    return false;
  }

  size_t change_count = 0;

  // NOTE: The SQLITE `MAX` and `MIN` return `NULL` if any value is `NULL`.
  // That's why `COALESCE` is used.
  static constexpr char kClearAllExpiredBouncesTableSql[] =  // clang-format off
    "DELETE FROM bounces "
    "WHERE MAX("
      "COALESCE(last_user_activation_time,last_web_authn_assertion_time),"
      "COALESCE(last_web_authn_assertion_time,last_user_activation_time)"
    ")<?";
  // clang-format on

  DCHECK(db_->IsSQLValid(kClearAllExpiredBouncesTableSql));
  sql::Statement bounces_statement(
      db_->GetCachedStatement(SQL_FROM_HERE, kClearAllExpiredBouncesTableSql));
  bounces_statement.BindTime(
      0, clock_->Now() - features::kBtmInteractionTtl.Get());
  if (!bounces_statement.Run()) {
    return 0;
  }
  change_count += db_->GetLastChangeCount();

  static constexpr char kClearAllExpiredPopupsTableSql[] =
      "DELETE FROM popups "
      "WHERE last_popup_time<?";

  DCHECK(db_->IsSQLValid(kClearAllExpiredPopupsTableSql));
  sql::Statement popups_statement(
      db_->GetCachedStatement(SQL_FROM_HERE, kClearAllExpiredPopupsTableSql));
  popups_statement.BindTime(0, clock_->Now() - kPopupTtl);
  if (!popups_statement.Run()) {
    return 0;
  }
  change_count += db_->GetLastChangeCount();

  return change_count;
}

bool BtmDatabase::RemoveRow(const BtmDatabaseTable table,
                            std::string_view site) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return false;
  }

  ClearExpiredRows();

  if (table == BtmDatabaseTable::kBounces) {
    static constexpr char kRemoveSql[] = "DELETE FROM bounces WHERE site=?";
    DCHECK(db_->IsSQLValid(kRemoveSql));
    sql::Statement statement(
        db_->GetCachedStatement(SQL_FROM_HERE, kRemoveSql));
    statement.BindString(0, site);
    return statement.Run();
  } else if (table == BtmDatabaseTable::kPopups) {
    static constexpr char kRemoveSql[] =
        "DELETE FROM popups WHERE opener_site=? OR popup_site=?";
    DCHECK(db_->IsSQLValid(kRemoveSql));
    sql::Statement statement(
        db_->GetCachedStatement(SQL_FROM_HERE, kRemoveSql));
    statement.BindString(0, site);
    statement.BindString(1, site);
    return statement.Run();
  }

  // This should never be called - both BtmDatabaseTable types are handled and
  // return above.
  return false;
}

bool BtmDatabase::RemoveRows(const BtmDatabaseTable table,
                             const std::vector<std::string>& sites) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return false;
  }

  if (sites.empty()) {
    return true;
  }

  SCOPED_UMA_HISTOGRAM_TIMER("Privacy.DIPS.Database.Operation.RemoveRowsTime");

  const std::string site_list =
      base::JoinString(std::vector<std::string_view>(sites.size(), "?"), ",");

  if (table == BtmDatabaseTable::kBounces) {
    sql::Statement statement(db_->GetUniqueStatement(base::StrCat(
        {"DELETE FROM bounces ", "WHERE site IN(", site_list, ")"})));
    for (size_t i = 0; i < sites.size(); i++) {
      statement.BindString(i, sites[i]);
    }
    return statement.Run();
  } else if (table == BtmDatabaseTable::kPopups) {
    sql::Statement statement(db_->GetUniqueStatement(
        base::StrCat({"DELETE FROM popups ", "WHERE opener_site IN(", site_list,
                      ") OR popup_site IN(", site_list, ")"})));
    for (size_t i = 0; i < sites.size(); i++) {
      // There are 2 * sites.size() total bind locations, in the first and
      // second site_list. Each site should be bound in both lists.
      statement.BindString(i, sites[i]);
      statement.BindString(i + sites.size(), sites[i]);
    }
    return statement.Run();
  }

  // This should never be called - both BtmDatabaseTable types are handled and
  // return above.
  return false;
}

bool BtmDatabase::RemoveEventsByTime(const base::Time& delete_begin,
                                     const base::Time& delete_end,
                                     const BtmEventRemovalType type) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return false;
  }

  ClearExpiredRows();

  sql::Transaction transaction(db_.get());
  if (!transaction.Begin()) {
    return false;
  }

  GarbageCollect();

  return (ClearTimestamps(delete_begin, delete_end, type) &&
          transaction.Commit());
}

bool BtmDatabase::RemoveEventsBySite(bool preserve,
                                     const std::vector<std::string>& sites,
                                     const BtmEventRemovalType type) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return false;
  }

  sql::Transaction transaction(db_.get());
  if (!transaction.Begin()) {
    return false;
  }

  GarbageCollect();

  if (!ClearTimestampsBySite(preserve, sites, type)) {
    return false;
  }

  return transaction.Commit();
}

bool BtmDatabase::ClearTimestamps(const base::Time& delete_begin,
                                  const base::Time& delete_end,
                                  const BtmEventRemovalType type) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return false;
  }

  SCOPED_UMA_HISTOGRAM_TIMER(
      "Privacy.DIPS.Database.Operation.ClearTimestampsTime");

  ClearExpiredRows();

  if ((type & BtmEventRemovalType::kHistory) == BtmEventRemovalType::kHistory) {
    static constexpr char kClearUserActivationSql[] =  // clang-format off
        "UPDATE bounces SET "
            "first_user_activation_time=NULL,"
            "last_user_activation_time=NULL "
            "WHERE first_user_activation_time>=? AND "
                  "last_user_activation_time<=?";
    // clang-format on
    DCHECK(db_->IsSQLValid(kClearUserActivationSql));

    sql::Statement s_clear_user_activation(
        db_->GetCachedStatement(SQL_FROM_HERE, kClearUserActivationSql));
    s_clear_user_activation.BindTime(0, delete_begin);
    s_clear_user_activation.BindTime(1, delete_end);

    if (!s_clear_user_activation.Run()) {
      return false;
    }

    static constexpr char kClearWaaSql[] =  // clang-format off
        "UPDATE bounces SET "
            "first_web_authn_assertion_time=NULL,"
            "last_web_authn_assertion_time=NULL "
            "WHERE first_web_authn_assertion_time>=? AND "
                  "last_web_authn_assertion_time<=?";
    // clang-format on
    DCHECK(db_->IsSQLValid(kClearWaaSql));

    sql::Statement s_clear_waa(
        db_->GetCachedStatement(SQL_FROM_HERE, kClearWaaSql));
    s_clear_waa.BindTime(0, delete_begin);
    s_clear_waa.BindTime(1, delete_end);

    if (!s_clear_waa.Run()) {
      return false;
    }

    static constexpr char kClearPopupsSql[] =  // clang-format off
        "DELETE FROM popups "
        "WHERE last_popup_time>=? AND last_popup_time<=?";
    // clang-format on
    DCHECK(db_->IsSQLValid(kClearPopupsSql));

    sql::Statement s_clear_popups(
        db_->GetCachedStatement(SQL_FROM_HERE, kClearPopupsSql));
    s_clear_popups.BindTime(0, delete_begin);
    s_clear_popups.BindTime(1, delete_end);

    if (!s_clear_popups.Run()) {
      return false;
    }
  }

  if ((type & BtmEventRemovalType::kStorage) == BtmEventRemovalType::kStorage) {
    static constexpr char kClearBounceSql[] =  // clang-format off
        "UPDATE bounces SET "
            "first_bounce_time=NULL,"
            "last_bounce_time=NULL "
            "WHERE first_bounce_time>=? AND "
                  "last_bounce_time<=?";
    // clang-format on
    DCHECK(db_->IsSQLValid(kClearBounceSql));

    sql::Statement s_clear_bounce(
        db_->GetCachedStatement(SQL_FROM_HERE, kClearBounceSql));
    s_clear_bounce.BindTime(0, delete_begin);
    s_clear_bounce.BindTime(1, delete_end);

    if (!s_clear_bounce.Run()) {
      return false;
    }
  }

  return (RemoveEmptyRows() &&
          AdjustFirstTimestamps(delete_begin, delete_end, type) &&
          AdjustLastTimestamps(delete_begin, delete_end, type));
}

bool BtmDatabase::AdjustFirstTimestamps(const base::Time& delete_begin,
                                        const base::Time& delete_end,
                                        const BtmEventRemovalType type) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return false;
  }

  ClearExpiredRows();

  if (delete_end == base::Time::Max()) {
    // When `delete_end` is `base::Time::Max()`, any timestamp range that would
    // be altered by the below queries should have already been removed by
    // ClearTimestamps(), which MUST always be called before this method.
    return true;
  }

  if ((type & BtmEventRemovalType::kHistory) == BtmEventRemovalType::kHistory) {
    static constexpr char kUpdateFirstUserActivationSql[] =  // clang-format off
        "UPDATE bounces SET first_user_activation_time=?2 "
            "WHERE first_user_activation_time>=?1 AND "
                  "first_user_activation_time<?2";
    // clang-format on
    DCHECK(db_->IsSQLValid(kUpdateFirstUserActivationSql));

    sql::Statement s_first_user_activation(
        db_->GetCachedStatement(SQL_FROM_HERE, kUpdateFirstUserActivationSql));
    s_first_user_activation.BindTime(0, delete_begin);
    s_first_user_activation.BindTime(1, delete_end);

    if (!s_first_user_activation.Run()) {
      return false;
    }

    static constexpr char kUpdateFirstWaaSql[] =  // clang-format off
        "UPDATE bounces SET first_web_authn_assertion_time=?2 "
            "WHERE first_web_authn_assertion_time>=?1 AND "
                  "first_web_authn_assertion_time<?2";
    // clang-format on
    DCHECK(db_->IsSQLValid(kUpdateFirstWaaSql));

    sql::Statement s_first_waa(
        db_->GetCachedStatement(SQL_FROM_HERE, kUpdateFirstWaaSql));
    s_first_waa.BindTime(0, delete_begin);
    s_first_waa.BindTime(1, delete_end);

    if (!s_first_waa.Run()) {
      return false;
    }
  }

  if ((type & BtmEventRemovalType::kStorage) == BtmEventRemovalType::kStorage) {
    static constexpr char kUpdateFirstBounceSql[] =  // clang-format off
        "UPDATE bounces SET first_bounce_time=?2 "
            "WHERE first_bounce_time>=?1 AND "
                  "first_bounce_time<?2";
    // clang-format on
    DCHECK(db_->IsSQLValid(kUpdateFirstBounceSql));

    sql::Statement s_first_bounce(
        db_->GetCachedStatement(SQL_FROM_HERE, kUpdateFirstBounceSql));
    s_first_bounce.BindTime(0, delete_begin);
    s_first_bounce.BindTime(1, delete_end);

    if (!s_first_bounce.Run()) {
      return false;
    }
  }

  return true;
}

bool BtmDatabase::AdjustLastTimestamps(const base::Time& delete_begin,
                                       const base::Time& delete_end,
                                       const BtmEventRemovalType type) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return false;
  }

  ClearExpiredRows();

  if (delete_begin == base::Time::Min()) {
    // When `delete_begin` is `base::Time::Min()`, any timestamp range that
    // would be altered by the below queries should have already been removed by
    // ClearTimestamps(), which MUST always be called before this method.
    return true;
  }

  if ((type & BtmEventRemovalType::kHistory) == BtmEventRemovalType::kHistory) {
    static constexpr char kUpdateLastUserActivationSql[] =  // clang-format off
        "UPDATE bounces SET last_user_activation_time=?1 "
            "WHERE last_user_activation_time>?1 AND "
                  "last_user_activation_time<=?2";
    // clang-format on
    DCHECK(db_->IsSQLValid(kUpdateLastUserActivationSql));

    sql::Statement s_last_user_activation(
        db_->GetCachedStatement(SQL_FROM_HERE, kUpdateLastUserActivationSql));
    s_last_user_activation.BindTime(0, delete_begin);
    s_last_user_activation.BindTime(1, delete_end);

    if (!s_last_user_activation.Run()) {
      return false;
    }

    static constexpr char kUpdateLastWaaSql[] =  // clang-format off
        "UPDATE bounces SET last_web_authn_assertion_time=?1 "
            "WHERE last_web_authn_assertion_time>?1 AND "
                  "last_web_authn_assertion_time<=?2";
    // clang-format on
    DCHECK(db_->IsSQLValid(kUpdateLastWaaSql));

    sql::Statement s_last_waa(
        db_->GetCachedStatement(SQL_FROM_HERE, kUpdateLastWaaSql));
    s_last_waa.BindTime(0, delete_begin);
    s_last_waa.BindTime(1, delete_end);

    if (!s_last_waa.Run()) {
      return false;
    }
  }

  if ((type & BtmEventRemovalType::kStorage) == BtmEventRemovalType::kStorage) {
    static constexpr char kUpdateLastBounceSql[] =  // clang-format off
        "UPDATE bounces SET last_bounce_time=?1 "
            "WHERE last_bounce_time>?1 AND "
                  "last_bounce_time<=?2";
    // clang-format on
    DCHECK(db_->IsSQLValid(kUpdateLastBounceSql));

    sql::Statement s_last_bounce(
        db_->GetCachedStatement(SQL_FROM_HERE, kUpdateLastBounceSql));
    s_last_bounce.BindTime(0, delete_begin);
    s_last_bounce.BindTime(1, delete_end);

    if (!s_last_bounce.Run()) {
      return false;
    }
  }

  return true;
}

bool BtmDatabase::ClearTimestampsBySite(bool preserve,
                                        const std::vector<std::string>& sites,
                                        const BtmEventRemovalType type) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);

  if (sites.empty()) {
    return true;
  }

  std::string placeholders =
      base::JoinString(std::vector<std::string_view>(sites.size(), "?"), ",");

  if ((type & BtmEventRemovalType::kStorage) == BtmEventRemovalType::kStorage) {
    sql::Statement s_clear_storage(db_->GetUniqueStatement(  // clang-format off
        base::StrCat({"UPDATE bounces SET "
                          "first_bounce_time=NULL,"
                          "last_bounce_time=NULL "
                          "WHERE site ", (preserve ? "NOT " : ""),
                              "IN(", placeholders, ")" })  // clang-format on
        ));

    for (size_t i = 0; i < sites.size(); i++) {
      s_clear_storage.BindString(i, sites[i]);
    }

    if (!s_clear_storage.Run()) {
      return false;
    }
  }

  return RemoveEmptyRows();
}

bool BtmDatabase::RemoveEmptyRows() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);

  static constexpr char kCleanUpSql[] =  // clang-format off
    "DELETE FROM bounces "
    "WHERE first_user_activation_time IS NULL "
      "AND last_user_activation_time IS NULL "
      "AND first_bounce_time IS NULL "
      "AND last_bounce_time IS NULL "
      "AND first_web_authn_assertion_time IS NULL "
      "AND last_web_authn_assertion_time IS NULL";
  // clang-format on
  DCHECK(db_->IsSQLValid(kCleanUpSql));
  sql::Statement s_clean(db_->GetCachedStatement(SQL_FROM_HERE, kCleanUpSql));

  // Clearing the `popups` table is unnecessary because there are no operations
  // to nullify individual rows.

  return s_clean.Run();
}

size_t BtmDatabase::GetEntryCount(const BtmDatabaseTable table) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return 0;
  }

  ClearExpiredRows();

  if (table == BtmDatabaseTable::kBounces) {
    static constexpr char kBounceTableEntryCountSqlStr[] =
        "SELECT COUNT(*) FROM bounces";
    sql::Statement statement(
        db_->GetCachedStatement(SQL_FROM_HERE, kBounceTableEntryCountSqlStr));
    return (statement.Step() ? statement.ColumnInt(0) : 0);
  } else if (table == BtmDatabaseTable::kPopups) {
    static constexpr char kPopupTableEntryCountSqlStr[] =
        "SELECT COUNT(*) FROM popups";
    sql::Statement statement(
        db_->GetCachedStatement(SQL_FROM_HERE, kPopupTableEntryCountSqlStr));
    return (statement.Step() ? statement.ColumnInt(0) : 0);
  }

  // This should never be called - both BtmDatabaseTable types are handled and
  // return above.
  return false;
}

size_t BtmDatabase::GarbageCollect() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return 0;
  }

  size_t num_deleted = ClearExpiredRows();

  for (const BtmDatabaseTable table :
       {BtmDatabaseTable::kBounces, BtmDatabaseTable::kPopups}) {
    // NOTE: `GetEntryCount()` might perform other row deletions whilst
    // re-calling `ClearExpiredRows()`, but possible precision lost in the final
    // num_delete isn't deemed crucial.
    const size_t num_entries = GetEntryCount(table);
    if (num_entries <= max_entries_) {
      continue;
    }

    const int purge_goal = num_entries - (max_entries_ - purge_entries_);
    DCHECK_GT(purge_goal, 0);
    num_deleted += GarbageCollectOldest(table, purge_goal);
  }

  return num_deleted;
}

size_t BtmDatabase::GarbageCollectOldest(const BtmDatabaseTable table,
                                         int purge_goal) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return 0;
  }

  if (table == BtmDatabaseTable::kBounces) {
    static constexpr char kGarbageCollectOldestSql[] =  // clang-format off
    "DELETE FROM bounces "
    "WHERE site IN("
      "SELECT site FROM bounces "
      "ORDER BY "
        "MAX("
          "COALESCE("
            "last_user_activation_time,"
            "last_web_authn_assertion_time"
          "),"
          "COALESCE("
            "last_web_authn_assertion_time,"
            "last_user_activation_time"
          ")"
        ") ASC,"
        "last_user_activation_time ASC,"
        "last_web_authn_assertion_time ASC "
      "LIMIT ?"
    ")";
    // clang-format on
    DCHECK(db_->IsSQLValid(kGarbageCollectOldestSql));

    sql::Statement statement(
        db_->GetCachedStatement(SQL_FROM_HERE, kGarbageCollectOldestSql));
    statement.BindInt(0, purge_goal);
    return statement.Run() ? db_->GetLastChangeCount() : 0;
  } else if (table == BtmDatabaseTable::kPopups) {
    static constexpr char kGarbageCollectOldestSql[] =  // clang-format off
    "DELETE FROM popups "
    "WHERE (opener_site,popup_site) IN("
      "SELECT opener_site,popup_site "
      "FROM popups "
      "ORDER BY last_popup_time ASC "
      "LIMIT ?"
    ")";
    // clang-format on
    DCHECK(db_->IsSQLValid(kGarbageCollectOldestSql));

    sql::Statement statement(
        db_->GetCachedStatement(SQL_FROM_HERE, kGarbageCollectOldestSql));
    statement.BindInt(0, purge_goal);
    return statement.Run() ? db_->GetLastChangeCount() : 0;
  }

  // This should never be called - both BtmDatabaseTable types are handled and
  // return above.
  return false;
}

std::vector<std::string> BtmDatabase::GetGarbageCollectOldestSitesForTesting(
    BtmDatabaseTable table) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return {};
  }

  std::vector<std::string> sites;
  if (table == BtmDatabaseTable::kBounces) {
    static constexpr char kReadSql[] =  // clang-format off
    "SELECT site FROM bounces "
    "ORDER BY "
      "MAX("
        "COALESCE("
          "last_user_activation_time,"
          "last_web_authn_assertion_time"
        "),"
        "COALESCE("
          "last_web_authn_assertion_time,"
          "last_user_activation_time"
        ")"
      ") ASC,"
      "last_user_activation_time ASC,"
      "last_web_authn_assertion_time ASC";
    // clang-format on
    DCHECK(db_->IsSQLValid(kReadSql));

    sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE, kReadSql));
    while (statement.Step()) {
      sites.push_back(statement.ColumnString(0));
    }
  } else if (table == BtmDatabaseTable::kPopups) {
    static constexpr char kReadSql[] =
        "SELECT opener_site,popup_site "
        "FROM popups "
        "ORDER BY last_popup_time ASC";
    DCHECK(db_->IsSQLValid(kReadSql));

    sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE, kReadSql));
    while (statement.Step()) {
      sites.push_back(statement.ColumnString(0));
    }
  }

  return sites;
}

bool BtmDatabase::SetConfigValue(std::string_view key, int64_t value) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return false;
  }

  static constexpr char kInsertValueSql[] =
      "INSERT OR REPLACE INTO config(key,int_value) VALUES(?,?)";
  DCHECK(db_->IsSQLValid(kInsertValueSql));
  sql::Statement statement(
      db_->GetCachedStatement(SQL_FROM_HERE, kInsertValueSql));
  statement.BindString(0, key);
  statement.BindInt64(1, value);

  return statement.Run();
}

std::optional<int64_t> BtmDatabase::GetConfigValue(std::string_view key) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!CheckDBInit()) {
    return std::nullopt;
  }

  static constexpr char kSelectValueSql[] =
      "SELECT int_value FROM config WHERE key = ?";
  DCHECK(db_->IsSQLValid(kSelectValueSql));
  sql::Statement statement(
      db_->GetCachedStatement(SQL_FROM_HERE, kSelectValueSql));
  statement.BindString(0, key);

  if (!statement.Step()) {
    return std::nullopt;
  }

  return statement.ColumnInt64(0);
}

std::optional<base::Time> BtmDatabase::GetTimerLastFired() {
  std::optional<int64_t> raw_value = GetConfigValue(kTimerLastFiredKey);
  if (!raw_value.has_value()) {
    return std::nullopt;
  }

  return base::Time::FromDeltaSinceWindowsEpoch(base::Microseconds(*raw_value));
}

bool BtmDatabase::SetTimerLastFired(base::Time time) {
  return SetConfigValue(kTimerLastFiredKey,
                        time.ToDeltaSinceWindowsEpoch().InMicroseconds());
}

bool BtmDatabase::IsNullOrExpired(std::optional<base::Time> time) {
  return !time.has_value() ||
         time.value() + features::kBtmInteractionTtl.Get() < clock_->Now();
}

}  // namespace content