// Copyright (c) 2013 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 "ash/system/chromeos/power/power_status.h"

#include <algorithm>
#include <cmath>

#include "ash/shell.h"
#include "ash/shell_delegate.h"
#include "base/logging.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/utf_string_conversions.h"
#include "chromeos/dbus/dbus_thread_manager.h"
#include "chromeos/dbus/power_manager_client.h"
#include "grit/ash_resources.h"
#include "grit/ash_strings.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/l10n/time_format.h"
#include "ui/base/resource/resource_bundle.h"
#include "ui/gfx/image/image.h"
#include "ui/gfx/image/image_skia_operations.h"
#include "ui/gfx/rect.h"

namespace ash {
namespace internal {

namespace {

// Updates |proto| to ensure that its fields are consistent.
void SanitizeProto(power_manager::PowerSupplyProperties* proto) {
  DCHECK(proto);

  if (proto->battery_state() ==
      power_manager::PowerSupplyProperties_BatteryState_FULL)
    proto->set_battery_percent(100.0);

  if (!proto->is_calculating_battery_time()) {
    const bool on_line_power = proto->external_power() !=
        power_manager::PowerSupplyProperties_ExternalPower_DISCONNECTED;
    if ((on_line_power && proto->battery_time_to_full_sec() < 0) ||
        (!on_line_power && proto->battery_time_to_empty_sec() < 0))
      proto->set_is_calculating_battery_time(true);
  }
}

base::string16 GetBatteryTimeAccessibilityString(int hour, int min) {
  DCHECK(hour || min);
  if (hour && !min) {
    return ui::TimeFormat::TimeDurationLong(base::TimeDelta::FromHours(hour));
  }
  if (min && !hour) {
    return ui::TimeFormat::TimeDurationLong(base::TimeDelta::FromMinutes(min));
  }
  return l10n_util::GetStringFUTF16(
      IDS_ASH_STATUS_TRAY_BATTERY_TIME_ACCESSIBLE,
      ui::TimeFormat::TimeDurationLong(base::TimeDelta::FromHours(hour)),
      ui::TimeFormat::TimeDurationLong(base::TimeDelta::FromMinutes(min)));
}

static PowerStatus* g_power_status = NULL;

// Minimum battery percentage rendered in UI.
const int kMinBatteryPercent = 1;

// Width and height of battery images.
const int kBatteryImageHeight = 25;
const int kBatteryImageWidth = 25;

// Number of different power states.
const int kNumPowerImages = 15;

}  // namespace

const int PowerStatus::kMaxBatteryTimeToDisplaySec = 24 * 60 * 60;

// static
void PowerStatus::Initialize() {
  CHECK(!g_power_status);
  g_power_status = new PowerStatus();
}

// static
void PowerStatus::Shutdown() {
  CHECK(g_power_status);
  delete g_power_status;
  g_power_status = NULL;
}

// static
bool PowerStatus::IsInitialized() {
  return g_power_status != NULL;
}

// static
PowerStatus* PowerStatus::Get() {
  CHECK(g_power_status) << "PowerStatus::Get() called before Initialize().";
  return g_power_status;
}

// static
bool PowerStatus::ShouldDisplayBatteryTime(const base::TimeDelta& time) {
  return time >= base::TimeDelta::FromMinutes(1) &&
      time.InSeconds() <= kMaxBatteryTimeToDisplaySec;
}

// static
void PowerStatus::SplitTimeIntoHoursAndMinutes(const base::TimeDelta& time,
                                               int* hours,
                                               int* minutes) {
  DCHECK(hours);
  DCHECK(minutes);
  *hours = time.InHours();
  const double seconds =
      (time - base::TimeDelta::FromHours(*hours)).InSecondsF();
  *minutes = static_cast<int>(seconds / 60.0 + 0.5);
}

void PowerStatus::AddObserver(Observer* observer) {
  DCHECK(observer);
  observers_.AddObserver(observer);
}

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

void PowerStatus::RequestStatusUpdate() {
  chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
      RequestStatusUpdate();
}

bool PowerStatus::IsBatteryPresent() const {
  return proto_.battery_state() !=
      power_manager::PowerSupplyProperties_BatteryState_NOT_PRESENT;
}

bool PowerStatus::IsBatteryFull() const {
  return proto_.battery_state() ==
      power_manager::PowerSupplyProperties_BatteryState_FULL;
}

bool PowerStatus::IsBatteryCharging() const {
  return proto_.battery_state() ==
      power_manager::PowerSupplyProperties_BatteryState_CHARGING;
}

bool PowerStatus::IsBatteryDischargingOnLinePower() const {
  return IsLinePowerConnected() && proto_.battery_state() ==
      power_manager::PowerSupplyProperties_BatteryState_DISCHARGING;
}

double PowerStatus::GetBatteryPercent() const {
  return proto_.battery_percent();
}

int PowerStatus::GetRoundedBatteryPercent() const {
  return std::max(kMinBatteryPercent,
      static_cast<int>(GetBatteryPercent() + 0.5));
}

bool PowerStatus::IsBatteryTimeBeingCalculated() const {
  return proto_.is_calculating_battery_time();
}

base::TimeDelta PowerStatus::GetBatteryTimeToEmpty() const {
  return base::TimeDelta::FromSeconds(proto_.battery_time_to_empty_sec());
}

base::TimeDelta PowerStatus::GetBatteryTimeToFull() const {
  return base::TimeDelta::FromSeconds(proto_.battery_time_to_full_sec());
}

bool PowerStatus::IsLinePowerConnected() const {
  return proto_.external_power() !=
      power_manager::PowerSupplyProperties_ExternalPower_DISCONNECTED;
}

bool PowerStatus::IsMainsChargerConnected() const {
  return proto_.external_power() ==
      power_manager::PowerSupplyProperties_ExternalPower_AC;
}

bool PowerStatus::IsUsbChargerConnected() const {
  return proto_.external_power() ==
      power_manager::PowerSupplyProperties_ExternalPower_USB;
}

gfx::ImageSkia PowerStatus::GetBatteryImage(IconSet icon_set) const {
  gfx::Image all;
  if (IsUsbChargerConnected()) {
    all = ui::ResourceBundle::GetSharedInstance().GetImageNamed(
        icon_set == ICON_DARK ?
        IDR_AURA_UBER_TRAY_POWER_SMALL_CHARGING_UNRELIABLE_DARK :
        IDR_AURA_UBER_TRAY_POWER_SMALL_CHARGING_UNRELIABLE);
  } else {
    all = ui::ResourceBundle::GetSharedInstance().GetImageNamed(
        icon_set == ICON_DARK ?
        IDR_AURA_UBER_TRAY_POWER_SMALL_DARK : IDR_AURA_UBER_TRAY_POWER_SMALL);
  }

  // Get the horizontal offset in the battery icon array image. The USB /
  // "unreliable charging" image has a single column of icons; the other
  // image contains a "battery" column on the left and a "line power"
  // column on the right.
  int offset = IsUsbChargerConnected() ? 0 : (IsLinePowerConnected() ? 1 : 0);

  // Get the vertical offset corresponding to the current battery level.
  int index = -1;
  if (GetBatteryPercent() >= 100.0) {
    index = kNumPowerImages - 1;
  } else if (!IsBatteryPresent()) {
    index = kNumPowerImages;
  } else {
    index = static_cast<int>(
        GetBatteryPercent() / 100.0 * (kNumPowerImages - 1));
    index = std::max(std::min(index, kNumPowerImages - 2), 0);
  }

  gfx::Rect region(
      offset * kBatteryImageWidth, index * kBatteryImageHeight,
      kBatteryImageWidth, kBatteryImageHeight);
  return gfx::ImageSkiaOperations::ExtractSubset(*all.ToImageSkia(), region);
}

base::string16 PowerStatus::GetAccessibleNameString() const {
  ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
  if (IsBatteryFull()) {
    return rb.GetLocalizedString(
        IDS_ASH_STATUS_TRAY_BATTERY_FULL_CHARGE_ACCESSIBLE);
  }

  base::string16 battery_percentage_accessible = l10n_util::GetStringFUTF16(
      IsBatteryCharging() ?
      IDS_ASH_STATUS_TRAY_BATTERY_PERCENT_CHARGING_ACCESSIBLE :
      IDS_ASH_STATUS_TRAY_BATTERY_PERCENT_ACCESSIBLE,
      base::IntToString16(GetRoundedBatteryPercent()));
  base::string16 battery_time_accessible = base::string16();
  const base::TimeDelta time = IsBatteryCharging() ? GetBatteryTimeToFull() :
      GetBatteryTimeToEmpty();

  if (IsUsbChargerConnected()) {
    battery_time_accessible = rb.GetLocalizedString(
        IDS_ASH_STATUS_TRAY_BATTERY_CHARGING_UNRELIABLE_ACCESSIBLE);
  } else if (IsBatteryTimeBeingCalculated()) {
    battery_time_accessible = rb.GetLocalizedString(
        IDS_ASH_STATUS_TRAY_BATTERY_CALCULATING_ACCESSIBLE);
  } else if (ShouldDisplayBatteryTime(time) &&
             !IsBatteryDischargingOnLinePower()) {
    int hour = 0, min = 0;
    PowerStatus::SplitTimeIntoHoursAndMinutes(time, &hour, &min);
    base::string16 minute = min < 10 ?
        ASCIIToUTF16("0") + base::IntToString16(min) :
        base::IntToString16(min);
    battery_time_accessible =
        l10n_util::GetStringFUTF16(
            IsBatteryCharging() ?
            IDS_ASH_STATUS_TRAY_BATTERY_TIME_UNTIL_FULL_ACCESSIBLE :
            IDS_ASH_STATUS_TRAY_BATTERY_TIME_LEFT_ACCESSIBLE,
            GetBatteryTimeAccessibilityString(hour, min));
  }
  return battery_time_accessible.empty() ?
      battery_percentage_accessible :
      battery_percentage_accessible + ASCIIToUTF16(". ") +
      battery_time_accessible;
}

PowerStatus::PowerStatus() {
  chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
      AddObserver(this);
  chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
      RequestStatusUpdate();
}

PowerStatus::~PowerStatus() {
  chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
      RemoveObserver(this);
}

void PowerStatus::SetProtoForTesting(
    const power_manager::PowerSupplyProperties& proto) {
  proto_ = proto;
  SanitizeProto(&proto_);
}

void PowerStatus::PowerChanged(
    const power_manager::PowerSupplyProperties& proto) {
  proto_ = proto;
  SanitizeProto(&proto_);
  FOR_EACH_OBSERVER(Observer, observers_, OnPowerStatusChanged());
}

}  // namespace internal
}  // namespace ash