// Copyright 2017 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include "DolphinQt2/Settings/AdvancedPane.h"

#include <QCheckBox>
#include <QDateTimeEdit>
#include <QGroupBox>
#include <QHBoxLayout>
#include <QLabel>
#include <QSlider>
#include <QVBoxLayout>
#include <cmath>

#include "Core/ConfigManager.h"
#include "Core/Core.h"
#include "Core/HW/SystemTimers.h"
#include "DolphinQt2/Settings.h"

AdvancedPane::AdvancedPane(QWidget* parent) : QWidget(parent)
{
  CreateLayout();
  Update();

  ConnectLayout();

  connect(&Settings::Instance(), &Settings::EmulationStateChanged, this, &AdvancedPane::Update);
}

void AdvancedPane::CreateLayout()
{
  auto* main_layout = new QVBoxLayout();
  setLayout(main_layout);

  auto* cpu_options = new QGroupBox(tr("CPU Options"));
  auto* cpu_options_layout = new QVBoxLayout();
  cpu_options->setLayout(cpu_options_layout);
  main_layout->addWidget(cpu_options);

  m_cpu_clock_override_checkbox = new QCheckBox(tr("Enable Emulated CPU Clock Override"));
  cpu_options_layout->addWidget(m_cpu_clock_override_checkbox);

  auto* cpu_clock_override_slider_layout = new QHBoxLayout();
  cpu_clock_override_slider_layout->setContentsMargins(0, 0, 0, 0);
  cpu_options_layout->addLayout(cpu_clock_override_slider_layout);

  m_cpu_clock_override_slider = new QSlider(Qt::Horizontal);
  m_cpu_clock_override_slider->setRange(0, 150);
  cpu_clock_override_slider_layout->addWidget(m_cpu_clock_override_slider);

  m_cpu_clock_override_slider_label = new QLabel();
  cpu_clock_override_slider_layout->addWidget(m_cpu_clock_override_slider_label);

  auto* cpu_clock_override_description =
      new QLabel(tr("Adjusts the emulated CPU's clock rate.\n\n"
                    "Higher values may make variable-framerate games run at a higher framerate, "
                    "at the expense of performance. Lower values may activate a game's "
                    "internal frameskip, potentially improving performance.\n\n"
                    "WARNING: Changing this from the default (100%) can and will "
                    "break games and cause glitches. Do so at your own risk. "
                    "Please do not report bugs that occur with a non-default clock."));
  cpu_clock_override_description->setWordWrap(true);
  cpu_options_layout->addWidget(cpu_clock_override_description);

  auto* rtc_options = new QGroupBox(tr("Custom RTC Options"));
  rtc_options->setLayout(new QVBoxLayout());
  main_layout->addWidget(rtc_options);

  m_custom_rtc_checkbox = new QCheckBox(tr("Enable Custom RTC"));
  rtc_options->layout()->addWidget(m_custom_rtc_checkbox);

  m_custom_rtc_datetime = new QDateTimeEdit();
  if (!m_custom_rtc_datetime->displayFormat().contains(QStringLiteral("yyyy")))
  {
    // Always show the full year, no matter what the locale specifies. Otherwise, two-digit years
    // will always be interpreted as in the 21st century.
    m_custom_rtc_datetime->setDisplayFormat(m_custom_rtc_datetime->displayFormat().replace(
        QStringLiteral("yy"), QStringLiteral("yyyy")));
  }
  m_custom_rtc_datetime->setDateRange({2000, 1, 1}, {2099, 12, 31});
  rtc_options->layout()->addWidget(m_custom_rtc_datetime);

  auto* custom_rtc_description =
      new QLabel(tr("This setting allows you to set a custom real time clock (RTC) separate from "
                    "your current system time.\n\nIf you're unsure, leave this disabled."));
  custom_rtc_description->setWordWrap(true);
  rtc_options->layout()->addWidget(custom_rtc_description);

  main_layout->addStretch(1);
}

void AdvancedPane::ConnectLayout()
{
  m_cpu_clock_override_checkbox->setChecked(SConfig::GetInstance().m_OCEnable);
  connect(m_cpu_clock_override_checkbox, &QCheckBox::toggled, [this](bool enable_clock_override) {
    SConfig::GetInstance().m_OCEnable = enable_clock_override;
    Update();
  });

  m_cpu_clock_override_slider->setValue(
      static_cast<int>(std::ceil(std::log2f(SConfig::GetInstance().m_OCFactor) * 25.f + 100.f)));
  connect(m_cpu_clock_override_slider, &QSlider::valueChanged, [this](int oc_factor) {
    // Vaguely exponential scaling?
    SConfig::GetInstance().m_OCFactor =
        std::exp2f((m_cpu_clock_override_slider->value() - 100.f) / 25.f);
    Update();
  });

  m_custom_rtc_checkbox->setChecked(SConfig::GetInstance().bEnableCustomRTC);
  connect(m_custom_rtc_checkbox, &QCheckBox::toggled, [this](bool enable_custom_rtc) {
    SConfig::GetInstance().bEnableCustomRTC = enable_custom_rtc;
    Update();
  });

  QDateTime initial_date_time;
  initial_date_time.setTime_t(SConfig::GetInstance().m_customRTCValue);
  m_custom_rtc_datetime->setDateTime(initial_date_time);
  connect(m_custom_rtc_datetime, &QDateTimeEdit::dateTimeChanged, [this](QDateTime date_time) {
    SConfig::GetInstance().m_customRTCValue = date_time.toTime_t();
    Update();
  });
}

void AdvancedPane::Update()
{
  const bool running = Core::GetState() != Core::State::Uninitialized;
  const bool enable_cpu_clock_override_widgets = SConfig::GetInstance().m_OCEnable;
  const bool enable_custom_rtc_widgets = SConfig::GetInstance().bEnableCustomRTC && !running;

  m_cpu_clock_override_slider->setEnabled(enable_cpu_clock_override_widgets);
  m_cpu_clock_override_slider_label->setEnabled(enable_cpu_clock_override_widgets);

  m_cpu_clock_override_slider_label->setText([] {
    int core_clock = SystemTimers::GetTicksPerSecond() / std::pow(10, 6);
    int percent = static_cast<int>(std::round(SConfig::GetInstance().m_OCFactor * 100.f));
    int clock = static_cast<int>(std::round(SConfig::GetInstance().m_OCFactor * core_clock));
    return tr("%1 % (%2 MHz)").arg(QString::number(percent), QString::number(clock));
  }());

  m_custom_rtc_checkbox->setEnabled(!running);
  m_custom_rtc_datetime->setEnabled(enable_custom_rtc_widgets);
}