// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "ui/display/manager/display_change_observer.h"

#include <algorithm>
#include <cmath>
#include <map>
#include <set>
#include <string>
#include <tuple>
#include <utility>
#include <vector>

#include "base/check.h"
#include "base/check_op.h"
#include "base/command_line.h"
#include "base/json/json_reader.h"
#include "base/notreached.h"
#include "base/values.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/user_activity/user_activity_detector.h"
#include "ui/display/display.h"
#include "ui/display/display_features.h"
#include "ui/display/display_layout.h"
#include "ui/display/display_switches.h"
#include "ui/display/manager/display_layout_store.h"
#include "ui/display/manager/display_manager.h"
#include "ui/display/manager/display_properties_parser.h"
#include "ui/display/manager/touch_device_manager.h"
#include "ui/display/manager/util/display_manager_util.h"
#include "ui/display/types/display_constants.h"
#include "ui/display/types/display_mode.h"
#include "ui/display/types/display_snapshot.h"
#include "ui/display/util/display_util.h"
#include "ui/display/util/edid_parser.h"
#include "ui/events/devices/device_data_manager.h"
#include "ui/events/devices/touchscreen_device.h"
#include "ui/strings/grit/ui_strings.h"

namespace display {

namespace {

// The DPI threshold to determine the device scale factor.
// DPI higher than |dpi| will use |device_scale_factor|.
struct DeviceScaleFactorDPIThreshold {
  float dpi;
  float device_scale_factor;
};

// Update the list of zoom levels whenever a new device scale factor is added
// here. See zoom level list in /ui/display/manager/util/display_manager_util.cc
const std::array<DeviceScaleFactorDPIThreshold, 7>
    kThresholdTableForLcdInternal{{
        {310.f, kDsf_2_666},
        {270.0f, 2.4f},
        {230.0f, 2.0f},
        {220.0f, kDsf_1_777},
        {180.0f, 1.6f},
        {150.0f, 1.25f},
        {0.0f, 1.0f},
    }};

// Same as |kThresholdTableForLcdInternal|, but used for Oled displays with
// |display::features::kOledScaleFactorEnabled| set.
const std::array<DeviceScaleFactorDPIThreshold, 8>
    kThresholdTableForOledInternal{{
        {310.f, kDsf_2_666},
        {270.0f, 2.4f},
        {230.0f, 2.0f},
        {220.0f, kDsf_1_777},
        {180.0f, 1.6f},
        {160.0f, kDsf_1_333},
        {140.0f, 1.25f},
        {0.0f, 1.0f},
    }};

// Return the diagonal length of the rect.
float GetDiagonalLength(const gfx::Size& rect) {
  return std::sqrt(std::pow(rect.width(), 2) + std::pow(rect.height(), 2));
}

// Only use if the ops-display-scale-factor feature flag is set to true and
// physical size is valid. OPS stands for Open Pluggable Specification.
float GetOpsDisplayScaleFactor(const gfx::Size& physical_size,
                               const gfx::Size& size_in_pixels) {
  // Common OPS displays are over 50 inches.
  constexpr float kMinSizeForOps = 50.0f;
  // The diagonal length of the display in inches.
  const float diagonal_length = GetDiagonalLength(physical_size) / kInchInMm;
  // Check against this number to not capture user using the device as
  // ChromeBox.
  if (diagonal_length < kMinSizeForOps) {
    return 1.0f;
  }

  // These are the scale factors that will result in non-fractional logical
  // pixels for 4k UHD (3840 x 2160) and 4k WUHD (5120 x 2160) displays.
  // Note: List should be sorted.
  constexpr float kScaleFactorsForOPSDisplay[] = {
      1.0f, 1.25f, kDsf_1_333, 1.6f, kDsf_1_777, 2.0f, kDsf_2_666};

  const float original_dpi =
      GetDiagonalLength(size_in_pixels) / diagonal_length;
  // Ideal scale factor to dpi ratio is 1.0f to 40pi. We try to find the closest
  // valid display scale factor based on the target display's dpi.
  const float ideal_scale_factor = original_dpi / 40.0f;
  float closest_dsf = 1.0f;
  float dsf_delta = std::abs(ideal_scale_factor - closest_dsf);
  for (const float scale_factor : kScaleFactorsForOPSDisplay) {
    const float delta = std::abs(ideal_scale_factor - scale_factor);
    if (delta <= dsf_delta) {
      // Check if the scaling will result in fractional pixels.
      gfx::RectF f(size_in_pixels);
      f.InvScale(scale_factor);
      float int_part;
      if (std::modf(f.width(), &int_part) == 0 &&
          std::modf(f.height(), &int_part) == 0) {
        closest_dsf = scale_factor;
        dsf_delta = delta;
      }

    } else {
      return closest_dsf;
    }
  }
  return closest_dsf;
}

// External Display size is always set to 1.0 unless otherwise specified.
float GetExternalDisplayScaleFactor(const gfx::Size& physical_size,
                                    const gfx::Size& size_in_pixels) {
  if (features::IsOpsDisplayScaleFactorEnabled()) {
    return GetOpsDisplayScaleFactor(physical_size, size_in_pixels);
  }
  return 1.0f;
}

// Returns a list of display modes for the given |output| that doesn't exclude
// any mode. The returned list is sorted by size, then by refresh rate, then by
// is_interlaced.
ManagedDisplayInfo::ManagedDisplayModeList GetModeListWithAllRefreshRates(
    const DisplaySnapshot& output) {
  ManagedDisplayInfo::ManagedDisplayModeList display_mode_list;
  for (const auto& mode_info : output.modes()) {
    display_mode_list.emplace_back(
        mode_info->size(), mode_info->refresh_rate(),
        mode_info->is_interlaced(), output.native_mode() == mode_info.get(),
        GetExternalDisplayScaleFactor(output.physical_size(),
                                      mode_info->size()));
  }

  std::sort(
      display_mode_list.begin(), display_mode_list.end(),
      [](const ManagedDisplayMode& lhs, const ManagedDisplayMode& rhs) {
        return std::forward_as_tuple(lhs.size().width(), lhs.size().height(),
                                     lhs.refresh_rate(), lhs.is_interlaced()) <
               std::forward_as_tuple(rhs.size().width(), rhs.size().height(),
                                     rhs.refresh_rate(), rhs.is_interlaced());
      });

  return display_mode_list;
}

std::optional<gfx::RoundedCornersF> ParsePanelRadiiFromCommandLine() {
  if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kDisplayProperties)) {
    return std::nullopt;
  }

  std::optional<base::Value> display_switch_value = base::JSONReader::Read(
      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
          switches::kDisplayProperties));

  if (!display_switch_value.has_value()) {
    return std::nullopt;
  }

  return ParseDisplayPanelRadii(&display_switch_value.value());
}

}  // namespace

// static
ManagedDisplayInfo::ManagedDisplayModeList
DisplayChangeObserver::GetInternalManagedDisplayModeList(
    const ManagedDisplayInfo& display_info,
    const DisplaySnapshot& output) {
  const DisplayMode* ui_native_mode = output.native_mode();
  ManagedDisplayMode native_mode(ui_native_mode->size(),
                                 ui_native_mode->refresh_rate(),
                                 ui_native_mode->is_interlaced(), true,
                                 display_info.device_scale_factor());
  return CreateInternalManagedDisplayModeList(native_mode);
}

// static
ManagedDisplayInfo::ManagedDisplayModeList
DisplayChangeObserver::GetExternalManagedDisplayModeList(
    const DisplaySnapshot& output) {
  if (display::features::IsListAllDisplayModesEnabled())
    return GetModeListWithAllRefreshRates(output);

  struct SizeComparator {
    constexpr bool operator()(const gfx::Size& lhs,
                              const gfx::Size& rhs) const {
      return std::forward_as_tuple(lhs.width(), lhs.height()) <
             std::forward_as_tuple(rhs.width(), rhs.height());
    }
  };

  using DisplayModeMap =
      std::map<gfx::Size, ManagedDisplayMode, SizeComparator>;
  DisplayModeMap display_mode_map;

  ManagedDisplayMode native_mode;
  for (const auto& mode_info : output.modes()) {
    const gfx::Size size = mode_info->size();

    ManagedDisplayMode display_mode(
        mode_info->size(), mode_info->refresh_rate(),
        mode_info->is_interlaced(), output.native_mode() == mode_info.get(),
        GetExternalDisplayScaleFactor(output.physical_size(),
                                      mode_info->size()));
    if (display_mode.native())
      native_mode = display_mode;

    // Add the display mode if it isn't already present and override interlaced
    // display modes with non-interlaced ones. We prioritize having non
    // interlaced mode over refresh rate. A mode having lower refresh rate
    // but is not interlaced will be picked over a mode having high refresh
    // rate but is interlaced.
    auto display_mode_it = display_mode_map.find(size);
    if (display_mode_it == display_mode_map.end()) {
      display_mode_map.emplace(size, display_mode);
    } else if (display_mode_it->second.is_interlaced() &&
               !display_mode.is_interlaced()) {
      display_mode_it->second = std::move(display_mode);
    } else if (!display_mode.is_interlaced() &&
               display_mode_it->second.refresh_rate() <
                   display_mode.refresh_rate()) {
      display_mode_it->second = std::move(display_mode);
    }
  }

  if (output.native_mode()) {
    const gfx::Size size = native_mode.size();

    auto it = display_mode_map.find(size);
    CHECK(it != display_mode_map.end())
        << "Native mode must be part of the mode list.";

    // If the native mode was replaced (e.g. by a mode with similar size but
    // higher refresh rate), we overwrite that mode with the native mode. The
    // native mode will always be chosen as the best mode for this size (see
    // DisplayConfigurator::FindDisplayModeMatchingSize()).
    if (!it->second.native())
      it->second = native_mode;
  }

  ManagedDisplayInfo::ManagedDisplayModeList display_mode_list;
  for (const auto& display_mode_pair : display_mode_map)
    display_mode_list.push_back(std::move(display_mode_pair.second));

  return display_mode_list;
}

DisplayChangeObserver::DisplayChangeObserver(DisplayManager* display_manager)
    : internal_panel_radii_(ParsePanelRadiiFromCommandLine()),
      display_manager_(display_manager) {
  ui::DeviceDataManager::GetInstance()->AddObserver(this);
}

DisplayChangeObserver::~DisplayChangeObserver() {
  ui::DeviceDataManager::GetInstance()->RemoveObserver(this);
}

MultipleDisplayState DisplayChangeObserver::GetStateForDisplayIds(
    const DisplayConfigurator::DisplayStateList& display_states) {
  UpdateInternalDisplay(display_states);
  if (display_states.size() == 1)
    return MULTIPLE_DISPLAY_STATE_SINGLE;
  DisplayIdList list =
      GenerateDisplayIdList(display_states, &DisplaySnapshot::display_id);
  return display_manager_->ShouldSetMirrorModeOn(
             list, /*should_check_hardware_mirroring=*/true)
             ? MULTIPLE_DISPLAY_STATE_MULTI_MIRROR
             : MULTIPLE_DISPLAY_STATE_MULTI_EXTENDED;
}

bool DisplayChangeObserver::GetSelectedModeForDisplayId(
    int64_t display_id,
    ManagedDisplayMode* out_mode) const {
  return display_manager_->GetSelectedModeForDisplayId(display_id, out_mode);
}

void DisplayChangeObserver::OnDisplayConfigurationChanged(
    const DisplayConfigurator::DisplayStateList& display_states) {
  UpdateInternalDisplay(display_states);

  std::vector<ManagedDisplayInfo> displays;
  for (const DisplaySnapshot* state : display_states) {
    const DisplayMode* mode_info = state->current_mode();
    if (!mode_info)
      continue;

    displays.emplace_back(CreateManagedDisplayInfoInternal(state, mode_info));
  }

  display_manager_->touch_device_manager()->AssociateTouchscreens(
      &displays, ui::DeviceDataManager::GetInstance()->GetTouchscreenDevices());
  display_manager_->OnNativeDisplaysChanged(displays);

  // For the purposes of user activity detection, ignore synthetic mouse events
  // that are triggered by screen resizes: http://crbug.com/360634
  ui::UserActivityDetector::Get()->OnDisplayPowerChanging();
}

void DisplayChangeObserver::OnDisplayConfigurationChangeFailed(
    const DisplayConfigurator::DisplayStateList& displays,
    MultipleDisplayState failed_new_state) {
  // If display configuration failed during startup, simply update the display
  // manager with detected displays. If no display is detected, it will
  // create a pseudo display.
  if (display_manager_->GetNumDisplays() == 0)
    OnDisplayConfigurationChanged(displays);
}

void DisplayChangeObserver::OnInputDeviceConfigurationChanged(
    uint8_t input_device_types) {
  if (input_device_types & ui::InputDeviceEventObserver::kTouchscreen) {
    // If there are no cached display snapshots, either there are no attached
    // displays or the cached snapshots have been invalidated. For the first
    // case there aren't any touchscreens to associate. For the second case,
    // the displays and touch input-devices will get associated when display
    // configuration finishes.
    const auto& cached_displays =
        display_manager_->configurator()->cached_displays();
    if (!cached_displays.empty())
      OnDisplayConfigurationChanged(cached_displays);
  }
}

// static
float DisplayChangeObserver::FindDeviceScaleFactor(
    float dpi,
    const gfx::Size& size_in_pixels) {
  // Nocturne has special scale factor 3000/1332=2.252.. for the panel 3kx2k.
  constexpr gfx::Size k225DisplaySizeHackNocturne = kNocturne;  // (3000, 2000);
  // Keep the Chell's scale factor 2.252 until we make decision.
  constexpr gfx::Size k2DisplaySizeHackChell = kQHD_PLUS;  // (3200, 1800);
  constexpr gfx::Size k18DisplaySizeHackCoachZ = kLux;     // (2160, 1440);

  if (size_in_pixels == k225DisplaySizeHackNocturne) {
    return kDsf_2_252;
  }
  if (size_in_pixels == k2DisplaySizeHackChell) {
    return 2.f;
  }
  if (size_in_pixels == k18DisplaySizeHackCoachZ) {
    return kDsf_1_8;
  }

  if (features::IsOledScaleFactorEnabled()) {
    for (const DeviceScaleFactorDPIThreshold& threshold :
         kThresholdTableForOledInternal) {
      if (dpi >= threshold.dpi) {
        return threshold.device_scale_factor;
      }
    }
  } else {
    for (const DeviceScaleFactorDPIThreshold& threshold :
         kThresholdTableForLcdInternal) {
      if (dpi >= threshold.dpi) {
        return threshold.device_scale_factor;
      }
    }
  }

  return 1.0f;
}

// static
ManagedDisplayInfo DisplayChangeObserver::CreateManagedDisplayInfo(
    const DisplaySnapshot* snapshot,
    const DisplayMode* mode_info,
    bool native,
    float device_scale_factor,
    float dpi,
    const std::string& name,
    const gfx::RoundedCornersF& panel_radii) {
  const bool has_overscan = snapshot->has_overscan();
  const int64_t id = snapshot->display_id();

  ManagedDisplayInfo new_info = ManagedDisplayInfo(id, name, has_overscan);

  new_info.set_port_display_id(snapshot->port_display_id());
  new_info.set_edid_display_id(snapshot->edid_display_id());
  new_info.set_connector_index(snapshot->connector_index());

  if (snapshot->product_code() != DisplaySnapshot::kInvalidProductCode) {
    uint16_t manufacturer_id = 0;
    uint16_t product_id = 0;
    EdidParser::SplitProductCodeInManufacturerIdAndProductId(
        snapshot->product_code(), &manufacturer_id, &product_id);
    new_info.set_manufacturer_id(
        EdidParser::ManufacturerIdToString(manufacturer_id));
    new_info.set_product_id(EdidParser::ProductIdToString(product_id));
  }
  new_info.set_year_of_manufacture(snapshot->year_of_manufacture());

  new_info.set_panel_orientation(snapshot->panel_orientation());
  new_info.set_sys_path(snapshot->sys_path());
  new_info.set_from_native_platform(true);

  new_info.set_native(native);
  new_info.set_device_scale_factor(device_scale_factor);

  const gfx::Rect display_bounds(snapshot->origin(), mode_info->size());
  new_info.SetBounds(display_bounds);
  new_info.set_is_aspect_preserving_scaling(
      snapshot->is_aspect_preserving_scaling());
  if (dpi)
    new_info.set_device_dpi(dpi);

  // TODO(crbug.com/40652358): Remove kEnableUseHDRTransferFunction usage when
  // HDR is fully supported on ChromeOS.
  const bool allow_high_bit_depth =
      base::FeatureList::IsEnabled(features::kUseHDRTransferFunction);
  new_info.set_display_color_spaces(
      CreateDisplayColorSpaces(snapshot->color_space(), allow_high_bit_depth,
                               snapshot->hdr_static_metadata()));
  new_info.SetSnapshotColorSpace(snapshot->color_space());
  constexpr int32_t kNormalBitDepth = 8;
  new_info.set_bits_per_channel(
      allow_high_bit_depth ? snapshot->bits_per_channel() : kNormalBitDepth);

  new_info.set_refresh_rate(mode_info->refresh_rate());
  new_info.set_is_interlaced(mode_info->is_interlaced());
  new_info.set_vsync_rate_min(mode_info->vsync_rate_min());
  new_info.set_variable_refresh_rate_state(
      snapshot->variable_refresh_rate_state());
  new_info.set_connection_type(snapshot->type());
  new_info.set_physical_size(snapshot->physical_size());

  ManagedDisplayInfo::ManagedDisplayModeList display_modes =
      (snapshot->type() == DISPLAY_CONNECTION_TYPE_INTERNAL)
          ? GetInternalManagedDisplayModeList(new_info, *snapshot)
          : GetExternalManagedDisplayModeList(*snapshot);
  new_info.SetManagedDisplayModes(display_modes);

  new_info.set_maximum_cursor_size(snapshot->maximum_cursor_size());

  new_info.set_panel_corners_radii(panel_radii);

  new_info.SetDRMFormatsAndModifiers(snapshot->GetDRMFormatsAndModifiers());

  return new_info;
}

void DisplayChangeObserver::UpdateInternalDisplay(
    const DisplayConfigurator::DisplayStateList& display_states) {
  bool force_first_display_internal = ForceFirstDisplayInternal();

  for (display::DisplaySnapshot* state : display_states) {
    if (state->type() == DISPLAY_CONNECTION_TYPE_INTERNAL ||
        (force_first_display_internal &&
         (!HasInternalDisplay() || IsInternalDisplayId(state->display_id())))) {
      if (HasInternalDisplay()) {
        DCHECK_EQ(Display::InternalDisplayId(), state->display_id());
      }
      SetInternalDisplayIds({state->display_id()});

      if (state->native_mode() &&
          (!display_manager_->IsDisplayIdValid(state->display_id()) ||
           !state->current_mode())) {
        // Register the internal display info if
        // 1) If it's not already registered. It'll be treated as
        // new display in |UpdateDisplaysWith()|.
        // 2) If it's not connected, because the display info will not
        // be updated in |UpdateDisplaysWith()|, which will skips the
        // disconnected displays.
        ManagedDisplayInfo new_info =
            CreateManagedDisplayInfoInternal(state, state->native_mode());
        display_manager_->UpdateInternalDisplay(new_info);
      }
      return;
    }
  }
}

ManagedDisplayInfo DisplayChangeObserver::CreateManagedDisplayInfoInternal(
    const DisplaySnapshot* snapshot,
    const DisplayMode* mode_info) {
  bool native = false;
  float device_scale_factor = 1.0f;
  // Sets dpi only if the screen size is valid.
  const float dpi = IsDisplaySizeValid(snapshot->physical_size())
                        ? kInchInMm * mode_info->size().width() /
                              snapshot->physical_size().width()
                        : 0;
  if (snapshot->type() == DISPLAY_CONNECTION_TYPE_INTERNAL) {
    native = true;
    device_scale_factor = FindDeviceScaleFactor(dpi, mode_info->size());
  } else {
    // DisplaySnapshot stores the native_mode info. For external display, use it
    // to determine if current mode_info is native or not.
    const DisplayMode* native_mode = snapshot->native_mode();
    native = *mode_info == *native_mode;

    CHECK(snapshot->type() != DISPLAY_CONNECTION_TYPE_INTERNAL);
    device_scale_factor =
        IsDisplaySizeValid(snapshot->physical_size())
            ? GetExternalDisplayScaleFactor(snapshot->physical_size(),
                                            mode_info->size())
            : 1.0f;
  }
  std::string name = (snapshot->type() == DISPLAY_CONNECTION_TYPE_INTERNAL)
                         ? l10n_util::GetStringUTF8(IDS_DISPLAY_NAME_INTERNAL)
                         : snapshot->display_name();

  if (name.empty()) {
    name = l10n_util::GetStringUTF8(IDS_DISPLAY_NAME_UNKNOWN);
  }

  gfx::RoundedCornersF panel_radii;

  if (snapshot->type() == display::DISPLAY_CONNECTION_TYPE_INTERNAL) {
    panel_radii = internal_panel_radii_.value_or(gfx::RoundedCornersF());
  }

  return CreateManagedDisplayInfo(snapshot, mode_info, native,
                                  device_scale_factor, dpi, name, panel_radii);
}

}  // namespace display