// 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.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "ui/display/mac/test/virtual_display_util_mac.h"

#include <CoreGraphics/CoreGraphics.h>
#import <Foundation/Foundation.h>
#include <memory>

#include <map>

#include "base/apple/scoped_cftyperef.h"
#include "base/check.h"
#include "base/check_op.h"
#include "base/strings/sys_string_conversions.h"
#include "ui/display/display.h"
#include "ui/display/screen.h"
#include "ui/gfx/geometry/size.h"

// These interfaces were generated from CoreGraphics binaries.
@interface CGVirtualDisplay : NSObject

@property(readonly, nonatomic) unsigned int vendorID;
@property(readonly, nonatomic) unsigned int productID;
@property(readonly, nonatomic) unsigned int serialNum;
@property(readonly, nonatomic) NSString* name;
@property(readonly, nonatomic) struct CGSize sizeInMillimeters;
@property(readonly, nonatomic) unsigned int maxPixelsWide;
@property(readonly, nonatomic) unsigned int maxPixelsHigh;
@property(readonly, nonatomic) struct CGPoint redPrimary;
@property(readonly, nonatomic) struct CGPoint greenPrimary;
@property(readonly, nonatomic) struct CGPoint bluePrimary;
@property(readonly, nonatomic) struct CGPoint whitePoint;
@property(readonly, nonatomic) id queue;
@property(readonly, nonatomic) id terminationHandler;
@property(readonly, nonatomic) unsigned int displayID;
@property(readonly, nonatomic) unsigned int hiDPI;
@property(readonly, nonatomic) NSArray* modes;
@property(readonly, nonatomic) unsigned int serialNumber;
@property(readonly, nonatomic) unsigned int rotation;
- (BOOL)applySettings:(id)arg1;
- (void)dealloc;
- (id)initWithDescriptor:(id)arg1;

@end

// These interfaces were generated from CoreGraphics binaries.
@interface CGVirtualDisplayDescriptor : NSObject

@property(nonatomic) unsigned int vendorID;
@property(nonatomic) unsigned int productID;
@property(nonatomic) unsigned int serialNum;
@property(strong, nonatomic) NSString* name;
@property(nonatomic) struct CGSize sizeInMillimeters;
@property(nonatomic) unsigned int maxPixelsWide;
@property(nonatomic) unsigned int maxPixelsHigh;
@property(nonatomic) struct CGPoint redPrimary;
@property(nonatomic) struct CGPoint greenPrimary;
@property(nonatomic) struct CGPoint bluePrimary;
@property(nonatomic) struct CGPoint whitePoint;
@property(strong, nonatomic) id queue;
@property(copy, nonatomic) id terminationHandler;
@property(nonatomic) unsigned int serialNumber;
- (void)dealloc;
- (id)init;
- (id)dispatchQueue;
- (void)setDispatchQueue:(id)arg1;

@end

// These interfaces were generated from CoreGraphics binaries.
@interface CGVirtualDisplayMode : NSObject

@property(readonly, nonatomic) unsigned int width;
@property(readonly, nonatomic) unsigned int height;
@property(readonly, nonatomic) double refreshRate;
@property(copy, nonatomic) id transferFunction API_AVAILABLE(macos(13.3));
- (id)initWithWidth:(unsigned int)arg1
             height:(unsigned int)arg2
        refreshRate:(double)arg3;
- (id)initWithWidth:(unsigned int)arg1
              height:(unsigned int)arg2
         refreshRate:(double)arg3
    transferFunction:(id)arg4 API_AVAILABLE(macos(13.3));

@end

// These interfaces were generated from CoreGraphics binaries.
@interface CGVirtualDisplaySettings : NSObject

@property(strong, nonatomic) NSArray* modes;
@property(nonatomic) unsigned int hiDPI;
@property(nonatomic) unsigned int rotation;
- (void)dealloc;
- (id)init;

@end

namespace {

static bool g_need_display_removal_workaround = true;

// A global singleton that tracks the current set of mocked displays.
std::map<int64_t, CGVirtualDisplay * __strong> g_display_map;

// A helper function for creating virtual display and return CGVirtualDisplay
// object.
CGVirtualDisplay* CreateVirtualDisplay(int width,
                                       int height,
                                       int ppi,
                                       BOOL hiDPI,
                                       NSString* name,
                                       int serial_number) {
  CGVirtualDisplayDescriptor* descriptor =
      [[CGVirtualDisplayDescriptor alloc] init];
  descriptor.queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0);
  descriptor.name = name;
  descriptor.whitePoint = CGPointMake(0.3125, 0.3291);
  descriptor.bluePrimary = CGPointMake(0.1494, 0.0557);
  descriptor.greenPrimary = CGPointMake(0.2559, 0.6983);
  descriptor.redPrimary = CGPointMake(0.6797, 0.3203);
  descriptor.maxPixelsHigh = height;
  descriptor.maxPixelsWide = width;
  descriptor.sizeInMillimeters =
      CGSizeMake(25.4 * width / ppi, 25.4 * height / ppi);
  // macOS 14 expects different virtual displays to have different serial
  // numbers.
  descriptor.serialNum = serial_number;
  descriptor.productID = 0;
  // macOS 14 expects a non-zero vendorID. Choose an arbitrary value.
  int kVendorID = 505;
  descriptor.vendorID = kVendorID;
  descriptor.terminationHandler = nil;
  descriptor.serialNumber = serial_number;

  CGVirtualDisplay* display =
      [[CGVirtualDisplay alloc] initWithDescriptor:descriptor];
  if (!display) {
    LOG(ERROR) << __func__ << " - CGVirtualDisplay initWithDescriptor failed";
    return nil;
  }

  CGVirtualDisplaySettings* settings = [[CGVirtualDisplaySettings alloc] init];
  settings.hiDPI = hiDPI;
  settings.rotation = 0;

  CGVirtualDisplayMode* mode =
      [[CGVirtualDisplayMode alloc] initWithWidth:(hiDPI ? width / 2 : width)
                                           height:(hiDPI ? height / 2 : height)
                                      refreshRate:60];
  settings.modes = @[ mode ];
  if (![display applySettings:settings]) {
    LOG(ERROR) << __func__ << " - CGVirtualDisplay applySettings failed";
  }
  return display;
}

// This method detects whether the local machine is running headless.
// Typically returns true when the session is curtained or if there are no
// physical monitors attached.  In those two scenarios, the online display will
// be marked as virtual.
bool IsRunningHeadless() {
  // Most machines will have < 4 displays but a larger upper bound won't hurt.
  constexpr UInt32 kMaxDisplaysToQuery = 32;
  // 0x76697274 is a 4CC value for 'virt' which indicates the display is
  // virtual.
  constexpr CGDirectDisplayID kVirtualDisplayID = 0x76697274;

  CGDirectDisplayID online_displays[kMaxDisplaysToQuery];
  UInt32 online_display_count = 0;
  CGError return_code = CGGetOnlineDisplayList(
      kMaxDisplaysToQuery, online_displays, &online_display_count);
  if (return_code != kCGErrorSuccess) {
    LOG(ERROR) << __func__
               << " - CGGetOnlineDisplayList() failed: " << return_code << ".";
    // If this fails, assume machine is headless to err on the side of caution.
    return true;
  }

  bool is_running_headless = true;
  for (UInt32 i = 0; i < online_display_count; i++) {
    if (CGDisplayModelNumber(online_displays[i]) != kVirtualDisplayID) {
      // At least one monitor is attached so the machine is not headless.
      is_running_headless = false;
      break;
    }
  }

  // TODO(crbug.com/40148077): Please remove this log or replace it with
  // [D]CHECK() ASAP when the TEST is stable.
  LOG(INFO) << __func__ << " - Is running headless: " << is_running_headless
            << ". Online display count: " << online_display_count << ".";

  return is_running_headless;
}

// Observer for display metrics change notifications.
class DisplayMetricsChangeObserver : public display::DisplayObserver {
 public:
  DisplayMetricsChangeObserver(int64_t display_id,
                               const gfx::Size& size,
                               uint32_t expected_changed_metrics,
                               display::Screen* screen)
      : display_id_(display_id),
        size_(size),
        expected_changed_metrics_(expected_changed_metrics),
        screen_(screen) {
    screen_->AddObserver(this);
  }
  ~DisplayMetricsChangeObserver() override { screen_->RemoveObserver(this); }

  DisplayMetricsChangeObserver(const DisplayMetricsChangeObserver&) = delete;
  DisplayMetricsChangeObserver& operator=(const DisplayMetricsChangeObserver&) =
      delete;

  // Runs a loop until the display metrics change is seen (unless one has
  // already been observed, in which case it returns immediately).
  void Wait() {
    if (observed_change_)
      return;

    run_loop_.Run();
  }

 private:
  // display::DisplayObserver:
  void OnDisplayMetricsChanged(const display::Display& display,
                               uint32_t changed_metrics) override {
    if (!(display.id() == display_id_ && display.size() == size_ &&
          (changed_metrics & expected_changed_metrics_))) {
      return;
    }

    observed_change_ = true;
    if (run_loop_.running())
      run_loop_.Quit();
  }
  void OnDisplayAdded(const display::Display& new_display) override {}
  void OnDisplaysRemoved(const display::Displays& removed_displays) override {}

  const int64_t display_id_;
  const gfx::Size size_;
  const uint32_t expected_changed_metrics_;
  raw_ptr<display::Screen> screen_;
  bool observed_change_ = false;
  base::RunLoop run_loop_;
};

void EnsureDisplayWithResolution(display::Screen* screen,
                                 CGDirectDisplayID display_id,
                                 const gfx::Size& size) {
  CHECK(screen);
  base::apple::ScopedCFTypeRef<CGDisplayModeRef> current_display_mode(
      CGDisplayCopyDisplayMode(display_id));
  if (gfx::Size(CGDisplayModeGetWidth(current_display_mode.get()),
                CGDisplayModeGetHeight(current_display_mode.get())) == size) {
    return;
  }

  base::apple::ScopedCFTypeRef<CFArrayRef> display_modes(
      CGDisplayCopyAllDisplayModes(display_id, nullptr));
  DCHECK(display_modes);

  CGDisplayModeRef preferred_display_mode = nullptr;
  for (CFIndex i = 0; i < CFArrayGetCount(display_modes.get()); ++i) {
    CGDisplayModeRef display_mode =
        (CGDisplayModeRef)CFArrayGetValueAtIndex(display_modes.get(), i);
    if (gfx::Size(CGDisplayModeGetWidth(display_mode),
                  CGDisplayModeGetHeight(display_mode)) == size) {
      preferred_display_mode = display_mode;
      break;
    }
  }
  DCHECK(preferred_display_mode);

  uint32_t expected_changed_metrics =
      display::DisplayObserver::DISPLAY_METRIC_BOUNDS |
      display::DisplayObserver::DISPLAY_METRIC_WORK_AREA |
      display::DisplayObserver::DISPLAY_METRIC_DEVICE_SCALE_FACTOR;
  DisplayMetricsChangeObserver display_metrics_change_observer(
      display_id, size, expected_changed_metrics, screen);

  // This operation is always synchronous. The function doesn’t return until the
  // mode switch is complete.
  CGError result =
      CGDisplaySetDisplayMode(display_id, preferred_display_mode, nullptr);
  DCHECK_EQ(result, kCGErrorSuccess);

  // Wait for `display::Screen` and `display::Display` structures to be updated.
  display_metrics_change_observer.Wait();
}

// static
uint64_t SynthesizeSerialNumber() {
  static uint64_t synthesized_serial_num = 1;
  CHECK_LT(synthesized_serial_num, std::numeric_limits<uint64_t>::max())
      << "All synthesized display IDs in use.";
  return synthesized_serial_num++;
}

}  // namespace

namespace display::test {

VirtualDisplayUtilMac::VirtualDisplayUtilMac(Screen* screen) : screen_(screen) {
  CHECK(screen);
  screen->AddObserver(this);
}

VirtualDisplayUtilMac::~VirtualDisplayUtilMac() {
  ResetDisplays();
  screen_->RemoveObserver(this);
}

int64_t VirtualDisplayUtilMac::AddDisplay(const DisplayParams& display_params) {
  int64_t serial_number = SynthesizeSerialNumber();
  return AddDisplay(serial_number, display_params);
}

void VirtualDisplayUtilMac::RemoveDisplay(int64_t display_id) {
  auto it = g_display_map.find(display_id);
  DCHECK(it != g_display_map.end());

  // The first display removal has known flaky timeouts if removed
  // individually. Remove another display simultaneously during the first
  // display removal.
  // TODO(crbug.com/40148077): Resolve this defect in a more hermetic manner.
  if (g_need_display_removal_workaround) {
    const int64_t tmp_display_id = AddDisplay(0, k1920x1080);
    auto tmp_it = g_display_map.find(tmp_display_id);
    DCHECK(tmp_it != g_display_map.end());

    waiting_for_ids_.insert(display_id);
    waiting_for_ids_.insert(tmp_display_id);

    g_display_map.erase(it);
    g_display_map.erase(tmp_it);

    g_need_display_removal_workaround = false;

    StartWaiting();

    return;
  }

  g_display_map.erase(it);

  // TODO(crbug.com/40148077): Please remove this log or replace it with
  // [D]CHECK() ASAP when the TEST is stable.
  LOG(INFO) << "VirtualDisplayUtilMac::" << __func__
            << " - display id: " << display_id << ". Erase success.";

  WaitForDisplay(display_id, /*added=*/false);

  // TODO(crbug.com/40148077): Please remove this log or replace it with
  // [D]CHECK() ASAP when the TEST is stable.
  LOG(INFO) << "VirtualDisplayUtilMac::" << __func__
            << " - display id: " << display_id << ". WaitForDisplay success.";
}

void VirtualDisplayUtilMac::ResetDisplays() {
  int display_count = g_display_map.size();

  // TODO(crbug.com/40148077): Please remove this log or replace it with
  // [D]CHECK() ASAP when the TEST is stable.
  LOG(INFO) << "VirtualDisplayUtilMac::" << __func__
            << " - display count: " << display_count << ".";

  if (display_count < 1) {
    return;
  }

  if (display_count == 1 && g_need_display_removal_workaround) {
    RemoveDisplay(g_display_map.begin()->first);
    return;
  }

  for (const auto& [id, display] : g_display_map) {
    waiting_for_ids_.insert(id);
  }

  g_display_map.clear();

  StartWaiting();
}

int64_t VirtualDisplayUtilMac::AddDisplay(int64_t serial_number,
                                          const DisplayParams& display_params) {
  CHECK(!display_params.resolution.IsEmpty());
  CHECK(!display_params.dpi.IsZero());
  CHECK_EQ(display_params.dpi.x(), display_params.dpi.y());

  NSString* display_name =
      [NSString stringWithFormat:@"Virtual Display #%lld", serial_number];
  CGVirtualDisplay* display = CreateVirtualDisplay(
      display_params.resolution.width(), display_params.resolution.height(),
      display_params.dpi.x(), /*hiDPI=*/display_params.dpi.x() >= 200,
      display_name, serial_number);
  DCHECK(display);

  // TODO(crbug.com/40148077): Please remove this log or replace it with
  // [D]CHECK() ASAP when the TEST is stable.
  LOG(INFO) << "VirtualDisplayUtilMac::" << __func__
            << " - serial number: " << serial_number
            << ". CreateVirtualDisplay success.";

  int64_t id = display.displayID;
  DCHECK_NE(id, 0u);

  WaitForDisplay(id, /*added=*/true);

  EnsureDisplayWithResolution(screen_, id,
                              gfx::Size(display_params.resolution.width(),
                                        display_params.resolution.height()));

  // TODO(crbug.com/40148077): Please remove this log or replace it with
  // [D]CHECK() ASAP when the TEST is stable.
  LOG(INFO) << "VirtualDisplayUtilMac::" << __func__
            << " - serial number: " << serial_number << "(" << id
            << "). WaitForDisplay success.";

  DCHECK(!g_display_map[id]);
  g_display_map[id] = display;

  return id;
}

// static
bool VirtualDisplayUtilMac::IsAPIAvailable() {
  // TODO(crbug.com/40148077): Support headless bots.
  LOG_IF(INFO, IsRunningHeadless()) << "Headless Mac environment detected.";
  return !IsRunningHeadless();
}

// Predefined display configurations from
// https://en.wikipedia.org/wiki/Graphics_display_resolution and
// https://www.theverge.com/tldr/2016/3/21/11278192/apple-iphone-ipad-screen-sizes-pixels-density-so-many-choices.
const DisplayParams VirtualDisplayUtilMac::k6016x3384 = {
    gfx::Size(6016, 3384), gfx::Vector2d(218, 218), "Apple Pro Display XDR"};
const DisplayParams VirtualDisplayUtilMac::k5120x2880 = {
    gfx::Size(5120, 2880), gfx::Vector2d(218, 218),
    "27-inch iMac with Retina 5K display"};
const DisplayParams VirtualDisplayUtilMac::k4096x2304 = {
    gfx::Size(4096, 2304), gfx::Vector2d(219, 219),
    "21.5-inch iMac with Retina 4K display"};
const DisplayParams VirtualDisplayUtilMac::k3840x2400 = {
    gfx::Size(3840, 2400), gfx::Vector2d(200, 200), "WQUXGA"};
const DisplayParams VirtualDisplayUtilMac::k3840x2160 = {
    gfx::Size(3840, 2160), gfx::Vector2d(200, 200), "UHD"};
const DisplayParams VirtualDisplayUtilMac::k3840x1600 = {
    gfx::Size(3840, 1600), gfx::Vector2d(200, 200), "WQHD+, UW-QHD+"};
const DisplayParams VirtualDisplayUtilMac::k3840x1080 = {
    gfx::Size(3840, 1080), gfx::Vector2d(200, 200), "DFHD"};
const DisplayParams VirtualDisplayUtilMac::k3072x1920 = {
    gfx::Size(3072, 1920), gfx::Vector2d(226, 226),
    "16-inch MacBook Pro with Retina display"};
const DisplayParams VirtualDisplayUtilMac::k2880x1800 = {
    gfx::Size(2880, 1800), gfx::Vector2d(220, 220),
    "15.4-inch MacBook Pro with Retina display"};
const DisplayParams VirtualDisplayUtilMac::k2560x1600 = {
    gfx::Size(2560, 1600), gfx::Vector2d(227, 227),
    "WQXGA, 13.3-inch MacBook Pro with Retina display"};
const DisplayParams VirtualDisplayUtilMac::k2560x1440 = {
    gfx::Size(2560, 1440), gfx::Vector2d(109, 109),
    "27-inch Apple Thunderbolt display"};
const DisplayParams VirtualDisplayUtilMac::k2304x1440 = {
    gfx::Size(2304, 1440), gfx::Vector2d(226, 226),
    "12-inch MacBook with Retina display"};
const DisplayParams VirtualDisplayUtilMac::k2048x1536 = {
    gfx::Size(2048, 1536), gfx::Vector2d(150, 150), "QXGA"};
const DisplayParams VirtualDisplayUtilMac::k2048x1152 = {
    gfx::Size(2048, 1152), gfx::Vector2d(150, 150), "QWXGA"};
const DisplayParams VirtualDisplayUtilMac::k1920x1200 = {
    gfx::Size(1920, 1200), gfx::Vector2d(150, 150), "WUXGA"};
const DisplayParams VirtualDisplayUtilMac::k1600x1200 = {
    gfx::Size(1600, 1200), gfx::Vector2d(125, 125), "UXGA"};
const DisplayParams VirtualDisplayUtilMac::k1920x1080 = {
    gfx::Size(1920, 1080), gfx::Vector2d(125, 125), "HD, 21.5-inch iMac"};
const DisplayParams VirtualDisplayUtilMac::k1680x1050 = {
    gfx::Size(1680, 1050), gfx::Vector2d(99, 99),
    "WSXGA+, Apple Cinema Display (20-inch), 20-inch iMac"};
const DisplayParams VirtualDisplayUtilMac::k1440x900 = {
    gfx::Size(1440, 900), gfx::Vector2d(127, 127),
    "WXGA+, 13.3-inch MacBook Air"};
const DisplayParams VirtualDisplayUtilMac::k1400x1050 = {
    gfx::Size(1400, 1050), gfx::Vector2d(125, 125), "SXGA+"};
const DisplayParams VirtualDisplayUtilMac::k1366x768 = {
    gfx::Size(1366, 768), gfx::Vector2d(135, 135), "11.6-inch MacBook Air"};
const DisplayParams VirtualDisplayUtilMac::k1280x1024 = {
    gfx::Size(1280, 1024), gfx::Vector2d(100, 100), "SXGA"};
const DisplayParams VirtualDisplayUtilMac::k1280x1800 = {
    gfx::Size(1280, 800), gfx::Vector2d(113, 113), "13.3-inch MacBook Pro"};

VirtualDisplayUtilMac::DisplaySleepBlocker::DisplaySleepBlocker() {
  IOReturn result = IOPMAssertionCreateWithName(
      kIOPMAssertionTypeNoDisplaySleep, kIOPMAssertionLevelOn,
      CFSTR("DisplaySleepBlocker"), &assertion_id_);
  DCHECK_EQ(result, kIOReturnSuccess);
}

VirtualDisplayUtilMac::DisplaySleepBlocker::~DisplaySleepBlocker() {
  IOReturn result = IOPMAssertionRelease(assertion_id_);
  DCHECK_EQ(result, kIOReturnSuccess);
}

void VirtualDisplayUtilMac::OnDisplayMetricsChanged(
    const display::Display& display,
    uint32_t changed_metrics) {
  LOG(INFO) << "VirtualDisplayUtilMac::" << __func__
            << " - display id: " << display.id()
            << ", changed_metrics: " << changed_metrics << ".";
}

void VirtualDisplayUtilMac::OnDisplayAdded(
    const display::Display& new_display) {
  // TODO(crbug.com/40148077): Please remove this log or replace it with
  // [D]CHECK() ASAP when the TEST is stable.
  LOG(INFO) << "VirtualDisplayUtilMac::" << __func__
            << " - display id: " << new_display.id() << ".";

  OnDisplayAddedOrRemoved(new_display.id());
}

void VirtualDisplayUtilMac::OnDisplaysRemoved(
    const display::Displays& removed_displays) {
  for (const auto& display : removed_displays) {
    // TODO(crbug.com/40148077): Please remove this log or replace it with
    // [D]CHECK() ASAP when the TEST is stable.
    LOG(INFO) << "VirtualDisplayUtilMac::" << __func__
              << " - display id: " << display.id() << ".";
    OnDisplayAddedOrRemoved(display.id());
  }
}

void VirtualDisplayUtilMac::OnDisplayAddedOrRemoved(int64_t id) {
  if (!waiting_for_ids_.count(id)) {
    // TODO(crbug.com/40148077): Please remove this log or replace it with
    // [D]CHECK() ASAP when the TEST is stable.
    LOG(INFO) << "VirtualDisplayUtilMac::" << __func__
              << " - unexpected display id: " << id << ".";

    return;
  }

  waiting_for_ids_.erase(id);
  if (!waiting_for_ids_.empty()) {
    return;
  }

  StopWaiting();
}

void VirtualDisplayUtilMac::WaitForDisplay(int64_t id, bool added) {
  display::Display d;
  if (screen_->GetDisplayWithDisplayId(id, &d) == added) {
    return;
  }

  waiting_for_ids_.insert(id);

  // TODO(crbug.com/40148077): Please remove this log or replace it with
  // [D]CHECK() ASAP when the TEST is stable.
  LOG(INFO) << "VirtualDisplayUtilMac::" << __func__ << " - display id: " << id
            << "(added: " << added << "). Start waiting.";

  StartWaiting();
}

void VirtualDisplayUtilMac::StartWaiting() {
  DCHECK(!run_loop_);
  run_loop_ = std::make_unique<base::RunLoop>();
  run_loop_->Run();
  run_loop_.reset();
}

void VirtualDisplayUtilMac::StopWaiting() {
  DCHECK(run_loop_);
  run_loop_->Quit();
}

// static
std::unique_ptr<VirtualDisplayUtil> VirtualDisplayUtil::TryCreate(
    Screen* screen) {
  if (!VirtualDisplayUtilMac::IsAPIAvailable()) {
    return nullptr;
  }
  return std::make_unique<VirtualDisplayUtilMac>(screen);
}

}  // namespace display::test