// Copyright 2016 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 "ui/display/manager/fake_display_delegate.h"

#include <string>
#include <utility>

#include "base/command_line.h"
#include "base/hash.h"
#include "base/logging.h"
#include "base/strings/string_split.h"
#include "base/strings/stringprintf.h"
#include "base/time/time.h"
#include "ui/display/display.h"
#include "ui/display/display_switches.h"
#include "ui/display/types/display_constants.h"
#include "ui/display/types/native_display_observer.h"
#include "ui/display/util/display_util.h"

namespace display {

namespace {

// The EDID specification marks the top bit of the manufacturer id as reserved.
constexpr uint16_t kReservedManufacturerID = 1 << 15;

// A random product name hash.
constexpr uint32_t kProductCodeHash = 3692486807;

// Delay for Configure().
constexpr base::TimeDelta kConfigureDisplayDelay =
    base::TimeDelta::FromMilliseconds(200);

}  // namespace

FakeDisplayDelegate::FakeDisplayDelegate() {}

FakeDisplayDelegate::~FakeDisplayDelegate() {}

int64_t FakeDisplayDelegate::AddDisplay(const gfx::Size& display_size) {
  DCHECK(!display_size.IsEmpty());

  if (next_display_id_ == 0xFF) {
    LOG(ERROR) << "Exceeded display id limit";
    return kInvalidDisplayId;
  }

  int64_t id = GenerateDisplayID(kReservedManufacturerID, kProductCodeHash,
                                 ++next_display_id_);

  FakeDisplaySnapshot::Builder builder;
  builder.SetId(id).SetNativeMode(display_size);

  return AddDisplay(builder.Build()) ? id : kInvalidDisplayId;
}

bool FakeDisplayDelegate::AddDisplay(std::unique_ptr<DisplaySnapshot> display) {
  DCHECK(display);

  int64_t display_id = display->display_id();
  // Check there is no existing display with the same id.
  for (auto& existing_display : displays_) {
    if (existing_display->display_id() == display_id) {
      LOG(ERROR) << "Display with id " << display_id << " already exists";
      return false;
    }
  }

  DVLOG(1) << "Added display " << display->ToString();
  displays_.push_back(std::move(display));
  OnConfigurationChanged();

  return true;
}

bool FakeDisplayDelegate::RemoveDisplay(int64_t display_id) {
  // Find display snapshot with matching id and remove it.
  for (auto iter = displays_.begin(); iter != displays_.end(); ++iter) {
    if ((*iter)->display_id() == display_id) {
      DVLOG(1) << "Removed display " << (*iter)->ToString();
      displays_.erase(iter);
      OnConfigurationChanged();
      return true;
    }
  }

  return false;
}

void FakeDisplayDelegate::Initialize() {
  DCHECK(!initialized_);

  // The default display will be an internal display with a native resolution
  // of 1366x768 if --screen-config not specified on the command line.
  std::string command_str = "1366x768/i";

  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
  if (command_line->HasSwitch(switches::kScreenConfig))
    command_str = command_line->GetSwitchValueASCII(switches::kScreenConfig);

  CreateDisplaysFromSpecString(command_str);
  initialized_ = true;
}

void FakeDisplayDelegate::TakeDisplayControl(DisplayControlCallback callback) {
  std::move(callback).Run(false);
}

void FakeDisplayDelegate::RelinquishDisplayControl(
    DisplayControlCallback callback) {
  std::move(callback).Run(false);
}

void FakeDisplayDelegate::GetDisplays(GetDisplaysCallback callback) {
  std::vector<DisplaySnapshot*> displays;
  for (auto& display : displays_)
    displays.push_back(display.get());
  std::move(callback).Run(displays);
}

void FakeDisplayDelegate::Configure(const DisplaySnapshot& output,
                                    const DisplayMode* mode,
                                    const gfx::Point& origin,
                                    ConfigureCallback callback) {
  bool configure_success = false;

  if (!mode) {
    // This is a request to turn off the display.
    configure_success = true;
  } else {
    // Check that |mode| is appropriate for the display snapshot.
    for (const auto& existing_mode : output.modes()) {
      if (existing_mode.get() == mode) {
        configure_success = true;
        break;
      }
    }
  }

  configure_callbacks_.push(
      base::BindOnce(std::move(callback), configure_success));

  // Start the timer if it's not already running. If there are multiple queued
  // configuration requests then ConfigureDone() will handle starting the
  // next request.
  if (!configure_timer_.IsRunning()) {
    configure_timer_.Start(FROM_HERE, kConfigureDisplayDelay, this,
                           &FakeDisplayDelegate::ConfigureDone);
  }
}

void FakeDisplayDelegate::GetHDCPState(const DisplaySnapshot& output,
                                       GetHDCPStateCallback callback) {
  std::move(callback).Run(false, HDCP_STATE_UNDESIRED);
}

void FakeDisplayDelegate::SetHDCPState(const DisplaySnapshot& output,
                                       HDCPState state,
                                       SetHDCPStateCallback callback) {
  std::move(callback).Run(false);
}

bool FakeDisplayDelegate::SetColorCorrection(
    const DisplaySnapshot& output,
    const std::vector<GammaRampRGBEntry>& degamma_lut,
    const std::vector<GammaRampRGBEntry>& gamma_lut,
    const std::vector<float>& correction_matrix) {
  return false;
}

void FakeDisplayDelegate::AddObserver(NativeDisplayObserver* observer) {
  observers_.AddObserver(observer);
}

void FakeDisplayDelegate::RemoveObserver(NativeDisplayObserver* observer) {
  observers_.RemoveObserver(observer);
}

FakeDisplayController* FakeDisplayDelegate::GetFakeDisplayController() {
  return this;
}

void FakeDisplayDelegate::CreateDisplaysFromSpecString(const std::string& str) {
  // Start without any displays.
  if (str == "none")
    return;

  // Split on commas and parse each display string.
  for (const std::string& part : base::SplitString(
           str, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL)) {
    int64_t id = GenerateDisplayID(kReservedManufacturerID, kProductCodeHash,
                                   next_display_id_);
    std::unique_ptr<DisplaySnapshot> snapshot =
        FakeDisplaySnapshot::CreateFromSpec(id, part);
    if (snapshot) {
      AddDisplay(std::move(snapshot));
      next_display_id_++;
    } else {
      LOG(FATAL) << "Bad --" << switches::kScreenConfig << " flag provided.";
    }
  }
}

void FakeDisplayDelegate::OnConfigurationChanged() {
  if (!initialized_)
    return;

  for (NativeDisplayObserver& observer : observers_)
    observer.OnConfigurationChanged();
}

void FakeDisplayDelegate::ConfigureDone() {
  DCHECK(!configure_callbacks_.empty());
  std::move(configure_callbacks_.front()).Run();
  configure_callbacks_.pop();

  // If there are more configuration requests waiting then restart the timer.
  if (!configure_callbacks_.empty()) {
    configure_timer_.Start(FROM_HERE, kConfigureDisplayDelay, this,
                           &FakeDisplayDelegate::ConfigureDone);
  }
}

}  // namespace display