// Copyright (c) 2012 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 "device/gamepad/gamepad_platform_data_fetcher_win.h"

#include <stddef.h>
#include <string.h>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/single_thread_task_runner.h"
#include "base/strings/stringprintf.h"
#include "base/trace_event/trace_event.h"
#include "base/win/windows_version.h"

namespace device {

namespace {

// See http://goo.gl/5VSJR. These are not available in all versions of the
// header, but they can be returned from the driver, so we define our own
// versions here.
static const BYTE kDeviceSubTypeGamepad = 1;
static const BYTE kDeviceSubTypeWheel = 2;
static const BYTE kDeviceSubTypeArcadeStick = 3;
static const BYTE kDeviceSubTypeFlightStick = 4;
static const BYTE kDeviceSubTypeDancePad = 5;
static const BYTE kDeviceSubTypeGuitar = 6;
static const BYTE kDeviceSubTypeGuitarAlternate = 7;
static const BYTE kDeviceSubTypeDrumKit = 8;
static const BYTE kDeviceSubTypeGuitarBass = 11;
static const BYTE kDeviceSubTypeArcadePad = 19;

float NormalizeXInputAxis(SHORT value) {
  return ((value + 32768.f) / 32767.5f) - 1.f;
}

const UChar* GamepadSubTypeName(BYTE sub_type) {
  switch (sub_type) {
    case kDeviceSubTypeGamepad:
      return L"GAMEPAD";
    case kDeviceSubTypeWheel:
      return L"WHEEL";
    case kDeviceSubTypeArcadeStick:
      return L"ARCADE_STICK";
    case kDeviceSubTypeFlightStick:
      return L"FLIGHT_STICK";
    case kDeviceSubTypeDancePad:
      return L"DANCE_PAD";
    case kDeviceSubTypeGuitar:
      return L"GUITAR";
    case kDeviceSubTypeGuitarAlternate:
      return L"GUITAR_ALTERNATE";
    case kDeviceSubTypeDrumKit:
      return L"DRUM_KIT";
    case kDeviceSubTypeGuitarBass:
      return L"GUITAR_BASS";
    case kDeviceSubTypeArcadePad:
      return L"ARCADE_PAD";
    default:
      return L"<UNKNOWN>";
  }
}

const UChar* XInputDllFileName() {
  // Xinput.h defines filename (XINPUT_DLL) on different Windows versions, but
  // Xinput.h specifies it in build time. Approach here uses the same values
  // and it is resolving dll filename based on Windows version it is running on.
  if (base::win::GetVersion() >= base::win::VERSION_WIN8) {
    // For Windows 8+, XINPUT_DLL is xinput1_4.dll.
    return FILE_PATH_LITERAL("xinput1_4.dll");
  }
  return FILE_PATH_LITERAL("xinput9_1_0.dll");
}

}  // namespace

GamepadPlatformDataFetcherWin::GamepadPlatformDataFetcherWin()
    : xinput_available_(false) {}

GamepadPlatformDataFetcherWin::~GamepadPlatformDataFetcherWin() {
}

GamepadSource GamepadPlatformDataFetcherWin::source() {
  return Factory::static_source();
}

void GamepadPlatformDataFetcherWin::OnAddedToProvider() {
  xinput_dll_.Reset(
      base::LoadNativeLibrary(base::FilePath(XInputDllFileName()), nullptr));
  xinput_available_ = GetXInputDllFunctions();
}

void GamepadPlatformDataFetcherWin::EnumerateDevices() {
  TRACE_EVENT0("GAMEPAD", "EnumerateDevices");

  if (xinput_available_) {
    for (size_t i = 0; i < XUSER_MAX_COUNT; ++i) {
      // Check to see if the xinput device is connected
      XINPUT_CAPABILITIES caps;
      DWORD res = xinput_get_capabilities_(i, XINPUT_FLAG_GAMEPAD, &caps);
      xinuput_connected_[i] = (res == ERROR_SUCCESS);
      if (!xinuput_connected_[i])
        continue;

      PadState* state = GetPadState(i);
      if (!state)
        continue;  // No slot available for this gamepad.

      Gamepad& pad = state->data;

      if (state->active_state == GAMEPAD_NEWLY_ACTIVE) {
        // This is the first time we've seen this device, so do some one-time
        // initialization
        pad.connected = true;
        swprintf(pad.id, Gamepad::kIdLengthCap,
                 L"Xbox 360 Controller (XInput STANDARD %ls)",
                 GamepadSubTypeName(caps.SubType));
        swprintf(pad.mapping, Gamepad::kMappingLengthCap, L"standard");
      }
    }
  }
}

void GamepadPlatformDataFetcherWin::GetGamepadData(bool devices_changed_hint) {
  TRACE_EVENT0("GAMEPAD", "GetGamepadData");

  if (!xinput_available_)
    return;

  // A note on XInput devices:
  // If we got notification that system devices have been updated, then
  // run GetCapabilities to update the connected status and the device
  // identifier. It can be slow to do to both GetCapabilities and
  // GetState on unconnected devices, so we want to avoid a 2-5ms pause
  // here by only doing this when the devices are updated (despite
  // documentation claiming it's OK to call it any time).
  if (devices_changed_hint)
    EnumerateDevices();

  for (size_t i = 0; i < XUSER_MAX_COUNT; ++i) {
    if (xinuput_connected_[i])
      GetXInputPadData(i);
  }
}

void GamepadPlatformDataFetcherWin::GetXInputPadData(int i) {
  PadState* pad_state = provider()->GetPadState(GAMEPAD_SOURCE_WIN_XINPUT, i);
  if (!pad_state)
    return;

  Gamepad& pad = pad_state->data;

  XINPUT_STATE state;
  memset(&state, 0, sizeof(XINPUT_STATE));
  TRACE_EVENT_BEGIN1("GAMEPAD", "XInputGetState", "id", i);
  DWORD dwResult = xinput_get_state_(i, &state);
  TRACE_EVENT_END1("GAMEPAD", "XInputGetState", "id", i);

  if (dwResult == ERROR_SUCCESS) {
    pad.timestamp = state.dwPacketNumber;
    pad.buttons_length = 0;
    WORD val = state.Gamepad.wButtons;
#define ADD(b)                                                \
  pad.buttons[pad.buttons_length].pressed = (val & (b)) != 0; \
  pad.buttons[pad.buttons_length++].value = ((val & (b)) ? 1.f : 0.f);
    ADD(XINPUT_GAMEPAD_A);
    ADD(XINPUT_GAMEPAD_B);
    ADD(XINPUT_GAMEPAD_X);
    ADD(XINPUT_GAMEPAD_Y);
    ADD(XINPUT_GAMEPAD_LEFT_SHOULDER);
    ADD(XINPUT_GAMEPAD_RIGHT_SHOULDER);

    pad.buttons[pad.buttons_length].pressed =
        state.Gamepad.bLeftTrigger >= XINPUT_GAMEPAD_TRIGGER_THRESHOLD;
    pad.buttons[pad.buttons_length++].value =
        state.Gamepad.bLeftTrigger / 255.f;

    pad.buttons[pad.buttons_length].pressed =
        state.Gamepad.bRightTrigger >= XINPUT_GAMEPAD_TRIGGER_THRESHOLD;
    pad.buttons[pad.buttons_length++].value =
        state.Gamepad.bRightTrigger / 255.f;

    ADD(XINPUT_GAMEPAD_BACK);
    ADD(XINPUT_GAMEPAD_START);
    ADD(XINPUT_GAMEPAD_LEFT_THUMB);
    ADD(XINPUT_GAMEPAD_RIGHT_THUMB);
    ADD(XINPUT_GAMEPAD_DPAD_UP);
    ADD(XINPUT_GAMEPAD_DPAD_DOWN);
    ADD(XINPUT_GAMEPAD_DPAD_LEFT);
    ADD(XINPUT_GAMEPAD_DPAD_RIGHT);
#undef ADD
    pad.axes_length = 0;

    float value = 0.0;
#define ADD(a, factor)                     \
  value = factor * NormalizeXInputAxis(a); \
  pad.axes[pad.axes_length++] = value;

    // XInput are +up/+right, -down/-left, we want -up/-left.
    ADD(state.Gamepad.sThumbLX, 1);
    ADD(state.Gamepad.sThumbLY, -1);
    ADD(state.Gamepad.sThumbRX, 1);
    ADD(state.Gamepad.sThumbRY, -1);
#undef ADD
  }
}

bool GamepadPlatformDataFetcherWin::GetXInputDllFunctions() {
  xinput_get_capabilities_ = NULL;
  xinput_get_state_ = NULL;
  XInputEnableFunc xinput_enable = reinterpret_cast<XInputEnableFunc>(
      xinput_dll_.GetFunctionPointer("XInputEnable"));
  xinput_get_capabilities_ = reinterpret_cast<XInputGetCapabilitiesFunc>(
      xinput_dll_.GetFunctionPointer("XInputGetCapabilities"));
  if (!xinput_get_capabilities_)
    return false;
  xinput_get_state_ = reinterpret_cast<XInputGetStateFunc>(
      xinput_dll_.GetFunctionPointer("XInputGetState"));
  if (!xinput_get_state_)
    return false;
  if (xinput_enable) {
    // XInputEnable is unavailable before Win8 and deprecated in Win10.
    xinput_enable(true);
  }
  return true;
}

}  // namespace device