// 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.

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

#include <algorithm>
#include <iterator>

#include "base/strings/utf_string_conversions.h"
#include "chrome/test/chromedriver/chrome/ui_events.h"
#include "chrome/test/chromedriver/keycode_text_conversion.h"
#include "ui/base/x/x11_util.h"
#include "ui/events/keycodes/keyboard_code_conversion_x.h"
#include "ui/gfx/x/connection.h"
#include "ui/gfx/x/keysyms/keysyms.h"

namespace {

struct KeyCodeAndXKeyCode {
  ui::KeyboardCode key_code;
  int x_key_code;
};

// Contains a list of keyboard codes, in order, with their corresponding
// X key code. This list is not complete.
// TODO(kkania): Merge this table with the existing one in
// keyboard_code_conversion_x.cc.
constexpr KeyCodeAndXKeyCode kKeyCodeToXKeyCode[] = {
    {ui::VKEY_BACK, 22},      {ui::VKEY_TAB, 23},
    {ui::VKEY_RETURN, 36},    {ui::VKEY_SHIFT, 50},
    {ui::VKEY_CONTROL, 37},   {ui::VKEY_MENU, 64},
    {ui::VKEY_CAPITAL, 66},   {ui::VKEY_HANGUL, 130},
    {ui::VKEY_HANJA, 131},    {ui::VKEY_ESCAPE, 9},
    {ui::VKEY_SPACE, 65},     {ui::VKEY_PRIOR, 112},
    {ui::VKEY_NEXT, 117},     {ui::VKEY_END, 115},
    {ui::VKEY_HOME, 110},     {ui::VKEY_LEFT, 113},
    {ui::VKEY_UP, 111},       {ui::VKEY_RIGHT, 114},
    {ui::VKEY_DOWN, 116},     {ui::VKEY_INSERT, 118},
    {ui::VKEY_DELETE, 119},   {ui::VKEY_0, 19},
    {ui::VKEY_1, 10},         {ui::VKEY_2, 11},
    {ui::VKEY_3, 12},         {ui::VKEY_4, 13},
    {ui::VKEY_5, 14},         {ui::VKEY_6, 15},
    {ui::VKEY_7, 16},         {ui::VKEY_8, 17},
    {ui::VKEY_9, 18},         {ui::VKEY_A, 38},
    {ui::VKEY_B, 56},         {ui::VKEY_C, 54},
    {ui::VKEY_D, 40},         {ui::VKEY_E, 26},
    {ui::VKEY_F, 41},         {ui::VKEY_G, 42},
    {ui::VKEY_H, 43},         {ui::VKEY_I, 31},
    {ui::VKEY_J, 44},         {ui::VKEY_K, 45},
    {ui::VKEY_L, 46},         {ui::VKEY_M, 58},
    {ui::VKEY_N, 57},         {ui::VKEY_O, 32},
    {ui::VKEY_P, 33},         {ui::VKEY_Q, 24},
    {ui::VKEY_R, 27},         {ui::VKEY_S, 39},
    {ui::VKEY_T, 28},         {ui::VKEY_U, 30},
    {ui::VKEY_V, 55},         {ui::VKEY_W, 25},
    {ui::VKEY_X, 53},         {ui::VKEY_Y, 29},
    {ui::VKEY_Z, 52},         {ui::VKEY_LWIN, 133},
    {ui::VKEY_NUMPAD0, 90},   {ui::VKEY_NUMPAD1, 87},
    {ui::VKEY_NUMPAD2, 88},   {ui::VKEY_NUMPAD3, 89},
    {ui::VKEY_NUMPAD4, 83},   {ui::VKEY_NUMPAD5, 84},
    {ui::VKEY_NUMPAD6, 85},   {ui::VKEY_NUMPAD7, 79},
    {ui::VKEY_NUMPAD8, 80},   {ui::VKEY_NUMPAD9, 81},
    {ui::VKEY_MULTIPLY, 63},  {ui::VKEY_ADD, 86},
    {ui::VKEY_SUBTRACT, 82},  {ui::VKEY_DECIMAL, 129},
    {ui::VKEY_DIVIDE, 106},   {ui::VKEY_F1, 67},
    {ui::VKEY_F2, 68},        {ui::VKEY_F3, 69},
    {ui::VKEY_F4, 70},        {ui::VKEY_F5, 71},
    {ui::VKEY_F6, 72},        {ui::VKEY_F7, 73},
    {ui::VKEY_F8, 74},        {ui::VKEY_F9, 75},
    {ui::VKEY_F10, 76},       {ui::VKEY_F11, 95},
    {ui::VKEY_F12, 96},       {ui::VKEY_NUMLOCK, 77},
    {ui::VKEY_SCROLL, 78},    {ui::VKEY_OEM_1, 47},
    {ui::VKEY_OEM_PLUS, 21},  {ui::VKEY_OEM_COMMA, 59},
    {ui::VKEY_OEM_MINUS, 20}, {ui::VKEY_OEM_PERIOD, 60},
    {ui::VKEY_OEM_2, 61},     {ui::VKEY_OEM_3, 49},
    {ui::VKEY_OEM_4, 34},     {ui::VKEY_OEM_5, 51},
    {ui::VKEY_OEM_6, 35},     {ui::VKEY_OEM_7, 48}};

// Returns the equivalent X key code for the given key code. Returns -1 if
// no X equivalent was found.
int KeyboardCodeToXKeyCode(ui::KeyboardCode key_code) {
  KeyCodeAndXKeyCode find = {.key_code = key_code};
  const KeyCodeAndXKeyCode* found = std::ranges::lower_bound(
      kKeyCodeToXKeyCode, find,
      [](const KeyCodeAndXKeyCode& a, const KeyCodeAndXKeyCode& b) {
        return a.key_code < b.key_code;
      });
  if (found >= std::end(kKeyCodeToXKeyCode) || found->key_code != key_code) {
    return -1;
  }
  return found->x_key_code;
}

// Gets the X modifier mask (Mod1Mask through Mod5Mask) for the given
// modifier. Only checks the alt, meta, and num lock keys currently.
// Returns true on success.
bool GetXModifierMask(x11::Connection* connection,
                      int modifier,
                      x11::KeyButMask* x_modifier) {
  auto mod_map = connection->GetModifierMapping().Sync();
  if (!mod_map) {
    return false;
  }
  bool found = false;
  size_t key_idx = 0;
  for (; !found && key_idx < mod_map->keycodes.size(); ++key_idx) {
    auto key = mod_map->keycodes[key_idx];
    auto keysym = x11::Connection::Get()->KeycodeToKeysym(key, 0);
    found = (modifier == kAltKeyModifierMask &&
             (keysym == XK_Alt_L || keysym == XK_Alt_R)) ||
            (modifier == kMetaKeyModifierMask &&
             (keysym == XK_Meta_L || keysym == XK_Meta_R)) ||
            (modifier == kNumLockKeyModifierMask && keysym == XK_Num_Lock);
  }
  if (found) {
    int max_mod_keys = mod_map->keycodes_per_modifier;
    int mod_index = key_idx / max_mod_keys;
    *x_modifier = static_cast<x11::KeyButMask>(1 << mod_index);
  }
  return found;
}

}  // namespace

bool ConvertKeyCodeToText(ui::KeyboardCode key_code,
                          int modifiers,
                          std::string* text,
                          std::string* error_msg) {
  auto* connection = x11::Connection::Get();
  if (!connection || !connection->Ready()) {
    return ConvertKeyCodeToTextOzone(key_code, modifiers, text, error_msg);
  }

  *error_msg = std::string();
  int x_key_code = KeyboardCodeToXKeyCode(key_code);
  if (x_key_code == -1) {
    *text = std::string();
    return true;
  }

  x11::KeyEvent key_event;
  x11::KeyButMask state{};
  key_event.detail = static_cast<x11::KeyCode>(x_key_code);
  if (modifiers & kShiftKeyModifierMask)
    state = state | x11::KeyButMask::Shift;
  if (modifiers & kControlKeyModifierMask)
    state = state | x11::KeyButMask::Control;

  // Make a best attempt for non-standard modifiers.
  x11::KeyButMask x_modifier;
  if (modifiers & kAltKeyModifierMask &&
      GetXModifierMask(connection, kAltKeyModifierMask, &x_modifier)) {
    state = state | x_modifier;
  }
  if (modifiers & kMetaKeyModifierMask &&
      GetXModifierMask(connection, kMetaKeyModifierMask, &x_modifier)) {
    state = state | x_modifier;
  }
  if (modifiers & kNumLockKeyModifierMask &&
      GetXModifierMask(connection, kNumLockKeyModifierMask, &x_modifier)) {
    state = state | x_modifier;
  }
  key_event.state = state;
  key_event.opcode = x11::KeyEvent::Press;
  x11::Event event(false, std::move(key_event));
  uint16_t character = ui::GetCharacterFromXEvent(event);
  if (character) {
    *text = base::UTF16ToUTF8(std::u16string(1, character));
  } else {
    *text = std::string();
  }
  return true;
}

bool ConvertCharToKeyCode(char16_t key,
                          ui::KeyboardCode* key_code,
                          int* necessary_modifiers,
                          std::string* error_msg) {
  if (!x11::Connection::Get()->Ready()) {
    return ConvertCharToKeyCodeOzone(key, key_code, necessary_modifiers,
                                     error_msg);
  }

  std::string key_string(base::UTF16ToUTF8(std::u16string(1, key)));
  bool found = false;
  ui::KeyboardCode test_code;
  int test_modifiers;
  *error_msg = std::string();
  std::string conv_string;
  for (auto& i : kKeyCodeToXKeyCode) {
    test_code = i.key_code;
    // Skip the numpad keys.
    if (test_code >= ui::VKEY_NUMPAD0 && test_code <= ui::VKEY_DIVIDE)
      continue;
    test_modifiers = 0;
    if (!ConvertKeyCodeToText(test_code, test_modifiers, &conv_string,
                              error_msg))
      return false;
    if (conv_string == key_string) {
      found = true;
      break;
    }
    test_modifiers = kShiftKeyModifierMask;
    if (!ConvertKeyCodeToText(test_code, test_modifiers, &conv_string,
                              error_msg))
      return false;
    if (conv_string == key_string) {
      found = true;
      break;
    }
  }
  if (found) {
    *key_code = test_code;
    *necessary_modifiers = test_modifiers;
  }
  return found;
}