// Copyright (c) 2011 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/events/keycodes/keyboard_code_conversion.h"

#include <algorithm>

#include "ui/events/event_constants.h"
#include "ui/events/keycodes/dom/dom_code.h"
#include "ui/events/keycodes/dom/dom_key.h"
#include "ui/events/keycodes/dom_us_layout_data.h"
#include "ui/events/types/event_type.h"

namespace ui {

namespace {

bool IsRightSideDomCode(DomCode code) {
  return (code == DomCode::SHIFT_RIGHT) || (code == DomCode::CONTROL_RIGHT) ||
         (code == DomCode::ALT_RIGHT) || (code == DomCode::META_RIGHT);
}

}  // anonymous namespace

char16_t DomCodeToUsLayoutCharacter(DomCode dom_code, int flags) {
  DomKey dom_key;
  KeyboardCode key_code;
  if (DomCodeToUsLayoutDomKey(dom_code, flags, &dom_key, &key_code) &&
      dom_key.IsCharacter()) {
    return dom_key.ToCharacter();
  }
  return 0;
}

bool DomCodeToNonPrintableDomKey(DomCode dom_code,
                                 DomKey* out_dom_key,
                                 KeyboardCode* out_key_code) {
  for (const auto& it : kNonPrintableCodeMap) {
    if (it.dom_code == dom_code) {
      *out_dom_key = it.dom_key;
      *out_key_code = NonPrintableDomKeyToKeyboardCode(it.dom_key);
      return true;
    }
  }
  return false;
}

bool DomCodeToUsLayoutDomKey(DomCode dom_code,
                             int flags,
                             DomKey* out_dom_key,
                             KeyboardCode* out_key_code) {
  for (const auto& it : kPrintableCodeMap) {
    if (it.dom_code == dom_code) {
      int state = ((flags & EF_SHIFT_DOWN) == EF_SHIFT_DOWN);
      char16_t ch = it.character[state];
      if ((flags & EF_CAPS_LOCK_ON) == EF_CAPS_LOCK_ON) {
        ch |= 0x20;
        if ((ch >= 'a') && (ch <= 'z'))
          ch = it.character[state ^ 1];
      }
      *out_dom_key = DomKey::FromCharacter(ch);
      *out_key_code = DomCodeToUsLayoutNonLocatedKeyboardCode(dom_code);
      return true;
    }
  }

  return DomCodeToNonPrintableDomKey(dom_code, out_dom_key, out_key_code);
}

bool DomCodeToControlCharacter(DomCode dom_code,
                               int flags,
                               DomKey* dom_key,
                               KeyboardCode* key_code) {
  if ((flags & EF_CONTROL_DOWN) == 0)
    return false;

  int code = static_cast<int>(dom_code);
  const int kKeyA = static_cast<int>(DomCode::US_A);
  // Control-A - Control-Z map to 0x01 - 0x1A.
  if (code >= kKeyA && code <= static_cast<int>(DomCode::US_Z)) {
    *dom_key = DomKey::FromCharacter(code - kKeyA + 1);
    *key_code = static_cast<KeyboardCode>(code - kKeyA + VKEY_A);
    switch (dom_code) {
      case DomCode::US_H:
        *key_code = VKEY_BACK;
        break;
      case DomCode::US_I:
        *key_code = VKEY_TAB;
        break;
      case DomCode::US_M:
        *key_code = VKEY_RETURN;
        break;
      default:
        break;
    }
    return true;
  }

  if (flags & EF_SHIFT_DOWN) {
    switch (dom_code) {
      case DomCode::DIGIT2:
        // NUL
        *dom_key = DomKey::FromCharacter(0);
        *key_code = VKEY_2;
        return true;
      case DomCode::DIGIT6:
        // RS
        *dom_key = DomKey::FromCharacter(0x1E);
        *key_code = VKEY_6;
        return true;
      case DomCode::MINUS:
        // US
        *dom_key = DomKey::FromCharacter(0x1F);
        *key_code = VKEY_OEM_MINUS;
        return true;
      default:
        return false;
    }
  }

  switch (dom_code) {
    case DomCode::ENTER:
      // NL
      *dom_key = DomKey::FromCharacter(0x0A);
      *key_code = VKEY_RETURN;
      return true;
    case DomCode::BRACKET_LEFT:
      // ESC
      *dom_key = DomKey::FromCharacter(0x1B);
      *key_code = VKEY_OEM_4;
      return true;
    case DomCode::BACKSLASH:
      // FS
      *dom_key = DomKey::FromCharacter(0x1C);
      *key_code = VKEY_OEM_5;
      return true;
    case DomCode::BRACKET_RIGHT:
      // GS
      *dom_key = DomKey::FromCharacter(0x1D);
      *key_code = VKEY_OEM_6;
      return true;
    default:
      return false;
  }
}

// Returns a Windows-based VKEY for a non-printable DOM Level 3 |key|.
// The returned VKEY is non-positional (e.g. VKEY_SHIFT).
KeyboardCode NonPrintableDomKeyToKeyboardCode(DomKey dom_key) {
  for (const auto& it : kDomKeyToKeyboardCodeMap) {
    if (it.dom_key == dom_key)
      return it.key_code;
  }
  return VKEY_UNKNOWN;
}

// Determine the non-located VKEY corresponding to a located VKEY.
KeyboardCode LocatedToNonLocatedKeyboardCode(KeyboardCode key_code) {
  switch (key_code) {
    case VKEY_RWIN:
      return VKEY_LWIN;
    case VKEY_LSHIFT:
    case VKEY_RSHIFT:
      return VKEY_SHIFT;
    case VKEY_LCONTROL:
    case VKEY_RCONTROL:
      return VKEY_CONTROL;
    case VKEY_LMENU:
    case VKEY_RMENU:
      return VKEY_MENU;
    case VKEY_NUMPAD0:
      return VKEY_0;
    case VKEY_NUMPAD1:
      return VKEY_1;
    case VKEY_NUMPAD2:
      return VKEY_2;
    case VKEY_NUMPAD3:
      return VKEY_3;
    case VKEY_NUMPAD4:
      return VKEY_4;
    case VKEY_NUMPAD5:
      return VKEY_5;
    case VKEY_NUMPAD6:
      return VKEY_6;
    case VKEY_NUMPAD7:
      return VKEY_7;
    case VKEY_NUMPAD8:
      return VKEY_8;
    case VKEY_NUMPAD9:
      return VKEY_9;
    default:
      return key_code;
  }
}

// Determine the located VKEY corresponding to a non-located VKEY.
KeyboardCode NonLocatedToLocatedKeyboardCode(KeyboardCode key_code,
                                             DomCode dom_code) {
  switch (key_code) {
    case VKEY_SHIFT:
      return IsRightSideDomCode(dom_code) ? VKEY_RSHIFT : VKEY_LSHIFT;
    case VKEY_CONTROL:
      return IsRightSideDomCode(dom_code) ? VKEY_RCONTROL : VKEY_LCONTROL;
    case VKEY_MENU:
      return IsRightSideDomCode(dom_code) ? VKEY_RMENU : VKEY_LMENU;
    case VKEY_LWIN:
      return IsRightSideDomCode(dom_code) ? VKEY_RWIN : VKEY_LWIN;
    case VKEY_0:
      return (dom_code == DomCode::NUMPAD0) ? VKEY_NUMPAD0 : VKEY_0;
    case VKEY_1:
      return (dom_code == DomCode::NUMPAD1) ? VKEY_NUMPAD1 : VKEY_1;
    case VKEY_2:
      return (dom_code == DomCode::NUMPAD2) ? VKEY_NUMPAD2 : VKEY_2;
    case VKEY_3:
      return (dom_code == DomCode::NUMPAD3) ? VKEY_NUMPAD3 : VKEY_3;
    case VKEY_4:
      return (dom_code == DomCode::NUMPAD4) ? VKEY_NUMPAD4 : VKEY_4;
    case VKEY_5:
      return (dom_code == DomCode::NUMPAD5) ? VKEY_NUMPAD5 : VKEY_5;
    case VKEY_6:
      return (dom_code == DomCode::NUMPAD6) ? VKEY_NUMPAD6 : VKEY_6;
    case VKEY_7:
      return (dom_code == DomCode::NUMPAD7) ? VKEY_NUMPAD7 : VKEY_7;
    case VKEY_8:
      return (dom_code == DomCode::NUMPAD8) ? VKEY_NUMPAD8 : VKEY_8;
    case VKEY_9:
      return (dom_code == DomCode::NUMPAD9) ? VKEY_NUMPAD9 : VKEY_9;
    default:
      return key_code;
  }
}

DomCode UsLayoutKeyboardCodeToDomCode(KeyboardCode key_code) {
  key_code = NonLocatedToLocatedKeyboardCode(key_code, DomCode::NONE);
  for (const auto& it : kDomCodeToKeyboardCodeMap) {
    if (it.key_code == key_code)
      return it.dom_code;
  }
  for (const auto& it : kFallbackKeyboardCodeToDomCodeMap) {
    if (it.key_code == key_code)
      return it.dom_code;
  }
  return DomCode::NONE;
}

KeyboardCode DomCodeToUsLayoutKeyboardCode(DomCode dom_code) {
  const DomCodeToKeyboardCodeEntry* end =
      kDomCodeToKeyboardCodeMap + std::size(kDomCodeToKeyboardCodeMap);
  const DomCodeToKeyboardCodeEntry* found = std::lower_bound(
      kDomCodeToKeyboardCodeMap, end, dom_code,
      [](const DomCodeToKeyboardCodeEntry& a, DomCode b) {
        return static_cast<int>(a.dom_code) < static_cast<int>(b);
      });
  if ((found != end) && (found->dom_code == dom_code))
    return found->key_code;

  return VKEY_UNKNOWN;
}

KeyboardCode DomCodeToUsLayoutNonLocatedKeyboardCode(DomCode dom_code) {
  return LocatedToNonLocatedKeyboardCode(
      DomCodeToUsLayoutKeyboardCode(dom_code));
}

int ModifierDomKeyToEventFlag(DomKey key) {
  switch (key) {
    case DomKey::ALT:
      return EF_ALT_DOWN;
    case DomKey::ALT_GRAPH:
      return EF_ALTGR_DOWN;
    case DomKey::CAPS_LOCK:
      return EF_CAPS_LOCK_ON;
    case DomKey::CONTROL:
      return EF_CONTROL_DOWN;
    case DomKey::META:
      return EF_COMMAND_DOWN;
    case DomKey::SHIFT:
      return EF_SHIFT_DOWN;
    case DomKey::SHIFT_LEVEL5:
      return EF_MOD3_DOWN;
    default:
      return EF_NONE;
  }
  // Not represented:
  //   DomKey::ACCEL
  //   DomKey::FN
  //   DomKey::FN_LOCK
  //   DomKey::HYPER
  //   DomKey::NUM_LOCK
  //   DomKey::SCROLL_LOCK
  //   DomKey::SUPER
  //   DomKey::SYMBOL_LOCK
}

DomCode UsLayoutDomKeyToDomCode(DomKey dom_key) {
  if (dom_key.IsCharacter()) {
    char16_t c = dom_key.ToCharacter();
    for (const auto& it : kPrintableCodeMap) {
      if (it.character[0] == c || it.character[1] == c) {
        return it.dom_code;
      }
    }
  }

  for (const auto& it : kNonPrintableCodeMap) {
    if (it.dom_key == dom_key)
      return it.dom_code;
  }
  return DomCode::NONE;
}

}  // namespace ui