// 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 "ui/base/ime/ash/extension_ime_util.h"

#include "base/strings/strcat.h"
#include "base/strings/string_util.h"
#include "build/branding_buildflags.h"

namespace ash {

namespace {

const char kExtensionIMEPrefix[] = "_ext_ime_";
const int kExtensionIMEPrefixLength =
    sizeof(kExtensionIMEPrefix) / sizeof(kExtensionIMEPrefix[0]) - 1;
const char kComponentExtensionIMEPrefix[] = "_comp_ime_";
const int kComponentExtensionIMEPrefixLength =
    sizeof(kComponentExtensionIMEPrefix) /
        sizeof(kComponentExtensionIMEPrefix[0]) -
    1;
const char kArcIMEPrefix[] = "_arc_ime_";
const int kArcIMEPrefixLength =
    sizeof(kArcIMEPrefix) / sizeof(kArcIMEPrefix[0]) - 1;
const int kExtensionIdLength = 32;

}  // namespace

namespace extension_ime_util {

std::string GetInputMethodID(const std::string& extension_id,
                             const std::string& engine_id) {
  DCHECK(!extension_id.empty());
  DCHECK(!engine_id.empty());
  return kExtensionIMEPrefix + extension_id + engine_id;
}

std::string GetComponentInputMethodID(const std::string& extension_id,
                                      const std::string& engine_id) {
  DCHECK(!extension_id.empty());
  DCHECK(!engine_id.empty());
  return kComponentExtensionIMEPrefix + extension_id + engine_id;
}

std::string GetArcInputMethodID(const std::string& extension_id,
                                const std::string& engine_id) {
  DCHECK(!extension_id.empty());
  DCHECK(!engine_id.empty());
  return kArcIMEPrefix + extension_id + engine_id;
}

std::string GetExtensionIDFromInputMethodID(
    const std::string& input_method_id) {
  if (IsExtensionIME(input_method_id)) {
    return input_method_id.substr(kExtensionIMEPrefixLength,
                                  kExtensionIdLength);
  }
  if (IsComponentExtensionIME(input_method_id)) {
    return input_method_id.substr(kComponentExtensionIMEPrefixLength,
                                  kExtensionIdLength);
  }
  if (IsArcIME(input_method_id)) {
    return input_method_id.substr(kArcIMEPrefixLength, kExtensionIdLength);
  }
  return "";
}

std::string GetComponentIDByInputMethodID(const std::string& input_method_id) {
  if (IsComponentExtensionIME(input_method_id)) {
    return input_method_id.substr(kComponentExtensionIMEPrefixLength +
                                  kExtensionIdLength);
  }
  if (IsExtensionIME(input_method_id)) {
    return input_method_id.substr(kExtensionIMEPrefixLength +
                                  kExtensionIdLength);
  }
  if (IsArcIME(input_method_id)) {
    return input_method_id.substr(kArcIMEPrefixLength + kExtensionIdLength);
  }
  return input_method_id;
}

std::string GetInputMethodIDByEngineID(const std::string& engine_id) {
  if (engine_id.starts_with(kComponentExtensionIMEPrefix) ||
      engine_id.starts_with(kExtensionIMEPrefix) ||
      engine_id.starts_with(kArcIMEPrefix)) {
    return engine_id;
  }
  if (engine_id.starts_with("xkb:")) {
    return GetComponentInputMethodID(kXkbExtensionId, engine_id);
  }
  if (engine_id.starts_with("vkd_")) {
    return GetComponentInputMethodID(kM17nExtensionId, engine_id);
  }
  if (engine_id.starts_with("nacl_mozc_")) {
    return GetComponentInputMethodID(kMozcExtensionId, engine_id);
  }
  if (engine_id.starts_with("hangul_")) {
    return GetComponentInputMethodID(kHangulExtensionId, engine_id);
  }

  if (engine_id.starts_with("zh-") &&
      engine_id.find("pinyin") != std::string::npos) {
    return GetComponentInputMethodID(kChinesePinyinExtensionId, engine_id);
  }
  if (engine_id.starts_with("zh-") &&
      engine_id.find("zhuyin") != std::string::npos) {
    return GetComponentInputMethodID(kChineseZhuyinExtensionId, engine_id);
  }
  if (engine_id.starts_with("zh-") &&
      engine_id.find("cangjie") != std::string::npos) {
    return GetComponentInputMethodID(kChineseCangjieExtensionId, engine_id);
  }
  if (engine_id.find("-t-i0-") != std::string::npos) {
    return GetComponentInputMethodID(kT13nExtensionId, engine_id);
  }

  return engine_id;
}

bool IsExtensionIME(const std::string& input_method_id) {
  return input_method_id.starts_with(kExtensionIMEPrefix) &&
         input_method_id.size() >
             kExtensionIMEPrefixLength + kExtensionIdLength;
}

bool IsComponentExtensionIME(const std::string& input_method_id) {
  return input_method_id.starts_with(kComponentExtensionIMEPrefix) &&
         input_method_id.size() >
             kComponentExtensionIMEPrefixLength + kExtensionIdLength;
}

bool IsArcIME(const std::string& input_method_id) {
  return input_method_id.starts_with(kArcIMEPrefix) &&
         input_method_id.size() > kArcIMEPrefixLength + kExtensionIdLength;
}

bool IsKeyboardLayoutExtension(const std::string& input_method_id) {
  if (IsComponentExtensionIME(input_method_id)) {
    return GetComponentIDByInputMethodID(input_method_id).starts_with("xkb:");
  }
  return false;
}

bool IsCros1pKorean(const std::string& input_method_id) {
  // TODO(crbug.com/1162211): Input method IDs are tuples of extension type,
  // extension ID, and extension-local input method ID. However, currently
  // they're just concats of the three constituent pieces of info, hence StrCat
  // here. Replace StrCat once they're no longer unstructured string concats.

#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
  return input_method_id == base::StrCat({kComponentExtensionIMEPrefix,
                                          kXkbExtensionId, "ko-t-i0-und"});
#else
  return false;
#endif
}

}  // namespace extension_ime_util
}  // namespace ash