/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsCollation.h"
#include "mozilla/intl/LocaleService.h"
#include "nsString.h"

NS_IMPL_ISUPPORTS(nsCollation, nsICollation)

nsCollation::nsCollation()
    : mInit(false),
      mHasCollator(false),
      mLastStrength(-1),
      mCollatorICU(nullptr) {}

nsCollation::~nsCollation() {
#ifdef DEBUG
  nsresult res =
#endif
      CleanUpCollator();
  NS_ASSERTION(NS_SUCCEEDED(res), "CleanUpCollator failed");
}

nsresult nsCollation::ConvertStrength(const int32_t aNSStrength,
                                      UCollationStrength* aICUStrength,
                                      UColAttributeValue* aCaseLevelOut) {
  NS_ENSURE_ARG_POINTER(aICUStrength);
  NS_ENSURE_TRUE((aNSStrength < 4), NS_ERROR_FAILURE);

  UCollationStrength strength = UCOL_DEFAULT;
  UColAttributeValue caseLevel = UCOL_OFF;
  switch (aNSStrength) {
    case kCollationCaseInSensitive:
      strength = UCOL_PRIMARY;
      break;
    case kCollationCaseInsensitiveAscii:
      strength = UCOL_SECONDARY;
      break;
    case kCollationAccentInsenstive:
      caseLevel = UCOL_ON;
      strength = UCOL_PRIMARY;
      break;
    case kCollationCaseSensitive:
      strength = UCOL_TERTIARY;
      break;
    default:
      NS_WARNING("Bad aNSStrength passed to ConvertStrength.");
      return NS_ERROR_FAILURE;
  }

  *aICUStrength = strength;
  *aCaseLevelOut = caseLevel;

  return NS_OK;
}

nsresult nsCollation::EnsureCollator(const int32_t newStrength) {
  NS_ENSURE_TRUE(mInit, NS_ERROR_NOT_INITIALIZED);
  if (mHasCollator && (mLastStrength == newStrength)) return NS_OK;

  nsresult res;
  res = CleanUpCollator();
  NS_ENSURE_SUCCESS(res, res);

  UErrorCode status;
  status = U_ZERO_ERROR;
  mCollatorICU = ucol_open(mLocale.get(), &status);
  NS_ENSURE_TRUE(U_SUCCESS(status), NS_ERROR_FAILURE);

  UCollationStrength strength;
  UColAttributeValue caseLevel;
  res = ConvertStrength(newStrength, &strength, &caseLevel);
  NS_ENSURE_SUCCESS(res, res);

  status = U_ZERO_ERROR;
  ucol_setAttribute(mCollatorICU, UCOL_STRENGTH, strength, &status);
  NS_ENSURE_TRUE(U_SUCCESS(status), NS_ERROR_FAILURE);
  ucol_setAttribute(mCollatorICU, UCOL_CASE_LEVEL, caseLevel, &status);
  NS_ENSURE_TRUE(U_SUCCESS(status), NS_ERROR_FAILURE);
  ucol_setAttribute(mCollatorICU, UCOL_ALTERNATE_HANDLING, UCOL_DEFAULT,
                    &status);
  NS_ENSURE_TRUE(U_SUCCESS(status), NS_ERROR_FAILURE);
  ucol_setAttribute(mCollatorICU, UCOL_NUMERIC_COLLATION, UCOL_OFF, &status);
  NS_ENSURE_TRUE(U_SUCCESS(status), NS_ERROR_FAILURE);
  ucol_setAttribute(mCollatorICU, UCOL_NORMALIZATION_MODE, UCOL_ON, &status);
  NS_ENSURE_TRUE(U_SUCCESS(status), NS_ERROR_FAILURE);
  ucol_setAttribute(mCollatorICU, UCOL_CASE_FIRST, UCOL_DEFAULT, &status);
  NS_ENSURE_TRUE(U_SUCCESS(status), NS_ERROR_FAILURE);

  mHasCollator = true;

  mLastStrength = newStrength;
  return NS_OK;
}

nsresult nsCollation::CleanUpCollator(void) {
  if (mHasCollator) {
    ucol_close(mCollatorICU);
    mHasCollator = false;
  }

  return NS_OK;
}

NS_IMETHODIMP
nsCollation::Initialize(const nsACString& locale) {
  NS_ENSURE_TRUE((!mInit), NS_ERROR_ALREADY_INITIALIZED);

  // Check whether locale parameter is valid.  If no, use application locale
  UErrorCode status = U_ZERO_ERROR;
  UCollator* collator = ucol_open(PromiseFlatCString(locale).get(), &status);
  if (U_SUCCESS(status)) {
    mLocale = locale;
  } else {
    status = U_ZERO_ERROR;
    mozilla::LocaleService::GetInstance()->GetAppLocaleAsBCP47(mLocale);
    collator = ucol_open(mLocale.get(), &status);
    if (NS_WARN_IF(U_FAILURE(status))) {
      return NS_ERROR_UNEXPECTED;
    }
  }
  ucol_close(collator);

  mInit = true;
  return NS_OK;
}

NS_IMETHODIMP
nsCollation::AllocateRawSortKey(int32_t strength, const nsAString& stringIn,
                                nsTArray<uint8_t>& key) {
  NS_ENSURE_TRUE(mInit, NS_ERROR_NOT_INITIALIZED);

  nsresult res = EnsureCollator(strength);
  NS_ENSURE_SUCCESS(res, res);

  uint32_t stringInLen = stringIn.Length();

  const UChar* str = (const UChar*)stringIn.BeginReading();

  int32_t keyLength =
      ucol_getSortKey(mCollatorICU, str, stringInLen, nullptr, 0);
  NS_ENSURE_TRUE((stringInLen == 0 || keyLength > 0), NS_ERROR_FAILURE);

  key.SetLength(keyLength + 1);

  keyLength = ucol_getSortKey(mCollatorICU, str, stringInLen, key.Elements(),
                              keyLength + 1);
  NS_ENSURE_TRUE((stringInLen == 0 || keyLength > 0), NS_ERROR_FAILURE);

  key.SetLength(keyLength);
  return NS_OK;
}

NS_IMETHODIMP
nsCollation::CompareString(int32_t strength, const nsAString& string1,
                           const nsAString& string2, int32_t* result) {
  NS_ENSURE_TRUE(mInit, NS_ERROR_NOT_INITIALIZED);
  NS_ENSURE_ARG_POINTER(result);
  *result = 0;

  nsresult rv = EnsureCollator(strength);
  NS_ENSURE_SUCCESS(rv, rv);

  UCollationResult uresult;
  uresult = ucol_strcoll(mCollatorICU, (const UChar*)string1.BeginReading(),
                         string1.Length(), (const UChar*)string2.BeginReading(),
                         string2.Length());
  int32_t res;
  switch (uresult) {
    case UCOL_LESS:
      res = -1;
      break;
    case UCOL_EQUAL:
      res = 0;
      break;
    case UCOL_GREATER:
      res = 1;
      break;
    default:
      MOZ_CRASH("ucol_strcoll returned bad UCollationResult");
  }
  *result = res;
  return NS_OK;
}

NS_IMETHODIMP
nsCollation::CompareRawSortKey(const nsTArray<uint8_t>& key1,
                               const nsTArray<uint8_t>& key2, int32_t* result) {
  NS_ENSURE_TRUE(mInit, NS_ERROR_NOT_INITIALIZED);
  NS_ENSURE_ARG_POINTER(result);
  *result = 0;

  size_t minLength = std::min(key1.Length(), key2.Length());
  int32_t tmpResult = strncmp((const char*)key1.Elements(),
                              (const char*)key2.Elements(), minLength);
  int32_t res;
  if (tmpResult < 0) {
    res = -1;
  } else if (tmpResult > 0) {
    res = 1;
  } else if (key1.Length() > minLength) {
    // First string contains second one, so comes later, hence return > 0.
    res = 1;
  } else if (key2.Length() > minLength) {
    // First string is a substring of second one, so comes earlier,
    // hence return < 0.
    res = -1;
  } else {
    res = 0;
  }
  *result = res;
  return NS_OK;
}