/*
 * Open Chinese Convert
 *
 * Copyright 2020 Carbo Kuo <byvoid@byvoid.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <algorithm>

#include "Lexicon.hpp"

namespace opencc {

namespace {

DictEntry* ParseKeyValues(const char* buff, size_t lineNum) {
  size_t length;
  if (buff == nullptr || UTF8Util::IsLineEndingOrFileEnding(*buff)) {
    return nullptr;
  }
  const char* pbuff = UTF8Util::FindNextInline(buff, '\t');
  if (UTF8Util::IsLineEndingOrFileEnding(*pbuff)) {
    throw InvalidTextDictionary("Tabular not found " + std::string(buff),
                                lineNum);
  }
  length = static_cast<size_t>(pbuff - buff);
  std::string key = UTF8Util::FromSubstr(buff, length);
  std::vector<std::string> values;
  while (!UTF8Util::IsLineEndingOrFileEnding(*pbuff)) {
    buff = pbuff = UTF8Util::NextChar(pbuff);
    pbuff = UTF8Util::FindNextInline(buff, ' ');
    length = static_cast<size_t>(pbuff - buff);
    const std::string& value = UTF8Util::FromSubstr(buff, length);
    values.push_back(value);
  }
  if (values.size() == 0) {
    throw InvalidTextDictionary("No value in an item", lineNum);
  } else if (values.size() == 1) {
    return DictEntryFactory::New(key, values.at(0));
  } else {
    return DictEntryFactory::New(key, values);
  }
}

} // namespace

void Lexicon::Sort() {
  std::sort(entries.begin(), entries.end(), DictEntry::UPtrLessThan);
}

bool Lexicon::IsSorted() {
  return std::is_sorted(entries.begin(), entries.end(),
                        DictEntry::UPtrLessThan);
}

bool Lexicon::IsUnique(std::string* dupkey) {
  for (size_t i = 1; i < entries.size(); ++i) {
    if (entries[i - 1]->Key() == entries[i]->Key()) {
      if (dupkey) {
        *dupkey = entries[i]->Key();
      }
      return false;
    }
  }
  return true;
}

LexiconPtr Lexicon::ParseLexiconFromFile(FILE* fp) {
  const int ENTRY_BUFF_SIZE = 4096;
  char buff[ENTRY_BUFF_SIZE];
  LexiconPtr lexicon(new Lexicon);
  UTF8Util::SkipUtf8Bom(fp);
  size_t lineNum = 1;
  while (fgets(buff, ENTRY_BUFF_SIZE, fp)) {
    DictEntry* entry = ParseKeyValues(buff, lineNum);
    if (entry != nullptr) {
      lexicon->Add(entry);
    }
    lineNum++;
  }
  return lexicon;
}

} // namespace opencc