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#include "dictionary/zip_code_dictionary_builder.h"

#include <cmath>
#include <string>
#include <vector>

#include "base/base.h"
#include "base/util.h"
#include "base/file_stream.h"
#include "converter/pos_matcher.h"

namespace mozc {
namespace {
const uint32 kOffset = 30000;
const uint32 kScoreMax = 32767;

uint32 GetScore(int64 freq) {
  if (freq <= 0) {
    return kOffset;
  }
  uint32 score = kOffset - log(static_cast<double>(freq));
  if (score > kScoreMax) {  // cost should be within 15 bits
    score = kScoreMax;
  }
  return score;
}
}  // namespace

ZipCodeDictionaryBuilder::ZipCodeDictionaryBuilder(const string &input,
                                                   const string &output)
    : input_filename_(input), output_filename_(output) {
}

ZipCodeDictionaryBuilder::~ZipCodeDictionaryBuilder() {}

void ZipCodeDictionaryBuilder::Build() {
  const uint16 zip_code_pos = POSMatcher::GetZipcodeId();
  InputFileStream ifs(input_filename_.c_str());
  CHECK(ifs);
  string line;
  vector<string> tokens;

  OutputFileStream ofs(output_filename_.c_str());
  CHECK(ofs);

  while (getline(ifs, line)) {
    if (line.size() <= 0 || line[0] == '#') {
      continue;
    }
    tokens.clear();
    Util::SplitStringUsing(line, "\t", &tokens);
    if (tokens.size() < 3) {
      LOG(ERROR) << "format error: " << line;
      continue;
    }
    const string &key = tokens[0];
    const string &value = tokens[1];
    const int64 freq = static_cast<int64>(strtod(tokens[2].c_str(), NULL));
    const uint32 score = GetScore(freq);

    ofs << key << "\t" << zip_code_pos << "\t" << zip_code_pos << "\t"
        << score << "\t" << value << endl;
  }
}
}  // namespace mozc