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#include "dictionary/suffix_dictionary.h"

#include <algorithm>
#include <cstring>
#include <limits>
#include <string>

#include "base/iterator_adapter.h"
#include "base/logging.h"
#include "base/util.h"
#include "dictionary/dictionary_token.h"
#include "dictionary/suffix_dictionary_token.h"

namespace mozc {

SuffixDictionary::SuffixDictionary(const SuffixToken *suffix_tokens,
                                   size_t suffix_tokens_size)
    : suffix_tokens_(suffix_tokens),
      suffix_tokens_size_(suffix_tokens_size) {}

SuffixDictionary::~SuffixDictionary() {}

namespace {

struct SuffixTokenKeyAdapter : public AdapterBase<const char *> {
  value_type operator()(const SuffixToken *token) const {
    return token->key;
  }
};

class ComparePrefix {
 public:
  explicit ComparePrefix(size_t max_len) : max_len_(max_len) {}

  // Note: the inputs don't need to be null-terminated.
  bool operator()(const char *x, const char *y) const {
    return std::strncmp(x, y, max_len_) < 0;
  }

 private:
  const size_t max_len_;
};

}  // namespace

bool SuffixDictionary::HasValue(StringPiece value) const {
  // SuffixDictionary::HasValue() is never called and unnecessary to
  // implement. To avoid accidental calls of this method, the method simply dies
  // so that we can immediately notice this unimplemented method during
  // development.
  LOG(FATAL) << "bool SuffixDictionary::HasValue() is not implemented";
  return false;
}

void SuffixDictionary::LookupPredictive(
    StringPiece key,
    bool,  // use_kana_modifier_insensitive_lookup
    Callback *callback) const {
  typedef IteratorAdapter<const SuffixToken *, SuffixTokenKeyAdapter> Iter;
  pair<Iter, Iter> range = equal_range(
      MakeIteratorAdapter(suffix_tokens_, SuffixTokenKeyAdapter()),
      MakeIteratorAdapter(suffix_tokens_ + suffix_tokens_size_,
                          SuffixTokenKeyAdapter()),
      key.data(), ComparePrefix(key.size()));

  Token token;
  token.attributes = Token::NONE;  // Common for all suffix tokens.
  for (; range.first != range.second; ++range.first) {
    const SuffixToken &suffix_token = *range.first.base();
    token.key = suffix_token.key;
    switch (callback->OnKey(token.key)) {
      case Callback::TRAVERSE_DONE:
        return;
      case Callback::TRAVERSE_NEXT_KEY:
        continue;
      case Callback::TRAVERSE_CULL:
        LOG(FATAL) << "Culling is not supported.";
        continue;
      default:
        break;
    }
    token.value = (suffix_token.value == NULL) ? token.key : suffix_token.value;
    token.lid = suffix_token.lid;
    token.rid = suffix_token.rid;
    token.cost = suffix_token.wcost;
    if (callback->OnToken(token.key, token.key, token) !=
        Callback::TRAVERSE_CONTINUE) {
      break;
    }
  }
}

void SuffixDictionary::LookupPrefix(StringPiece key,
                                    bool use_kana_modifier_insensitive_lookup,
                                    Callback *callback) const {
}

void SuffixDictionary::LookupReverse(StringPiece str,
                                     NodeAllocatorInterface *allocator,
                                     Callback *callback) const {
}

void SuffixDictionary::LookupExact(StringPiece key, Callback *callback) const {
}

}  // namespace mozc