/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * 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.
 */

#ifndef LIBTEXTCLASSIFIER_ANNOTATOR_GRAMMAR_GRAMMAR_ANNOTATOR_H_
#define LIBTEXTCLASSIFIER_ANNOTATOR_GRAMMAR_GRAMMAR_ANNOTATOR_H_

#include <vector>

#include "annotator/model_generated.h"
#include "annotator/types.h"
#include "utils/flatbuffers.h"
#include "utils/grammar/lexer.h"
#include "utils/i18n/locale.h"
#include "utils/tokenizer.h"
#include "utils/utf8/unicodetext.h"
#include "utils/utf8/unilib.h"

namespace libtextclassifier3 {

// Grammar backed annotator.
class GrammarAnnotator {
 public:
  enum class Callback : grammar::CallbackId {
    kRuleMatch = 1,
  };

  explicit GrammarAnnotator(
      const UniLib* unilib, const GrammarModel* model,
      const ReflectiveFlatbufferBuilder* entity_data_builder);

  // Annotates a given text.
  // Returns true if the text was successfully annotated.
  bool Annotate(const std::vector<Locale>& locales, const UnicodeText& text,
                std::vector<AnnotatedSpan>* result) const;

  // Classifies a span in a text.
  // Returns true if the span was classified by a grammar rule.
  bool ClassifyText(const std::vector<Locale>& locales, const UnicodeText& text,
                    const CodepointSpan& selection,
                    ClassificationResult* classification_result) const;

  // Suggests text selections in a text.
  // Returns true if a span was suggested by a grammar rule.
  bool SuggestSelection(const std::vector<Locale>& locales,
                        const UnicodeText& text, const CodepointSpan& selection,
                        AnnotatedSpan* result) const;

 private:
  const UniLib& unilib_;
  const GrammarModel* model_;
  const grammar::Lexer lexer_;
  const Tokenizer tokenizer_;
  const ReflectiveFlatbufferBuilder* entity_data_builder_;

  // Pre-parsed locales of the rules.
  const std::vector<std::vector<Locale>> rules_locales_;
};

}  // namespace libtextclassifier3

#endif  // LIBTEXTCLASSIFIER_ANNOTATOR_GRAMMAR_GRAMMAR_ANNOTATOR_H_