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 *   Copyright 2023-Present Couchbase, Inc.
 *
 *   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.
 */

#pragma once

#include <couchbase/search_query.hxx>

#include <optional>
#include <string>

namespace couchbase
{
/**
 * The input text is analyzed and a phrase query is built with the terms resulting from the analysis. This type of query searches for terms
 * occurring in the specified positions and offsets. This depends on term vectors, which are consulted to determine phrase distance.
 *
 * For example, a match phrase query for `"location for functions"` is matched with `"locate the function"`, if the standard analyzer is
 * used: this analyzer uses a **stemmer**, which tokenizes `"location"` and `"locate"` to `"locat"`, and reduces `"functions"` and
 * `"function"` to `"function"`. Additionally, the analyzer employs stop removal, which removes small and less significant words from input
 * and target text, so that matches are attempted on only the more significant elements of vocabulary: in this case `"for"` and `"the"` are
 * removed. Following this processing, the tokens `"locat"` and `"function"` are recognized as common to both input and target; and also as
 * being both in the same sequence as, and at the same distance from one another; and therefore a match is made.
 * @snippet test_unit_search.cxx search-match-phrase
 *
 * @see https://docs.couchbase.com/server/current/fts/fts-supported-queries-match-phrase.html
 *
 * @since 1.0.0
 * @committed
 */
class match_phrase_query : public search_query
{
  public:
    /**
     * Create a new match phrase query.
     *
     * @param match_phrase the input string to be matched against
     *
     * @since 1.0.0
     * @committed
     */
    explicit match_phrase_query(std::string match_phrase)
      : match_phrase_{ std::move(match_phrase) }
    {
    }

    /**
     * Analyzers are used to transform input text into a stream of tokens for indexing. The Server comes with built-in analyzers and the
     * users can create their own.
     *
     * @param analyzer_name the name of the analyzer used
     *
     * @return this query for chaining purposes.
     *
     * @since 1.0.0
     * @committed
     */
    auto analyzer(std::string analyzer_name) -> match_phrase_query&
    {
        analyzer_ = std::move(analyzer_name);
        return *this;
    }

    /**
     * If a field is specified, only terms in that field will be matched.
     *
     * This can also affect the used analyzer if one isn't specified explicitly.
     *
     * @param field_name name of the field to be matched
     *
     * @return this query for chaining purposes.
     *
     * @since 1.0.0
     * @committed
     */
    auto field(std::string field_name) -> match_phrase_query&
    {
        field_ = std::move(field_name);
        return *this;
    }

    /**
     * @return encoded representation of the query.
     *
     * @since 1.0.0
     * @internal
     */
    [[nodiscard]] auto encode() const -> encoded_search_query override;

  private:
    std::string match_phrase_;
    std::optional<std::string> analyzer_{};
    std::optional<std::string> field_{};
};
} // namespace couchbase