/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 <functional>
#include <memory>
#include <vector>

#include "paimon/global_index/global_index_result.h"
#include "paimon/predicate/full_text_search.h"
#include "paimon/predicate/function_visitor.h"
#include "paimon/predicate/vector_search.h"
#include "paimon/visibility.h"

namespace paimon {
/// Reads and evaluates filter predicates against a global file index.
///
/// Derived classes are expected to implement the visitor methods (e.g., `VisitEqual`,
/// `VisitIsNull`, etc.) to return index-based results that indicate which
/// rows satisfy the given predicate.
class PAIMON_EXPORT GlobalIndexReader : public FunctionVisitor<std::shared_ptr<GlobalIndexResult>> {
 public:
    /// VisitVectorSearch performs approximate vector similarity search.
    /// @warning `VisitVectorSearch` may return error status when it is incorrectly invoked (e.g.,
    /// BitmapGlobalIndexReader call `VisitVectorSearch`).
    virtual Result<std::shared_ptr<ScoredGlobalIndexResult>> VisitVectorSearch(
        const std::shared_ptr<VectorSearch>& vector_search) = 0;

    /// VisitFullTextSearch performs full text search.
    virtual Result<std::shared_ptr<GlobalIndexResult>> VisitFullTextSearch(
        const std::shared_ptr<FullTextSearch>& full_text_search) = 0;

    /// @return true if the reader is thread-safe; false otherwise.
    virtual bool IsThreadSafe() const = 0;

    /// @return An identifier representing the index type. (e.g., "btree", "lumina").
    virtual std::string GetIndexType() const = 0;
};

}  // namespace paimon
