// 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 <cstddef>

#include <map>

#include <memory>

#include <string>

#include <unordered_map>

#include <unordered_set>

#include <vector>

#include "common/status.h"

#include "format/generic_reader.h"

#include "format/jni/jni_data_bridge.h"

#include "runtime/runtime_profile.h"

#include "util/jni-util.h"

#include "util/profile_collector.h"

#include "util/string_util.h"

namespace doris {

class RuntimeProfile;

class RuntimeState;

class SlotDescriptor;

class Block;

} // namespace doris

namespace doris {

/**

 * JniReader is the base class for all JNI-based readers. It directly manages

 * the JNI lifecycle (open/read/close) for Java scanners that extend

 * org.apache.doris.common.jni.JniScanner.

 *

 * Subclasses only need to:

 * 1. Build scanner_params/column_names in their constructor

 * 2. Pass them to JniReader's constructor

 * 3. Call open() in their init_reader()

 *

 * This class replaces the old JniConnector intermediary.

 */

class JniReader : public GenericReader {

public:

    /**

     * Constructor for scan mode.

     * @param file_slot_descs  Slot descriptors for the output columns

     * @param state            Runtime state

     * @param profile          Runtime profile for metrics

     * @param connector_class  Java scanner class path (e.g. "org/apache/doris/paimon/PaimonJniScanner")

     * @param scanner_params   Configuration map passed to Java scanner constructor

     * @param column_names     Fields to read (also the required_fields in scanner_params)

     * @param self_split_weight  Weight for this split (for profile conditition counter)

     */

    JniReader(const std::vector<SlotDescriptor*>& file_slot_descs, RuntimeState* state,

              RuntimeProfile* profile, std::string connector_class,

              std::map<std::string, std::string> scanner_params,

              std::vector<std::string> column_names, int64_t self_split_weight = -1);

    /**

     * Constructor for table-schema-only mode (no data reading).

     * @param connector_class  Java scanner class path

     * @param scanner_params   Configuration map passed to Java scanner constructor

     */

    JniReader(std::string connector_class, std::map<std::string, std::string> scanner_params);

    ~JniReader() override = default;

    /**

     * Open the java scanner: set up profile counters, create Java object,

     * get method IDs, and call JniScanner#open.

     */

    Status open(RuntimeState* state, RuntimeProfile* profile);

    Status get_columns(std::unordered_map<std::string, DataTypePtr>* name_to_type,

                       std::unordered_set<std::string>* missing_cols) override {

        for (const auto& desc : _file_slot_descs) {

            name_to_type->emplace(desc->col_name(), desc->type());

        }

        return Status::OK();

    }

    /**

     * Read next batch from Java scanner and fill the block.

     */

    virtual Status get_next_block(Block* block, size_t* read_rows, bool* eof) override;

    /**

     * Get table schema from Java scanner (used by Avro schema discovery).

     */

    Status get_table_schema(std::string& table_schema_str);

    /**

     * Close the scanner and release JNI resources.

     */

    Status close() override;

    /**

     * Set column name to block index map from FileScanner to avoid repeated map creation.

     */

    void set_col_name_to_block_idx(

            const std::unordered_map<std::string, uint32_t>* col_name_to_block_idx) {

        _col_name_to_block_idx = col_name_to_block_idx;

    }

protected:

    void _collect_profile_before_close() override;

    /**

     * Update scanner params and column names after construction.

     * Used by Avro which builds params in init_reader/init_schema_reader

     * rather than in the constructor.

     */

    void _update_scanner_params(std::map<std::string, std::string> params,

                                std::vector<std::string> column_names) {

        _scanner_params = std::move(params);

        _column_names = std::move(column_names);

    }

    const std::vector<SlotDescriptor*>& _file_slot_descs;

    RuntimeState* _state = nullptr;

    RuntimeProfile* _profile = nullptr;

private:

    static const std::vector<SlotDescriptor*> _s_empty_slot_descs;

    Status _init_jni_scanner(JNIEnv* env, int batch_size);

    Status _fill_block(Block* block, size_t num_rows);

    Status _get_statistics(JNIEnv* env, std::map<std::string, std::string>* result);

    std::string _connector_name;

    std::string _connector_class;

    std::map<std::string, std::string> _scanner_params;

    std::vector<std::string> _column_names;

    int32_t _self_split_weight = -1;

    bool _is_table_schema = false;

    RuntimeProfile::Counter* _open_scanner_time = nullptr;

    RuntimeProfile::Counter* _java_scan_time = nullptr;

    RuntimeProfile::Counter* _java_append_data_time = nullptr;

    RuntimeProfile::Counter* _java_create_vector_table_time = nullptr;

    RuntimeProfile::Counter* _fill_block_time = nullptr;

    RuntimeProfile::ConditionCounter* _max_time_split_weight_counter = nullptr;

    int64_t _jni_scanner_open_watcher = 0;

    int64_t _java_scan_watcher = 0;

    int64_t _fill_block_watcher = 0;

    size_t _has_read = 0;

    bool _closed = false;

    bool _scanner_opened = false;

    Jni::GlobalClass _jni_scanner_cls;

    Jni::GlobalObject _jni_scanner_obj;

    Jni::MethodId _jni_scanner_open;

    Jni::MethodId _jni_scanner_get_append_data_time;

    Jni::MethodId _jni_scanner_get_create_vector_table_time;

    Jni::MethodId _jni_scanner_get_next_batch;

    Jni::MethodId _jni_scanner_get_table_schema;

    Jni::MethodId _jni_scanner_close;

    Jni::MethodId _jni_scanner_release_column;

    Jni::MethodId _jni_scanner_release_table;

    Jni::MethodId _jni_scanner_get_statistics;

    JniDataBridge::TableMetaAddress _table_meta;

    // Column name to block index map, passed from FileScanner to avoid repeated map creation

    const std::unordered_map<std::string, uint32_t>* _col_name_to_block_idx = nullptr;

    void _set_meta(long meta_addr) { _table_meta.set_meta(meta_addr); }

};

/**

 * The demo usage of JniReader, showing how to read data from java scanner.

 * The java side is also a mock reader that provide values for each type.

 * This class will only be retained during the functional testing phase to verify that

 * the communication and data exchange with the jvm are correct.

 */

class MockJniReader : public JniReader {

public:

    MockJniReader(const std::vector<SlotDescriptor*>& file_slot_descs, RuntimeState* state,

                  RuntimeProfile* profile);

    ~MockJniReader() override = default;

    Status init_reader();

};

} // namespace doris