/**
 *    Copyright (C) 2023-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#pragma once

#include "mongo/bson/timestamp.h"
#include "mongo/client/connection_string.h"
#include "mongo/db/commands/bulk_write_gen.h"
#include "mongo/db/repl/optime.h"
#include "mongo/s/ns_targeter.h"
#include "mongo/s/write_ops/batch_write_op.h"
#include "mongo/s/write_ops/write_op.h"

namespace mongo {
namespace bulk_write_exec {
/**
 * Executes a client bulkWrite request by sending child batches to several shard endpoints, and
 * returns a vector of BulkWriteReplyItem (each of which is a reply for an individual op).
 *
 * This function does not throw, any errors are reported via the function return.
 */
std::vector<BulkWriteReplyItem> execute(OperationContext* opCtx,
                                        const std::vector<std::unique_ptr<NSTargeter>>& targeters,
                                        const BulkWriteCommandRequest& clientRequest);

/**
 * The BulkWriteOp class manages the lifecycle of a bulkWrite request received by mongos. Each op in
 * the ops array is tracked via a WriteOp, and the function of the BulkWriteOp is to aggregate the
 * dispatched requests and responses for the underlying WriteOps.
 *
 * Overall, the BulkWriteOp lifecycle is similar to the WriteOp lifecycle, with the following
 * stages:
 *
 * 0) Client request comes in, a BulkWriteOp is initialized.
 *
 * 1a) One or more ops in the bulkWrite are targeted, resulting in TargetedWriteBatches for these
 *     ops.
 * 1b) There are targeting errors, and the batch must be retargeted after refreshing the NSTargeter.
 *
 * 2) Child bulkWrite requests are built for each TargetedWriteBatch before sending.
 *
 * 3) Responses for sent TargetedWriteBatches are noted, errors are stored and aggregated
 *    per-write-op. Errors the caller is interested in are returned.
 *
 * 4) If the whole bulkWrite is not finished, goto 0.
 *
 * 5) When all responses come back for all write ops, errors are aggregated and returned in
 *    a client response.
 *
 */
class BulkWriteOp {
    BulkWriteOp(const BulkWriteOp&) = delete;
    BulkWriteOp& operator=(const BulkWriteOp&) = delete;

public:
    BulkWriteOp() = delete;
    BulkWriteOp(OperationContext* opCtx, const BulkWriteCommandRequest& clientRequest);
    ~BulkWriteOp() = default;

    /**
     * Targets one or more of the next write ops in this bulkWrite request using the given
     * NSTargeters (targeters[i] corresponds to the targeter of the collection in nsInfo[i]). The
     * resulting TargetedWrites are aggregated together in the returned TargetedWriteBatches.
     *
     * If 'recordTargetErrors' is false, any targeting error will abort all current batches and
     * the method will return the targeting error. No targetedBatches will be returned on error.
     *
     * Otherwise, if 'recordTargetErrors' is true, targeting errors will be recorded for each
     * write op that fails to target, and the method will return OK.
     *
     * (The idea here is that if we are sure our NSTargeters are up-to-date we should record
     * targeting errors, but if not we should refresh once first.)
     *
     * Returned TargetedWriteBatches are owned by the caller.
     * If a write without a shard key is detected, return an OK StatusWith that has 'true' as the
     * value.
     */
    StatusWith<bool> target(const std::vector<std::unique_ptr<NSTargeter>>& targeters,
                            bool recordTargetErrors,
                            TargetedBatchMap& targetedBatches);

    /**
     * Fills a BulkWriteCommandRequest from a TargetedWriteBatch for this BulkWriteOp.
     */
    BulkWriteCommandRequest buildBulkCommandRequest(const TargetedWriteBatch& targetedBatch) const;

    /**
     * Returns false if the bulk write op needs more processing.
     */
    bool isFinished() const;

    const WriteOp& getWriteOp_forTest(int i) const;

    int numWriteOpsIn(WriteOpState opState) const;

    /**
     * Aborts any further writes in the batch with the provided error status.  There must be no
     * pending ops awaiting results when a batch is aborted.
     *
     * Batch is finished immediately after aborting.
     */
    void abortBatch(const Status& status);

    // TODO(SERVER-72792): Finish this and process real batch responses.
    void noteBatchResponse(const TargetedWriteBatch& targetedBatch);

    /**
     * Returns a vector of BulkWriteReplyItem based on the end state of each individual write in
     * this bulkWrite operation.
     */
    std::vector<BulkWriteReplyItem> generateReplyItems() const;

private:
    // The OperationContext the client bulkWrite request is run on.
    OperationContext* const _opCtx;

    // The incoming client bulkWrite request.
    const BulkWriteCommandRequest& _clientRequest;

    // Array of ops being processed from the client bulkWrite request.
    std::vector<WriteOp> _writeOps;

    // Cached transaction number (if one is present on the operation contex).
    boost::optional<TxnNumber> _txnNum;

    // The write concern that the bulk write command was issued with.
    WriteConcernOptions _writeConcern;

    // Set to true if this write is part of a transaction.
    const bool _inTransaction{false};
    const bool _isRetryableWrite{false};
};

}  // namespace bulk_write_exec
}  // namespace mongo