// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
/**
 * @class storage::api::ReturnCode
 * @ingroup messageapi
 *
 * @brief Class for representing return values from the processing chain
 *
 * @version $Id$
 */

#pragma once

#include <vespa/documentapi/messagebus/documentprotocol.h>


namespace storage::api {

class ReturnCode {
public:
    using Protocol = documentapi::DocumentProtocol;

    /** Return status codes */
    enum Result {
        OK                            = mbus::ErrorCode::NONE,
        ENCODE_ERROR                  = mbus::ErrorCode::ENCODE_ERROR,

        EXISTS                        = Protocol::ERROR_EXISTS,

        NOT_READY                     = Protocol::ERROR_NODE_NOT_READY,
        WRONG_DISTRIBUTION            = Protocol::ERROR_WRONG_DISTRIBUTION,
        REJECTED                      = Protocol::ERROR_REJECTED,
        ABORTED                       = Protocol::ERROR_ABORTED,
        BUCKET_NOT_FOUND              = Protocol::ERROR_BUCKET_NOT_FOUND,
        BUCKET_DELETED                = Protocol::ERROR_BUCKET_DELETED,
        TIMESTAMP_EXIST               = Protocol::ERROR_TIMESTAMP_EXIST,
        STALE_TIMESTAMP               = Protocol::ERROR_STALE_TIMESTAMP,
        TEST_AND_SET_CONDITION_FAILED = Protocol::ERROR_TEST_AND_SET_CONDITION_FAILED,

        // Wrong use
        UNKNOWN_COMMAND               = Protocol::ERROR_UNKNOWN_COMMAND,
        NOT_IMPLEMENTED               = Protocol::ERROR_NOT_IMPLEMENTED,
        ILLEGAL_PARAMETERS            = Protocol::ERROR_ILLEGAL_PARAMETERS,
        IGNORED                       = Protocol::ERROR_IGNORED,
        UNPARSEABLE                   = Protocol::ERROR_UNPARSEABLE,

        // Network failure
        NOT_CONNECTED                 = Protocol::ERROR_NOT_CONNECTED,
        TIMEOUT                       = mbus::ErrorCode::TIMEOUT,
        BUSY                          = Protocol::ERROR_BUSY,

        // Disk operations
        NO_SPACE                      = Protocol::ERROR_NO_SPACE,
        DISK_FAILURE                  = Protocol::ERROR_DISK_FAILURE,
        IO_FAILURE                    = Protocol::ERROR_IO_FAILURE,

        // Don't know what happened (catch-all)
        INTERNAL_FAILURE              = Protocol::ERROR_INTERNAL_FAILURE
    };

private:
    Result _result;
    std::unique_ptr<vespalib::string> _message;
public:
    ReturnCode()
        : _result(OK),
          _message()
      { }
    explicit ReturnCode(Result result)
        : _result(result),
          _message()
    {}
    ReturnCode(Result result, vespalib::stringref msg);
    ReturnCode(const ReturnCode &);
    ReturnCode & operator = (const ReturnCode &);
    ReturnCode(ReturnCode &&) noexcept = default;
    ReturnCode & operator = (ReturnCode &&) noexcept;

    vespalib::stringref getMessage() const {
        return _message
               ? _message->operator vespalib::stringref()
               : vespalib::stringref();
    }

    Result getResult() const { return _result; }

    /**
     * Translate from status code to human-readable string
     * @param result Status code returned from getResult()
     */
    static vespalib::string getResultString(Result result);

    bool failed() const { return (_result != OK); }
    bool success() const { return (_result == OK); }

    bool operator==(Result res) const { return _result == res; }
    bool operator!=(Result res) const { return _result != res; }
    bool operator==(const ReturnCode& code) const;
    bool operator!=(const ReturnCode& code) const;

    // To avoid lots of code matching various return codes in storage, we define
    // some functions they can use to match those codes that corresponds to what
    // they want to match.

    bool isBusy() const;
    bool isNodeDownOrNetwork() const;
    bool isCriticalForMaintenance() const;
    bool isCriticalForVisitor() const;
    bool isCriticalForVisitorDispatcher() const;
    bool isShutdownRelated() const;
    bool isBucketDisappearance() const;
    bool isNonCriticalForIntegrityChecker() const;
    vespalib::string toString() const;
};

std::ostream & operator << (std::ostream & os, const ReturnCode & returnCode);

}