RequestMessageFormat.cpp

/*
 * MIT License
 *
 * Copyright (c) 2026 Adriano dos Santos Fernandes
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
 
#include "RequestMessageFormat.h"
#include "firebird/impl/blr.h"
 
 
namespace fbcpp::request
{
    static std::uint8_t scaleToByte(int scale) noexcept
    {
        return static_cast<std::uint8_t>(static_cast<unsigned>(scale) & 0xFFu);
    }
 
 
    RequestMessageFormat& RequestMessageFormat::addField(DescriptorAdjustedType adjustedType, unsigned dataLength,
        unsigned alignment, int scale, unsigned charSetId, int subType, bool isNullable)
    {
        const auto alignedOffset = static_cast<unsigned>((length + alignment - 1u) & ~(alignment - 1u));
 
        Descriptor descriptor{
            .originalType = static_cast<DescriptorOriginalType>(adjustedType),
            .adjustedType = adjustedType,
            .scale = scale,
            .length = dataLength,
            .offset = alignedOffset,
            .nullOffset = 0,
            .isNullable = isNullable,
            .name = {},
            .relation = {},
            .alias = {},
            .owner = {},
            .charSetId = charSetId,
            .subType = subType,
        };
 
        length = alignedOffset + dataLength;
        blrFieldIndexes.push_back(static_cast<unsigned>(descriptors.size()) + nullableCount);
 
        if (isNullable)
        {
            descriptor.nullOffset = (length + 1u) & ~1u;
            length = descriptor.nullOffset + 2u;
            ++nullableCount;
        }
 
        descriptors.push_back(std::move(descriptor));
        return *this;
    }
 
    std::vector<std::byte> RequestMessageFormat::buildBlrMessageClause(unsigned messageNumber) const
    {
        if (messageNumber > 255u)
            throw FbCppException("Message number must be between 0 and 255");
 
        unsigned entryCount = static_cast<unsigned>(descriptors.size());
        for (const auto& descriptor : descriptors)
        {
            if (descriptor.isNullable)
                ++entryCount;
        }
 
        std::vector<std::byte> blr;
        blr.reserve(3u + 64u * entryCount);
 
        appendByte(blr, blr_message);
        appendByte(blr, static_cast<std::uint8_t>(messageNumber));
        appendWord(blr, static_cast<std::uint16_t>(entryCount));
 
        for (const auto& descriptor : descriptors)
        {
            appendBlrDataType(blr, descriptor);
 
            if (descriptor.isNullable)
            {
                appendByte(blr, blr_short);
                appendByte(blr, 0u);
            }
        }
 
        return blr;
    }
 
    void RequestMessageFormat::appendBlrDataType(std::vector<std::byte>& blr, const Descriptor& descriptor) const
    {
        switch (descriptor.adjustedType)
        {
            case DescriptorAdjustedType::BOOLEAN:
                appendByte(blr, blr_bool);
                break;
 
            case DescriptorAdjustedType::INT16:
                appendByte(blr, blr_short);
                appendByte(blr, scaleToByte(descriptor.scale));
                break;
 
            case DescriptorAdjustedType::INT32:
                appendByte(blr, blr_long);
                appendByte(blr, scaleToByte(descriptor.scale));
                break;
 
            case DescriptorAdjustedType::INT64:
                appendByte(blr, blr_int64);
                appendByte(blr, scaleToByte(descriptor.scale));
                break;
 
            case DescriptorAdjustedType::INT128:
                appendByte(blr, blr_int128);
                appendByte(blr, scaleToByte(descriptor.scale));
                break;
 
            case DescriptorAdjustedType::FLOAT:
                appendByte(blr, blr_float);
                break;
 
            case DescriptorAdjustedType::DOUBLE:
                appendByte(blr, blr_double);
                break;
 
            case DescriptorAdjustedType::DECFLOAT16:
                appendByte(blr, blr_dec64);
                break;
 
            case DescriptorAdjustedType::DECFLOAT34:
                appendByte(blr, blr_dec128);
                break;
 
            case DescriptorAdjustedType::DATE:
                appendByte(blr, blr_sql_date);
                break;
 
            case DescriptorAdjustedType::TIME:
                appendByte(blr, blr_sql_time);
                break;
 
            case DescriptorAdjustedType::TIMESTAMP:
                appendByte(blr, blr_timestamp);
                break;
 
            case DescriptorAdjustedType::TIME_TZ:
                appendByte(blr, blr_sql_time_tz);
                break;
 
            case DescriptorAdjustedType::TIMESTAMP_TZ:
                appendByte(blr, blr_timestamp_tz);
                break;
 
            case DescriptorAdjustedType::BLOB:
                appendByte(blr, blr_quad);
                appendByte(blr, 0u);
                break;
 
            case DescriptorAdjustedType::STRING:
                if (descriptor.charSetId != 0)
                {
                    appendByte(blr, blr_varying2);
                    appendWord(blr, static_cast<std::uint16_t>(descriptor.charSetId));
                }
                else
                    appendByte(blr, blr_varying);
 
                appendWord(blr, static_cast<std::uint16_t>(descriptor.length - sizeof(std::uint16_t)));
                break;
 
            default:
                throw FbCppException("Unsupported descriptor type");
        }
    }
}  // namespace fbcpp::request