#include <cstdlib>
#include <Processors/Formats/Impl/MsgPackRowInputFormat.h>
#include <Common/assert_cast.h>
#include <IO/ReadHelpers.h>

#include <DataTypes/DataTypeArray.h>
#include <DataTypes/DataTypeDateTime.h>
#include <DataTypes/DataTypeDateTime64.h>
#include <DataTypes/DataTypeNullable.h>

#include <Columns/ColumnArray.h>
#include <Columns/ColumnFixedString.h>
#include <Columns/ColumnNullable.h>
#include <Columns/ColumnString.h>
#include <Columns/ColumnsNumber.h>

namespace DB
{

namespace ErrorCodes
{
    extern const int ILLEGAL_COLUMN;
    extern const int INCORRECT_DATA;
}

MsgPackRowInputFormat::MsgPackRowInputFormat(const Block & header_, ReadBuffer & in_, Params params_)
    : IRowInputFormat(header_, in_, std::move(params_)), buf(in), ctx(&reference_func, nullptr, msgpack::unpack_limit()), data_types(header_.getDataTypes()) {}

int MsgPackRowInputFormat::unpack(msgpack::zone & zone, size_t & offset)
{
    offset = 0;
    ctx.init();
    ctx.user().set_zone(zone);
    return ctx.execute(buf.position(), buf.buffer().end() - buf.position(), offset);
}

bool MsgPackRowInputFormat::readObject()
{
    if (buf.eof())
        return false;

    PeekableReadBufferCheckpoint checkpoint{buf};
    std::unique_ptr<msgpack::zone> zone(new msgpack::zone);
    size_t offset;
    while(!unpack(*zone, offset))
    {
        buf.position() = buf.buffer().end();
        if (buf.eof())
            throw Exception("Unexpected end of file while parsing msgpack object.", ErrorCodes::INCORRECT_DATA);
        buf.position() = buf.buffer().end();
        buf.makeContinuousMemoryFromCheckpointToPos();
        buf.rollbackToCheckpoint();
    }
    buf.position() += offset;
    object_handle = msgpack::object_handle(ctx.data(), std::move(zone));
    return true;
}

void MsgPackRowInputFormat::insertObject(IColumn & column, DataTypePtr data_type, const msgpack::object & object)
{
    switch (data_type->getTypeId())
    {
        case TypeIndex::UInt8:
        {
            assert_cast<ColumnUInt8 &>(column).insertValue(object.as<uint8_t>());
            return;
        }
        case TypeIndex::Date: [[fallthrough]];
        case TypeIndex::UInt16:
        {
            assert_cast<ColumnUInt16 &>(column).insertValue(object.as<UInt16>());
            return;
        }
        case TypeIndex::DateTime: [[fallthrough]];
        case TypeIndex::UInt32:
        {
            assert_cast<ColumnUInt32 &>(column).insertValue(object.as<UInt32>());
            return;
        }
        case TypeIndex::UInt64:
        {
            assert_cast<ColumnUInt64 &>(column).insertValue(object.as<UInt64>());
            return;
        }
        case TypeIndex::Int8:
        {
            assert_cast<ColumnInt8 &>(column).insertValue(object.as<Int8>());
            return;
        }
        case TypeIndex::Int16:
        {
            assert_cast<ColumnInt16 &>(column).insertValue(object.as<Int16>());
            return;
        }
        case TypeIndex::Int32:
        {
            assert_cast<ColumnInt32 &>(column).insertValue(object.as<Int32>());
            return;
        }
        case TypeIndex::Int64:
        {
            assert_cast<ColumnInt64 &>(column).insertValue(object.as<Int64>());
            return;
        }
        case TypeIndex::Float32:
        {
            assert_cast<ColumnFloat32 &>(column).insertValue(object.as<Float32>());
            return;
        }
        case TypeIndex::Float64:
        {
            assert_cast<ColumnFloat64 &>(column).insertValue(object.as<Float64>());
            return;
        }
        case TypeIndex::DateTime64:
        {
            assert_cast<DataTypeDateTime64::ColumnType &>(column).insertValue(object.as<UInt64>());
            return;
        }
        case TypeIndex::FixedString: [[fallthrough]];
        case TypeIndex::String:
        {
            msgpack::object_str obj_str = object.via.str;
            column.insertData(obj_str.ptr, obj_str.size);
            return;
        }
        case TypeIndex::Array:
        {
            msgpack::object_array object_array = object.via.array;
            auto nested_type = assert_cast<const DataTypeArray &>(*data_type).getNestedType();
            ColumnArray & column_array = assert_cast<ColumnArray &>(column);
            ColumnArray::Offsets & offsets = column_array.getOffsets();
            IColumn & nested_column = column_array.getData();
            for (size_t i = 0; i != object_array.size; ++i)
            {
                insertObject(nested_column, nested_type, object_array.ptr[i]);
            }
            offsets.push_back(offsets.back() + object_array.size);
            return;
        }
        case TypeIndex::Nullable:
        {
            auto nested_type = removeNullable(data_type);
            ColumnNullable & column_nullable = assert_cast<ColumnNullable &>(column);
            if (object.type == msgpack::type::NIL)
                column_nullable.insertDefault();
            else
                insertObject(column_nullable.getNestedColumn(), nested_type, object);
            return;
        }
        case TypeIndex::Nothing:
        {
            // Nothing to insert, MsgPack object is nil.
            return;
        }
        default:
            break;
    }
    throw Exception("Type " + data_type->getName() + " is not supported for MsgPack input format", ErrorCodes::ILLEGAL_COLUMN);
}

bool MsgPackRowInputFormat::readRow(MutableColumns & columns, RowReadExtension &)
{
    size_t column_index = 0;
    bool has_more_data = true;
    for (; column_index != columns.size(); ++column_index)
    {
        has_more_data = readObject();
        if (!has_more_data)
            break;
        insertObject(*columns[column_index], data_types[column_index], object_handle.get());
    }
    if (!has_more_data)
    {
        if (column_index != 0)
            throw Exception("Not enough values to complete the row.", ErrorCodes::INCORRECT_DATA);
        return false;
    }
    return true;
}

void registerInputFormatProcessorMsgPack(FormatFactory & factory)
{
    factory.registerInputFormatProcessor("MsgPack", [](
            ReadBuffer & buf,
            const Block & sample,
            const RowInputFormatParams & params,
            const FormatSettings &)
    {
        return std::make_shared<MsgPackRowInputFormat>(sample, buf, params);
    });
}

}