#include <ext/size.h>
#include <Dictionaries/HashedDictionary.h>
#include <Dictionaries/DictionaryBlockInputStream.h>

namespace DB
{

namespace ErrorCodes
{
    extern const int TYPE_MISMATCH;
    extern const int ARGUMENT_OUT_OF_BOUND;
    extern const int BAD_ARGUMENTS;
    extern const int DICTIONARY_IS_EMPTY;
}


HashedDictionary::HashedDictionary(const std::string & name, const DictionaryStructure & dict_struct,
    DictionarySourcePtr source_ptr, const DictionaryLifetime dict_lifetime, bool require_nonempty)
    : name{name}, dict_struct(dict_struct), source_ptr{std::move(source_ptr)}, dict_lifetime(dict_lifetime),
        require_nonempty(require_nonempty)
{
    createAttributes();

    try
    {
        loadData();
        calculateBytesAllocated();
    }
    catch (...)
    {
        creation_exception = std::current_exception();
    }

    creation_time = std::chrono::system_clock::now();
}

HashedDictionary::HashedDictionary(const HashedDictionary & other)
    : HashedDictionary{other.name, other.dict_struct, other.source_ptr->clone(), other.dict_lifetime, other.require_nonempty}
{
}


void HashedDictionary::toParent(const PaddedPODArray<Key> & ids, PaddedPODArray<Key> & out) const
{
    const auto null_value = std::get<UInt64>(hierarchical_attribute->null_values);

    getItemsNumber<UInt64>(*hierarchical_attribute, ids,
        [&] (const size_t row, const UInt64 value) { out[row] = value; },
        [&] (const size_t) { return null_value; });
}


/// Allow to use single value in same way as array.
static inline HashedDictionary::Key getAt(const PaddedPODArray<HashedDictionary::Key> & arr, const size_t idx) { return arr[idx]; }
static inline HashedDictionary::Key getAt(const HashedDictionary::Key & value, const size_t) { return value; }

template <typename ChildType, typename AncestorType>
void HashedDictionary::isInImpl(
    const ChildType & child_ids,
    const AncestorType & ancestor_ids,
    PaddedPODArray<UInt8> & out) const
{
    const auto null_value = std::get<UInt64>(hierarchical_attribute->null_values);
    const auto & attr = *std::get<CollectionPtrType<Key>>(hierarchical_attribute->maps);
    const auto rows = out.size();

    for (const auto row : ext::range(0, rows))
    {
        auto id = getAt(child_ids, row);
        const auto ancestor_id = getAt(ancestor_ids, row);

        while (id != null_value && id != ancestor_id)
        {
            auto it = attr.find(id);
            if (it != std::end(attr))
                id = it->second;
            else
                break;
        }

        out[row] = id != null_value && id == ancestor_id;
    }

    query_count.fetch_add(rows, std::memory_order_relaxed);
}

void HashedDictionary::isInVectorVector(
    const PaddedPODArray<Key> & child_ids,
    const PaddedPODArray<Key> & ancestor_ids,
    PaddedPODArray<UInt8> & out) const
{
    isInImpl(child_ids, ancestor_ids, out);
}

void HashedDictionary::isInVectorConstant(
    const PaddedPODArray<Key> & child_ids,
    const Key ancestor_id,
    PaddedPODArray<UInt8> & out) const
{
    isInImpl(child_ids, ancestor_id, out);
}

void HashedDictionary::isInConstantVector(
    const Key child_id,
    const PaddedPODArray<Key> & ancestor_ids,
    PaddedPODArray<UInt8> & out) const
{
    isInImpl(child_id, ancestor_ids, out);
}


#define DECLARE(TYPE)\
void HashedDictionary::get##TYPE(const std::string & attribute_name, const PaddedPODArray<Key> & ids, PaddedPODArray<TYPE> & out) const\
{\
    const auto & attribute = getAttribute(attribute_name);\
    if (!isAttributeTypeConvertibleTo(attribute.type, AttributeUnderlyingType::TYPE))\
        throw Exception{\
            name + ": type mismatch: attribute " + attribute_name + " has type " + toString(attribute.type),\
            ErrorCodes::TYPE_MISMATCH};\
    \
    const auto null_value = std::get<TYPE>(attribute.null_values);\
    \
    getItemsNumber<TYPE>(attribute, ids,\
        [&] (const size_t row, const auto value) { out[row] = value; },\
        [&] (const size_t) { return null_value; });\
}
DECLARE(UInt8)
DECLARE(UInt16)
DECLARE(UInt32)
DECLARE(UInt64)
DECLARE(UInt128)
DECLARE(Int8)
DECLARE(Int16)
DECLARE(Int32)
DECLARE(Int64)
DECLARE(Float32)
DECLARE(Float64)
#undef DECLARE

void HashedDictionary::getString(const std::string & attribute_name, const PaddedPODArray<Key> & ids, ColumnString * out) const
{
    const auto & attribute = getAttribute(attribute_name);
    if (!isAttributeTypeConvertibleTo(attribute.type, AttributeUnderlyingType::String))
        throw Exception{
            name + ": type mismatch: attribute " + attribute_name + " has type " + toString(attribute.type),
            ErrorCodes::TYPE_MISMATCH};

    const auto & null_value = StringRef{std::get<String>(attribute.null_values)};

    getItemsImpl<StringRef, StringRef>(attribute, ids,
        [&] (const size_t, const StringRef value) { out->insertData(value.data, value.size); },
        [&] (const size_t) { return null_value; });
}

#define DECLARE(TYPE)\
void HashedDictionary::get##TYPE(\
    const std::string & attribute_name, const PaddedPODArray<Key> & ids, const PaddedPODArray<TYPE> & def,\
    PaddedPODArray<TYPE> & out) const\
{\
    const auto & attribute = getAttribute(attribute_name);\
    if (!isAttributeTypeConvertibleTo(attribute.type, AttributeUnderlyingType::TYPE))\
        throw Exception{\
            name + ": type mismatch: attribute " + attribute_name + " has type " + toString(attribute.type),\
            ErrorCodes::TYPE_MISMATCH};\
    \
    getItemsNumber<TYPE>(attribute, ids,\
        [&] (const size_t row, const auto value) { out[row] = value; },\
        [&] (const size_t row) { return def[row]; });\
}
DECLARE(UInt8)
DECLARE(UInt16)
DECLARE(UInt32)
DECLARE(UInt64)
DECLARE(UInt128)
DECLARE(Int8)
DECLARE(Int16)
DECLARE(Int32)
DECLARE(Int64)
DECLARE(Float32)
DECLARE(Float64)
#undef DECLARE

void HashedDictionary::getString(
    const std::string & attribute_name, const PaddedPODArray<Key> & ids, const ColumnString * const def,
    ColumnString * const out) const
{
    const auto & attribute = getAttribute(attribute_name);
    if (!isAttributeTypeConvertibleTo(attribute.type, AttributeUnderlyingType::String))
        throw Exception{
            name + ": type mismatch: attribute " + attribute_name + " has type " + toString(attribute.type),
            ErrorCodes::TYPE_MISMATCH};

    getItemsImpl<StringRef, StringRef>(attribute, ids,
        [&] (const size_t, const StringRef value) { out->insertData(value.data, value.size); },
        [&] (const size_t row) { return def->getDataAt(row); });
}

#define DECLARE(TYPE)\
void HashedDictionary::get##TYPE(\
    const std::string & attribute_name, const PaddedPODArray<Key> & ids, const TYPE & def, PaddedPODArray<TYPE> & out) const\
{\
    const auto & attribute = getAttribute(attribute_name);\
    if (!isAttributeTypeConvertibleTo(attribute.type, AttributeUnderlyingType::TYPE))\
        throw Exception{\
            name + ": type mismatch: attribute " + attribute_name + " has type " + toString(attribute.type),\
            ErrorCodes::TYPE_MISMATCH};\
    \
    getItemsNumber<TYPE>(attribute, ids,\
        [&] (const size_t row, const auto value) { out[row] = value; },\
        [&] (const size_t) { return def; });\
}
DECLARE(UInt8)
DECLARE(UInt16)
DECLARE(UInt32)
DECLARE(UInt64)
DECLARE(UInt128)
DECLARE(Int8)
DECLARE(Int16)
DECLARE(Int32)
DECLARE(Int64)
DECLARE(Float32)
DECLARE(Float64)
#undef DECLARE

void HashedDictionary::getString(
    const std::string & attribute_name, const PaddedPODArray<Key> & ids, const String & def,
    ColumnString * const out) const
{
    const auto & attribute = getAttribute(attribute_name);
    if (!isAttributeTypeConvertibleTo(attribute.type, AttributeUnderlyingType::String))
        throw Exception{
            name + ": type mismatch: attribute " + attribute_name + " has type " + toString(attribute.type),
            ErrorCodes::TYPE_MISMATCH};

    getItemsImpl<StringRef, StringRef>(attribute, ids,
        [&] (const size_t, const StringRef value) { out->insertData(value.data, value.size); },
        [&] (const size_t) { return StringRef{def}; });
}

void HashedDictionary::has(const PaddedPODArray<Key> & ids, PaddedPODArray<UInt8> & out) const
{
    const auto & attribute = attributes.front();

    switch (attribute.type)
    {
        case AttributeUnderlyingType::UInt8: has<UInt8>(attribute, ids, out); break;
        case AttributeUnderlyingType::UInt16: has<UInt16>(attribute, ids, out); break;
        case AttributeUnderlyingType::UInt32: has<UInt32>(attribute, ids, out); break;
        case AttributeUnderlyingType::UInt64: has<UInt64>(attribute, ids, out); break;
        case AttributeUnderlyingType::UInt128: has<UInt128>(attribute, ids, out); break;
        case AttributeUnderlyingType::Int8: has<Int8>(attribute, ids, out); break;
        case AttributeUnderlyingType::Int16: has<Int16>(attribute, ids, out); break;
        case AttributeUnderlyingType::Int32: has<Int32>(attribute, ids, out); break;
        case AttributeUnderlyingType::Int64: has<Int64>(attribute, ids, out); break;
        case AttributeUnderlyingType::Float32: has<Float32>(attribute, ids, out); break;
        case AttributeUnderlyingType::Float64: has<Float64>(attribute, ids, out); break;
        case AttributeUnderlyingType::String: has<StringRef>(attribute, ids, out); break;
    }
}

void HashedDictionary::createAttributes()
{
    const auto size = dict_struct.attributes.size();
    attributes.reserve(size);

    for (const auto & attribute : dict_struct.attributes)
    {
        attribute_index_by_name.emplace(attribute.name, attributes.size());
        attributes.push_back(createAttributeWithType(attribute.underlying_type, attribute.null_value));

        if (attribute.hierarchical)
        {
            hierarchical_attribute = &attributes.back();

            if (hierarchical_attribute->type != AttributeUnderlyingType::UInt64)
                throw Exception{
                    name + ": hierarchical attribute must be UInt64.",
                    ErrorCodes::TYPE_MISMATCH};
        }
    }
}

void HashedDictionary::loadData()
{
    auto stream = source_ptr->loadAll();
    stream->readPrefix();

    while (const auto block = stream->read())
    {
        const auto & id_column = *block.safeGetByPosition(0).column;

        element_count += id_column.size();

        for (const auto attribute_idx : ext::range(0, attributes.size()))
        {
            const auto & attribute_column = *block.safeGetByPosition(attribute_idx + 1).column;
            auto & attribute = attributes[attribute_idx];

            for (const auto row_idx : ext::range(0, id_column.size()))
                setAttributeValue(attribute, id_column[row_idx].get<UInt64>(), attribute_column[row_idx]);
        }
    }

    stream->readSuffix();

    if (require_nonempty && 0 == element_count)
        throw Exception{
            name + ": dictionary source is empty and 'require_nonempty' property is set.",
            ErrorCodes::DICTIONARY_IS_EMPTY};
}

template <typename T>
void HashedDictionary::addAttributeSize(const Attribute & attribute)
{
    const auto & map_ref = std::get<CollectionPtrType<T>>(attribute.maps);
    bytes_allocated += sizeof(CollectionType<T>) + map_ref->getBufferSizeInBytes();
    bucket_count = map_ref->getBufferSizeInCells();
}

void HashedDictionary::calculateBytesAllocated()
{
    bytes_allocated += attributes.size() * sizeof(attributes.front());

    for (const auto & attribute : attributes)
    {
        switch (attribute.type)
        {
            case AttributeUnderlyingType::UInt8: addAttributeSize<UInt8>(attribute); break;
            case AttributeUnderlyingType::UInt16: addAttributeSize<UInt16>(attribute); break;
            case AttributeUnderlyingType::UInt32: addAttributeSize<UInt32>(attribute); break;
            case AttributeUnderlyingType::UInt64: addAttributeSize<UInt64>(attribute); break;
            case AttributeUnderlyingType::UInt128: addAttributeSize<UInt128>(attribute); break;
            case AttributeUnderlyingType::Int8: addAttributeSize<Int8>(attribute); break;
            case AttributeUnderlyingType::Int16: addAttributeSize<Int16>(attribute); break;
            case AttributeUnderlyingType::Int32: addAttributeSize<Int32>(attribute); break;
            case AttributeUnderlyingType::Int64: addAttributeSize<Int64>(attribute); break;
            case AttributeUnderlyingType::Float32: addAttributeSize<Float32>(attribute); break;
            case AttributeUnderlyingType::Float64: addAttributeSize<Float64>(attribute); break;
            case AttributeUnderlyingType::String:
            {
                addAttributeSize<StringRef>(attribute);
                bytes_allocated += sizeof(Arena) + attribute.string_arena->size();

                break;
            }
        }
    }
}

template <typename T>
void HashedDictionary::createAttributeImpl(Attribute & attribute, const Field & null_value)
{
    std::get<T>(attribute.null_values) = null_value.get<typename NearestFieldType<T>::Type>();
    std::get<CollectionPtrType<T>>(attribute.maps) = std::make_unique<CollectionType<T>>();
}

HashedDictionary::Attribute HashedDictionary::createAttributeWithType(const AttributeUnderlyingType type, const Field & null_value)
{
    Attribute attr{type, {}, {}, {}};

    switch (type)
    {
        case AttributeUnderlyingType::UInt8: createAttributeImpl<UInt8>(attr, null_value); break;
        case AttributeUnderlyingType::UInt16: createAttributeImpl<UInt16>(attr, null_value); break;
        case AttributeUnderlyingType::UInt32: createAttributeImpl<UInt32>(attr, null_value); break;
        case AttributeUnderlyingType::UInt64: createAttributeImpl<UInt64>(attr, null_value); break;
        case AttributeUnderlyingType::UInt128: createAttributeImpl<UInt128>(attr, null_value); break;
        case AttributeUnderlyingType::Int8: createAttributeImpl<Int8>(attr, null_value); break;
        case AttributeUnderlyingType::Int16: createAttributeImpl<Int16>(attr, null_value); break;
        case AttributeUnderlyingType::Int32: createAttributeImpl<Int32>(attr, null_value); break;
        case AttributeUnderlyingType::Int64: createAttributeImpl<Int64>(attr, null_value); break;
        case AttributeUnderlyingType::Float32: createAttributeImpl<Float32>(attr, null_value); break;
        case AttributeUnderlyingType::Float64: createAttributeImpl<Float64>(attr, null_value); break;
        case AttributeUnderlyingType::String:
        {
            std::get<String>(attr.null_values) = null_value.get<String>();
            std::get<CollectionPtrType<StringRef>>(attr.maps) = std::make_unique<CollectionType<StringRef>>();
            attr.string_arena = std::make_unique<Arena>();
            break;
        }
    }

    return attr;
}


template <typename OutputType, typename ValueSetter, typename DefaultGetter>
void HashedDictionary::getItemsNumber(
    const Attribute & attribute,
    const PaddedPODArray<Key> & ids,
    ValueSetter && set_value,
    DefaultGetter && get_default) const
{
    if (false) {}
#define DISPATCH(TYPE) \
    else if (attribute.type == AttributeUnderlyingType::TYPE) \
        getItemsImpl<TYPE, OutputType>(attribute, ids, std::forward<ValueSetter>(set_value), std::forward<DefaultGetter>(get_default));
    DISPATCH(UInt8)
    DISPATCH(UInt16)
    DISPATCH(UInt32)
    DISPATCH(UInt64)
    DISPATCH(UInt128)
    DISPATCH(Int8)
    DISPATCH(Int16)
    DISPATCH(Int32)
    DISPATCH(Int64)
    DISPATCH(Float32)
    DISPATCH(Float64)
#undef DISPATCH
    else
        throw Exception("Unexpected type of attribute: " + toString(attribute.type), ErrorCodes::LOGICAL_ERROR);
}

template <typename AttributeType, typename OutputType, typename ValueSetter, typename DefaultGetter>
void HashedDictionary::getItemsImpl(
    const Attribute & attribute,
    const PaddedPODArray<Key> & ids,
    ValueSetter && set_value,
    DefaultGetter && get_default) const
{
    const auto & attr = *std::get<CollectionPtrType<AttributeType>>(attribute.maps);
    const auto rows = ext::size(ids);

    for (const auto i : ext::range(0, rows))
    {
        const auto it = attr.find(ids[i]);
        set_value(i, it != attr.end() ? static_cast<OutputType>(it->second) : get_default(i));
    }

    query_count.fetch_add(rows, std::memory_order_relaxed);
}


template <typename T>
void HashedDictionary::setAttributeValueImpl(Attribute & attribute, const Key id, const T value)
{
    auto & map = *std::get<CollectionPtrType<T>>(attribute.maps);
    map.insert({ id, value });
}

void HashedDictionary::setAttributeValue(Attribute & attribute, const Key id, const Field & value)
{
    switch (attribute.type)
    {
        case AttributeUnderlyingType::UInt8: setAttributeValueImpl<UInt8>(attribute, id, value.get<UInt64>()); break;
        case AttributeUnderlyingType::UInt16: setAttributeValueImpl<UInt16>(attribute, id, value.get<UInt64>()); break;
        case AttributeUnderlyingType::UInt32: setAttributeValueImpl<UInt32>(attribute, id, value.get<UInt64>()); break;
        case AttributeUnderlyingType::UInt64: setAttributeValueImpl<UInt64>(attribute, id, value.get<UInt64>()); break;
        case AttributeUnderlyingType::UInt128: setAttributeValueImpl<UInt128>(attribute, id, value.get<UInt128>()); break;
        case AttributeUnderlyingType::Int8: setAttributeValueImpl<Int8>(attribute, id, value.get<Int64>()); break;
        case AttributeUnderlyingType::Int16: setAttributeValueImpl<Int16>(attribute, id, value.get<Int64>()); break;
        case AttributeUnderlyingType::Int32: setAttributeValueImpl<Int32>(attribute, id, value.get<Int64>()); break;
        case AttributeUnderlyingType::Int64: setAttributeValueImpl<Int64>(attribute, id, value.get<Int64>()); break;
        case AttributeUnderlyingType::Float32: setAttributeValueImpl<Float32>(attribute, id, value.get<Float64>()); break;
        case AttributeUnderlyingType::Float64: setAttributeValueImpl<Float64>(attribute, id, value.get<Float64>()); break;
        case AttributeUnderlyingType::String:
        {
            auto & map = *std::get<CollectionPtrType<StringRef>>(attribute.maps);
            const auto & string = value.get<String>();
            const auto string_in_arena = attribute.string_arena->insert(string.data(), string.size());
            map.insert({ id, StringRef{string_in_arena, string.size()} });
            break;
        }
    }
}

const HashedDictionary::Attribute & HashedDictionary::getAttribute(const std::string & attribute_name) const
{
    const auto it = attribute_index_by_name.find(attribute_name);
    if (it == std::end(attribute_index_by_name))
        throw Exception{
            name + ": no such attribute '" + attribute_name + "'",
            ErrorCodes::BAD_ARGUMENTS};

    return attributes[it->second];
}

template <typename T>
void HashedDictionary::has(const Attribute & attribute, const PaddedPODArray<Key> & ids, PaddedPODArray<UInt8> & out) const
{
    const auto & attr = *std::get<CollectionPtrType<T>>(attribute.maps);
    const auto rows = ext::size(ids);

    for (const auto i : ext::range(0, rows))
        out[i] = attr.find(ids[i]) != std::end(attr);

    query_count.fetch_add(rows, std::memory_order_relaxed);
}

template <typename T>
PaddedPODArray<HashedDictionary::Key> HashedDictionary::getIds(const Attribute & attribute) const
{
    const HashMap<UInt64, T> & attr = *std::get<CollectionPtrType<T>>(attribute.maps);

    PaddedPODArray<Key> ids;
    ids.reserve(attr.size());
    for (const auto & value : attr)
        ids.push_back(value.first);

    return ids;
}

PaddedPODArray<HashedDictionary::Key> HashedDictionary::getIds() const
{
    const auto & attribute = attributes.front();

    switch (attribute.type)
    {
        case AttributeUnderlyingType::UInt8: return getIds<UInt8>(attribute); break;
        case AttributeUnderlyingType::UInt16: return getIds<UInt16>(attribute); break;
        case AttributeUnderlyingType::UInt32: return getIds<UInt32>(attribute); break;
        case AttributeUnderlyingType::UInt64: return getIds<UInt64>(attribute); break;
        case AttributeUnderlyingType::UInt128: return getIds<UInt128>(attribute); break;
        case AttributeUnderlyingType::Int8: return getIds<Int8>(attribute); break;
        case AttributeUnderlyingType::Int16: return getIds<Int16>(attribute); break;
        case AttributeUnderlyingType::Int32: return getIds<Int32>(attribute); break;
        case AttributeUnderlyingType::Int64: return getIds<Int64>(attribute); break;
        case AttributeUnderlyingType::Float32: return getIds<Float32>(attribute); break;
        case AttributeUnderlyingType::Float64: return getIds<Float64>(attribute); break;
        case AttributeUnderlyingType::String: return getIds<StringRef>(attribute); break;
    }
    return PaddedPODArray<Key>();
}

BlockInputStreamPtr HashedDictionary::getBlockInputStream(const Names & column_names, size_t max_block_size) const
{
    using BlockInputStreamType = DictionaryBlockInputStream<HashedDictionary, Key>;
    return std::make_shared<BlockInputStreamType>(shared_from_this(), max_block_size, getIds(), column_names);
}

}