FeatherMC/src/nbt/NBT.cpp

#include "NBT.h"

#include "cNBT/nbt.h"

#include <cstring>
#include <sstream>
#include <cstdio>
#include <cstdlib>

namespace NBT
{
    nbt_node* Internal::FindByName(nbt_node* tree, const char* name)
    {
        return nbt_find_by_name(tree, name);
    }

    nbt_node* Internal::ListItem(nbt_node* list, int32_t index)
    {
        return nbt_list_item(list, index);
    }

    list_head* Internal::GetFirstItem(nbt_node* list)
    {
        // The first node in nbt_list is the sentinel node,
        // so the first node is the one right after it.
        return GetNextItem(&(list->payload.tag_list->entry));
    }

    list_head* Internal::GetNextItem(list_head* item)
    {
        return item->flink;
    }

    nbt_node* Internal::GetListEntry(list_head* item)
    {
        // In C, the type could have been 'const struct nbt_list'
        // but in C++ we have to use this monstrosity because of anonymous innter structs
        return list_entry(item, nbt_node::nbt_payload::nbt_list, entry)->data;
    }

    DataBuffer::~DataBuffer()
    {
        // equivalent to buffer_free in cNBT buffer.h
        // FIXME
        //free(data);
    }

    Tag Tag::CreateTag(nbt_node *node)
    {
        switch (node->type)
        {
            case TAG_BYTE:      return DataTag<int8_t>(node);
            case TAG_SHORT:     return DataTag<int16_t>(node);
            case TAG_INT:       return DataTag<int32_t>(node);
            case TAG_LONG:      return DataTag<int64_t>(node);
            case TAG_FLOAT:     return DataTag<float>(node);
            case TAG_DOUBLE:    return DataTag<double>(node);
            case TAG_BYTE_ARRAY:    return ArrayTag<int8_t>(node);
            case TAG_STRING:        return StringTag(node);
            case TAG_LIST:          return CreateListTag(node);
            case TAG_COMPOUND:      return CompoundTag(node);
            case TAG_INT_ARRAY:     return ArrayTag<int32_t>(node);
            case TAG_LONG_ARRAY:    return ArrayTag<int64_t>(node);

            case TAG_INVALID:
            default:
                return NULL;
        }
    }

    Tag Tag::CreateListTag(nbt_node* node)
    {
        nbt_type type = node->payload.tag_list->data->type;
        switch (type)
        {
            case TAG_BYTE:      return ListTag<int8_t>(node);
            case TAG_SHORT:     return ListTag<int16_t>(node);
            case TAG_INT:       return ListTag<int32_t>(node);
            case TAG_LONG:      return ListTag<int64_t>(node);
            case TAG_FLOAT:     return ListTag<float>(node);
            case TAG_DOUBLE:    return ListTag<double>(node);
            case TAG_BYTE_ARRAY:    return ListTag<ArrayTag<int8_t>>(node);
            case TAG_STRING:        return ListTag<StringTag>(node);
            case TAG_LIST:          return CreateListTag(node);
            case TAG_COMPOUND:      return ListTag<CompoundTag>(node);
            case TAG_INT_ARRAY:     return ListTag<ArrayTag<int32_t>>(node);
            case TAG_LONG_ARRAY:    return ListTag<ArrayTag<int64_t>>(node);

            case TAG_INVALID:
            default:
                return NULL;
        }
    }

    const char *Tag::GetName() const
    {
        return m_node->name ? m_node->name : "<null>";
    }

    size_t Tag::GetLength() const
    {
        switch (m_node->type)
        {
            case TAG_BYTE_ARRAY:
                return m_node->payload.tag_byte_array.length;
            case TAG_INT_ARRAY:
                return m_node->payload.tag_int_array.length;
            case TAG_LONG_ARRAY:
                return m_node->payload.tag_long_array.length;
            
            case TAG_STRING:
                // cNBT does not store string length so compute here
                return strlen(m_node->payload.tag_string);
            
            case TAG_LIST:
                return list_length(&(m_node->payload.tag_list->entry));
            case TAG_COMPOUND:
                return list_length(&(m_node->payload.tag_compound->entry));
            
            // nbt_size(node) is only used for non-list types because
            // it gets the total number of nodes, rather than immediate children
            // and it treats arrays as consisting of one node
            default:
                // will return 1 for most types and 0 for invalid
                return nbt_size(m_node);
        }
    }

    const DataBuffer Tag::GetData() const
    {
        buffer buf = nbt_dump_binary(m_node);
        DataBuffer result { buf.data, buf.len };
        return result;
    }

    const char *Tag::ToString() const
    {
        return nbt_dump_ascii(m_node);
    }

    Tag::operator bool() const
    {
        return m_node != NULL && m_node->type != TAG_INVALID;
    }

    std::ostream& operator<<(std::ostream& stream, const Tag& tag)
    {
        return stream << tag.ToString();
    }    

    //==================================================

    // TODO: still need this specialization?
    template <>
    Tag ListTag<Tag>::Get(int32_t index) const
    {
        nbt_node* result = nbt_list_item(m_node, index);
        return Tag::CreateTag(result);
    }

    //==================================================

    CompoundTag::CompoundTag(const char *filename)
        : CompoundTag(nbt_parse_path(filename), true) // m_isRoot = true, this calls malloc
    {
    }

    CompoundTag::CompoundTag(const void* data, size_t length)
        : CompoundTag(nbt_parse_compressed(data, length), true) // m_isRoot = true, this calls malloc
    {
    }

    CompoundTag::~CompoundTag()
    {
        if (m_isRoot)
            nbt_free(m_node);
    }

    const Tag CompoundTag::operator[](const char *name) const
    {
        nbt_node *result = nbt_find_by_name(m_node, name);
        
        return Tag::CreateTag(result);
    }

    //==================================================

    // Byte
    template <> int8_t DataTag<int8_t>::GetValue() const { return m_node->payload.tag_byte; }

    // Short
    template <> int16_t DataTag<int16_t>::GetValue() const { return m_node->payload.tag_short; }

    // Int
    template <> int32_t DataTag<int32_t>::GetValue() const { return m_node->payload.tag_int; }

    // Long
    template <> int64_t DataTag<int64_t>::GetValue() const { return m_node->payload.tag_long; }

    // Float
    template <> float DataTag<float>::GetValue() const { return m_node->payload.tag_float; }

    // Double
    template <> double DataTag<double>::GetValue() const { return m_node->payload.tag_double; }

    // String
    template <> const char* DataTag<const char*>::GetValue() const { return m_node->payload.tag_string; }

    //==================================================

    // Byte Array
    template <> const int8_t* ArrayTag<int8_t>::GetValue() const { return (const int8_t*)(m_node->payload.tag_byte_array.data); }

    // Int Array
    template <> const int32_t* ArrayTag<int32_t>::GetValue() const { return m_node->payload.tag_int_array.data; }

    // Long Array
    template <> const int64_t* ArrayTag<int64_t>::GetValue() const { return m_node->payload.tag_long_array.data; }

    // String
    template <> const char* StringTag::GetValue() const { return m_node->payload.tag_string; }
}