sponge_parsing.kt

private fun StructureTemplate.readSpongeV1OrException(
    lookup: RegistryEntryLookup<Block>,
    nbt: NbtCompound,
): Throwable? {
    val version = nbt.getInt("DataVersion")
    val width = (nbt.getShort("Width") and 0xFFFF.toShort()).toInt()
    val height = (nbt.getShort("Height") and 0xFFFF.toShort()).toInt()
    val length = (nbt.getShort("Length") and 0xFFFF.toShort()).toInt()

    val metadata = nbt.getCompound("Metadata")

    // If the offset is too far, we simply ignore it
    // I think at some point schematica calculated
    // the offset based on the distance between the player position
    // and the schematic lower corner, so it would fuck up everything
    // when you tried to import and build it using Baritone
    // val minimumPosition = nbt.getIntArray("Offset")
    //     .takeIf { it.isNotEmpty() }
    //     ?.let { fastVectorOf(it[0], it[1], it[2]) }
    //     ?.takeIf { 274945015809L times 16 < it } ?: 0L

    val palette = nbt.getCompound("Palette")

    val paletteMax = nbt.getInt("PaletteMax")
    val newPalette = NbtList()

    if (palette.size != paletteMax) return IllegalStateException("Block palette size does not match the provided size (corrupted?)")

    palette.keys
        .sortedBy { palette.getInt(it) }
        .forEach { key ->
            val resource = key.substringBefore('[')
            val blockState = NbtCompound()

            // Why ?
            // I know it's supposed to be SNBT, but it cannot be parsed back
            key.substringAfter('[')
                .substringBefore(']')
                .takeIf { it != resource }
                ?.split(',')
                ?.associate { it.substringBefore('=') to it.substringAfter('=') }
                ?.forEach { (key, value) -> blockState.putString(key, value) }

            // Populate the list using the correct indices
            newPalette.add(NbtCompound().apply {
                putString("Name", resource)
                put("Properties", blockState)
            })
        }

    val newBlocks = NbtList()
    var blockIndex = 0
    VarIntIterator(nbt.getByteArray("BlockData"))
        .forEach { blockId ->
            val blockpos = positionFromIndex(width, length, blockIndex++)

            newBlocks.add(NbtCompound().apply {
                putIntList("pos", blockpos.x, blockpos.y, blockpos.z)
                putInt("state", blockId)
            })
        }

    // Construct a structure compatible nbt compound
    nbt.putIntList("size", width, height, length)
    nbt.put("palette", newPalette)
    nbt.put("blocks", newBlocks)
    nbt.putString("author", metadata.getString("Author"))

    // Fix the data for future versions
    DataFixTypes.STRUCTURE.update(mc.dataFixer, nbt, version)

    // Use the StructureTemplate NBT read utils in order to construct the template
    return readNbtOrException(lookup, nbt)
}