#include "voxel_map.h"
#include "core/os/os.h"
#include "cube_tables.h"

//----------------------------------------------------------------------------
// VoxelBlock
//----------------------------------------------------------------------------

MeshInstance *VoxelBlock::get_mesh_instance(const Node &root) {
	if (mesh_instance_path.is_empty())
		return NULL;
	Node *n = root.get_node(mesh_instance_path);
	if (n == NULL)
		return NULL;
	return n->cast_to<MeshInstance>();
}

// Helper
VoxelBlock *VoxelBlock::create(Vector3i bpos, Ref<VoxelBuffer> buffer, unsigned int size) {
	const int bs = size;
	ERR_FAIL_COND_V(buffer.is_null(), NULL);
	ERR_FAIL_COND_V(buffer->get_size() != Vector3i(bs, bs, bs), NULL);

	VoxelBlock *block = memnew(VoxelBlock);
	block->pos = bpos;

	block->voxels = buffer;
	//block->map = &map;
	return block;
}

VoxelBlock::VoxelBlock()
	: voxels(NULL) {
}

//----------------------------------------------------------------------------
// VoxelMap
//----------------------------------------------------------------------------

VoxelMap::VoxelMap()
	: _last_accessed_block(NULL) {

	// TODO Make it configurable in editor (with all necessary notifications and updatings!)
	set_block_size_pow2(4);

	for (unsigned int i = 0; i < VoxelBuffer::MAX_CHANNELS; ++i) {
		_default_voxel[i] = 0;
	}
}

VoxelMap::~VoxelMap() {
	clear();
}

void VoxelMap::set_block_size_pow2(unsigned int p) {

	// Limit to 8, 16, 32
	ERR_FAIL_COND(p < 3 || p > 5);

	_block_size_pow2 = p;
	_block_size = 1 << _block_size_pow2;
	_block_size_mask = _block_size_pow2 - 1;
}

int VoxelMap::get_voxel(Vector3i pos, unsigned int c) {
	Vector3i bpos = voxel_to_block(pos);
	VoxelBlock *block = get_block(bpos);
	if (block == NULL) {
		return _default_voxel[c];
	}
	return block->voxels->get_voxel(VoxelMap::to_local(pos), c);
}

void VoxelMap::set_voxel(int value, Vector3i pos, unsigned int c) {

	Vector3i bpos = voxel_to_block(pos);
	VoxelBlock *block = get_block(bpos);

	if (block == NULL) {

		Ref<VoxelBuffer> buffer(memnew(VoxelBuffer));
		buffer->create(_block_size, _block_size, _block_size);
		buffer->set_default_values(_default_voxel);

		block = VoxelBlock::create(bpos, buffer, _block_size);

		set_block(bpos, block);
	}

	block->voxels->set_voxel(value, VoxelMap::to_local(pos), c);
}

void VoxelMap::set_default_voxel(int value, unsigned int channel) {
	ERR_FAIL_INDEX(channel, VoxelBuffer::MAX_CHANNELS);
	_default_voxel[channel] = value;
}

int VoxelMap::get_default_voxel(unsigned int channel) {
	ERR_FAIL_INDEX_V(channel, VoxelBuffer::MAX_CHANNELS, 0);
	return _default_voxel[channel];
}

VoxelBlock *VoxelMap::get_block(Vector3i bpos) {
	if (_last_accessed_block && _last_accessed_block->pos == bpos) {
		return _last_accessed_block;
	}
	VoxelBlock **p = _blocks.getptr(bpos);
	if (p) {
		_last_accessed_block = *p;
		return _last_accessed_block;
	}
	return NULL;
}

void VoxelMap::set_block(Vector3i bpos, VoxelBlock *block) {
	ERR_FAIL_COND(block == NULL);
	if (_last_accessed_block == NULL || _last_accessed_block->pos == bpos) {
		_last_accessed_block = block;
	}
	_blocks.set(bpos, block);
}

void VoxelMap::set_block_buffer(Vector3i bpos, Ref<VoxelBuffer> buffer) {
	ERR_FAIL_COND(buffer.is_null());
	VoxelBlock *block = get_block(bpos);
	if (block == NULL) {
		block = VoxelBlock::create(bpos, *buffer, _block_size);
		set_block(bpos, block);
	} else {
		block->voxels = buffer;
	}
}

bool VoxelMap::has_block(Vector3i pos) const {
	return /*(_last_accessed_block != NULL && _last_accessed_block->pos == pos) ||*/ _blocks.has(pos);
}

bool VoxelMap::is_block_surrounded(Vector3i pos) const {
	for (unsigned int i = 0; i < 26; ++i) {
		Vector3i bpos = pos + CubeTables::g_moore_neighboring_3d[i];
		if (!has_block(bpos)) {
			return false;
		}
	}
	return true;
}

void VoxelMap::get_buffer_copy(Vector3i min_pos, VoxelBuffer &dst_buffer, unsigned int channels_mask) {

	Vector3i max_pos = min_pos + dst_buffer.get_size();

	Vector3i min_block_pos = voxel_to_block(min_pos);
	Vector3i max_block_pos = voxel_to_block(max_pos - Vector3i(1, 1, 1)) + Vector3i(1, 1, 1);
	ERR_FAIL_COND((max_block_pos - min_block_pos) != Vector3(3, 3, 3));

	const Vector3i block_size_v(_block_size, _block_size, _block_size);

	for (unsigned int channel = 0; channel < VoxelBuffer::MAX_CHANNELS; ++channel) {

		if (((1 << channel) & channels_mask) == 0) {
			continue;
		}

		Vector3i bpos;
		for (bpos.z = min_block_pos.z; bpos.z < max_block_pos.z; ++bpos.z) {
			for (bpos.x = min_block_pos.x; bpos.x < max_block_pos.x; ++bpos.x) {
				for (bpos.y = min_block_pos.y; bpos.y < max_block_pos.y; ++bpos.y) {

					VoxelBlock *block = get_block(bpos);
					if (block) {

						VoxelBuffer &src_buffer = **block->voxels;
						Vector3i offset = block_to_voxel(bpos);
						// Note: copy_from takes care of clamping the area if it's on an edge
						dst_buffer.copy_from(src_buffer, min_pos - offset, max_pos - offset, offset - min_pos, channel);

					} else {
						Vector3i offset = block_to_voxel(bpos);
						dst_buffer.fill_area(
								_default_voxel[channel],
								offset - min_pos,
								offset - min_pos + block_size_v);
					}
				}
			}
		}
	}
}

void VoxelMap::remove_blocks_not_in_area(Vector3i min, Vector3i max) {

	Vector3i::sort_min_max(min, max);

	Vector<Vector3i> to_remove;
	const Vector3i *key = NULL;

	while (key = _blocks.next(key)) {

		VoxelBlock *block_ref = _blocks.get(*key);
		ERR_FAIL_COND(block_ref == NULL); // Should never trigger

		if (block_ref->pos.is_contained_in(min, max)) {

			//if (_observer)
			//    _observer->block_removed(block);

			to_remove.push_back(*key);

			if (block_ref == _last_accessed_block)
				_last_accessed_block = NULL;
		}
	}

	for (unsigned int i = 0; i < to_remove.size(); ++i) {
		_blocks.erase(to_remove[i]);
	}
}

void VoxelMap::clear() {
	const Vector3i *key = NULL;
	while (key = _blocks.next(key)) {
		VoxelBlock *block_ref = _blocks.get(*key);
		if (block_ref == NULL) {
			OS::get_singleton()->printerr("Unexpected NULL in VoxelMap::clear()");
		}
		memdelete(block_ref);
	}
	_blocks.clear();
	_last_accessed_block = NULL;
}

void VoxelMap::_bind_methods() {

	ClassDB::bind_method(D_METHOD("get_voxel", "x", "y", "z", "c"), &VoxelMap::_get_voxel_binding, DEFVAL(0));
	ClassDB::bind_method(D_METHOD("set_voxel", "value", "x", "y", "z", "c"), &VoxelMap::_set_voxel_binding, DEFVAL(0));
	ClassDB::bind_method(D_METHOD("get_voxel_v", "pos", "c"), &VoxelMap::_get_voxel_v_binding, DEFVAL(0));
	ClassDB::bind_method(D_METHOD("set_voxel_v", "value", "pos", "c"), &VoxelMap::_set_voxel_v_binding, DEFVAL(0));
	ClassDB::bind_method(D_METHOD("get_default_voxel", "channel"), &VoxelMap::get_default_voxel, DEFVAL(0));
	ClassDB::bind_method(D_METHOD("set_default_voxel", "value", "channel"), &VoxelMap::set_default_voxel, DEFVAL(0));
	ClassDB::bind_method(D_METHOD("has_block", "x", "y", "z"), &VoxelMap::_has_block_binding);
	ClassDB::bind_method(D_METHOD("get_buffer_copy", "min_pos", "out_buffer", "channel"), &VoxelMap::_get_buffer_copy_binding, DEFVAL(0));
	ClassDB::bind_method(D_METHOD("set_block_buffer", "block_pos", "buffer"), &VoxelMap::_set_block_buffer_binding);
	ClassDB::bind_method(D_METHOD("voxel_to_block", "voxel_pos"), &VoxelMap::_voxel_to_block_binding);
	ClassDB::bind_method(D_METHOD("block_to_voxel", "block_pos"), &VoxelMap::_block_to_voxel_binding);
	ClassDB::bind_method(D_METHOD("get_block_size"), &VoxelMap::get_block_size);

	//ADD_PROPERTY(PropertyInfo(Variant::INT, "iterations"), _SCS("set_iterations"), _SCS("get_iterations"));
}

void VoxelMap::_get_buffer_copy_binding(Vector3 pos, Ref<VoxelBuffer> dst_buffer_ref, unsigned int channel) {
	ERR_FAIL_COND(dst_buffer_ref.is_null());
	get_buffer_copy(Vector3i(pos), **dst_buffer_ref, channel);
}