#include "voxel_tool_terrain.h"
#include "../terrain/voxel_map.h"
#include "../terrain/voxel_terrain.h"
#include "../util/voxel_raycast.h"

VoxelToolTerrain::VoxelToolTerrain(VoxelTerrain *terrain, Ref<VoxelMap> map) {
	ERR_FAIL_COND(terrain == nullptr);
	_terrain = terrain;
	_map = map;
	// Don't destroy the terrain while a voxel tool still references it
}

bool VoxelToolTerrain::is_area_editable(const Rect3i &box) const {
	ERR_FAIL_COND_V(_terrain == nullptr, false);
	return _map->is_area_fully_loaded(box.padded(1));
}

Ref<VoxelRaycastResult> VoxelToolTerrain::raycast(Vector3 pos, Vector3 dir, float max_distance) {

	// TODO Transform input if the terrain is rotated (in the future it can be made a Spatial node)

	struct RaycastPredicate {
		const VoxelTerrain &terrain;

		bool operator()(Vector3i pos) {
			//unsigned int channel = context->channel;

			Ref<VoxelMap> map = terrain.get_storage();
			int v0 = map->get_voxel(pos, VoxelBuffer::CHANNEL_TYPE);

			Ref<VoxelLibrary> lib_ref = terrain.get_voxel_library();
			if (lib_ref.is_null())
				return false;
			const VoxelLibrary &lib = **lib_ref;

			if (lib.has_voxel(v0) == false)
				return false;

			const Voxel &voxel = lib.get_voxel_const(v0);
			if (voxel.is_transparent() == false)
				return true;

			float v1 = map->get_voxel_f(pos, VoxelBuffer::CHANNEL_SDF);
			return v1 < 0;
		}
	};

	Vector3i hit_pos;
	Vector3i prev_pos;
	Ref<VoxelRaycastResult> res;

	RaycastPredicate predicate = { *_terrain };
	if (voxel_raycast(pos, dir, predicate, max_distance, hit_pos, prev_pos)) {

		res.instance();
		res->position = hit_pos;
		res->previous_position = prev_pos;
	}

	return res;
}

int VoxelToolTerrain::_get_voxel(Vector3i pos) {
	ERR_FAIL_COND_V(_terrain == nullptr, 0);
	return _map->get_voxel(pos, _channel);
}

float VoxelToolTerrain::_get_voxel_f(Vector3i pos) {
	ERR_FAIL_COND_V(_terrain == nullptr, 0);
	return _map->get_voxel_f(pos, _channel);
}

void VoxelToolTerrain::_set_voxel(Vector3i pos, int v) {
	ERR_FAIL_COND(_terrain == nullptr);
	_map->set_voxel(v, pos, _channel);
}

void VoxelToolTerrain::_set_voxel_f(Vector3i pos, float v) {
	ERR_FAIL_COND(_terrain == nullptr);
	_map->set_voxel_f(v, pos, _channel);
}

void VoxelToolTerrain::_post_edit(const Rect3i &box) {
	ERR_FAIL_COND(_terrain == nullptr);
	_terrain->make_area_dirty(box);
}