/*
Minetest
Copyright (C) 2010-2014 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "settings.h"
#include "wieldmesh.h"
#include "inventory.h"
#include "client.h"
#include "itemdef.h"
#include "nodedef.h"
#include "mesh.h"
#include "mapblock_mesh.h"
#include "client/tile.h"
#include "log.h"
#include "util/numeric.h"
#include <map>
#include <IMeshManipulator.h>

#define WIELD_SCALE_FACTOR 30.0
#define WIELD_SCALE_FACTOR_EXTRUDED 40.0

#define MIN_EXTRUSION_MESH_RESOLUTION 16
#define MAX_EXTRUSION_MESH_RESOLUTION 512

static scene::IMesh *createExtrusionMesh(int resolution_x, int resolution_y)
{
	const f32 r = 0.5;

	scene::IMeshBuffer *buf = new scene::SMeshBuffer();
	video::SColor c(255,255,255,255);
	v3f scale(1.0, 1.0, 0.1);

	// Front and back
	{
		video::S3DVertex vertices[8] = {
			// z-
			video::S3DVertex(-r,+r,-r, 0,0,-1, c, 0,0),
			video::S3DVertex(+r,+r,-r, 0,0,-1, c, 1,0),
			video::S3DVertex(+r,-r,-r, 0,0,-1, c, 1,1),
			video::S3DVertex(-r,-r,-r, 0,0,-1, c, 0,1),
			// z+
			video::S3DVertex(-r,+r,+r, 0,0,+1, c, 0,0),
			video::S3DVertex(-r,-r,+r, 0,0,+1, c, 0,1),
			video::S3DVertex(+r,-r,+r, 0,0,+1, c, 1,1),
			video::S3DVertex(+r,+r,+r, 0,0,+1, c, 1,0),
		};
		u16 indices[12] = {0,1,2,2,3,0,4,5,6,6,7,4};
		buf->append(vertices, 8, indices, 12);
	}

	f32 pixelsize_x = 1 / (f32) resolution_x;
	f32 pixelsize_y = 1 / (f32) resolution_y;

	for (int i = 0; i < resolution_x; ++i) {
		f32 pixelpos_x = i * pixelsize_x - 0.5;
		f32 x0 = pixelpos_x;
		f32 x1 = pixelpos_x + pixelsize_x;
		f32 tex0 = (i + 0.1) * pixelsize_x;
		f32 tex1 = (i + 0.9) * pixelsize_x;
		video::S3DVertex vertices[8] = {
			// x-
			video::S3DVertex(x0,-r,-r, -1,0,0, c, tex0,1),
			video::S3DVertex(x0,-r,+r, -1,0,0, c, tex1,1),
			video::S3DVertex(x0,+r,+r, -1,0,0, c, tex1,0),
			video::S3DVertex(x0,+r,-r, -1,0,0, c, tex0,0),
			// x+
			video::S3DVertex(x1,-r,-r, +1,0,0, c, tex0,1),
			video::S3DVertex(x1,+r,-r, +1,0,0, c, tex0,0),
			video::S3DVertex(x1,+r,+r, +1,0,0, c, tex1,0),
			video::S3DVertex(x1,-r,+r, +1,0,0, c, tex1,1),
		};
		u16 indices[12] = {0,1,2,2,3,0,4,5,6,6,7,4};
		buf->append(vertices, 8, indices, 12);
	}
	for (int i = 0; i < resolution_y; ++i) {
		f32 pixelpos_y = i * pixelsize_y - 0.5;
		f32 y0 = -pixelpos_y - pixelsize_y;
		f32 y1 = -pixelpos_y;
		f32 tex0 = (i + 0.1) * pixelsize_y;
		f32 tex1 = (i + 0.9) * pixelsize_y;
		video::S3DVertex vertices[8] = {
			// y-
			video::S3DVertex(-r,y0,-r, 0,-1,0, c, 0,tex0),
			video::S3DVertex(+r,y0,-r, 0,-1,0, c, 1,tex0),
			video::S3DVertex(+r,y0,+r, 0,-1,0, c, 1,tex1),
			video::S3DVertex(-r,y0,+r, 0,-1,0, c, 0,tex1),
			// y+
			video::S3DVertex(-r,y1,-r, 0,+1,0, c, 0,tex0),
			video::S3DVertex(-r,y1,+r, 0,+1,0, c, 0,tex1),
			video::S3DVertex(+r,y1,+r, 0,+1,0, c, 1,tex1),
			video::S3DVertex(+r,y1,-r, 0,+1,0, c, 1,tex0),
		};
		u16 indices[12] = {0,1,2,2,3,0,4,5,6,6,7,4};
		buf->append(vertices, 8, indices, 12);
	}

	// Create mesh object
	scene::SMesh *mesh = new scene::SMesh();
	mesh->addMeshBuffer(buf);
	buf->drop();
	scaleMesh(mesh, scale);  // also recalculates bounding box
	return mesh;
}

/*
	Caches extrusion meshes so that only one of them per resolution
	is needed. Also caches one cube (for convenience).

	E.g. there is a single extrusion mesh that is used for all
	16x16 px images, another for all 256x256 px images, and so on.

	WARNING: Not thread safe. This should not be a problem since
	rendering related classes (such as WieldMeshSceneNode) will be
	used from the rendering thread only.
*/
class ExtrusionMeshCache: public IReferenceCounted
{
public:
	// Constructor
	ExtrusionMeshCache()
	{
		for (int resolution = MIN_EXTRUSION_MESH_RESOLUTION;
				resolution <= MAX_EXTRUSION_MESH_RESOLUTION;
				resolution *= 2) {
			m_extrusion_meshes[resolution] =
				createExtrusionMesh(resolution, resolution);
		}
		m_cube = createCubeMesh(v3f(1.0, 1.0, 1.0));
	}
	// Destructor
	virtual ~ExtrusionMeshCache()
	{
		for (std::map<int, scene::IMesh*>::iterator
				it = m_extrusion_meshes.begin();
				it != m_extrusion_meshes.end(); ++it) {
			it->second->drop();
		}
		m_cube->drop();
	}
	// Get closest extrusion mesh for given image dimensions
	// Caller must drop the returned pointer
	scene::IMesh* create(core::dimension2d<u32> dim)
	{
		// handle non-power of two textures inefficiently without cache
		if (!is_power_of_two(dim.Width) || !is_power_of_two(dim.Height)) {
			return createExtrusionMesh(dim.Width, dim.Height);
		}

		int maxdim = MYMAX(dim.Width, dim.Height);

		std::map<int, scene::IMesh*>::iterator
			it = m_extrusion_meshes.lower_bound(maxdim);

		if (it == m_extrusion_meshes.end()) {
			// no viable resolution found; use largest one
			it = m_extrusion_meshes.find(MAX_EXTRUSION_MESH_RESOLUTION);
			sanity_check(it != m_extrusion_meshes.end());
		}

		scene::IMesh *mesh = it->second;
		mesh->grab();
		return mesh;
	}
	// Returns a 1x1x1 cube mesh with one meshbuffer (material) per face
	// Caller must drop the returned pointer
	scene::IMesh* createCube()
	{
		m_cube->grab();
		return m_cube;
	}

private:
	std::map<int, scene::IMesh*> m_extrusion_meshes;
	scene::IMesh *m_cube;
};

ExtrusionMeshCache *g_extrusion_mesh_cache = NULL;


WieldMeshSceneNode::WieldMeshSceneNode(
		scene::ISceneNode *parent,
		scene::ISceneManager *mgr,
		s32 id,
		bool lighting
):
	scene::ISceneNode(parent, mgr, id),
	m_meshnode(NULL),
	m_material_type(video::EMT_TRANSPARENT_ALPHA_CHANNEL_REF),
	m_lighting(lighting),
	m_bounding_box(0.0, 0.0, 0.0, 0.0, 0.0, 0.0)
{
	m_enable_shaders = g_settings->getBool("enable_shaders");
	m_anisotropic_filter = g_settings->getBool("anisotropic_filter");
	m_bilinear_filter = g_settings->getBool("bilinear_filter");
	m_trilinear_filter = g_settings->getBool("trilinear_filter");

	// If this is the first wield mesh scene node, create a cache
	// for extrusion meshes (and a cube mesh), otherwise reuse it
	if (g_extrusion_mesh_cache == NULL)
		g_extrusion_mesh_cache = new ExtrusionMeshCache();
	else
		g_extrusion_mesh_cache->grab();

	// Disable bounding box culling for this scene node
	// since we won't calculate the bounding box.
	setAutomaticCulling(scene::EAC_OFF);

	// Create the child scene node
	scene::IMesh *dummymesh = g_extrusion_mesh_cache->createCube();
	m_meshnode = SceneManager->addMeshSceneNode(dummymesh, this, -1);
	m_meshnode->setReadOnlyMaterials(false);
	m_meshnode->setVisible(false);
	dummymesh->drop(); // m_meshnode grabbed it
}

WieldMeshSceneNode::~WieldMeshSceneNode()
{
	sanity_check(g_extrusion_mesh_cache);
	if (g_extrusion_mesh_cache->drop())
		g_extrusion_mesh_cache = NULL;
}

void WieldMeshSceneNode::setCube(const ContentFeatures &f,
			v3f wield_scale, ITextureSource *tsrc)
{
	scene::IMesh *cubemesh = g_extrusion_mesh_cache->createCube();
	scene::SMesh *copy = cloneMesh(cubemesh);
	cubemesh->drop();
	postProcessNodeMesh(copy, f, false, true, &m_material_type, &m_colors);
	changeToMesh(copy);
	copy->drop();
	m_meshnode->setScale(wield_scale * WIELD_SCALE_FACTOR);
}

void WieldMeshSceneNode::setExtruded(const std::string &imagename,
		v3f wield_scale, ITextureSource *tsrc, u8 num_frames)
{
	video::ITexture *texture = tsrc->getTexture(imagename);
	if (!texture) {
		changeToMesh(NULL);
		return;
	}

	core::dimension2d<u32> dim = texture->getSize();
	// Detect animation texture and pull off top frame instead of using entire thing
	if (num_frames > 1) {
		u32 frame_height = dim.Height / num_frames;
		dim = core::dimension2d<u32>(dim.Width, frame_height);
	}
	scene::IMesh *mesh = g_extrusion_mesh_cache->create(dim);
	scene::SMesh *copy = cloneMesh(mesh);
	mesh->drop();
	changeToMesh(copy);
	copy->drop();

	m_meshnode->setScale(wield_scale * WIELD_SCALE_FACTOR_EXTRUDED);

	// Customize material
	video::SMaterial &material = m_meshnode->getMaterial(0);
	material.setTexture(0, tsrc->getTextureForMesh(imagename));
	material.TextureLayer[0].TextureWrapU = video::ETC_CLAMP_TO_EDGE;
	material.TextureLayer[0].TextureWrapV = video::ETC_CLAMP_TO_EDGE;
	material.MaterialType = m_material_type;
	material.setFlag(video::EMF_BACK_FACE_CULLING, true);
	// Enable bi/trilinear filtering only for high resolution textures
	if (dim.Width > 32) {
		material.setFlag(video::EMF_BILINEAR_FILTER, m_bilinear_filter);
		material.setFlag(video::EMF_TRILINEAR_FILTER, m_trilinear_filter);
	} else {
		material.setFlag(video::EMF_BILINEAR_FILTER, false);
		material.setFlag(video::EMF_TRILINEAR_FILTER, false);
	}
	material.setFlag(video::EMF_ANISOTROPIC_FILTER, m_anisotropic_filter);
	// mipmaps cause "thin black line" artifacts
#if (IRRLICHT_VERSION_MAJOR >= 1 && IRRLICHT_VERSION_MINOR >= 8) || IRRLICHT_VERSION_MAJOR >= 2
	material.setFlag(video::EMF_USE_MIP_MAPS, false);
#endif
	if (m_enable_shaders) {
		material.setTexture(2, tsrc->getShaderFlagsTexture(false));
	}
}

void WieldMeshSceneNode::setItem(const ItemStack &item, Client *client)
{
	ITextureSource *tsrc = client->getTextureSource();
	IItemDefManager *idef = client->getItemDefManager();
	IShaderSource *shdrsrc = client->getShaderSource();
	INodeDefManager *ndef = client->getNodeDefManager();
	const ItemDefinition &def = item.getDefinition(idef);
	const ContentFeatures &f = ndef->get(def.name);
	content_t id = ndef->getId(def.name);

	if (m_enable_shaders) {
		u32 shader_id = shdrsrc->getShader("wielded_shader", TILE_MATERIAL_BASIC, NDT_NORMAL);
		m_material_type = shdrsrc->getShaderInfo(shader_id).material;
	}

	// Color-related
	m_colors.clear();
	m_base_color = idef->getItemstackColor(item, client);

	// If wield_image is defined, it overrides everything else
	if (def.wield_image != "") {
		setExtruded(def.wield_image, def.wield_scale, tsrc, 1);
		m_colors.push_back(ItemPartColor());
		return;
	}
	// Handle nodes
	// See also CItemDefManager::createClientCached()
	else if (def.type == ITEM_NODE) {
		if (f.mesh_ptr[0]) {
			// e.g. mesh nodes and nodeboxes
			scene::SMesh *mesh = cloneMesh(f.mesh_ptr[0]);
			postProcessNodeMesh(mesh, f, m_enable_shaders, true,
				&m_material_type, &m_colors);
			changeToMesh(mesh);
			mesh->drop();
			// mesh is pre-scaled by BS * f->visual_scale
			m_meshnode->setScale(
					def.wield_scale * WIELD_SCALE_FACTOR
					/ (BS * f.visual_scale));
		} else if (f.drawtype == NDT_AIRLIKE) {
			changeToMesh(NULL);
		} else if (f.drawtype == NDT_PLANTLIKE) {
			setExtruded(tsrc->getTextureName(f.tiles[0].layers[0].texture_id),
				def.wield_scale, tsrc,
				f.tiles[0].layers[0].animation_frame_count);
		} else if (f.drawtype == NDT_NORMAL || f.drawtype == NDT_ALLFACES) {
			setCube(f, def.wield_scale, tsrc);
		} else {
			MeshMakeData mesh_make_data(client, false);
			MapNode mesh_make_node(id, 255, 0);
			mesh_make_data.fillSingleNode(&mesh_make_node);
			MapBlockMesh mapblock_mesh(&mesh_make_data, v3s16(0, 0, 0));
			scene::SMesh *mesh = cloneMesh(mapblock_mesh.getMesh());
			translateMesh(mesh, v3f(-BS, -BS, -BS));
			postProcessNodeMesh(mesh, f, m_enable_shaders, true,
				&m_material_type, &m_colors);
			changeToMesh(mesh);
			mesh->drop();
			m_meshnode->setScale(
					def.wield_scale * WIELD_SCALE_FACTOR
					/ (BS * f.visual_scale));
		}
		u32 material_count = m_meshnode->getMaterialCount();
		for (u32 i = 0; i < material_count; ++i) {
			video::SMaterial &material = m_meshnode->getMaterial(i);
			material.setFlag(video::EMF_BACK_FACE_CULLING, true);
			material.setFlag(video::EMF_BILINEAR_FILTER, m_bilinear_filter);
			material.setFlag(video::EMF_TRILINEAR_FILTER, m_trilinear_filter);
		}
		return;
	}
	else if (def.inventory_image != "") {
		setExtruded(def.inventory_image, def.wield_scale, tsrc, 1);
		m_colors.push_back(ItemPartColor());
		return;
	}

	// no wield mesh found
	changeToMesh(NULL);
}

void WieldMeshSceneNode::setColor(video::SColor c)
{
	assert(!m_lighting);
	scene::IMesh *mesh=m_meshnode->getMesh();
	if (mesh == NULL)
		return;

	u8 red = c.getRed();
	u8 green = c.getGreen();
	u8 blue = c.getBlue();
	u32 mc = mesh->getMeshBufferCount();
	for (u32 j = 0; j < mc; j++) {
		video::SColor bc(m_base_color);
		if ((m_colors.size() > j) && (m_colors[j].override_base))
			bc = m_colors[j].color;
		video::SColor buffercolor(255,
			bc.getRed() * red / 255,
			bc.getGreen() * green / 255,
			bc.getBlue() * blue / 255);
		scene::IMeshBuffer *buf = mesh->getMeshBuffer(j);
		colorizeMeshBuffer(buf, &buffercolor);
	}
}

void WieldMeshSceneNode::render()
{
	// note: if this method is changed to actually do something,
	// you probably should implement OnRegisterSceneNode as well
}

void WieldMeshSceneNode::changeToMesh(scene::IMesh *mesh)
{
	if (mesh == NULL) {
		scene::IMesh *dummymesh = g_extrusion_mesh_cache->createCube();
		m_meshnode->setVisible(false);
		m_meshnode->setMesh(dummymesh);
		dummymesh->drop();  // m_meshnode grabbed it
	} else {
		m_meshnode->setMesh(mesh);
	}

	m_meshnode->setMaterialFlag(video::EMF_LIGHTING, m_lighting);
	// need to normalize normals when lighting is enabled (because of setScale())
	m_meshnode->setMaterialFlag(video::EMF_NORMALIZE_NORMALS, m_lighting);
	m_meshnode->setVisible(true);
}

void getItemMesh(Client *client, const ItemStack &item, ItemMesh *result)
{
	ITextureSource *tsrc = client->getTextureSource();
	IItemDefManager *idef = client->getItemDefManager();
	INodeDefManager *ndef = client->getNodeDefManager();
	const ItemDefinition &def = item.getDefinition(idef);
	const ContentFeatures &f = ndef->get(def.name);
	content_t id = ndef->getId(def.name);

	if (!g_extrusion_mesh_cache) {
		g_extrusion_mesh_cache = new ExtrusionMeshCache();
	} else {
		g_extrusion_mesh_cache->grab();
	}

	scene::SMesh *mesh = NULL;

	// Shading is on by default
	result->needs_shading = true;

	// If inventory_image is defined, it overrides everything else
	if (def.inventory_image != "") {
		mesh = getExtrudedMesh(tsrc, def.inventory_image);
		result->buffer_colors.push_back(ItemPartColor());
		// Items with inventory images do not need shading
		result->needs_shading = false;
	} else if (def.type == ITEM_NODE) {
		if (f.mesh_ptr[0]) {
			mesh = cloneMesh(f.mesh_ptr[0]);
			scaleMesh(mesh, v3f(0.12, 0.12, 0.12));
		} else if (f.drawtype == NDT_PLANTLIKE) {
			mesh = getExtrudedMesh(tsrc,
				tsrc->getTextureName(f.tiles[0].layers[0].texture_id));
		} else if (f.drawtype == NDT_NORMAL || f.drawtype == NDT_ALLFACES
			|| f.drawtype == NDT_LIQUID || f.drawtype == NDT_FLOWINGLIQUID) {
			scene::IMesh *cube = g_extrusion_mesh_cache->createCube();
			mesh = cloneMesh(cube);
			cube->drop();
			scaleMesh(mesh, v3f(1.2, 1.2, 1.2));
		} else {
			MeshMakeData mesh_make_data(client, false);
			MapNode mesh_make_node(id, 255, 0);
			mesh_make_data.fillSingleNode(&mesh_make_node);
			MapBlockMesh mapblock_mesh(&mesh_make_data, v3s16(0, 0, 0));
			mesh = cloneMesh(mapblock_mesh.getMesh());
			translateMesh(mesh, v3f(-BS, -BS, -BS));
			scaleMesh(mesh, v3f(0.12, 0.12, 0.12));

			u32 mc = mesh->getMeshBufferCount();
			for (u32 i = 0; i < mc; ++i) {
				video::SMaterial &material1 =
					mesh->getMeshBuffer(i)->getMaterial();
				video::SMaterial &material2 =
					mapblock_mesh.getMesh()->getMeshBuffer(i)->getMaterial();
				material1.setTexture(0, material2.getTexture(0));
				material1.setTexture(1, material2.getTexture(1));
				material1.setTexture(2, material2.getTexture(2));
				material1.setTexture(3, material2.getTexture(3));
				material1.MaterialType = material2.MaterialType;
			}
		}

		u32 mc = mesh->getMeshBufferCount();