/*
 * Copyright 2011-2013 Blender Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef __SVM_H__
#define __SVM_H__

#include "render/attribute.h"
#include "render/graph.h"
#include "render/shader.h"

#include "util/util_array.h"
#include "util/util_set.h"
#include "util/util_string.h"
#include "util/util_thread.h"

CCL_NAMESPACE_BEGIN

class Device;
class DeviceScene;
class ImageManager;
class Scene;
class ShaderGraph;
class ShaderInput;
class ShaderNode;
class ShaderOutput;

/* Shader Manager */

class SVMShaderManager : public ShaderManager {
public:
	SVMShaderManager();
	~SVMShaderManager();

	void reset(Scene *scene);

	void device_update(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress);
	void device_free(Device *device, DeviceScene *dscene, Scene *scene);

protected:
	/* Lock used to synchronize threaded nodes compilation. */
	thread_spin_lock nodes_lock_;

	void device_update_shader(Scene *scene,
	                          Shader *shader,
	                          Progress *progress,
	                          array<int4> *global_svm_nodes);
};

/* Graph Compiler */

class SVMCompiler {
public:
	struct Summary {
		Summary();

		/* Number of SVM nodes shader was compiled into. */
		int num_svm_nodes;

		/* Peak stack usage during shader evaluation. */
		int peak_stack_usage;

		/* Time spent on surface graph finalization. */
		double time_finalize;

		/* Time spent on generating SVM nodes for surface shader. */
		double time_generate_surface;

		/* Time spent on generating SVM nodes for bump shader. */
		double time_generate_bump;

		/* Time spent on generating SVM nodes for volume shader. */
		double time_generate_volume;

		/* Time spent on generating SVM nodes for displacement shader. */
		double time_generate_displacement;

		/* Total time spent on all routines. */
		double time_total;

		/* A full multiline description of the state of the compiler after
		 * compilation.
		 */
		string full_report() const;
	};

	SVMCompiler(ShaderManager *shader_manager,
	            ImageManager *image_manager,
	            LightManager *light_manager);
	void compile(Scene *scene,
	             Shader *shader,
	             array<int4>& svm_nodes,
	             int index,
	             Summary *summary = NULL);

	int stack_assign(ShaderOutput *output);
	int stack_assign(ShaderInput *input);
	int stack_assign_if_linked(ShaderInput *input);
	int stack_assign_if_linked(ShaderOutput *output);
	int stack_find_offset(int size);
	int stack_find_offset(SocketType::Type type);
	void stack_clear_offset(SocketType::Type type, int offset);
	void stack_link(ShaderInput *input, ShaderOutput *output);

	void add_node(ShaderNodeType type, int a = 0, int b = 0, int c = 0);
	void add_node(int a = 0, int b = 0, int c = 0, int d = 0);
	void add_node(ShaderNodeType type, const float3& f);
	void add_node(const float4& f);
	uint attribute(ustring name);
	uint attribute(AttributeStandard std);
	uint attribute_standard(ustring name);
	uint encode_uchar4(uint x, uint y = 0, uint z = 0, uint w = 0);
	uint closure_mix_weight_offset() { return mix_weight_offset; }

	ShaderType output_type() { return current_type; }

	ImageManager *image_manager;
	ShaderManager *shader_manager;
	LightManager *light_manager;
	bool background;

protected:
	/* stack */
	struct Stack {
		Stack() { memset(users, 0, sizeof(users)); }
		Stack(const Stack& other) { memcpy(users, other.users, sizeof(users)); }
		Stack& operator=(const Stack& other) { memcpy(users, other.users, sizeof(users)); return *this; }

		bool empty()
		{
			for(int i = 0; i < SVM_STACK_SIZE; i++)
				if(users[i])
					return false;

			return true;
		}

		void print()
		{
			printf("stack <");

			for(int i = 0; i < SVM_STACK_SIZE; i++)
				printf((users[i])? "*": " ");

			printf(">\n");
		}

		int users[SVM_STACK_SIZE];
	};

	/* Global state of the compiler accessible from the compilation routines. */
	struct CompilerState {
		explicit CompilerState(ShaderGraph *graph);

		/* ** Global state, used by various compilation steps. ** */

		/* Set of nodes which were already compiled. */
		ShaderNodeSet nodes_done;

		/* Set of closures which were already compiled. */
		ShaderNodeSet closure_done;

		/* ** SVM nodes generation state ** */

		/* Flag whether the node with corresponding ID was already compiled or
		 * not. Array element with index i corresponds to a node with such if.
		 *
		 * TODO(sergey): This is actually a copy of nodes_done just in another
		 * notation. We can de-duplicate this storage actually after switching
		 * all areas to use this flags array.
		 */
		vector<bool> nodes_done_flag;
	};

	void stack_clear_temporary(ShaderNode *node);
	int stack_size(SocketType::Type type);
	void stack_clear_users(ShaderNode *node, ShaderNodeSet& done);

	bool node_skip_input(ShaderNode *node, ShaderInput *input);

	/* single closure */
	void find_dependencies(ShaderNodeSet& dependencies,
	                       const ShaderNodeSet& done,
	                       ShaderInput *input,
	                       ShaderNode *skip_node = NULL);
	void generate_node(ShaderNode *node, ShaderNodeSet& done);
	void generate_closure_node(ShaderNode *node, CompilerState *state);
	void generated_shared_closure_nodes(ShaderNode *root_node,
	                                    ShaderNode *node,
	                                    CompilerState *state,
	                                    const ShaderNodeSet& shared);
	void generate_svm_nodes(const ShaderNodeSet& nodes,
	                        CompilerState *state);

	/* multi closure */
	void generate_multi_closure(ShaderNode *root_node,
	                            ShaderNode *node,
	                            CompilerState *state);

	/* compile */
	void compile_type(Shader *shader, ShaderGraph *graph, ShaderType type);

	array<int4> current_svm_nodes;
	ShaderType current_type;
	Shader *current_shader;
	ShaderGraph *current_graph;
	Stack active_stack;
	int max_stack_use;
	uint mix_weight_offset;
	bool compile_failed;
};

CCL_NAMESPACE_END

#endif  /* __SVM_H__ */