/*************************************************************************/
/*  test_shader_lang.cpp                                                 */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur.                 */
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/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
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/* The above copyright notice and this permission notice shall be        */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
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/*************************************************************************/
#include "test_shader_lang.h"


#include "os/main_loop.h"
#include "os/os.h"
#include "os/file_access.h"

#include "scene/gui/control.h"
#include "scene/gui/text_edit.h"
#include "print_string.h"
#include "servers/visual/shader_language.h"
//#include "drivers/gles2/shader_compiler_gles2.h"


typedef ShaderLanguage SL;

namespace TestShaderLang {


static String _mktab(int p_level) {

	String tb;
	for(int i=0;i<p_level;i++) {
		tb+="\t";
	}

	return tb;
}

static String _typestr(SL::DataType p_type) {

	return ShaderLanguage::get_datatype_name(p_type);

	return "";
}


static String _prestr(SL::DataPrecision p_pres) {


	switch(p_pres) {
		case SL::PRECISION_LOWP: return "lowp ";
		case SL::PRECISION_MEDIUMP: return "mediump ";
		case SL::PRECISION_HIGHP: return "highp ";
		case SL::PRECISION_DEFAULT: return "";
	}
	return "";
}


static String _opstr(SL::Operator p_op) {

	return ShaderLanguage::get_operator_text(p_op);


}


static String get_constant_text(SL::DataType p_type, const Vector<SL::ConstantNode::Value>& p_values) {

	switch(p_type) {
		case SL::TYPE_BOOL:  return p_values[0].boolean?"true":"false";
		case SL::TYPE_BVEC2:  return String()+"bvec2("+(p_values[0].boolean?"true":"false")+(p_values[1].boolean?"true":"false")+")";
		case SL::TYPE_BVEC3:  return String()+"bvec3("+(p_values[0].boolean?"true":"false")+","+(p_values[1].boolean?"true":"false")+","+(p_values[2].boolean?"true":"false")+")";
		case SL::TYPE_BVEC4:  return String()+"bvec4("+(p_values[0].boolean?"true":"false")+","+(p_values[1].boolean?"true":"false")+","+(p_values[2].boolean?"true":"false")+","+(p_values[3].boolean?"true":"false")+")";
		case SL::TYPE_INT:  return rtos(p_values[0].sint);
		case SL::TYPE_IVEC2:  return String()+"ivec2("+rtos(p_values[0].sint)+","+rtos(p_values[1].sint)+")";
		case SL::TYPE_IVEC3:  return String()+"ivec3("+rtos(p_values[0].sint)+","+rtos(p_values[1].sint)+","+rtos(p_values[2].sint)+")";
		case SL::TYPE_IVEC4:  return String()+"ivec4("+rtos(p_values[0].sint)+","+rtos(p_values[1].sint)+","+rtos(p_values[2].sint)+","+rtos(p_values[3].sint)+")";
		case SL::TYPE_UINT:  return rtos(p_values[0].real);
		case SL::TYPE_UVEC2:  return String()+"uvec2("+rtos(p_values[0].real)+","+rtos(p_values[1].real)+")";
		case SL::TYPE_UVEC3:  return String()+"uvec3("+rtos(p_values[0].real)+","+rtos(p_values[1].real)+","+rtos(p_values[2].real)+")";
		case SL::TYPE_UVEC4:  return String()+"uvec4("+rtos(p_values[0].real)+","+rtos(p_values[1].real)+","+rtos(p_values[2].real)+","+rtos(p_values[3].real)+")";
		case SL::TYPE_FLOAT:  return rtos(p_values[0].real);
		case SL::TYPE_VEC2:  return String()+"vec2("+rtos(p_values[0].real)+","+rtos(p_values[1].real)+")";
		case SL::TYPE_VEC3:  return String()+"vec3("+rtos(p_values[0].real)+","+rtos(p_values[1].real)+","+rtos(p_values[2].real)+")";
		case SL::TYPE_VEC4:  return String()+"vec4("+rtos(p_values[0].real)+","+rtos(p_values[1].real)+","+rtos(p_values[2].real)+","+rtos(p_values[3].real)+")";
		default: ERR_FAIL_V(String());
	}
}

static String dump_node_code(SL::Node *p_node,int p_level) {

	String code;

	switch(p_node->type) {

		case SL::Node::TYPE_SHADER: {

			SL::ShaderNode *pnode=(SL::ShaderNode*)p_node;

			for(Map<StringName,SL::ShaderNode::Uniform>::Element *E=pnode->uniforms.front();E;E=E->next()) {

				String ucode="uniform ";
				ucode+=_prestr(E->get().precission);
				ucode+=_typestr(E->get().type);
				ucode+=" "+String(E->key());

				if (E->get().default_value.size()) {
					ucode+=" = "+get_constant_text(E->get().type,E->get().default_value);
				}

				static const char*hint_name[SL::ShaderNode::Uniform::HINT_MAX]={
					"",
					"color",
					"range",
					"albedo",
					"normal",
					"black",
					"white"
				};

				if (E->get().hint)
					ucode+=" : "+String(hint_name[E->get().hint]);

				code+=ucode+"\n";

			}

			for(Map<StringName,SL::ShaderNode::Varying>::Element *E=pnode->varyings.front();E;E=E->next()) {

				String vcode="varying ";
				vcode+=_prestr(E->get().precission);
				vcode+=_typestr(E->get().type);
				vcode+=" "+String(E->key());

				code+=vcode+"\n";

			}
			for(int i=0;i<pnode->functions.size();i++) {

				SL::FunctionNode *fnode=pnode->functions[i].function;

				String header;
				header=_typestr(fnode->return_type)+" "+fnode->name+"(";
				for(int i=0;i<fnode->arguments.size();i++) {

					if (i>0)
						header+=", ";
					header+=_prestr(fnode->arguments[i].precision)+_typestr(fnode->arguments[i].type)+" "+fnode->arguments[i].name;
				}

				header+=")\n";
				code+=header;
				code+=dump_node_code(fnode->body,p_level+1);
			}

			//code+=dump_node_code(pnode->body,p_level);
		} break;
		case SL::Node::TYPE_FUNCTION: {

		} break;
		case SL::Node::TYPE_BLOCK: {
			SL::BlockNode *bnode=(SL::BlockNode*)p_node;

			//variables
			code+=_mktab(p_level-1)+"{\n";
			for(Map<StringName,SL::BlockNode::Variable>::Element *E=bnode->variables.front();E;E=E->next()) {

				code+=_mktab(p_level)+_prestr(E->get().precision)+_typestr(E->get().type)+" "+E->key()+";\n";
			}

			for(int i=0;i<bnode->statements.size();i++) {

				String scode = dump_node_code(bnode->statements[i],p_level);

				if (bnode->statements[i]->type==SL::Node::TYPE_CONTROL_FLOW || bnode->statements[i]->type==SL::Node::TYPE_CONTROL_FLOW) {
					code+=scode; //use directly
				} else {
					code+=_mktab(p_level)+scode+";\n";
				}
			}
			code+=_mktab(p_level-1)+"}\n";


		} break;
		case SL::Node::TYPE_VARIABLE: {
			SL::VariableNode *vnode=(SL::VariableNode*)p_node;
			code=vnode->name;

		} break;
		case SL::Node::TYPE_CONSTANT: {
			SL::ConstantNode *cnode=(SL::ConstantNode*)p_node;
			return get_constant_text(cnode->datatype,cnode->values);

		} break;
		case SL::Node::TYPE_OPERATOR: {
			SL::OperatorNode *onode=(SL::OperatorNode*)p_node;


			switch(onode->op) {

				case SL::OP_ASSIGN:
				case SL::OP_ASSIGN_ADD:
				case SL::OP_ASSIGN_SUB:
				case SL::OP_ASSIGN_MUL:
				case SL::OP_ASSIGN_DIV:
				case SL::OP_ASSIGN_SHIFT_LEFT:
				case SL::OP_ASSIGN_SHIFT_RIGHT:
				case SL::OP_ASSIGN_MOD:
				case SL::OP_ASSIGN_BIT_AND:
				case SL::OP_ASSIGN_BIT_OR:
				case SL::OP_ASSIGN_BIT_XOR:
					code=dump_node_code(onode->arguments[0],p_level)+_opstr(onode->op)+dump_node_code(onode->arguments[1],p_level);
					break;
				case SL::OP_BIT_INVERT:
				case SL::OP_NEGATE:
				case SL::OP_NOT:
				case SL::OP_DECREMENT:
				case SL::OP_INCREMENT:
					code=_opstr(onode->op)+dump_node_code(onode->arguments[0],p_level);
					break;
				case SL::OP_POST_DECREMENT:
				case SL::OP_POST_INCREMENT:
					code=dump_node_code(onode->arguments[0],p_level)+_opstr(onode->op);
					break;
				case SL::OP_CALL:
				case SL::OP_CONSTRUCT:
					code=dump_node_code(onode->arguments[0],p_level)+"(";
					for(int i=1;i<onode->arguments.size();i++) {
						if (i>1)
							code+=", ";
						code+=dump_node_code(onode->arguments[i],p_level);
					}
					code+=")";
					break;
				default: {

					code="("+dump_node_code(onode->arguments[0],p_level)+_opstr(onode->op)+dump_node_code(onode->arguments[1],p_level)+")";
					break;

				}
			}

		} break;
		case SL::Node::TYPE_CONTROL_FLOW: {
			SL::ControlFlowNode *cfnode=(SL::ControlFlowNode*)p_node;
			if (cfnode->flow_op==SL::FLOW_OP_IF) {

				code+=_mktab(p_level)+"if ("+dump_node_code(cfnode->expressions[0],p_level)+")\n";
				code+=dump_node_code(cfnode->blocks[0],p_level+1);
				if (cfnode->blocks.size()==2) {

					code+=_mktab(p_level)+"else\n";
					code+=dump_node_code(cfnode->blocks[1],p_level+1);
				}


			} else if (cfnode->flow_op==SL::FLOW_OP_RETURN) {

				if (cfnode->blocks.size()) {
					code="return "+dump_node_code(cfnode->blocks[0],p_level);
				} else {
					code="return";
				}
			}

		} break;
		case SL::Node::TYPE_MEMBER: {
			SL::MemberNode *mnode=(SL::MemberNode*)p_node;
			code=dump_node_code(mnode->owner,p_level)+"."+mnode->name;

		} break;
	}

	return code;

}

static Error recreate_code(void *p_str,SL::ShaderNode *p_program) {


	String *str=(String*)p_str;

	*str=dump_node_code(p_program,0);

	return OK;
}


MainLoop* test() {

	List<String> cmdlargs = OS::get_singleton()->get_cmdline_args();

	if (cmdlargs.empty()) {
		//try editor!
		print_line("usage: godot -test shader_lang <shader>");
		return NULL;
	}

	String test = cmdlargs.back()->get();

	FileAccess *fa = FileAccess::open(test,FileAccess::READ);

	if (!fa) {
		ERR_FAIL_V(NULL);
	}

	String code;

	while(true) {
		CharType c = fa->get_8();
		if (fa->eof_reached())
			break;
		code+=c;
	}

	SL sl;
	print_line("tokens:\n\n"+sl.token_debug(code));

	Map<StringName,Map<StringName,SL::DataType> > dt;
	dt["fragment"]["ALBEDO"]=SL::TYPE_VEC3;

	Set<String> rm;
	rm.insert("popo");

	Error err = sl.compile(code,dt,rm);

	if (err) {

		print_line("Error at line: "+rtos(sl.get_error_line())+": "+sl.get_error_text());
		return NULL;
	} else {
		String code;
		recreate_code(&code,sl.get_shader());
		print_line("code:\n\n"+code);
	}

	return NULL;
}


}