/*
Open Asset Import Library (ASSIMP)
----------------------------------------------------------------------

Copyright (c) 2006-2010, ASSIMP Development Team
All rights reserved.

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with or without modification, are permitted provided that the 
following conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
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* Neither the name of the ASSIMP team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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*/

/** @file  STEPFileReader.cpp
 *  @brief Implementation of the STEP file parser, which fills a 
 *     STEP::DB with data read from a file.
 */
#include "AssimpPCH.h"
#include "STEPFileReader.h"
#include "TinyFormatter.h"
#include "fast_atof.h"

using namespace Assimp;
namespace EXPRESS = STEP::EXPRESS;

#include <functional>

// ------------------------------------------------------------------------------------------------
// From http://stackoverflow.com/questions/216823/whats-the-best-way-to-trim-stdstring

// trim from start
static inline std::string &ltrim(std::string &s) {
	s.erase(s.begin(), std::find_if(s.begin(), s.end(), std::not1( std::ptr_fun(Assimp::IsSpace<char>))));
	return s;
}

// trim from end
static inline std::string &rtrim(std::string &s) {
	s.erase(std::find_if(s.rbegin(), s.rend(), std::not1( std::ptr_fun(Assimp::IsSpace<char>))).base(),s.end());
	return s;
}
// trim from both ends
static inline std::string &trim(std::string &s) {
	return ltrim(rtrim(s));
}




// ------------------------------------------------------------------------------------------------
std::string AddLineNumber(const std::string& s,uint64_t line /*= LINE_NOT_SPECIFIED*/, const std::string& prefix = "") 
{
	return line == STEP::SyntaxError::LINE_NOT_SPECIFIED ? prefix+s : static_cast<std::string>( (Formatter::format(),prefix,"(line ",line,") ",s) );
}


// ------------------------------------------------------------------------------------------------
std::string AddEntityID(const std::string& s,uint64_t entity /*= ENTITY_NOT_SPECIFIED*/, const std::string& prefix = "") 
{
	return entity == STEP::TypeError::ENTITY_NOT_SPECIFIED ? prefix+s : static_cast<std::string>( (Formatter::format(),prefix,"(entity #",entity,") ",s));
}


// ------------------------------------------------------------------------------------------------
STEP::SyntaxError::SyntaxError (const std::string& s,uint64_t line /* = LINE_NOT_SPECIFIED */)
: DeadlyImportError(AddLineNumber(s,line))
{

}

// ------------------------------------------------------------------------------------------------
STEP::TypeError::TypeError (const std::string& s,uint64_t entity /* = ENTITY_NOT_SPECIFIED */,uint64_t line /*= LINE_NOT_SPECIFIED*/)
: DeadlyImportError(AddLineNumber(AddEntityID(s,entity),line))
{

}


// ------------------------------------------------------------------------------------------------
STEP::DB* STEP::ReadFileHeader(boost::shared_ptr<IOStream> stream)
{
	boost::shared_ptr<StreamReaderLE> reader = boost::shared_ptr<StreamReaderLE>(new StreamReaderLE(stream));
	std::auto_ptr<STEP::DB> db = std::auto_ptr<STEP::DB>(new STEP::DB(reader));

	LineSplitter& splitter = db->GetSplitter();
	if (!splitter || *splitter != "ISO-10303-21;") {
		throw STEP::SyntaxError("expected magic token: ISO-10303-21",1);
	}

	HeaderInfo& head = db->GetHeader();
	for(++splitter; splitter; ++splitter) {
		const std::string& s = *splitter;
		if (s == "DATA;") {
			// here we go, header done, start of data section
			++splitter;
			break;
		}

		// want one-based line numbers for human readers, so +1
		const uint64_t line = splitter.get_index()+1;

		if (s.substr(0,11) == "FILE_SCHEMA") {
			const char* sz = s.c_str()+11;
			SkipSpaces(sz,&sz);
			boost::shared_ptr< const EXPRESS::DataType > schema = EXPRESS::DataType::Parse(sz);

			// the file schema should be a regular list entity, although it usually contains exactly one entry
			// since the list itself is contained in a regular parameter list, we actually have
			// two nested lists.
			const EXPRESS::LIST* list = dynamic_cast<const EXPRESS::LIST*>(schema.get());
			if (list && list->GetSize()) {
				list = dynamic_cast<const EXPRESS::LIST*>( (*list)[0].get() );
				if (!list) {
					throw STEP::SyntaxError("expected FILE_SCHEMA to be a list",line);
				}

				// XXX need support for multiple schemas?
				if (list->GetSize() > 1)	{
					DefaultLogger::get()->warn(AddLineNumber("multiple schemas currently not supported",line));
				}
				const EXPRESS::STRING* string;
				if (!list->GetSize() || !(string=dynamic_cast<const EXPRESS::STRING*>( (*list)[0].get() ))) {
					throw STEP::SyntaxError("expected FILE_SCHEMA to contain a single string literal",line);
				}
				head.fileSchema =  *string;
			}
		}

		// XXX handle more header fields
	}

	return db.release();
}


// ------------------------------------------------------------------------------------------------
void STEP::ReadFile(DB& db,const EXPRESS::ConversionSchema& scheme,
	const char* const* types_to_track, size_t len,
	const char* const* inverse_indices_to_track, size_t len2)
{
	db.SetSchema(scheme);
	db.SetTypesToTrack(types_to_track,len);
	db.SetInverseIndicesToTrack(inverse_indices_to_track,len2);

	const DB::ObjectMap& map = db.GetObjects();
	LineSplitter& splitter = db.GetSplitter();
	for(; splitter; ++splitter) {
		const std::string& s = *splitter;
		if (s == "ENDSEC;") {
			break;
		}

		// want one-based line numbers for human readers, so +1
		const uint64_t line = splitter.get_index()+1;

		// LineSplitter already ignores empty lines
		ai_assert(s.length());
		if (s[0] != '#') {
			DefaultLogger::get()->warn(AddLineNumber("expected token \'#\'",line));
			continue;
		}

		// ---
		// extract id, entity class name and argument string,
		// but don't create the actual object yet. 
		// ---

		const std::string::size_type n0 = s.find_first_of('=');
		if (n0 == std::string::npos) {
			DefaultLogger::get()->warn(AddLineNumber("expected token \'=\'",line));
			continue;
		}

		const uint64_t id = strtoul10_64(s.substr(1,n0-1).c_str());
		if (!id) {
			DefaultLogger::get()->warn(AddLineNumber("expected positive, numeric entity id",line));
			continue;
		}

		const std::string::size_type n1 = s.find_first_of('(',n0);
		if (n1 == std::string::npos) {
			DefaultLogger::get()->warn(AddLineNumber("expected token \'(\'",line));
			continue;
		}

		const std::string::size_type n2 = s.find_last_of(')');
		if (n2 == std::string::npos || n2 < n1) {
			DefaultLogger::get()->warn(AddLineNumber("expected token \')\'",line));
			continue;
		}

		if (map.find(id) != map.end()) {
			DefaultLogger::get()->warn(AddLineNumber((Formatter::format(),"an object with the id #",id," already exists"),line));
		}

		std::string::size_type ns = n0;
		do ++ns; while( IsSpace(s.at(ns)));

		std::string::size_type ne = n1;
		do --ne; while( IsSpace(s.at(ne)));

		std::string type = s.substr(ns,ne-ns+1);
		std::transform( type.begin(), type.end(), type.begin(), &Assimp::ToLower<char>  );

		const char* sz = scheme.GetStaticStringForToken(type);
		if(sz) {
		
			const std::string::size_type len = n2-n1+1;
			char* const copysz = new char[len+1];
			std::copy(s.c_str()+n1,s.c_str()+n2+1,copysz);
			copysz[len] = '\0';

			db.InternInsert(new LazyObject(db,id,line,sz,copysz));
		}
	}

	if (!splitter) {
		DefaultLogger::get()->warn("STEP: ignoring unexpected EOF");
	}

	if ( !DefaultLogger::isNullLogger() ){
		DefaultLogger::get()->debug((Formatter::format(),"STEP: got ",map.size()," object records with ",
			db.GetRefs().size()," inverse index entries"));
	}
}


// ------------------------------------------------------------------------------------------------
boost::shared_ptr<const EXPRESS::DataType> EXPRESS::DataType::Parse(const char*& inout,uint64_t line, const EXPRESS::ConversionSchema* schema /*= NULL*/)
{
	const char* cur = inout;
	SkipSpaces(&cur);

	if (*cur == ',' || IsSpaceOrNewLine(*cur)) {
		throw STEP::SyntaxError("unexpected token, expected parameter",line);
	}

	// just skip over constructions such as IFCPLANEANGLEMEASURE(0.01) and read only the value
	if (schema) {
		bool ok = false;
		for(const char* t = cur; *t && *t != ')' && *t != ','; ++t) {
			if (*t=='(') {
				if (!ok) {
					break;
				}
				for(--t;IsSpace(*t);--t);
				std::string s(cur,static_cast<size_t>(t-cur+1));
				std::transform(s.begin(),s.end(),s.begin(),&ToLower<char> );
				if (schema->IsKnownToken(s)) {
					for(cur = t+1;*cur++ != '(';);
					const boost::shared_ptr<const EXPRESS::DataType> dt = Parse(cur);
					inout = *cur ? cur+1 : cur;
					return dt;
				}
				break;
			}
			else if (!IsSpace(*t)) {
				ok = true;
			}
		}
	}

	if (*cur == '*' ) {
		inout = cur+1;
		return boost::make_shared<EXPRESS::ISDERIVED>();
	}
	else if (*cur == '$' ) {
		inout = cur+1;
		return boost::make_shared<EXPRESS::UNSET>();
	}
	else if (*cur == '(' ) {
		// start of an aggregate, further parsing is done by the LIST factory constructor
		inout = cur;
		return EXPRESS::LIST::Parse(inout,line,schema);
	}
	else if (*cur == '.' ) {
		// enum (includes boolean)
		const char* start = ++cur;
		for(;*cur != '.';++cur) {
			if (*cur == '\0') {
				throw STEP::SyntaxError("enum not closed",line);
			}
		}
		inout = cur+1;
		return boost::make_shared<EXPRESS::ENUMERATION>(std::string(start, static_cast<size_t>(cur-start) ));
	}
	else if (*cur == '#' ) {
		// object reference
		return boost::make_shared<EXPRESS::ENTITY>(strtoul10_64(++cur,&inout));
	}
	else if (*cur == '\'' ) {
		// string literal
		const char* start = ++cur;
		for(;*cur != '\'';++cur) {
			if (*cur == '\0') {
				throw STEP::SyntaxError("string literal not closed",line);
			}
		}
		if (cur[1]=='\'') {
			for(cur+=2;*cur != '\'';++cur) {
				if (*cur == '\0') {
					throw STEP::SyntaxError("string literal not closed",line);
				}
			}
		}
		inout = cur+1;
		return boost::make_shared<EXPRESS::STRING>(std::string(start, static_cast<size_t>(cur-start) ));
	}
	else if (*cur == '\"' ) {
		throw STEP::SyntaxError("binary data not supported yet",line);
	}

	// else -- must be a number. if there is a decimal dot in it,
	// parse it as real value, otherwise as integer.
	const char* start = cur;
	for(;*cur  && *cur != ',' && *cur != ')' && !IsSpace(*cur);++cur) {
		if (*cur == '.') {
			// XXX many STEP files contain extremely accurate data, float's precision may not suffice in many cases
			float f;
			inout = fast_atof_move(start,f);
			return boost::make_shared<EXPRESS::REAL>(f);
		}
	}

	bool neg = false;
	if (*start == '-') {
		neg = true;
		++start;
	}
	else if (*start == '+') {
		++start;
	}
	int64_t num = static_cast<int64_t>( strtoul10_64(start,&inout) );
	return boost::make_shared<EXPRESS::INTEGER>(neg?-num:num);
}


// ------------------------------------------------------------------------------------------------
boost::shared_ptr<const EXPRESS::LIST> EXPRESS::LIST::Parse(const char*& inout,uint64_t line, const EXPRESS::ConversionSchema* schema /*= NULL*/)
{
	const boost::shared_ptr<EXPRESS::LIST> list = boost::make_shared<EXPRESS::LIST>();
	EXPRESS::LIST::MemberList& members = list->members;

	const char* cur = inout;
	if (*cur++ != '(') {
		throw STEP::SyntaxError("unexpected token, expected \'(\' token at beginning of list",line);
	}

	// estimate the number of items upfront - lists can grow large
	size_t count = 1;
	for(const char* c=cur; *c && *c != ')'; ++c) {
		count += (*c == ',' ? 1 : 0);
	}

	members.reserve(count);

	for(;;++cur) {
		if (!*cur) {
			throw STEP::SyntaxError("unexpected end of line while reading list");
		}
		SkipSpaces(cur,&cur);
		if (*cur == ')') {
			break;
		}
		
		members.push_back( EXPRESS::DataType::Parse(cur,line,schema));
		SkipSpaces(cur,&cur);

		if (*cur != ',') {
			if (*cur == ')') {
				break;
			}
			throw STEP::SyntaxError("unexpected token, expected \',\' or \')\' token after list element",line);
		}
	}

	inout = cur+1;
	return list;
}


// ------------------------------------------------------------------------------------------------
STEP::LazyObject::LazyObject(DB& db, uint64_t id,uint64_t /*line*/, const char* const type,const char* args)
	: id(id)
	, type(type)
	, db(db)
	, args(args)
	, obj()
{
	// find any external references and store them in the database.
	// this helps us emulate STEPs INVERSE fields.
	if (db.KeepInverseIndicesForType(type)) {
		const char* a  = args;
	
		// do a quick scan through the argument tuple and watch out for entity references
		int64_t skip_depth = 0;
		while(*a) {
			if (*a == '(') {
				++skip_depth;
			}
			else if (*a == ')') {
				--skip_depth;
			}

			if (skip_depth == 1 && *a=='#') {
				const char* tmp;
				const int64_t num = static_cast<int64_t>( strtoul10_64(a+1,&tmp) );
				db.MarkRef(num,id);
			}
			++a;
		}

	}
}

// ------------------------------------------------------------------------------------------------
STEP::LazyObject::~LazyObject() 
{
	// make sure the right dtor/operator delete get called
	if (obj) {
		delete obj;
	}
	else delete[] args;
}

// ------------------------------------------------------------------------------------------------
void STEP::LazyObject::LazyInit() const
{
	const EXPRESS::ConversionSchema& schema = db.GetSchema();
	STEP::ConvertObjectProc proc = schema.GetConverterProc(type);

	if (!proc) {
		throw STEP::TypeError("unknown object type: " + std::string(type),id);
	}

	const char* acopy = args;
	boost::shared_ptr<const EXPRESS::LIST> conv_args = EXPRESS::LIST::Parse(acopy,STEP::SyntaxError::LINE_NOT_SPECIFIED,&db.GetSchema());
	delete[] args;
	args = NULL;

	// if the converter fails, it should throw an exception, but it should never return NULL
	try {
		obj = proc(db,*conv_args);
	}
	catch(const TypeError& t) {
		// augment line and entity information
		throw TypeError(t.what(),id);
	}
	++db.evaluated_count;
	ai_assert(obj);

	// store the original id in the object instance
	obj->SetID(id);
}

