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

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  following disclaimer.

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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 == '.') {
			float f;
			inout = fast_atoreal_move<float>(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);
}

