/*************************************************/
/*  image_loader_jpg.cpp                         */
/*************************************************/
/*            This file is part of:              */
/*                GODOT ENGINE                   */
/*************************************************/
/*       Source code within this file is:        */
/*  (c) 2007-2016 Juan Linietsky, Ariel Manzur   */
/*             All Rights Reserved.              */
/*************************************************/

#include "bitmap_loader_pnm.h"
#include "os/file_access.h"
#include "scene/resources/bit_mask.h"


static bool _get_token(FileAccessRef& f,uint8_t &saved,DVector<uint8_t>& r_token,bool p_binary=false,bool p_single_chunk=false) {


	int token_max = r_token.size();
	DVector<uint8_t>::Write w;
	if (token_max)
		w=r_token.write();
	int ofs=0;
	bool lf=false;


	while(true) {

		uint8_t b;
		if (saved) {
			b=saved;
			saved=0;
		} else {
			b = f->get_8();
		}
		if (f->eof_reached()) {
			if (ofs) {
				w=DVector<uint8_t>::Write();
				r_token.resize(ofs);
				return true;
			} else {
				return false;
			}
		}

		if (!ofs && !p_binary && b=='#') {
			//skip comment
			while(b!='\n') {
				if (f->eof_reached()) {
					return false;
				}

				b = f->get_8();
			}

			lf=true;

		} else if (b<=32 && !(p_binary && (ofs || lf))) {

			if (b=='\n') {
				lf=true;
			}


			if (ofs && !p_single_chunk) {
				w=DVector<uint8_t>::Write();
				r_token.resize(ofs);
				saved=b;

				return true;
			}
		} else {

			bool resized=false;
			while (ofs>=token_max) {
				if (token_max)
					token_max<<=1;
				else
					token_max=1;
				resized=true;
			}
			if (resized) {
				w=DVector<uint8_t>::Write();
				r_token.resize(token_max);
				w=r_token.write();
			}
			w[ofs++]=b;
		}
	}

	return false;
}

static int _get_number_from_token(DVector<uint8_t>& r_token) {

	int len = r_token.size();
	DVector<uint8_t>::Read r = r_token.read();
	return String::to_int((const char*)r.ptr(),len);

}


RES ResourceFormatPBM::load(const String &p_path,const String& p_original_path,Error *r_error) {

#define _RETURN(m_err)\
{\
	if (r_error)\
		*r_error=m_err;\
	ERR_FAIL_V(RES());\
}


	FileAccessRef f=FileAccess::open(p_path,FileAccess::READ);
	uint8_t saved=0;
	if (!f)
		_RETURN(ERR_CANT_OPEN);

	DVector<uint8_t> token;

	if (!_get_token(f,saved,token)) {
		_RETURN(ERR_PARSE_ERROR);
	}

	if (token.size()!=2) {
		_RETURN(ERR_FILE_CORRUPT);
	}
	if (token[0]!='P') {
		_RETURN(ERR_FILE_CORRUPT);
	}
	if (token[1]!='1' && token[1]!='4') {
		_RETURN(ERR_FILE_CORRUPT);
	}

	bool bits = token[1]=='4';

	if (!_get_token(f,saved,token)) {
		_RETURN(ERR_PARSE_ERROR);
	}

	int width = _get_number_from_token(token);
	if (width<=0) {
		_RETURN(ERR_FILE_CORRUPT);
	}


	if (!_get_token(f,saved,token)) {
		_RETURN(ERR_PARSE_ERROR);
	}

	int height = _get_number_from_token(token);
	if (height<=0) {
		_RETURN(ERR_FILE_CORRUPT);
	}


	Ref<BitMap> bm;
	bm.instance();
	bm->create(Size2i(width,height));

	if (!bits) {

		int required_bytes = width*height;
		if (!_get_token(f,saved,token,false,true)) {
			_RETURN(ERR_PARSE_ERROR);
		}

		if (token.size()<required_bytes) {
			_RETURN(ERR_FILE_CORRUPT);
		}

		DVector<uint8_t>::Read r=token.read();

		for(int i=0;i<height;i++) {
			for(int j=0;j<width;j++) {


				char num = r[i*width+j];
				bm->set_bit(Point2i(j,i),num=='0');
			}

		}



	} else {
		//a single, entire token of bits!
		if (!_get_token(f,saved,token,true)) {
			_RETURN(ERR_PARSE_ERROR);
		}
		int required_bytes = Math::ceil((width*height)/8.0);
		if (token.size()<required_bytes) {
			_RETURN(ERR_FILE_CORRUPT);
		}

		DVector<uint8_t>::Read r=token.read();

		for(int i=0;i<height;i++) {
			for(int j=0;j<width;j++) {

				int ofs = width*i+j;

				uint8_t byte = r[ofs/8];
				bool bit = (byte>>(7-(ofs%8)))&1;

				bm->set_bit(Point2i(j,i),!bit);

			}

		}

	}

	return bm;


}

void ResourceFormatPBM::get_recognized_extensions(List<String> *p_extensions) const {
	p_extensions->push_back("pbm");
}
bool ResourceFormatPBM::handles_type(const String& p_type) const {
	return p_type=="BitMap";
}
String ResourceFormatPBM::get_resource_type(const String &p_path) const {

	if (p_path.extension().to_lower()=="pbm")
		return "BitMap";
	return "";
}