/*************************************************************************/
/*  resource_saver_png.cpp                                               */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* 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    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
/*************************************************************************/
#include "resource_saver_png.h"

#include "core/image.h"
#include "globals.h"
#include "os/file_access.h"
#include "scene/resources/texture.h"

#include <png.h>

static void _write_png_data(png_structp png_ptr,png_bytep data, png_size_t p_length) {

	FileAccess *f = (FileAccess*)png_get_io_ptr(png_ptr);
	f->store_buffer( (const uint8_t*)data,p_length);
}

Error ResourceSaverPNG::save(const String &p_path,const RES& p_resource,uint32_t p_flags) {

	Ref<ImageTexture> texture=p_resource;

	ERR_FAIL_COND_V(!texture.is_valid(),ERR_INVALID_PARAMETER);
	ERR_EXPLAIN("Can't save empty texture as PNG");
	ERR_FAIL_COND_V(!texture->get_width() || !texture->get_height(),ERR_INVALID_PARAMETER);


	Image img = texture->get_data();

	Error err = save_image(p_path, img);

	if (err == OK) {

		bool global_filter = Globals::get_singleton()->get("image_loader/filter");
		bool global_mipmaps = Globals::get_singleton()->get("image_loader/gen_mipmaps");
		bool global_repeat = Globals::get_singleton()->get("image_loader/repeat");

		String text;

		if (global_filter!=bool(texture->get_flags()&Texture::FLAG_FILTER)) {
			text+=bool(texture->get_flags()&Texture::FLAG_FILTER)?"filter=true\n":"filter=false\n";
		}
		if (global_mipmaps!=bool(texture->get_flags()&Texture::FLAG_MIPMAPS)) {
			text+=bool(texture->get_flags()&Texture::FLAG_MIPMAPS)?"gen_mipmaps=true\n":"gen_mipmaps=false\n";
		}
		if (global_repeat!=bool(texture->get_flags()&Texture::FLAG_REPEAT)) {
			text+=bool(texture->get_flags()&Texture::FLAG_REPEAT)?"repeat=true\n":"repeat=false\n";
		}
		if (bool(texture->get_flags()&Texture::FLAG_ANISOTROPIC_FILTER)) {
			text+="anisotropic=true\n";
		}
		if (bool(texture->get_flags()&Texture::FLAG_CONVERT_TO_LINEAR)) {
			text+="tolinear=true\n";
		}
		if (bool(texture->get_flags()&Texture::FLAG_MIRRORED_REPEAT)) {
			text+="mirroredrepeat=true\n";
		}

		if (text!="" || FileAccess::exists(p_path+".flags")) {

			FileAccess* f = FileAccess::open(p_path+".flags",FileAccess::WRITE);
			if (f) {

				f->store_string(text);
				memdelete(f);
			}
		}
	}


	return err;
};

Error ResourceSaverPNG::save_image(const String &p_path, Image &p_img) {

	if (p_img.get_format() > Image::FORMAT_INDEXED_ALPHA)
		p_img.decompress();

	ERR_FAIL_COND_V(p_img.get_format() > Image::FORMAT_INDEXED_ALPHA, ERR_INVALID_PARAMETER);

	png_structp png_ptr;
	png_infop info_ptr;
	png_bytep * row_pointers;


	/* initialize stuff */
	png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);

	ERR_FAIL_COND_V(!png_ptr,ERR_CANT_CREATE);

	info_ptr = png_create_info_struct(png_ptr);

	ERR_FAIL_COND_V(!info_ptr,ERR_CANT_CREATE);

	if (setjmp(png_jmpbuf(png_ptr))) {
		ERR_FAIL_V(ERR_CANT_OPEN);
	}
	//change this
	Error err;
	FileAccess* f = FileAccess::open(p_path,FileAccess::WRITE,&err);
	if (err) {
		ERR_FAIL_V(err);
	}

	png_set_write_fn(png_ptr,f,_write_png_data,NULL);

	/* write header */
	if (setjmp(png_jmpbuf(png_ptr))) {
		ERR_FAIL_V(ERR_CANT_OPEN);
	}

	int pngf=0;
	int cs=0;


	switch(p_img.get_format()) {

		case Image::FORMAT_GRAYSCALE: {

			pngf=PNG_COLOR_TYPE_GRAY;
			cs=1;
		} break;
		case Image::FORMAT_GRAYSCALE_ALPHA: {

			pngf=PNG_COLOR_TYPE_GRAY_ALPHA;
			cs=2;
		} break;
		case Image::FORMAT_RGB: {

			pngf=PNG_COLOR_TYPE_RGB;
			cs=3;
		} break;
		case Image::FORMAT_RGBA: {

			pngf=PNG_COLOR_TYPE_RGB_ALPHA;
			cs=4;
		} break;
		default: {

			if (p_img.detect_alpha()) {

				p_img.convert(Image::FORMAT_RGBA);
				pngf=PNG_COLOR_TYPE_RGB_ALPHA;
				cs=4;
			} else {

				p_img.convert(Image::FORMAT_RGB);
				pngf=PNG_COLOR_TYPE_RGB;
				cs=3;
			}

		}
	}

	int w = p_img.get_width();
	int h = p_img.get_height();
	png_set_IHDR(png_ptr, info_ptr, w,h,
		     8, pngf, PNG_INTERLACE_NONE,
		     PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);

	png_write_info(png_ptr, info_ptr);


	/* write bytes */
	if (setjmp(png_jmpbuf(png_ptr))) {
		memdelete(f);
		ERR_FAIL_V(ERR_CANT_OPEN);
	}


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

	row_pointers = (png_bytep*)memalloc(sizeof(png_bytep)*h);
	for(int i=0;i<h;i++) {

		row_pointers[i]=(png_bytep)&r[i*w*cs];
	}
	png_write_image(png_ptr, row_pointers);

	memfree(row_pointers);

	/* end write */
	if (setjmp(png_jmpbuf(png_ptr))) {

		memdelete(f);
		ERR_FAIL_V(ERR_CANT_OPEN);
	}

	png_write_end(png_ptr, NULL);
	memdelete(f);

	/* cleanup heap allocation */
	png_destroy_write_struct(&png_ptr, &info_ptr);

	return OK;
}

bool ResourceSaverPNG::recognize(const RES& p_resource) const {

	return (p_resource.is_valid() && p_resource->is_type("ImageTexture"));
}
void ResourceSaverPNG::get_recognized_extensions(const RES& p_resource,List<String> *p_extensions) const{

	if (p_resource->cast_to<Texture>()) {
		p_extensions->push_back("png");
	}

}

ResourceSaverPNG::ResourceSaverPNG() {

	Image::save_png_func = &save_image;
};