/*
   client/video.cc
   This file is part of the Osirion project and is distributed under 
   the terms and conditions of the GNU General Public License version 2 
*/

#include <fstream>
#include <sstream>

#include "client/video.h"
#include "client/view.h"
#include "render/render.h"
#include "core/core.h"
#include "filesystem/filesystem.h"
#include "sys/sys.h"

#include <SDL/SDL.h>

using namespace render;

namespace client {

namespace video {

int width =  0;
int height = 0;

int width_prev = 0;
int height_prev = 0;

const int width_default = 1024;
const int height_default = 768;

float aspect = 1;

//--- cvars -------------------------------------------------------

core::Cvar *r_width;
core::Cvar *r_height;
core::Cvar *r_fullscreen;

void reset()
{
	// recalculate the video aspect
	aspect = (float) width / (float) height;

	// settup our viewport.
	gl::viewport(0, 0, width, height );

	// reset the view
	view::reset();
}

bool init() 
{
	con_print << "Initializing video..." << std::endl;

	// initialize cvars
	r_width = core::Cvar::get("r_width", width_default, core::Cvar::Archive);
	r_height = core::Cvar::get("r_height", height_default, core::Cvar::Archive);
	r_fullscreen = core::Cvar::get("r_fullscreen", "0", core::Cvar::Archive);

	int bpp = 0;
	int flags = 0;

	if( SDL_InitSubSystem(SDL_INIT_VIDEO) < 0 ) {
		con_error << "SDL_InitSubSystem() failed: " << SDL_GetError() << std::endl;
		return false;
	}

	const SDL_VideoInfo* sdl_videoinfo = SDL_GetVideoInfo();
	if( !sdl_videoinfo) {
		con_error << "SDL_GetVideoInfo() failed: " << SDL_GetError() << std::endl;
		return false;
	}

	width_prev = width;
	height_prev = height;
	width = (int) r_width->value();
	height = (int) r_height->value();

	bpp = sdl_videoinfo->vfmt->BitsPerPixel;

	SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 5 );
	SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 5 );
	SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 5 );
	SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 );
	SDL_GL_SetAttribute( SDL_GL_ALPHA_SIZE, 2);
	SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );

	if (r_fullscreen->value()) flags = SDL_OPENGL | SDL_FULLSCREEN;
	else flags = SDL_OPENGL;

	if(!SDL_SetVideoMode(width, height, bpp, flags )) {
		con_warn << "Failed to set video mode " << width << "x" << height << "x" << bpp << "bpp" << std::endl;
		if (width_prev && height_prev) {
			width = width_prev;
			height = height_prev;
			if(!SDL_SetVideoMode(width, height, bpp, flags )) {
				con_error << "Failed to restore video mode " << width << "x" << height << "x" << bpp << "bpp" << std::endl;
				return false;
			}
		} else
			return false;
	}
	con_print << "  video mode " << width << "x" << height << "x" << bpp << "bpp" << std::endl;
	
	aspect = (float) width / (float) height;
	(*r_width) = width;
	(*r_height) = height;

	std::string version(core::name());
	version += ' ';
	version.append(core::version());
	SDL_WM_SetCaption(version.c_str(), 0);

	render::init();

	video::reset();	
	
	view::init();

	return true;
}

void frame(float seconds)
{
	// render a client frame
	view::frame(seconds);
	
	SDL_GL_SwapBuffers();
}

void shutdown()
{
	con_print << "Shutting down video..." << std::endl;
	
	view::shutdown();

	render::shutdown();

	width = 0;
	height = 0;

	SDL_QuitSubSystem(SDL_INIT_VIDEO);
}

void screenshot()
{
        int number = 0;
        bool available = false;
	std::string shortname;
	std::string filename;

	// make sure the screenshots folder exists
	filename.assign(filesystem::writedir);
	filename.append("screenshots/");
	sys::mkdir(filename);

        // find the first available screenshotxxx.tga
        do {
		std::stringstream nstr;
		nstr << number;
		shortname.assign(nstr.str());

		while(shortname.size() < 3)
			shortname.insert(0, 1, '0');
		
                shortname.insert(0, "screenshots/osirion");
		shortname.append(".tga");

		filename.assign(filesystem::writedir);
		filename.append(shortname);

                FILE *handle = fopen(filename.c_str(), "r");
                if (handle) {
                        fclose(handle);
                        number++;
                } else {
                        available = true;
                }
        } while (!available);

        std::ofstream ofs(filename.c_str());

        if (!ofs.is_open()) {
                con_warn << "Could not write " << shortname << std::endl;
                return;
        }

	// TGA header
	// TODO: RL-encoding, image ID 

	// note: see http://www.fileformat.info/format/tga/egff.htm
	unsigned char header[18];
	memset(header, 0, sizeof(header));
	
	// byte 0 	- image ID field lenght		= 0 (no image ID field present)
	// byte 1 	- color map type 		= 0 (no palette present)
	// byte 2 	- image type 			= 2 (truecolor without RLE)
	header[2] = 2;
	// byte 3-11	- palette data (not used)
	// byte 12+13	- image width
	header[12] = (video::width & 0xff);
	header[13] = ((video::width >> 8) & 0xff);
	// byte 14+15	- image height
	header[14] = (video::height & 0xff);
	header[15] = ((video::height >> 8) & 0xff);
	// byte 16	- image color depth		= 24 (RGB)
	header[16] = 24;
	// byte 17	- image descriptor byte
	header[17] = 0;

        // allocate buffer to hold the RGB data
        unsigned char *rgb_data = (unsigned char *) malloc(video::width * video::height * 3);
	
	// read OpenGL pixels into the buffer
	//glReadBuffer(GL_FRONT);
	glReadPixels(0, 0, (GLsizei) video::width, (GLsizei) video::height, GL_RGB, GL_UNSIGNED_BYTE, (void *) rgb_data);

	// either OpenGL actually returns BGR, or TGA wants BGR
	for (size_t i = 0; i < (size_t) (video::width * video::height); i++) {
		unsigned char tmp = rgb_data[i*3];
		rgb_data[i*3] = rgb_data[i*3+2];
		rgb_data[i*3+2] = tmp;
	}

	ofs.write((char *)header, sizeof(header));
	ofs.write((char *)rgb_data, video::width * video::height * 3 );

	// free the buffer
	free(rgb_data);

        // close file
        ofs.close();

        con_print << "Wrote " << shortname << std::endl;
}


} // namespace video

} // namespace client