/* CRT SwitchRes Core 
 * Copyright (C) 2018 Ben Templeman.
 *
 * RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2017 - Daniel De Matteis
 *
 *  RetroArch is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
*/
#include <stddef.h>
#include <string.h>
#include <windows.h>
#include <stdlib.h>

#include <gfx/video_driver.h>

#include "video_crt_switch.h"

int first_run;
float fly_aspect;

void switch_res_core(int width, int height, float hz){
	/* ben_core_hz float passed from with in void video_driver_monitor_adjust_system_rates(void) */
		ben_core_width = width;		
		ben_core_height = height;
		ben_core_hz = hz;
		check_first_run();
		
		if (ben_tmp_height != ben_core_height || ben_core_width != ben_tmp_width){ /* detect resolution change and switch */
			screen_setup_aspect(width,height);
		}
		
		if (video_driver_get_aspect_ratio() != fly_aspect){	/* check aspect is correct else change */
				video_driver_set_aspect_ratio_value((float)fly_aspect);
				ben_poke_video();
		}
				

}

void check_first_run(){		/* ruin of first boot to get current display resolution */
	if (first_run != 1){
		orig_height = GetSystemMetrics(SM_CYSCREEN);
		orig_width = GetSystemMetrics(SM_CXSCREEN);
	}
	first_run = 1;
}

void screen_setup_aspect(int width, int height){ /* create correct aspect to fit video if resolution does not exist */
	switch_crt_hz();
	/* get original resolution of core */	
	if (width >= 1900){
		if (height == 4){						/* detect menu only */
			height = 480;
			aspect_ratio_switch(width,height);
		}
		if (height < 191 && height != 144){				
			aspect_ratio_switch(width,height);
			height = 200;
		}	
		if (height > 191){
			aspect_ratio_switch(width,height);
		}
		if (height == 144 && set_ben_core_hz == 50){				
			height = 288;
			aspect_ratio_switch(width,height);
		}
		if (height > 200 && height < 224){				
			aspect_ratio_switch(width,height);
			ben_core_height = 224;
		}
		if (height > 224 && height < 240){				
			aspect_ratio_switch(width,height);
			ben_core_height = 240;
		}
	
		if (height > 240 && height < 255 ){								
			aspect_ratio_switch(width,height);
			ben_core_height = 254;
		}
		if (height == 528 && set_ben_core_hz == 60){								
			aspect_ratio_switch(width,height);
			ben_core_height = 480;
		}
	
		if (height >= 240 && height < 255 && set_ben_core_hz == 55){
			aspect_ratio_switch(width,height);
			ben_core_height = 254;
		}
		
	}
	switch_res_crt(width, height);
}

void switch_res_crt(int width, int height){
		
	if ( height > 100){

			switch_res(width, height,0);
			ben_poke_video();
			ben_tmp_height = ben_core_height;
			ben_tmp_width = ben_core_width;
	
	}
	
}

void aspect_ratio_switch(int width,int height){  /* send aspect float to videeo_driver */
		fly_aspect = (float)width/height;
		video_driver_set_aspect_ratio_value((float)fly_aspect);
}

void switch_crt_hz(){  /* set hz float an int for windows switching */
	
	if (ben_core_hz != ben_tmp_core_hz){
		if (ben_core_hz < 53 ){
			set_ben_core_hz = 50;	
			
		}
		if (ben_core_hz >= 53  &&  ben_core_hz < 57){	
			set_ben_core_hz = 55;	
		}	
		if (ben_core_hz >= 57 ){	
			set_ben_core_hz = 60;	
		}	
		video_monitor_set_refresh_rate(ben_core_hz);
		ben_tmp_core_hz = ben_core_hz;
	}
	
}

void switch_res(int width, int height, int f_restore){  /* windows function to swith resolutions */
	
	DEVMODE curDevmode;
	DEVMODE devmode;
	DWORD flags = 0;
	int     iModeNum;
	int depth = 0;
	int freq;
	if (f_restore == 0){
		freq = set_ben_core_hz;
	} else {
		freq = 0;
	}
	
	EnumDisplaySettings(NULL, ENUM_CURRENT_SETTINGS, &curDevmode);
	
	if (width == curDevmode.dmPelsWidth){
		width  = 0;							/* used to stop superresolution bug */
	}

	if (width == 0) {
		width = curDevmode.dmPelsWidth;
	}
	if (height == 0) {
		height = curDevmode.dmPelsHeight;
	}
	if (depth == 0) {
		depth = curDevmode.dmBitsPerPel;
	}
	if (freq == 0) {
		freq = curDevmode.dmDisplayFrequency;
	}

	for (iModeNum = 0; ; iModeNum++) {
		if (EnumDisplaySettings(NULL, iModeNum, &devmode)) {
		
			if (devmode.dmPelsWidth != width) {
				continue;
			}

			if (devmode.dmPelsHeight != height) {
				continue;
			}

	
			if (devmode.dmBitsPerPel != depth) {
				continue;
			}

	
			if (devmode.dmDisplayFrequency != freq) {
				continue;
			}


			devmode.dmFields |= DM_PELSWIDTH | DM_PELSHEIGHT | DM_BITSPERPEL | DM_DISPLAYFREQUENCY;
			LONG res = ChangeDisplaySettings(&devmode, CDS_TEST);

			switch (res) {
			case DISP_CHANGE_SUCCESSFUL:
				res = ChangeDisplaySettings(&devmode, flags);
				switch (res) {
				case DISP_CHANGE_SUCCESSFUL:
					return;

				case DISP_CHANGE_NOTUPDATED:
			
					return;

				default:
			
					break;
				}
				break;

			case DISP_CHANGE_RESTART:
		
				break;

			default:
			
				break;
			}
		}
		else {
			break;
		}
	}



}

void video_restore(){
	switch_res(orig_width, orig_height,1);
}