#include "emul.h"

#include <stdio.h>
#include <stdlib.h>

void emul_init( emul_t *emul, cpu_6502_t *cpu, memory_t *memory )
{
	emul->cpu = cpu;
	emul->memory = memory;
	emul->gui = false;
}

void emul_start( emul_t *emul )
{
	if( emul->gui ) {
#ifdef WITH_GUI
		int rt = SDL_Init( SDL_INIT_TIMER | SDL_INIT_AUDIO | SDL_INIT_VIDEO );
		if( rt < 0 ) {
			fprintf( stderr, "ERROR: SDL_Init failed: %s\n", SDL_GetError( ) );
			exit( EXIT_FAILURE );
		}
		atexit( SDL_Quit );
		SDL_ShowCursor( SDL_ENABLE );
		
		int display = -1;
		for( int i = 0; i < SDL_GetNumVideoDisplays( ); i++ ) {
			SDL_Rect rect;
			if( SDL_GetDisplayBounds( i, &rect ) == 0 ) {
				fprintf( stderr, "INFO: display %d has dimensions %dx%d\n",
					i, rect.w, rect.h );
				display = i;
			} else {
				fprintf( stderr, "ERROR: SDL_GetDisplayBounds failed: %s\n", SDL_GetError( ) );
				exit( EXIT_FAILURE );
			}
		}
		if( display < 0 ) {
			fprintf( stderr, "ERROR: no video display found\n" );
			exit( EXIT_FAILURE );
		}
		
		emul->window = SDL_CreateWindow( "6502 emu",  
			SDL_WINDOWPOS_UNDEFINED_DISPLAY( display ),
			SDL_WINDOWPOS_UNDEFINED_DISPLAY( display ),
			600, 250, 0 );
		if( emul->window == NULL ) {
			fprintf( stderr, "ERROR: SDL_CreateWindow failed: %s\n", SDL_GetError( ) );
			exit( EXIT_FAILURE );
		}

		emul->renderer = SDL_CreateRenderer( emul->window, -1, 0 );
		if( emul->renderer == NULL ) {
			fprintf( stderr, "ERROR: SDL_Renderer failed: %s\n", SDL_GetError( ) );
			exit( EXIT_FAILURE );
		}
		
		SDL_ShowWindow( emul->window );
		SDL_SetRenderDrawColor( emul->renderer, 0, 0, 0, 255 );
		SDL_RenderClear( emul->renderer );
		
		emul->background_image = SDL_LoadBMP( "../other/breadboard.bmp" );
		emul->background_texture = SDL_CreateTextureFromSurface( emul->renderer, emul->background_image );
		SDL_RenderCopy( emul->renderer, emul->background_texture, NULL, NULL );
		
		SDL_RenderPresent( emul->renderer );
#else
		fprintf( stderr, "WARN: gui enabled and not compiled with WITH_GUI (SDL2)\n" );
#endif
	}
}

void emul_run( emul_t *emul )
{
#ifdef WITH_GUI
	if( emul->gui ) {
		SDL_Event event;
		bool done = false;
		while( !done ) {
			uint32_t frame_start = SDL_GetTicks( );
			
			SDL_PollEvent( &event );
			
			switch( event.type ) {
				case SDL_QUIT:
					done = true;
					break;
			}
			
			cpu_6502_run( emul->cpu, CPU_FREQUENCY / DISPLAY_FPS );
			
			cpu_6502_print_state( emul->cpu, 0 );
			SDL_RenderCopy( emul->renderer, emul->background_texture, NULL, NULL );
			SDL_RenderPresent( emul->renderer );

			uint32_t frame_end = SDL_GetTicks( );
			int delay = frame_start + 1000 / DISPLAY_FPS - frame_end;
			if( delay > 0 ) {
				SDL_Delay( delay );
			}
		}
	} else {
		cpu_6502_run( emul->cpu, 100 );
	}
#else
	cpu_6502_run( emul->cpu, 100 );
#endif
}

void emul_free( emul_t *emul )
{
#ifdef WITH_GUI
	if( emul->gui ) {
		SDL_DestroyTexture( emul->background_texture );
		SDL_FreeSurface( emul->background_image );
		SDL_DestroyRenderer( emul->renderer );
		SDL_DestroyWindow( emul->window );
	}
#endif
}