#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>

#include <SFML/System.h>
#include <SFML/Graphics.h>
#include <SFML/Window.h>

#include "config.h"
#include "events.c"
#include "cpu.c"
#include "memory.c"
#include "video.c"
#include "keyboard.c"


sfVertexArray *renderArray;
sfRenderWindow *window;
sfFont *font;
sfText *renderText;
sfRenderStates renderStates;
sfRectangleShape *haltRect;

uint8_t halt = 0;
uint8_t showHelp = 0;
uint8_t showDebug = 0;

int openFile(const char *inputFile){
    FILE *file = fopen(inputFile, "rb");
    int retCode = 0;
    
    if (file != NULL){
        fseek(file, 0, SEEK_END);
        long filelen = ftell(file);
        rewind(file);
        
        if (fread(rom, filelen, 1, file) != 1) retCode = 1;
    } else retCode = 1;
    
    fclose(file);
    
    return retCode;
}

void resetSystem(){
    initVideo();
    updateVideo();
    reset6502();
}

void updateRenderStates(){
    renderStates.transform = sfTransform_Identity;
    sfTransform_scale(&renderStates.transform, displayscale, displayscale);
}

void drawScreen(){
    sfRenderWindow_drawVertexArray(window, renderArray, &renderStates);
    if (halt){
        sfRenderWindow_drawRectangleShape(window, haltRect, &renderStates);
    }
    if (showHelp){
        sfText_setString(renderText, HELPKEYS);
        
        sfRenderWindow_drawText(window, renderText, &renderStates);
    }
}

void writeHelp(int type){
    if (!type)  printf(HELP);
    else        printf(HELPKEYS);
    
    exit(EXIT_SUCCESS);
}

void writePreamble() {
    printf(PREAMBLE);
}

void fetchArgs(int argc, char *argv[]){
    writePreamble();
    
    for (int i = 1; i < argc; i++) {
        if (!strcmp(argv[i], "--help"))                 writeHelp(0);
        else if (!strcmp(argv[i], "--help-keys"))       writeHelp(1);
        else if (!strcmp(argv[i], "--cpuspeed"))        cpuspeed = atoi(argv[++i]);
        else if (!strcmp(argv[i], "--scale"))           displayscale = atof(argv[++i]);
        else if (!strcmp(argv[i], "--singlestep"))      singlestep = 1;
        else if (!strcmp(argv[i], "--clocksteps"))      clocksteps = atoi(argv[++i]);
        //else if (!strcmp(argv[i], "--snapshot"))        snapshotFile = &argv[i];
        
        else {
            if (openFile(argv[i])){
                printf("Unknown parameter or file '%s'\nTry '--help' for help\n", argv[i]);
                exit(EXIT_FAILURE);
            }
        }
    }
}

int main(int argc, char *argv[]){
    fetchArgs(argc, argv);
    
    window = sfRenderWindow_create((sfVideoMode){800, 600, 24}, "LS7 Emulator", sfResize | sfClose, NULL);
    sfRenderWindow_setVerticalSyncEnabled(window, sfFalse);
    sfRenderWindow_setFramerateLimit(window, FPS);
    sfRenderWindow_setKeyRepeatEnabled(window, sfFalse);

    font = sfFont_createFromFile("bin/font.ttf");
    
    renderText = sfText_create();
    sfText_setPosition(renderText, (sfVector2f){ 50, 50 });
    sfText_setFont(renderText, font);
    sfText_setCharacterSize(renderText, 10);
    sfText_setFillColor(renderText, sfWhite);
    sfText_setOutlineColor(renderText, sfBlack);
    sfText_setOutlineThickness(renderText, 1);
    
    haltRect = sfRectangleShape_create();
    sfRectangleShape_setFillColor(haltRect, (sfColor){ 0, 0, 0, 128 });
    sfRectangleShape_setSize(haltRect, (sfVector2f){ 384, 256 });
    
    renderStates = sfRenderStates_default();
    sfTransform_scale(&renderStates.transform, displayscale, displayscale);
    
    resetSystem();

    while (sfRenderWindow_isOpen(window)){
        pollEvents(window);
        
        if (!singlestep && !halt){
            for (int i = 0; i < cpuspeed / FPS; i++) step6502();
            irq6502();
        }
        
        sfRenderWindow_clear(window, BACKCOLOR);
        updateVideo();
        drawScreen();
        sfRenderWindow_display(window);
    }
    
    sfRenderWindow_destroy(window);

    return EXIT_SUCCESS;
}