// ncurses.c
// Implements interface.h
// Provides an in-terminal interface to the emulator.

#include<ncurses.h>
#include"interface.h"
#include"signetics.c"
#include"../apple.h"
#include"../cpu/6502.h"


int TermX = 0;
int TermY = 0;

WINDOW *AppleWindow;


byte UserInput()
{
	int c = getch();
	byte C;
	
	switch(c)
	{
	// Convert special characters
	case KEY_BACKSPACE:
		C = 0xDF;
	case KEY_ENTER:
		C = 0x8D;
	case KEY_EXIT: //TODO: Figure out if this is Esc or not.
		C = 0x9B;
	// Convert regular characters
	default:
		if (c < 0x20 || c >= 0x60)
			return -1;

		if (c >= 0x40)
			C = c - 0x40;
		else
			C = c;

		break;
	}

	SetMemory(KBD, C);
	
	TerminalInput(c);
	

	return c;
}


#define FlagVisual(x, c)  (getFlag(x)) ? c : '.'

void PrintInfo()
{
	move(2, 43);
	printf("acc : %x", acc);
	move(3, 43);
	printf(" X  : %x",  X );
	move(4, 43);
	printf(" Y  : %x",  Y );
	move(5, 43);
	printf(" PC : %x",  PC);
	move(6, 43);
	printf("Flags : %c%c_%c%c%c%c%c",
		   getFlag(flag_N) ? 'N':'.' ,
		   getFlag(flag_V) ? 'V':'.' ,
		   getFlag(flag_B) ? 'B':'.' ,
		   getFlag(flag_D) ? 'D':'.' ,
		   getFlag(flag_I) ? 'I':'.' ,
		   getFlag(flag_Z) ? 'Z':'.' ,
		   getFlag(flag_C) ? 'C':'.'
	);
	refresh();
}



void TerminalInit()
{
	// ncurses initialization functions.
    initscr();
    cbreak();
    noecho();
    curs_set(0);
    keypad(stdscr, TRUE);

    // Draw decorative border.
    attron(A_REVERSE);
    move(0, 0);
    printw("                                          ");
    for (int i = 1; i <= 24; i++)
    {
        mvaddch(i,  0, ' ');
        mvaddch(i, 41, ' ');
    }
    mvprintw(25, 0, " ~                                        ");
    mvprintw(26, 0, "             Alekseis Apple I             ");
    mvprintw(27, 0, "                                          ");
    attroff(A_REVERSE);

	// Create seperate Apple screen window.
    AppleWindow = newwin(24, 40, 1, 1);
	
	// @ prompt.
    mvwaddch(AppleWindow, TermY, TermX, '@' | A_BLINK);

	// Initialize the terminal shift register variables.
    TerminalShiftRegister = (byte*)malloc(960);
    TerminalShiftRegisterPosition = TerminalShiftRegister;
    TerminalShiftRegisterOffset = 0;

    refresh();
}



void TerminalClose()
{
    free(TerminalShiftRegister);
	curs_set(1);
    endwin();
}



void TerminalInput(byte n)
{	
	// Place character
    mvwaddch(AppleWindow, TermY, TermX, ' ');
    mvwaddch(AppleWindow, TermY, TermX, CharacterROM[n]);
	
	// Add character to register
    *TerminalShiftRegisterPosition = n;
    TerminalShiftRegisterPosition++;
    if (TerminalShiftRegisterPosition >= (TerminalShiftRegister + 960))
        TerminalShiftRegisterPosition = TerminalShiftRegister;
    
    TermX++;
	// If X is past width..
    if (TermX >= 40) {
		//.. move to start of next line.
        TermX = 0;
        TermY++;
    }

	// If Y is past height..
    if (TermY >= 24) {
		//.. discard the first line..
		TerminalShiftRegisterOffset += 40;

		//.. verify the register offset..
		if (TerminalShiftRegisterOffset >= 960)
            TerminalShiftRegisterOffset = TerminalShiftRegister;

		//.. and create an offset variable to cycle through memory with.
        byte *offset = TerminalShiftRegister + TerminalShiftRegisterOffset;

        // Then, for every cell of the screen, fill with the contents of the video memory.
        for (int i = 0; i < 23; i++) {
        for (int j = 0; j < 40; j++) {
            if (offset >= (TerminalShiftRegister + 960))
                offset -= TerminalShiftRegister;
            mvwaddch(AppleWindow, i, j, CharacterROM[*offset] );
            offset++;
        }}
		
		// Set to start of final line, and clear line.
        TermY = 23;
        TermX = 0;
        mvwprintw(AppleWindow, TermY, TermX,
			"                                        ");
    }

	// @ prompt.
    mvwaddch(AppleWindow, TermY, TermX, '@' | A_BLINK);
    wrefresh(AppleWindow);
}