// 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"


int TermX = 0;
int TermY = 0;

WINDOW *AppleWindow;


byte UserInput()
{
	int c = getch();
	
	switch(c)
	{
	// Convert special characters
	case KEY_BACKSPACE:
		return 0xDF;
	case KEY_ENTER:
		return 0x8D;
	case KEY_EXIT: //TODO: Figure out if this is Esc or not.
		return 0x9B;
	// Convert regular characters
	default:
		if (c < 0x20 || c >= 0x60)
			return -1;
		if (c >= 0x40)
			c -= 0x40;
		break;
	}

	return c;
}



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)
{
	// Handle special characters and conversion.
	switch (n)
	{
	case 0xDF: // Backslash
	case 0x8D: // Enter
	case 0x9B: // Escape
		return;
	default:
		// Convert to ASCII
		if (n < 0x20) n += 0x40;
	}
	
	// Place character
    mvwaddch(AppleWindow, TermY, TermX, ' ');
    mvwaddch(AppleWindow, TermY, TermX, 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, (*offset < 0x20) ? *offset + 0x40 : *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);
}