/*
 * 86Box	A hypervisor and IBM PC system emulator that specializes in
 *		running old operating systems and software designed for IBM
 *		PC systems and compatibles from 1981 through fairly recent
 *		system designs based on the PCI bus.
 *
 *		This file is part of the 86Box distribution.
 *
 *		Implement the VNC remote renderer with LibVNCServer.
 *
 *
 *
 * Authors:	Fred N. van Kempen, <decwiz@yahoo.com>
 *		Based on raw code by RichardG, <richardg867@gmail.com>
 *
 *		Copyright 2017-2019 Fred N. van Kempen.
 */
#include <stdarg.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#include <rfb/rfb.h>
#define HAVE_STDARG_H
#include <86box/86box.h>
#include <86box/device.h>
#include <86box/video.h>
#include <86box/keyboard.h>
#include <86box/mouse.h>
#include <86box/plat.h>
#include <86box/ui.h>
#include <86box/vnc.h>


#define VNC_MIN_X	320
#define VNC_MAX_X	2048
#define VNC_MIN_Y	200
#define VNC_MAX_Y	2048


static rfbScreenInfoPtr	rfb = NULL;
static int	clients;
static int	updatingSize;
static int	allowedX,
		allowedY;
static int	ptr_x, ptr_y, ptr_but;


#ifdef ENABLE_VNC_LOG
int vnc_do_log = ENABLE_VNC_LOG;


static void
vnc_log(const char *fmt, ...)
{
    va_list ap;

    if (vnc_do_log) {
	va_start(ap, fmt);
	pclog_ex(fmt, ap);
	va_end(ap);
    }
}
#else
#define vnc_log(fmt, ...)
#endif


static void
vnc_kbdevent(rfbBool down, rfbKeySym k, rfbClientPtr cl)
{
    (void)cl;

    /* Handle it through the lookup tables. */
    vnc_kbinput(down?1:0, (int)k);
}


static void
vnc_ptrevent(int but, int x, int y, rfbClientPtr cl)
{
   if (x>=0 && x<allowedX && y>=0 && y<allowedY) {
	/* VNC uses absolute positions within the window, no deltas. */
	if (x != ptr_x || y != ptr_y) {
		mouse_x += (x - ptr_x) / 100;
		mouse_y += (y - ptr_y) / 100;
		ptr_x = x; ptr_y = y;
	}

	if (but != ptr_but) {
		mouse_buttons = 0;
		if (but & 0x01)
			mouse_buttons |= 0x01;
		if (but & 0x02)
			mouse_buttons |= 0x04;
		if (but & 0x04)
			mouse_buttons |= 0x02;
		ptr_but = but;
	}
   }

   rfbDefaultPtrAddEvent(but, x, y, cl);
}


static void
vnc_clientgone(rfbClientPtr cl)
{
    vnc_log("VNC: client disconnected: %s\n", cl->host);

    if (clients > 0)
	clients--;
    if (clients == 0) {
	/* No more clients, pause the emulator. */
	vnc_log("VNC: no clients, pausing..\n");

	/* Disable the mouse. */
	plat_mouse_capture(0);

	plat_pause(1);
    }
}


static enum rfbNewClientAction
vnc_newclient(rfbClientPtr cl)
{
    /* Hook the ClientGone function so we know when they're gone. */
    cl->clientGoneHook = vnc_clientgone;

    vnc_log("VNC: new client: %s\n", cl->host);
    if (++clients == 1) {
	/* Reset the mouse. */
	ptr_x = allowedX/2;
	ptr_y = allowedY/2;
	mouse_x = mouse_y = mouse_z = 0;
	mouse_buttons = 0x00;

	/* We now have clients, un-pause the emulator if needed. */
	vnc_log("VNC: unpausing..\n");

	/* Enable the mouse. */
	plat_mouse_capture(1);

	plat_pause(0);
    }

    /* For now, we always accept clients. */
    return(RFB_CLIENT_ACCEPT);
}


static void
vnc_display(rfbClientPtr cl)
{
    /* Avoid race condition between resize and update. */
    if (!updatingSize && cl->newFBSizePending) {
	updatingSize = 1;
    } else if (updatingSize && !cl->newFBSizePending) {
	updatingSize = 0;

	allowedX = rfb->width;
	allowedY = rfb->height;
    }
}


static void
vnc_blit(int x, int y, int w, int h)
{
    uint32_t *p;
    int yy;

    if ((x < 0) || (y < 0) || (w <= 0) || (h <= 0) || (w > 2048) || (h > 2048) || (buffer32 == NULL))
	return;

    for (yy=0; yy<h; yy++) {
	p = (uint32_t *)&(((uint32_t *)rfb->frameBuffer)[yy*VNC_MAX_X]);

	if ((y+yy) >= 0 && (y+yy) < VNC_MAX_Y)
		video_copy(p, &(buffer32->line[yy]), w*sizeof(uint32_t));
    }

    if (screenshots)
	video_screenshot((uint32_t *) rfb->frameBuffer, 0, 0, VNC_MAX_X);
 
    video_blit_complete();

    if (! updatingSize)
	rfbMarkRectAsModified(rfb, 0,0, allowedX,allowedY);
}


/* Initialize VNC for operation. */
int
vnc_init(UNUSED(void *arg))
{
    static char title[128];
    rfbPixelFormat rpf = {
	/*
	 * Screen format:
	 *	32bpp; 32 depth;
	 *	little endian;
	 *	true color;
	 *	max 255 R/G/B;
	 *	red shift 16; green shift 8; blue shift 0;
	 *	padding
	 */
	32, 32, 0, 1, 255,255,255, 16, 8, 0, 0, 0
    };

    cgapal_rebuild();

    if (rfb == NULL) {
	wcstombs(title, ui_window_title(NULL), sizeof(title));
	updatingSize = 0;
	allowedX = scrnsz_x;
	allowedY = scrnsz_y;
 
	rfb = rfbGetScreen(0, NULL, VNC_MAX_X, VNC_MAX_Y, 8, 3, 4);
	rfb->desktopName = title;
	rfb->frameBuffer = (char *)malloc(VNC_MAX_X*VNC_MAX_Y*4);

	rfb->serverFormat = rpf;
	rfb->alwaysShared = TRUE;
	rfb->displayHook = vnc_display;
	rfb->ptrAddEvent = vnc_ptrevent;
	rfb->kbdAddEvent = vnc_kbdevent;
	rfb->newClientHook = vnc_newclient;
 
	/* Set up our current resolution. */
	rfb->width = allowedX;
	rfb->height = allowedY;
 
	rfbInitServer(rfb);

	rfbRunEventLoop(rfb, -1, TRUE);
    }
 
    /* Set up our BLIT handlers. */
    video_setblit(vnc_blit);

    clients = 0;

    vnc_log("VNC: init complete.\n");

    return(1);
}


void
vnc_close(void)
{
    video_setblit(NULL);

    if (rfb != NULL) {
	free(rfb->frameBuffer);

	rfbScreenCleanup(rfb);

	rfb = NULL;
    }
}


void
vnc_resize(int x, int y)
{
    rfbClientIteratorPtr iterator;
    rfbClientPtr cl;

    if (rfb == NULL) return;

    /* TightVNC doesn't like certain sizes.. */
    if (x < VNC_MIN_X || x > VNC_MAX_X || y < VNC_MIN_Y || y > VNC_MAX_Y) {
	vnc_log("VNC: invalid resoltion %dx%d requested!\n", x, y);
	return;
    }

    if ((x != rfb->width || y != rfb->height) && x > 160 && y > 0) {
	vnc_log("VNC: updating resolution: %dx%d\n", x, y);
 
	allowedX = (rfb->width < x) ? rfb->width : x;
	allowedY = (rfb->width < y) ? rfb->width : y;
 
	rfb->width = x;
	rfb->height = y;
 
	iterator = rfbGetClientIterator(rfb);
	while ((cl = rfbClientIteratorNext(iterator)) != NULL) {
		LOCK(cl->updateMutex);
		cl->newFBSizePending = 1;
		UNLOCK(cl->updateMutex);
	}
    }
}
 

/* Tell them to pause if we have no clients. */
int
vnc_pause(void)
{
    return((clients > 0) ? 0 : 1);
}


void
vnc_take_screenshot(wchar_t *fn)
{
    vnc_log("VNC: take_screenshot\n");
}