/**
 * @file
 * @section AUTHORS
 *
 *  Authors:
 *       Eamon Walsh <ewalsh@tycho.nsa.gov>
 *
 * @section LICENSE
 *
 * This file is in the public domain.
 *
 * @section DESCRIPTION
 *
 * This is the "subclass" of display that implements the Combined
 * Desktop with views from multiple guest framebuffers stacked together.
 */

#include <sys/types.h>
#include <sys/select.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "common.h"
#include "sys-queue.h"
#include "xen_linpicker.h"
#include "client.h"
#include "display.h"
#include "sclient.h"

static struct display sd;
static fd_set keys_down;
static int nkeys;
static unsigned char *background;

static int
dclient_key(struct display *d, bool down, int keycode)
{
    /*
     * Make the mouse_client the focus_client if:
     * 1. The current focus_client is not mouse_client.
     * 2. A mouse button has been pressed.
     * 3. No keys or buttons were pressed before.
     */
    if (d->mouse_client != d->focus_client &&
	nkeys == 0 &&
	down &&
	keycode >= BTN_MISC &&
	keycode < KEY_OK)
    {
	d->focus_client = d->mouse_client;
	d->focus_view = d->mouse_view;
	display_update_seclabel(d);
	if (d->focus_view)
	    view_stack(d->focus_view, VIEW_STACK_TOP, NULL);
    }

    /* Update the key state. */
    if (down && !FD_ISSET(keycode, &keys_down)) {
	FD_SET(keycode, &keys_down);
	nkeys++;
    }
    if (!down && FD_ISSET(keycode, &keys_down)) {
	FD_CLR(keycode, &keys_down);
	nkeys--;
    }

    /* Forward the actual key event. */
    if (d->focus_client && d->focus_client->input)
	xenfb_send_key(d->focus_client->input, down, keycode);

    return 0;
}

static int
dclient_position(struct display *d, int x, int y)
{
    struct view *v;
    struct client *c;

    TAILQ_FOREACH(v, &d->views, display_next)
	if (x >= v->spos.x && x < (v->spos.x + v->spos.w) &&
	    y >= v->spos.y && y < (v->spos.y + v->spos.h) &&
	    v->mapped)
	    break;

    /* Track what view the mouse is over for use in dclient_key */
    if (d->mouse_view != v)
	d->mouse_view = v;

    /* What client is the mouse over? */
    c = v ? v->buffer->client : NULL;

    /*
     * Make this client the mouse_client if:
     * 1. The current mouse_client is not client.
     * 2. No keys or mouse buttons are pressed.
     */
    if (c != d->mouse_client && nkeys == 0)
    {
	d->mouse_client = c;
	display_update_mouselabel(d, c);
    }

    return 0;
}

static int
dclient_mouse(struct display *d, struct mouse_event *m)
{
    struct buffer *b;

    /* Update position */
    dclient_position(d, m->x, m->y);

    /* Forward the actual motion event. */
    if (d->mouse_client && d->mouse_client->input) {
	b = LIST_FIRST(&d->mouse_client->buffers);

	/* Remove the buffer offset */
	/* Clamp the position to the buffer bounds */
	/* Scale the position to the dimensions the frontend expects */
	if (b->xoff > 0 || b->yoff > 0) {
	    m->x = scale_value(m->x - b->xoff, b->desc.width, display_get_width());
	    m->y = scale_value(m->y - b->yoff, b->desc.height, display_get_height());
	}

	xen_linpicker_input_send(d->mouse_client->input, m);
    }

    return 0;
}

int
dclient_setup(void)
{
    DFBSurfaceDescription sdesc;
    struct buffer *b;
    int width = display_get_width();
    int height = display_get_height();

    background = malloc(width * height);
    if (!background)
	return -1;

    sclient_read_background_image(DESKTOP_BG_FILE, background, width, height);

    /* Set up preallocated DirectFB surface with the data */
    memset(&sdesc, 0, sizeof(sdesc));
    sdesc.flags  = DSDESC_WIDTH | DSDESC_HEIGHT | DSDESC_CAPS | DSDESC_PIXELFORMAT | DSDESC_PREALLOCATED;
    sdesc.width  = width;
    sdesc.height = height;
    sdesc.pixelformat = DSPF_RGB332;
    sdesc.preallocated[0].data = background;
    sdesc.preallocated[0].pitch = width;

    b = buffer_new(sd.client, &sdesc, BUFFER_FLAG_DESKTOP_BG);
    if (b == NULL) {
	free(background);
	return -1;
    }

    sd.bg_view = b->bg_view;
    return 0;
}

struct display *
dclient_new(void)
{
    struct client *c = client_add(-1, 1024, 1024);
    if (!c)
	return NULL;

    /* XXX Label the client */
    c->label.label = strdup("COMBINED DESKTOP");
    c->label.shortlabel = strdup("D");
    c->label.fg = (struct sec_color){ 0xff, 0xff, 0 };
    c->label.bg = (struct sec_color){ 0, 0, 0xff };

    /* Set up input methods */
    sd.send_key = dclient_key;
    sd.send_mouse = dclient_mouse;
    sd.update_position = dclient_position;

    sd.type = DISPLAY_DESKTOP;
    sd.client = c;
    LIST_INIT(&sd.buffers);
    TAILQ_INIT(&sd.views);

    return &sd;
}