#include <unistd.h>
#include <stdlib.h>
#include <string.h>

#include "app.h"


static xcb_connection_t *conn;
static GtkTreeStore *store;
xcb_window_t root;

static void
setup_x(const gchar *display)
{
    const xcb_setup_t *setup;
    xcb_screen_iterator_t iter;
    uint32_t mask, list;

    make_connection(display, &conn, NULL);

    setup = xcb_get_setup(conn);
    iter = xcb_setup_roots_iterator(setup);
    root = iter.data->root;

    atom_init(conn);

    /* Select for root window events */
    mask = XCB_CW_EVENT_MASK;
    list = XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY | XCB_EVENT_MASK_PROPERTY_CHANGE;
    xcb_change_window_attributes(conn, root, mask, &list);

    xcb_flush(conn);
}

static char *
get_prop_text(xcb_get_property_reply_t *reply)
{
    size_t size;
    char *data;

    if (!atom_is_string_type(reply->type))
	return NULL;

    size = (reply->format >> 3) * xcb_get_property_value_length(reply);

    data = malloc(size + 1);
    if (!data)
	APP_ERR(NULL, "Out of memory");

    memcpy(data, xcb_get_property_value(reply), size);
    data[size] = '\0';

    return scrub_text(data);
}

static gboolean
find_window(xcb_window_t window, GtkTreeIter *iter)
{
    GtkTreeModel *tree = GTK_TREE_MODEL(store);
    xcb_window_t cur;

    if (gtk_tree_model_get_iter_first(tree, iter)) {
	do {
	    gtk_tree_model_get(tree, iter, COL_WIN, &cur, -1);
	    if (cur == window)
		return TRUE;

	} while (gtk_tree_model_iter_next(tree, iter));
    }

    return FALSE;
}

static void
update_window_name(xcb_window_t window, const char *text)
{
    GtkTreeIter iter;
    char buf[128];

    if (find_window(window, &iter)) {
	snprintf(buf, sizeof(buf), "%s (%08x)", text, window);
	gtk_tree_store_set(store, &iter, COL_NAME, buf, -1);
    }
}

static void
add_item(GtkTreeIter *parent, GtkTreeIter *sibling,
	 xcb_window_t window, xcb_atom_t atom,
	 security_context_t octx, security_context_t dctx,
	 xcb_atom_t type, const char *data)
{
    GtkTreeIter iter;
    char *color;

    color = get_colors(octx, dctx);

    gtk_tree_store_insert_before(store, &iter, parent, sibling);
    gtk_tree_store_set(store, &iter,
		       COL_ICON, GTK_STOCK_FILE,
		       COL_ATOM, atom,
		       COL_WIN, window,
		       COL_DATA, data,
		       COL_NAME, atom_lookup(conn, atom),
		       COL_TYPE, atom_lookup(conn, type),
		       COL_OCTX, octx,
		       COL_DCTX, dctx,
		       COL_OFG, color,
		       COL_OBG, color + 8,
		       COL_DFG, color + 16,
		       COL_DBG, color + 24,
		       -1);

    free(color);
}

static void
remove_items(xcb_window_t window, xcb_atom_t atom)
{
    GtkTreeModel *tree = GTK_TREE_MODEL(store);
    GtkTreeIter iter, child;
    xcb_atom_t iatom;
    int more;

    if (!find_window(window, &iter))
	return;

    if (gtk_tree_model_iter_children(tree, &child, &iter)) {
	do {
	    gtk_tree_model_get(tree, &child, COL_ATOM, &iatom, -1);
	    if (atom == iatom)
		more = gtk_tree_store_remove(store, &child);
	    else
		more = gtk_tree_model_iter_next(tree, &child);
	} while (more);
    }
}

static int
update_item_matches(GtkTreeIter *iter, xcb_atom_t atom, security_context_t ctx)
{
    GtkTreeModel *tree = GTK_TREE_MODEL(store);
    xcb_atom_t iatom;
    security_context_t ictx;
    int result;

    gtk_tree_model_get(tree, iter, COL_ATOM, &iatom, COL_OCTX, &ictx, -1);
    result = (atom == iatom) && !strcmp(ctx, ictx);
    g_free(ictx);
    return result;
}

static gboolean
update_item_next(xcb_atom_t atom, GtkTreeIter *iter, GtkTreeIter **sibling)
{
    GtkTreeModel *tree = GTK_TREE_MODEL(store);
    xcb_atom_t iatom;
    const char *name, *iname;

    gtk_tree_model_get(tree, iter, COL_ATOM, &iatom, -1);
    name = atom_lookup(conn, atom);
    iname = atom_lookup(conn, iatom);

    if (strcasecmp(name, iname) < 0) {
	*sibling = iter;
	return FALSE;
    }

    *sibling = NULL;
    return gtk_tree_model_iter_next(tree, iter);
}

static void
update_item(xcb_window_t window, xcb_atom_t atom,
	    security_context_t octx, security_context_t dctx,
	    xcb_atom_t type, const char *data)
{
    GtkTreeModel *tree = GTK_TREE_MODEL(store);
    GtkTreeIter iter, child, *sibling = NULL;
    char *color;

    if (!find_window(window, &iter))
	return;

    if (gtk_tree_model_iter_children(tree, &child, &iter)) {
	do {
	    if (update_item_matches(&child, atom, octx)) {
		color = get_colors(NULL, dctx);
		gtk_tree_store_set(store, &child,
				   COL_DATA, data,
				   COL_TYPE, atom_lookup(conn, type),
				   COL_DCTX, dctx,
				   COL_DFG, color + 16,
				   COL_DBG, color + 24,
				   -1);
		free(color);
		return;
	    }
	} while (update_item_next(atom, &child, &sibling));
    }

    add_item(&iter, sibling, window, atom, octx, dctx, type, data);
}

static gboolean
update_is_managed(xcb_atom_t atom, xcb_atom_t wildcard)
{
    return (wildcard == XCB_NONE || wildcard == atom);
}

static void
update(xcb_window_t window, xcb_atom_t atom)
{
    xcb_selinux_list_properties_cookie_t cookie;
    xcb_selinux_list_properties_reply_t *reply;
    xcb_get_property_cookie_t *cookies;
    xcb_get_property_reply_t *propinfo;
    xcb_generic_error_t *error;
    xcb_selinux_list_item_iterator_t iter;
    security_context_t octx, dctx;
    char *text;
    int i;

    /* remove existing items if updating */
    if (atom != XCB_NONE)
	remove_items(window, atom);

    /* list all property instances on the window */
    cookie = xcb_selinux_list_properties(conn, window);
    reply = xcb_selinux_list_properties_reply(conn, cookie, &error);
    if (error) {
	/* window might have gone away */
	if (error->error_code == XCB_WINDOW) {
	    free(error);
	    return;
	}
	APP_ERR(error, "An error was received during ListProperties.\n");
    }

    iter = xcb_selinux_list_properties_properties_iterator(reply);
    cookies = malloc(iter.rem * sizeof(*cookies));
    if (!cookies)
	APP_ERR(NULL, "Out of memory\n");

    /* get the property type and text content */
    i = 0;
    while (iter.rem) {
	if (update_is_managed(iter.data->name, atom)) {
	    octx = xcb_selinux_list_item_object_context(iter.data);
	    xcb_selinux_set_property_use_context(conn, strlen(octx) + 1, octx);
	    cookies[i] = xcb_get_property(conn, FALSE, window, iter.data->name,
					  XCB_GET_PROPERTY_TYPE_ANY, 0, 1024);
	}
	xcb_selinux_list_item_next(&iter);
	++i;
    }

    /* process the replies */
    i = 0;
    iter = xcb_selinux_list_properties_properties_iterator(reply);
    while (iter.rem) {
	if (update_is_managed(iter.data->name, atom)) {
	    octx = xcb_selinux_list_item_object_context(iter.data);
	    dctx = xcb_selinux_list_item_data_context(iter.data);
	    propinfo = xcb_get_property_reply(conn, cookies[i], &error);
	    if (error) {
		free(error);
		goto out;
	    }

	    text = get_prop_text(propinfo);
	    update_item(window, iter.data->name, octx, dctx, propinfo->type, text);

	    /* special window updates */
	    if (iter.data->name == wm_name)
		update_window_name(window, text);

	    free(text);
	    free(propinfo);
	}
	xcb_selinux_list_item_next(&iter);
	++i;
    }

out:
    free(reply);
    free(cookies);
    xcb_flush(conn);
}

static void
add_window(xcb_window_t window)
{
    xcb_selinux_get_window_context_cookie_t cookie;
    xcb_selinux_get_window_context_reply_t *reply;
    xcb_generic_error_t *error;
    security_context_t octx;
    uint32_t mask, list;
    GtkTreeIter iter;
    char *color, buf[24];

    /* Get window context */
    cookie = xcb_selinux_get_window_context(conn, window);
    reply = xcb_selinux_get_window_context_reply(conn, cookie, &error);
    if (error) {
	/* window might have gone away */
	if (error->error_code == XCB_WINDOW) {
	    free(error);
	    return;
	}
	APP_ERR(error, "An error was received during GetWindowContext.\n");
    }

    octx = xcb_selinux_get_window_context_context(reply);

    /* Add window to list */
    color = get_colors(octx, NULL);
    if (window == root)
	snprintf(buf, sizeof(buf), "root (%08x)", window);
    else
	snprintf(buf, sizeof(buf), "unnamed (%08x)", window);

    gtk_tree_store_append(store, &iter, NULL);
    gtk_tree_store_set(store, &iter,
		       COL_ICON, GTK_STOCK_DIRECTORY,
		       COL_WIN, window,
		       COL_NAME, buf,
		       COL_OCTX, octx,
		       COL_OFG, color,
		       COL_OBG, color + 8,
		       -1);

    /* Select for window events */
    if (window != root) {
	mask = XCB_CW_EVENT_MASK;
	list = XCB_EVENT_MASK_STRUCTURE_NOTIFY | XCB_EVENT_MASK_PROPERTY_CHANGE;
	xcb_change_window_attributes(conn, window, mask, &list);
    }

    update(window, XCB_NONE);
    free(color);
    free(reply);
}

static void
add_windows(void)
{
    xcb_query_tree_cookie_t cookie;
    xcb_query_tree_reply_t *reply;
    xcb_generic_error_t *error;
    xcb_window_t *children;
    int i;

    cookie = xcb_query_tree(conn, root);
    reply = xcb_query_tree_reply(conn, cookie, &error);
    if (error)
	APP_ERR(error, "An error was received during QueryTree.\n");

    children = xcb_query_tree_children(reply);

    add_window(root);
    for (i = 0; i < reply->children_len; i++)
	add_window(children[i]);

    free(reply);
}

static void
del_window_helper(xcb_window_t window, GtkTreeIter *iter)
{
    GtkTreeModel *tree = GTK_TREE_MODEL(store);
    GtkTreeIter child;
    xcb_window_t cur;
    int more;

    do {
	gtk_tree_model_get(tree, iter, COL_WIN, &cur, -1);
	if (cur == window) {
	    if (gtk_tree_model_iter_children(tree, &child, iter))
		del_window_helper(window, &child);
	    more = gtk_tree_store_remove(store, iter);
	} else
	    more = gtk_tree_model_iter_next(tree, iter);
    } while (more);
}

static void
del_window(xcb_window_t window)
{
    GtkTreeModel *tree = GTK_TREE_MODEL(store);
    GtkTreeIter iter;

    if (gtk_tree_model_get_iter_first(tree, &iter))
	del_window_helper(window, &iter);
}

static void
handle_property(xcb_property_notify_event_t *event)
{
    update(event->window, event->atom);
}

static void
handle_create(xcb_create_notify_event_t *event)
{
    add_window(event->window);
}

static void
handle_destroy(xcb_destroy_notify_event_t *event)
{
    del_window(event->window);
}

static gboolean
handle_event(GIOChannel *source, GIOCondition condition, gpointer data)
{
    xcb_generic_event_t *event;

    while ((event = xcb_poll_for_event(conn))) {
	switch (event->response_type) {
	case XCB_PROPERTY_NOTIFY:
	    handle_property((xcb_property_notify_event_t *)event);
	    break;

	case XCB_CREATE_NOTIFY:
	    handle_create((xcb_create_notify_event_t *)event);
	    break;

	case XCB_DESTROY_NOTIFY:
	    handle_destroy((xcb_destroy_notify_event_t *)event);
	    break;

	case XCB_MAP_NOTIFY:
	case XCB_UNMAP_NOTIFY:
	case XCB_UNMAP_NOTIFY | 0x80:
	case XCB_CONFIGURE_NOTIFY:
	case XCB_CONFIGURE_NOTIFY | 0x80:
	case XCB_REPARENT_NOTIFY:
	case XCB_MAPPING_NOTIFY:
	case XCB_CLIENT_MESSAGE:
	case XCB_CLIENT_MESSAGE | 0x80:
	    /* do nothing */
	    break;

	default:
	    fprintf(stderr, "Monitor: %d event\n", event->response_type);
	    break;
	}
	free(event);
	xcb_flush(conn);
    }

    return TRUE;
}

int
prop_monitor_init(struct thread_data *data)
{
    int fd;
    GIOChannel *channel;

    store = GTK_TREE_STORE(data->store);

    setup_x(data->display);

    fd = xcb_get_file_descriptor(conn);
    channel = g_io_channel_unix_new(fd);
    g_io_channel_set_encoding(channel, NULL, NULL);
    g_io_add_watch(channel, G_IO_IN|G_IO_ERR|G_IO_HUP, handle_event, NULL);

    add_windows();
    handle_event(channel, 0, NULL);

    return 0;
}