#include "config.h"

#include <gdk/gdkx.h>
#include <X11/Xlib.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "e16keyedit.h"

#define gdk_window_foreign_new(xwin) \
    gdk_x11_window_foreign_new_for_display(gdk_display_get_default(), xwin)

#if USE_GTK == 3
#define gdk_error_trap_push() \
    gdk_x11_display_error_trap_push(gdk_display_get_default())
#define gdk_error_trap_pop() \
    gdk_x11_display_error_trap_pop(gdk_display_get_default())
#endif

typedef struct {
    Window          win;
    char           *msg;
#if 0
    char           *name;
    char           *clientname;
    char           *version;
    char           *author;
    char           *email;
    char           *web;
    char           *address;
    char           *info;
#endif
} Client;

static Display *dpy = NULL;
static Window   root_win = None;
static Window   comms_win = None;
static Window   my_msg_win = None;
static Client  *e_client = NULL;
static void     (*msg_receive_callback)(char *msg) = NULL;
static unsigned int Atom_ENL_MSG;

static int
CommsSetup(void)
{
    char           *str;

    dpy = gdk_x11_get_default_xdisplay();

    str = getenv("ENL_WM_ROOT");
    root_win = (str) ? strtoul(str, NULL, 0) : DefaultRootWindow(dpy);

    gdk_error_trap_push();
    my_msg_win = XCreateSimpleWindow(dpy, root_win, -10, -10, 1, 1, 0, 0, 0);
    XSync(dpy, False);
    if (gdk_error_trap_pop())
        return 1;

    Atom_ENL_MSG = XInternAtom(dpy, "ENL_MSG", False);

    return 0;
}

static          Window
CommsFindCommsWindow(void)
{
    unsigned char  *s;
    Atom            Atom_ENL_COMMS, ar;
    unsigned long   num, after;
    int             format;
    Window          win = None;
    Window          rt;
    int             dint;
    unsigned int    duint;

    Atom_ENL_COMMS = XInternAtom(dpy, "ENLIGHTENMENT_COMMS", True);
    if (Atom_ENL_COMMS == None)
        return None;

    s = NULL;
    XGetWindowProperty(dpy, root_win, Atom_ENL_COMMS, 0, 14, False,
                       AnyPropertyType, &ar, &format, &num, &after, &s);
    if (s)
    {
        sscanf((char *)s, "%*s %x", (unsigned int *)&win);
        XFree(s);
    }

    if (win == None)
        return None;

    if (!XGetGeometry(dpy, win, &rt,
                      &dint, &dint, &duint, &duint, &duint, &duint))
        return None;

    s = NULL;
    XGetWindowProperty(dpy, win, Atom_ENL_COMMS, 0, 14, False,
                       AnyPropertyType, &ar, &format, &num, &after, &s);
    if (!s)
        return None;

    XFree(s);

    return win;
}

static Client  *
ClientCreate(Window win)
{
    Client         *cl;

    cl = calloc(1, sizeof(Client));
    if (!cl)
        return cl;

    cl->win = win;

#if 0
    char            st[32];
    snprintf(st, sizeof(st), "%8x", (int)win);
    cl->name = strdup(st);
#endif

    return cl;
}

static char    *
CommsGet(XEvent *ev)
{
    char            buf[13], *msg;
    unsigned int    win;
    Client         *cl = e_client;

    if (!cl)
        return NULL;

    if (!ev)
        return NULL;
    if (ev->type != ClientMessage)
        return NULL;
    if (ev->xclient.message_type != Atom_ENL_MSG)
        return NULL;

    /* Message should start with comms_win but we don't check */
    memcpy(buf, ev->xclient.data.b, 8);
    buf[8] = 0;
    sscanf(buf, "%x", &win);

    memcpy(buf, ev->xclient.data.b + 8, 12);
    buf[12] = 0;

    if (cl->msg)
    {
        /* append text to end of msg */
        cl->msg = realloc(cl->msg, strlen(cl->msg) + strlen(buf) + 1);
        if (!cl->msg)
            return NULL;
        strcat(cl->msg, buf);
    }
    else
    {
        /* new msg */
        cl->msg = malloc(strlen(buf) + 1);
        if (!cl->msg)
            return NULL;
        strcpy(cl->msg, buf);
    }

    msg = NULL;
    if (strlen(buf) < 12)
    {
        msg = cl->msg;
        cl->msg = NULL;
    }
    return msg;
}

static          GdkFilterReturn
FilterCommsWin(GdkXEvent *gdk_xevent, GdkEvent *event __UNUSED__,
               void *data __UNUSED__)
{
    XEvent         *xevent = gdk_xevent;

    switch (xevent->type)
    {
    default:
        break;

    case DestroyNotify:
        exit(1);
    }

    return GDK_FILTER_REMOVE;
}

static          GdkFilterReturn
FilterMyMsgWin(GdkXEvent *gdk_xevent, GdkEvent *event __UNUSED__,
               void *data __UNUSED__)
{
    XEvent         *xevent = gdk_xevent;
    char           *msg;

    switch (xevent->type)
    {
    default:
        break;

    case ClientMessage:
        if (xevent->xclient.message_type != Atom_ENL_MSG)
            return GDK_FILTER_CONTINUE;

        msg = CommsGet(xevent);
        if (msg)
        {
            if (msg_receive_callback)
                (*msg_receive_callback) (msg);
            free(msg);
        }
        break;
    }

    return GDK_FILTER_REMOVE;
}

int
CommsInit(void  (*msg_receive_func)(char *msg))
{
    GdkWindow      *gdkwin;

    if (CommsSetup())
        return 1;

    comms_win = CommsFindCommsWindow();
    if (comms_win == None)
        return 1;

    e_client = ClientCreate(comms_win);

    gdkwin = gdk_window_foreign_new(comms_win);
    gdk_window_set_events(gdkwin, GDK_STRUCTURE_MASK);
    gdk_window_add_filter(gdkwin, FilterCommsWin, NULL);

    gdkwin = gdk_window_foreign_new(my_msg_win);
    gdk_window_add_filter(gdkwin, FilterMyMsgWin, NULL);

    msg_receive_callback = msg_receive_func;

    return 0;
}

void
CommsSend(const char *s)
{
    char            ss[21];
    int             i, j, k, len;
    XEvent          ev;
    Client         *cl = e_client;

    if (!s || !cl)
        return;

    len = strlen(s);

    ev.xclient.type = ClientMessage;
    ev.xclient.serial = 0;
    ev.xclient.send_event = True;
    ev.xclient.window = cl->win;
    ev.xclient.message_type = Atom_ENL_MSG;
    ev.xclient.format = 8;

    for (i = 0; i < len + 1; i += 12)
    {
        snprintf(ss, sizeof(ss), "%8x", (int)my_msg_win);
        for (j = 0; j < 12; j++)
        {
            ss[8 + j] = s[i + j];
            if (!s[i + j])
                j = 12;
        }
        ss[20] = 0;
        for (k = 0; k < 20; k++)
            ev.xclient.data.b[k] = ss[k];
        XSendEvent(dpy, cl->win, False, 0, &ev);
    }
    XFlush(dpy);
}