#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "comms.h"

#define EXID unsigned int

static EXID     comms_win = 0;
static EXID     my_win = 0;
static EXID     Atom_ENL_COMMS = 0;
static EXID     Atom_ENL_MSG = 0;

static          EXID
_CommsFindCommsWindow(void)
{
    unsigned char  *s;
    Atom            ar;
    unsigned long   num, after;
    int             format;
    EXID            cwin;

    /* Get root window ENLIGHTENMENT_COMMS property */
    cwin = 0;
    s = NULL;
    XGetWindowProperty(disp, root, Atom_ENL_COMMS, 0, 14, False,
                       AnyPropertyType, &ar, &format, &num, &after, &s);
    if (!s)
        goto done;

    sscanf((char *)s, "%*s %x", &cwin);
    XFree(s);

    /* Check that cwin exists and has ENLIGHTENMENT_COMMS */
    s = NULL;
    XGetWindowProperty(disp, cwin, Atom_ENL_COMMS, 0, 14, False,
                       AnyPropertyType, &ar, &format, &num, &after, &s);
    if (!s)
        goto done;
    XFree(s);

    XSelectInput(disp, cwin, StructureNotifyMask | SubstructureNotifyMask);

  done:
    return cwin;
}

void
CommsSetup(void)
{
    if (Atom_ENL_COMMS == 0)
        Atom_ENL_COMMS = XInternAtom(disp, "ENLIGHTENMENT_COMMS", False);
    if (Atom_ENL_MSG == 0)
        Atom_ENL_MSG = XInternAtom(disp, "ENL_MSG", False);

    for (;;)
    {
        comms_win = _CommsFindCommsWindow();
        if (comms_win != None)
            break;
        sleep(1);
    }

    if (!my_win)
    {
        my_win = XCreateWindow(disp, root, -10, -10, 1, 1, 0,
                               CopyFromParent, InputOnly, CopyFromParent,
                               0, NULL);
        XSelectInput(disp, my_win,
                     StructureNotifyMask | SubstructureNotifyMask);
    }
}

void
CommsHandleDestroy(Window xwin)
{
    if (xwin == comms_win)
        comms_win = 0;
}

int
CommsHandlePropertyNotify(XEvent *ev)
{
    if (comms_win)
        return 0;

    if (ev->xproperty.atom == Atom_ENL_COMMS)
        CommsSetup();

    if (comms_win)
        return 1;
    return 0;
}

int
CommsSend(const char *buf, unsigned int len)
{
    char            ss[21];
    unsigned int    i, j, k;
    XEvent          ev;

    ev.xclient.type = ClientMessage;
    ev.xclient.serial = 0;
    ev.xclient.send_event = True;
    ev.xclient.window = comms_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_win);
        for (j = 0; j < 12; j++)
        {
            ss[8 + j] = buf[i + j];
            if (!buf[i + j])
                j = 12;
        }
        ss[20] = 0;
        for (k = 0; k < 20; k++)
            ev.xclient.data.b[k] = ss[k];
        XSendEvent(disp, comms_win, False, 0, &ev);
    }

    return len;
}

static          Bool
ev_check(Display *d __UNUSED__, XEvent *ev, XPointer p __UNUSED__)
{
    if (ev->type == ClientMessage)
    {
        if (ev->xclient.window == my_win)
            return True;
    }
    else if (ev->type == DestroyNotify)
    {
        if (ev->xdestroywindow.window == comms_win)
            return True;
    }
    return False;
}

char           *
CommsWaitForMessage(void)
{
    XEvent          ev;
    char           *msg = NULL;

    for (;;)
    {
        XIfEvent(disp, &ev, ev_check, NULL);
        if (ev.type == DestroyNotify)
        {
            comms_win = 0;
            break;
        }
        else
        {
            msg = CommsHandleClientMessage(&ev);
            if (msg)
                break;
        }
    }
    return msg;
}

char           *
CommsHandleClientMessage(XEvent *ev)
{
    char            s[13], s2[9], *msg = NULL;
    int             i;
    Window          win = 0;
    static char    *c_msg = NULL;

    if (!ev)
        return NULL;
    if (ev->type != ClientMessage)
        return NULL;
    s[12] = 0;
    s2[8] = 0;
    msg = NULL;
    for (i = 0; i < 8; i++)
        s2[i] = ev->xclient.data.b[i];
    for (i = 0; i < 12; i++)
        s[i] = ev->xclient.data.b[i + 8];
    sscanf(s2, "%x", (int *)&win);
    if (win == comms_win)
    {
        if (c_msg)
        {
            c_msg = realloc(c_msg, strlen(c_msg) + strlen(s) + 1);
            if (!c_msg)
                return NULL;
            strcat(c_msg, s);
        }
        else
        {
            c_msg = malloc(strlen(s) + 1);
            if (!c_msg)
                return NULL;
            strcpy(c_msg, s);
        }
        if (strlen(s) < 12)
        {
            msg = c_msg;
            c_msg = NULL;
        }
    }
    return msg;
}