#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <cairo.h>
#include <cairo-xlib.h>
#include "mb_redraw_man.h"
#include "mb_timer.h"
#include "mb_X_supp.h"

#define ERR -1
#define OK 0

#define ONLY_MOUSE_MOVE_RAW 1

/*! \ingroup xkb
 * @{
 */
struct _X_kb_info {
    int keycode_min, keycode_max;
    int ksym_per_code;
    KeySym *syms;
    subject_t *kbevents;
    ob_factory_t *ob_factory;
};

/* @} */

struct _X_MB_runtime {
    Display *display;
    Window win;
    Visual *visual;
    cairo_surface_t *surface, *backend_surface;
    cairo_t *cr, *backend_cr;
    redraw_man_t *rdman;
    mb_tman_t *tman;
    mb_img_ldr_t *img_ldr;
    int w, h;

    X_kb_info_t kbinfo;

#ifndef ONLY_MOUSE_MOVE_RAW
    /* States */
    shape_t *last;
#endif
};

/*! \defgroup xkb X Keyboard Handling
 *
 * Accept keyboard events from X server and delivery it to
 * application through observer pattern.  There is a subject,
 * per X-connection, for that.
 * @{
 */
static int keycode2sym(X_kb_info_t *kbinfo, unsigned int keycode) {
    int sym_idx;
    int sym;

    sym_idx = kbinfo->ksym_per_code * (keycode - kbinfo->keycode_min);
    sym =  kbinfo->syms[sym_idx];
    return sym;
}

static int X_kb_init(X_kb_info_t *kbinfo, Display *display,
		     redraw_man_t *rdman) {
    int n_syms;
    ob_factory_t *factory;
    int r;

    r = XDisplayKeycodes(display,
			 &kbinfo->keycode_min,
			 &kbinfo->keycode_max);
    if(r == 0)
	return ERR;

    n_syms = kbinfo->keycode_max - kbinfo->keycode_min + 1;
    kbinfo->syms = XGetKeyboardMapping(display, kbinfo->keycode_min,
				       n_syms,
				       &kbinfo->ksym_per_code);
    if(kbinfo->syms == NULL)
	return ERR;

    factory = rdman_get_ob_factory(rdman);
    kbinfo->kbevents = subject_new(factory, kbinfo, OBJT_KB);
    if(kbinfo->kbevents == NULL)
	return ERR;
    /*! \todo Make sure ob_factory is still need. */
    kbinfo->ob_factory = factory;

    return OK;
}

static void X_kb_destroy(X_kb_info_t *kbinfo) {
    subject_free(kbinfo->kbevents);
    XFree(kbinfo->syms);
}

/*! \brief Accept X keyboard events from handle_x_event() and dispatch it.
 */
static void X_kb_handle_event(X_kb_info_t *kbinfo, XKeyEvent *xkey) {
    unsigned int code;
    int sym;
    X_kb_event_t event;

    code = xkey->keycode;
    sym = keycode2sym(kbinfo, code);
    if(xkey->type == KeyPress)
	event.event.type = EVT_KB_PRESS;
    else if(xkey->type == KeyRelease)
	event.event.type = EVT_KB_RELEASE;
    event.event.tgt = event.event.cur_tgt = kbinfo->kbevents;
    event.keycode = code;
    event.sym = sym;

    subject_notify(kbinfo->kbevents, &event.event);
}

/* @} */

static unsigned int get_button_state(unsigned int state) {
    unsigned int but = 0;

    if(state & Button1Mask)
	but |= MOUSE_BUT1;
    if(state & Button2Mask)
	but |= MOUSE_BUT2;
    if(state & Button3Mask)
	but |= MOUSE_BUT3;
    
    return but;
}

static unsigned int get_button(unsigned int button) {
    switch(button) {
    case Button1:
	return MOUSE_BUT1;
    case Button2:
	return MOUSE_BUT2;
    case Button3:
	return MOUSE_BUT3;
    }
    return 0;
}

/*! \brief Notify observers of the shape at specified
 *	position for mouse event.
 *
 * Observers of parent shapes may be called if the subject is not
 * with SUBF_STOP_PROPAGATE flag.  The subject of mouse event
 * for a shape is returned by sh_get_mouse_event_subject().
 */
static void notify_coord_or_shape(redraw_man_t *rdman,
				   mb_obj_t *obj,
				   co_aix x, co_aix y, int etype,
				   unsigned int state,
				   unsigned int button) {
    mouse_event_t mouse_event;
    subject_t *subject;

    mouse_event.event.type = etype;
    mouse_event.x = x;
    mouse_event.y = y;
    mouse_event.but_state = state;
    mouse_event.button = button;
    
    if(IS_MBO_SHAPES(obj))
	subject = sh_get_mouse_event_subject((shape_t *)obj);
    else
	subject = coord_get_mouse_event((coord_t *)obj);
    
    subject_notify(subject, (event_t *)&mouse_event);
}

/*! \brief Dispatch all X events in the queue.
 */
static void handle_x_event(X_MB_runtime_t *rt) {
    Display *display = rt->display;
    redraw_man_t *rdman = rt->rdman;
    XEvent evt;
    XMotionEvent *mevt;
    XButtonEvent *bevt;
    XExposeEvent *eevt;
    XKeyEvent *xkey;
    co_aix x, y, w, h;

    int eflag = 0;
    int ex1=0, ey1=0, ex2=0, ey2=0;

    shape_t *shape;
    coord_t *root;

    unsigned int state, button;
    int in_stroke;
    int r;

    while(XEventsQueued(display, QueuedAfterReading) > 0) {
	r = XNextEvent(display, &evt);
	if(r == -1)
	    break;

	switch(evt.type) {
	case ButtonPress:
	    bevt = (XButtonEvent *)&evt;
	    x = bevt->x;
	    y = bevt->y;
	    state = get_button_state(bevt->state);
	    button = get_button(bevt->button);

	    shape = find_shape_at_pos(rdman, x, y,
				      &in_stroke);
	    if(shape)
		notify_coord_or_shape(rdman, (mb_obj_t *)shape,
				      x, y, EVT_MOUSE_BUT_PRESS,
				      state, button);
	    break;

	case ButtonRelease:
	    bevt = (XButtonEvent *)&evt;
	    x = bevt->x;
	    y = bevt->y;
	    state = get_button_state(bevt->state);
	    button = get_button(bevt->button);

	    shape = find_shape_at_pos(rdman, x, y,
				      &in_stroke);
	    if(shape)
		notify_coord_or_shape(rdman, (mb_obj_t *)shape,
			      x, y, EVT_MOUSE_BUT_RELEASE,
			      state, button);
	    break;

	case MotionNotify:
	    mevt = (XMotionEvent *)&evt;
	    x = mevt->x;
	    y = mevt->y;
	    state = get_button_state(mevt->state);

	    shape = find_shape_at_pos(rdman, x, y,
				      &in_stroke);
#ifdef ONLY_MOUSE_MOVE_RAW
	    if(shape != NULL) {
		notify_coord_or_shape(rdman, (mb_obj_t *)shape,
			      x, y, EVT_MOUSE_MOVE_RAW, state, 0);
	    } else {
		root = rdman_get_root(rdman);
		notify_coord_or_shape(rdman, (mb_obj_t *)root,
			      x, y, EVT_MOUSE_MOVE_RAW, state, 0);
	    }
#else
	    if(shape != NULL) {
		if(rt->last != shape) {
		    if(rt->last)
			notify_coord_or_shape(rdman, rt->last, x, y,
				      EVT_MOUSE_OUT, state, 0);
		    notify_coord_or_shape(rdman, shape, x, y,
				  EVT_MOUSE_OVER, state, 0);
		    rt->last = shape;
		} else
		    notify_coord_or_shape(rdman, shape, x, y,
				  EVT_MOUSE_MOVE, state, 0);
	    } else {
		if(rt->last) {
		    notify_coord_or_shape(rdman, rt->last, x, y,
				  EVT_MOUSE_OUT, state, 0);
		    rt->last = NULL;
		}
	    }
#endif
	    break;

	case KeyPress:
	case KeyRelease:
	    xkey = &evt.xkey;
	    X_kb_handle_event(&rt->kbinfo, xkey);
	    break;

	case Expose:
	    eevt = &evt.xexpose;
	    x = eevt->x;
	    y = eevt->y;
	    w = eevt->width;
	    h = eevt->height;

	    if(eflag) {
		if(x < ex1)
		    ex1 = x;
		if(y < ey1)
		    ey1 = y;
		if((x + w) > ex2)
		    ex2 = x + w;
		if((y + h) > ey2)
		    ey2 = y + h;
	    } else {
		ex1 = x;
		ey1 = y;
		ex2 = x + w;
		ey2 = y + h;
		eflag = 1;
	    }
	    break;
	}
    }
    if(eflag) {
	rdman_redraw_area(rdman, ex1, ey1, (ex2 - ex1), (ey2 - ey1));
	eflag = 0;
    }
    XFlush(display);
}

/*! \brief Handle connection coming data and timeout of timers.
 *
 * \param display is a Display returned by XOpenDisplay().
 * \param rdman is a redraw manager.
 * \param tman is a timer manager.
 *
 * The display is managed by specified rdman and tman.  rdman draws
 * on the display, and tman trigger actions according timers.
 */
void X_MB_handle_connection(X_MB_runtime_t *rt) {
    Display *display = rt->display;
    redraw_man_t *rdman = rt->rdman;
    mb_tman_t *tman = rt->tman;
    int fd;
    mb_timeval_t now, tmo;
    struct timeval tv;
    fd_set rfds;
    int nfds;
    int r, r1;

    handle_x_event(rt);

    fd = XConnectionNumber(display);
    nfds = fd + 1;
    while(1) {
	FD_ZERO(&rfds);
	FD_SET(fd, &rfds);
	
	get_now(&now);
	r = mb_tman_next_timeout(tman, &now, &tmo);

	if(r == 0) {
	    tv.tv_sec = MB_TIMEVAL_SEC(&tmo);
	    tv.tv_usec = MB_TIMEVAL_USEC(&tmo);
	    r1 = select(nfds, &rfds, NULL, NULL, &tv);
	} else
	    r1 = select(nfds, &rfds, NULL, NULL, NULL);

	if(r1 == -1) {
	    perror("select");
	    break;
	}

	if(r1 == 0) {
	    get_now(&now);
	    mb_tman_handle_timeout(tman, &now);
	    rdman_redraw_changed(rdman);
	    XFlush(display);
	} else if(FD_ISSET(fd, &rfds)){
	    handle_x_event(rt);
	}
    }
}

#define ERR -1
#define OK 0

static int X_init_connection(const char *display_name,
			     int w, int h,
			     Display **displayp,
			     Visual **visualp,
			     Window *winp) {
    Display *display;
    Window root, win;
    Visual *visual;
    int screen;
    XSetWindowAttributes wattr;
    int depth;
    int x, y;
    int r;

    display = XOpenDisplay(display_name);
    if(display == NULL)
	return ERR;

    screen = DefaultScreen(display);
    root = DefaultRootWindow(display);
    visual = DefaultVisual(display, screen);
    depth = DefaultDepth(display, screen);
    wattr.override_redirect = False;
    x = 10;
    y = 10;
    win = XCreateWindow(display, root,
			 x, y,
			 w, h,
			 1, depth, InputOutput, visual,
			 CWOverrideRedirect, &wattr);
    r = XMapWindow(display, win);
    if(r == -1) {
	XCloseDisplay(display);
	return ERR;
    }

    XSelectInput(display, win, PointerMotionMask | ExposureMask |
		 ButtonPressMask | ButtonReleaseMask |
		 KeyPressMask | KeyReleaseMask);
    XFlush(display);

    *displayp = display;
    *visualp = visual;
    *winp = win;

    return OK;
}

/*! \brief Initialize a MadButterfy runtime for Xlib.
 *
 * It setups a runtime environment to run MadButterfly with Xlib.
 * Users should specify width and height of the opening window.
 */
static int X_MB_init(const char *display_name,
	      int w, int h, X_MB_runtime_t *xmb_rt) {
    mb_img_ldr_t *img_ldr;
    
    memset(xmb_rt, 0, sizeof(X_MB_runtime_t));

    xmb_rt->w = w;
    xmb_rt->h = h;
    X_init_connection(display_name, w, h, &xmb_rt->display,
		      &xmb_rt->visual, &xmb_rt->win);

    xmb_rt->surface =
	cairo_image_surface_create(CAIRO_FORMAT_ARGB32, w, h);
    
    xmb_rt->backend_surface =
	cairo_xlib_surface_create(xmb_rt->display,
				  xmb_rt->win,
				  xmb_rt->visual,
				  w, h);

    xmb_rt->cr = cairo_create(xmb_rt->surface);
    xmb_rt->backend_cr = cairo_create(xmb_rt->backend_surface);

    cairo_set_source_surface(xmb_rt->backend_cr, xmb_rt->surface, 0, 0);

    xmb_rt->rdman = (redraw_man_t *)malloc(sizeof(redraw_man_t));
    redraw_man_init(xmb_rt->rdman, xmb_rt->cr, xmb_rt->backend_cr);
    // FIXME: This is a wired loopback reference. This is inly required when we need 
    //        to get the xmb_rt->tman for the animation. We should relocate the tman
    //	      to the redraw_man_t instead.
    xmb_rt->rdman->rt = xmb_rt;

    xmb_rt->tman = mb_tman_new();

    img_ldr = simple_mb_img_ldr_new("./");
    xmb_rt->img_ldr = img_ldr;
    rdman_set_img_ldr(xmb_rt->rdman, img_ldr);
    
#ifndef ONLY_MOUSE_MOVE_RAW
    xmb_rt->last = NULL;
#endif

    X_kb_init(&xmb_rt->kbinfo, xmb_rt->display, xmb_rt->rdman);

    return OK;
}

static void X_MB_destroy(X_MB_runtime_t *xmb_rt) {
    if(xmb_rt->rdman) {
	redraw_man_destroy(xmb_rt->rdman);
	free(xmb_rt->rdman);
    }

    if(xmb_rt->tman)
	mb_tman_free(xmb_rt->tman);

    if(xmb_rt->img_ldr)
	MB_IMG_LDR_FREE(xmb_rt->img_ldr);

    if(xmb_rt->cr)
	cairo_destroy(xmb_rt->cr);
    if(xmb_rt->backend_cr)
	cairo_destroy(xmb_rt->backend_cr);

    if(xmb_rt->surface)
	cairo_surface_destroy(xmb_rt->surface);
    if(xmb_rt->backend_surface)
	cairo_surface_destroy(xmb_rt->backend_surface);

    if(xmb_rt->display)
	XCloseDisplay(xmb_rt->display);

    X_kb_destroy(&xmb_rt->kbinfo);
}

X_MB_runtime_t *X_MB_new(const char *display_name, int w, int h) {
    X_MB_runtime_t *rt;
    int r;

    rt = O_ALLOC(X_MB_runtime_t);
    if(rt == NULL)
	return NULL;

    r = X_MB_init(display_name, w, h, rt);
    if(r != OK)
	return NULL;

    return rt;
}

void X_MB_free(X_MB_runtime_t *rt) {
    X_MB_destroy(rt);
    free(rt);
}

subject_t *X_MB_kbevents(X_MB_runtime_t *xmb_rt) {
    return xmb_rt->kbinfo.kbevents;
}

redraw_man_t *X_MB_rdman(X_MB_runtime_t *xmb_rt) {
    return xmb_rt->rdman;
}

mb_tman_t *X_MB_tman(X_MB_runtime_t *xmb_rt) {
    return xmb_rt->tman;
}

ob_factory_t *X_MB_ob_factory(X_MB_runtime_t *xmb_rt) {
    ob_factory_t *factory;

    factory = rdman_get_ob_factory(xmb_rt->rdman);
    return factory;
}

mb_img_ldr_t *X_MB_img_ldr(X_MB_runtime_t *xmb_rt) {
    X_MB_runtime_t *img_ldr;

    img_ldr = xmb_rt->img_ldr;

    return img_ldr;
}