/*
 * (C)opyright MMVI Anselm R. Garbe <garbeam at gmail dot com>
 * See LICENSE file for license details.
 */
#include "dwm.h"
#include <stdlib.h>
#include <string.h>
#include <X11/Xatom.h>
#include <X11/Xutil.h>

/* static functions */

static void
detachstack(Client *c) {
	Client **tc;
	for(tc=&stack; *tc && *tc != c; tc=&(*tc)->snext);
	*tc = c->snext;
}

static void
grabbuttons(Client *c, Bool focused) {
	XUngrabButton(dpy, AnyButton, AnyModifier, c->win);

	if(focused) {
		XGrabButton(dpy, Button1, MODKEY, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button1, MODKEY | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button1, MODKEY | numlockmask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button1, MODKEY | numlockmask | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);

		XGrabButton(dpy, Button2, MODKEY, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button2, MODKEY | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button2, MODKEY | numlockmask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button2, MODKEY | numlockmask | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);

		XGrabButton(dpy, Button3, MODKEY, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button3, MODKEY | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button3, MODKEY | numlockmask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button3, MODKEY | numlockmask | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
	}
	else
		XGrabButton(dpy, AnyButton, AnyModifier, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
}

static void
resizetitle(Client *c) {
	c->tw = textw(c->name);
	if(c->tw > c->w)
		c->tw = c->w + 2;
	c->tx = c->x + c->w - c->tw + 2;
	c->ty = c->y;
	if(isvisible(c))
		XMoveResizeWindow(dpy, c->twin, c->tx, c->ty, c->tw, c->th);
	else
		XMoveResizeWindow(dpy, c->twin, c->tx + 2 * sw, c->ty, c->tw, c->th);
}

static int
xerrordummy(Display *dsply, XErrorEvent *ee) {
	return 0;
}

/* extern functions */

void
ban(Client *c) {
	XMoveWindow(dpy, c->win, c->x + 2 * sw, c->y);
	XMoveWindow(dpy, c->twin, c->tx + 2 * sw, c->ty);
}

void
focus(Client *c) {
	Client *old;

	if(!issel || (c && !isvisible(c)))
		return;
	if(!sel)
		sel = c;
	else if(sel != c) {
		old = sel;
		sel = c;
		if(old) {
			grabbuttons(old, False);
			drawtitle(old);
		}
	}
	if(c) {
		detachstack(c);
		c->snext = stack;
		stack = c;
		grabbuttons(c, True);
		drawtitle(c);
		XSetInputFocus(dpy, c->win, RevertToPointerRoot, CurrentTime);
	}
	else
		XSetInputFocus(dpy, root, RevertToPointerRoot, CurrentTime);
}

Client *
getclient(Window w) {
	Client *c;

	for(c = clients; c; c = c->next)
		if(c->win == w)
			return c;
	return NULL;
}

Client *
getctitle(Window w) {
	Client *c;

	for(c = clients; c; c = c->next)
		if(c->twin == w)
			return c;
	return NULL;
}

void
gravitate(Client *c, Bool invert) {
	int dx = 0, dy = 0;

	switch(c->grav) {
	default:
		break;
	case StaticGravity:
	case NorthWestGravity:
	case NorthGravity:
	case NorthEastGravity:
		dy = c->border;
		break;
	case EastGravity:
	case CenterGravity:
	case WestGravity:
		dy = -(c->h / 2) + c->border;
		break;
	case SouthEastGravity:
	case SouthGravity:
	case SouthWestGravity:
		dy = -(c->h);
		break;
	}

	switch (c->grav) {
	default:
		break;
	case StaticGravity:
	case NorthWestGravity:
	case WestGravity:
	case SouthWestGravity:
		dx = c->border;
		break;
	case NorthGravity:
	case CenterGravity:
	case SouthGravity:
		dx = -(c->w / 2) + c->border;
		break;
	case NorthEastGravity:
	case EastGravity:
	case SouthEastGravity:
		dx = -(c->w + c->border);
		break;
	}

	if(invert) {
		dx = -dx;
		dy = -dy;
	}
	c->x += dx;
	c->y += dy;
}

void
killclient(Arg *arg) {
	if(!sel)
		return;
	if(sel->proto & PROTODELWIN)
		sendevent(sel->win, wmatom[WMProtocols], wmatom[WMDelete]);
	else
		XKillClient(dpy, sel->win);
}

void
manage(Window w, XWindowAttributes *wa) {
	Client *c;
	Window trans;
	XSetWindowAttributes twa;

	c = emallocz(sizeof(Client));
	c->tags = emallocz(ntags * sizeof(Bool));
	c->win = w;
	c->x = c->tx = wa->x;
	c->y = c->ty = wa->y;
	c->w = c->tw = wa->width;
	c->h = wa->height;
	c->th = bh;
	c->rx = sx;
	c->ry = bh;
	c->rw = sw;
	c->rh = sh - bh;

	c->border = 0;
	updatesize(c);

	if(c->x + c->w + 2 > sw)
		c->x = sw - c->w - 2;
	if(c->x < 0)
		c->x = 0;
	if(c->y + c->h + 2 > sh)
		c->y = sh - c->h - 2;
	if(c->h != sh && c->y < bh)
		c->y = bh;

	c->proto = getproto(c->win);
	XSelectInput(dpy, c->win,
		StructureNotifyMask | PropertyChangeMask | EnterWindowMask);
	XGetTransientForHint(dpy, c->win, &trans);
	twa.override_redirect = 1;
	twa.background_pixmap = ParentRelative;
	twa.event_mask = ExposureMask | EnterWindowMask;

	c->twin = XCreateWindow(dpy, root, c->tx, c->ty, c->tw, c->th,
			0, DefaultDepth(dpy, screen), CopyFromParent,
			DefaultVisual(dpy, screen),
			CWOverrideRedirect | CWBackPixmap | CWEventMask, &twa);

	grabbuttons(c, False);
	settags(c, getclient(trans));
	if(!c->isfloat)
		c->isfloat = trans
			|| (c->maxw && c->minw &&
				c->maxw == c->minw && c->maxh == c->minh);

	if(clients)
		clients->prev = c;
	c->next = clients;
	c->snext = stack;
	stack = clients = c;

	updatetitle(c);
	ban(c);
	XMapWindow(dpy, c->win);
	XMapWindow(dpy, c->twin);
	if(isvisible(c))
		focus(c);
	arrange(NULL);
}

void
resize(Client *c, Bool sizehints, Corner sticky) {
	int bottom = c->y + c->h;
	int right = c->x + c->w;
	XWindowChanges wc;

	if(sizehints) {
		if(c->incw)
			c->w -= (c->w - c->basew) % c->incw;
		if(c->inch)
			c->h -= (c->h - c->baseh) % c->inch;
		if(c->minw && c->w < c->minw)
			c->w = c->minw;
		if(c->minh && c->h < c->minh)
			c->h = c->minh;
		if(c->maxw && c->w > c->maxw)
			c->w = c->maxw;
		if(c->maxh && c->h > c->maxh)
			c->h = c->maxh;
	}
	if(sticky == TopRight || sticky == BotRight)
		c->x = right - c->w;
	if(sticky == BotLeft || sticky == BotRight)
		c->y = bottom - c->h;

	/* offscreen appearance fixes */
	if(c->x + c->w < 0)
		c->x = 0;
	if(c->y + c->h < bh)
		c->y = bh;
	if(c->x > sw)
		c->x = sw - c->w;
	if(c->y > sh)
		c->y = sh - c->h;

	resizetitle(c);
	wc.x = c->x;
	wc.y = c->y;
	wc.width = c->w;
	wc.height = c->h;
	if(c->w == sw && c->h == sh)
		wc.border_width = 0;
	else
		wc.border_width = 1;
	XConfigureWindow(dpy, c->win, CWX | CWY | CWWidth | CWHeight | CWBorderWidth, &wc);
	XSync(dpy, False);
}

void
updatesize(Client *c) {
	long msize;
	XSizeHints size;

	if(!XGetWMNormalHints(dpy, c->win, &size, &msize) || !size.flags)
		size.flags = PSize;
	c->flags = size.flags;
	if(c->flags & PBaseSize) {
		c->basew = size.base_width;
		c->baseh = size.base_height;
	}
	else
		c->basew = c->baseh = 0;
	if(c->flags & PResizeInc) {
		c->incw = size.width_inc;
		c->inch = size.height_inc;
	}
	else
		c->incw = c->inch = 0;
	if(c->flags & PMaxSize) {
		c->maxw = size.max_width;
		c->maxh = size.max_height;
	}
	else
		c->maxw = c->maxh = 0;
	if(c->flags & PMinSize) {
		c->minw = size.min_width;
		c->minh = size.min_height;
	}
	else
		c->minw = c->minh = 0;
	if(c->flags & PWinGravity)
		c->grav = size.win_gravity;
	else
		c->grav = NorthWestGravity;
}

void
updatetitle(Client *c) {
	char **list = NULL;
	int n;
	XTextProperty name;

	name.nitems = 0;
	c->name[0] = 0;
	XGetTextProperty(dpy, c->win, &name, netatom[NetWMName]);
	if(!name.nitems)
		XGetWMName(dpy, c->win, &name);
	if(!name.nitems)
		return;
	if(name.encoding == XA_STRING)
		strncpy(c->name, (char *)name.value, sizeof(c->name));
	else {
		if(XmbTextPropertyToTextList(dpy, &name, &list, &n) >= Success
				&& n > 0 && *list)
		{
			strncpy(c->name, *list, sizeof(c->name));
			XFreeStringList(list);
		}
	}
	XFree(name.value);
	resizetitle(c);
}

void
unmanage(Client *c) {
	Client *nc;

	/* The server grab construct avoids race conditions. */
	XGrabServer(dpy);
	XSetErrorHandler(xerrordummy);

	detach(c);
	detachstack(c);
	if(sel == c) {
		for(nc = stack; nc && !isvisible(nc); nc = nc->snext);
		focus(nc);
	}

	XUngrabButton(dpy, AnyButton, AnyModifier, c->win);
	XDestroyWindow(dpy, c->twin);

	free(c->tags);
	free(c);

	XSync(dpy, False);
	XSetErrorHandler(xerror);
	XUngrabServer(dpy);
	arrange(NULL);
}