/*
 * geom.c -- backend-neutral window geometry constraint functions
 *
 * Contains only pure geometry arithmetic: no Xlib, no display calls.
 * Unit tests link this file standalone (without -lX11).
 *
 * Phase 5: extracted from window.c.
 */

#include "wconfig.h"

#include "WindowMaker.h"   /* WPreferences, wPreferences */
#include "screen.h"        /* WScreen */
#include "window.h"        /* WWindow, WNormalHints */
#include "geom.h"

/*
 *----------------------------------------------------------------------
 * wWindowConstrainSize--
 * 	Constrains size for the client window, taking the maximal size,
 * window resize increments and other size hints into account.
 *
 * Returns:
 * 	The closest size to what was given that the client window can
 * have.
 *
 *----------------------------------------------------------------------
 */
void wWindowConstrainSize(WWindow *wwin, unsigned int *nwidth, unsigned int *nheight)
{
	int width = (int)*nwidth;
	int height = (int)*nheight;
	int winc = 1;
	int hinc = 1;
	int minW = 1, minH = 1;
	int maxW = wwin->screen_ptr->scr_width * 2;
	int maxH = wwin->screen_ptr->scr_height * 2;
	int minAX = -1, minAY = -1;
	int maxAX = -1, maxAY = -1;
	int baseW = 0;
	int baseH = 0;

	if (wwin->normal_hints) {
		if (!wwin->flags.maximized) {
			winc = wwin->normal_hints->width_inc;
			hinc = wwin->normal_hints->height_inc;
		}
		if (wwin->normal_hints->min_width > minW)
			minW = wwin->normal_hints->min_width;
		if (wwin->normal_hints->min_height > minH)
			minH = wwin->normal_hints->min_height;
		if (wwin->normal_hints->max_width < maxW)
			maxW = wwin->normal_hints->max_width;
		if (wwin->normal_hints->max_height < maxH)
			maxH = wwin->normal_hints->max_height;

		if (wwin->normal_hints->flags & WNH_P_ASPECT) {
			minAX = wwin->normal_hints->min_aspect.x;
			minAY = wwin->normal_hints->min_aspect.y;
			maxAX = wwin->normal_hints->max_aspect.x;
			maxAY = wwin->normal_hints->max_aspect.y;
		}

		baseW = wwin->normal_hints->base_width;
		baseH = wwin->normal_hints->base_height;
	}

	/* trust the mins provided by the client but not the maxs */
	if (width < minW)
		width = minW;
	if (height < minH)
		height = minH;

	/* if only one dimension is over the top, set a default 4/3 ratio */
	if (width > maxW && height < maxH)
		width = height * 4 / 3;
	else if(height > maxH && width < maxW)
		height = width * 3 / 4;
	else if(width > maxW && height > maxH) {
		/* if both are over the top, set size to almost fullscreen */
		height = wwin->screen_ptr->scr_height - 2 * wPreferences.icon_size;
		width = wwin->screen_ptr->scr_width - 2 * wPreferences.icon_size;
	}

	/* aspect ratio code borrowed from olwm */
	if (minAX > 0) {
		/* adjust max aspect ratio */
		if (!(maxAX == 1 && maxAY == 1) && width * maxAY > height * maxAX) {
			if (maxAX > maxAY) {
				height = (width * maxAY) / maxAX;
				if (height > maxH) {
					height = maxH;
					width = (height * maxAX) / maxAY;
				}
			} else {
				width = (height * maxAX) / maxAY;
				if (width > maxW) {
					width = maxW;
					height = (width * maxAY) / maxAX;
				}
			}
		}

		/* adjust min aspect ratio */
		if (!(minAX == 1 && minAY == 1) && width * minAY < height * minAX) {
			if (minAX > minAY) {
				height = (width * minAY) / minAX;
				if (height < minH) {
					height = minH;
					width = (height * minAX) / minAY;
				}
			} else {
				width = (height * minAX) / minAY;
				if (width < minW) {
					width = minW;
					height = (width * minAY) / minAX;
				}
			}
		}
	}

	if (!wwin->flags.maximized) {
		if (baseW != 0)
			width = (((width - baseW) / winc) * winc) + baseW;
		else
			width = (((width - minW) / winc) * winc) + minW;

		if (baseH != 0)
			height = (((height - baseH) / hinc) * hinc) + baseH;
		else
			height = (((height - minH) / hinc) * hinc) + minH;
	}

	/* broken stupid apps may cause preposterous values for these.. */
	if (width > 0)
		*nwidth = width;
	if (height > 0)
		*nheight = height;
}

void wWindowCropSize(WWindow *wwin, unsigned int maxW, unsigned int maxH,
		     unsigned int *width, unsigned int *height)
{
	int baseW = 0, baseH = 0;
	int winc = 1, hinc = 1;

	if (wwin->normal_hints) {
		baseW = wwin->normal_hints->base_width;
		baseH = wwin->normal_hints->base_height;

		winc = wwin->normal_hints->width_inc;
		hinc = wwin->normal_hints->height_inc;
	}

	if (*width > maxW)
		*width = maxW - (maxW - baseW) % winc;

	if (*height > maxH)
		*height = maxH - (maxH - baseH) % hinc;
}