/****************************************************************************
 * Client placement functions.
 * Copyright (C) 2005 Joe Wingbermuehle
 ****************************************************************************/

#include "jwm.h"
#include "place.h"
#include "client.h"
#include "screen.h"
#include "border.h"
#include "move.h"
#include "tray.h"
#include "timing.h"
#include "main.h"

typedef struct BoundingBox {
	int x, y;
	int width, height;
} BoundingBox;

typedef struct Strut {
	ClientNode *client;
	BoundingBox box;
	struct Strut *prev;
	struct Strut *next;
} Strut;

static Strut *struts = NULL;
static Strut *strutsTail = NULL;

/* desktopCount x screenCount */
/* Note that we assume x and y are 0 based for all screens here. */

static void GetScreenBounds(const ScreenType *sp, BoundingBox *box);
static void UpdateTrayBounds(BoundingBox *box, unsigned int layer);
static void UpdateStrutBounds(BoundingBox *box);
static void SubtractBounds(const BoundingBox *src, BoundingBox *dest);

/****************************************************************************
 ****************************************************************************/
void InitializePlacement() {
}

/****************************************************************************
 ****************************************************************************/
void StartupPlacement() {
}

/****************************************************************************
 ****************************************************************************/
void ShutdownPlacement() {

	Strut *sp;

	while(struts) {
		sp = struts->next;
		Release(struts);
		struts = sp;
	}
	strutsTail = NULL;

}

/****************************************************************************
 ****************************************************************************/
void DestroyPlacement() {
}

/****************************************************************************
 ****************************************************************************/
void RemoveClientStrut(ClientNode *np) {

	Strut *sp;

	for(sp = struts; sp; sp = sp->next) {
		if(sp->client == np) {
			if(sp->prev) {
				sp->prev->next = sp->next;
			} else {
				struts = sp->next;
			}
			if(sp->next) {
				sp->next->prev = sp->prev;
			} else {
				strutsTail = sp->prev;
			}
			Release(sp);
		}
	}

}

/****************************************************************************
 ****************************************************************************/
void ReadClientStrut(ClientNode *np) {

	BoundingBox box;
	Strut *sp;
	int status;
	Atom actualType;
	int actualFormat;
	unsigned long count;
	unsigned long bytesLeft;
	unsigned char *value;
	long *lvalue;
	long leftWidth, rightWidth, topHeight, bottomHeight;
	long leftStart, leftEnd, rightStart, rightEnd;
	long topStart, topEnd, bottomStart, bottomEnd;

	RemoveClientStrut(np);

	box.x = 0;
	box.y = 0;
	box.width = 0;
	box.height = 0;

	/* First try to read _NET_WM_STRUT_PARTIAL */
	/* Format is:
	 *   left_width, right_width, top_width, bottom_width,
	 *   left_start_y, left_end_y, right_start_y, right_end_y,
	 *   top_start_x, top_end_x, bottom_start_x, bottom_end_x
	 */
	status = JXGetWindowProperty(display, np->window,
		atoms[ATOM_NET_WM_STRUT_PARTIAL], 0, 12, False, XA_CARDINAL,
		&actualType, &actualFormat, &count, &bytesLeft, &value);
	if(status == Success) {
		if(count == 12) {
			lvalue = (long*)value;
			leftWidth = lvalue[0];
			rightWidth = lvalue[1];
			topHeight = lvalue[2];
			bottomHeight = lvalue[3];
			leftStart = lvalue[4];
			leftEnd = lvalue[5];
			rightStart = lvalue[6];
			rightEnd = lvalue[7];
			topStart = lvalue[8];
			topEnd = lvalue[9];
			bottomStart = lvalue[10];
			bottomEnd = lvalue[11];

			if(leftWidth > 0) {
				box.width = leftWidth;
				box.x = leftStart;
			}

			if(rightWidth > 0) {
				box.width = rightWidth;
				box.x = rightStart;
			}

			if(topHeight > 0) {
				box.height = topHeight;
				box.y = topStart;
			}

			if(bottomHeight > 0) {
				box.height = bottomHeight;
				box.y = bottomStart;
			}

			sp = Allocate(sizeof(Strut));
			sp->client = np;
			sp->box = box;
			sp->prev = NULL;
			sp->next = struts;
			if(struts) {
				struts->prev = sp;
			} else {
				strutsTail = sp;
			}
			struts = sp;

		}
		JXFree(value);
		return;
	}

	/* Next try to read _NET_WM_STRUT */
	/* Format is: left_width, right_width, top_width, bottom_width */
	status = JXGetWindowProperty(display, np->window,
		atoms[ATOM_NET_WM_STRUT], 0, 4, False, XA_CARDINAL,
		&actualType, &actualFormat, &count, &bytesLeft, &value);
	if(status == Success) {
		if(count == 4) {
			lvalue = (long*)value;
			leftWidth = lvalue[0];
			rightWidth = lvalue[1];
			topHeight = lvalue[2];
			bottomHeight = lvalue[3];

			if(leftWidth > 0) {
				box.x = 0;
				box.width = leftWidth;
			}

			if(rightWidth > 0) {
				box.x = rootWidth - rightWidth;
				box.width = rightWidth;
			}

			if(topHeight > 0) {
				box.y = 0;
				box.height = topHeight;
			}

			if(bottomHeight > 0) {
				box.y = rootHeight - bottomHeight;
				box.height = bottomHeight;
			}

			sp = Allocate(sizeof(Strut));
			sp->client = np;
			sp->box = box;
			sp->prev = NULL;
			sp->next = struts;
			if(struts) {
				struts->prev = sp;
			} else {
				strutsTail = sp;
			}
			struts = sp;

		}
		JXFree(value);
		return;
	}

}

/****************************************************************************
 ****************************************************************************/
void GetScreenBounds(const ScreenType *sp, BoundingBox *box) {

	box->x = sp->x;
	box->y = sp->y;
	box->width = sp->width;
	box->height = sp->height;

}

/****************************************************************************
 * Shrink dest such that it does not intersect with src.
 ****************************************************************************/
void SubtractBounds(const BoundingBox *src, BoundingBox *dest) {

	BoundingBox boxes[4];

	if(src->x + src->width <= dest->x) {
		return;
	}
	if(src->y + src->height <= dest->y) {
		return;
	}
	if(dest->x + dest->width <= src->x) {
		return;
	}
	if(dest->y + dest->height <= src->y) {
		return;
	}

	/* There are four ways to do this:
	 *  0. Increase the x-coordinate and decrease the width of dest.
	 *  1. Increase the y-coordinate and decrease the height of dest.
	 *  2. Decrease the width of dest.
	 *  3. Decrease the height of dest.
	 * We will chose the option which leaves the greatest area.
	 * Note that negative areas are possible.
	 */

	/* 0 */
	boxes[0] = *dest;
	boxes[0].x = src->x + src->width;
	boxes[0].width = dest->x + dest->width - boxes[0].x;

	/* 1 */
	boxes[1] = *dest;
	boxes[1].y = src->y + src->height;
	boxes[1].height = dest->y + dest->height - boxes[1].y;

	/* 2 */
	boxes[2] = *dest;
	boxes[2].width = src->x - dest->x;

	/* 3 */
	boxes[3] = *dest;
	boxes[3].height = src->y - dest->y;

	/* 0 and 1, winner in 0. */
	if(boxes[0].width * boxes[0].height < boxes[1].width * boxes[1].height) {
		boxes[0] = boxes[1];
	}

	/* 2 and 3, winner in 2. */
	if(boxes[2].width * boxes[2].height < boxes[3].width * boxes[3].height) {
		boxes[2] = boxes[3];
	}

	/* 0 and 2, winner in dest. */
	if(boxes[0].width * boxes[0].height < boxes[2].width * boxes[2].height) {
		*dest = boxes[2];
	} else {
		*dest = boxes[0];
	}

}

/****************************************************************************
 ****************************************************************************/
void UpdateTrayBounds(BoundingBox *box, unsigned int layer) {

	TrayType *tp;
	BoundingBox src;
	BoundingBox last;

	for(tp = GetTrays(); tp; tp = tp->next) {

		if(tp->layer > layer && !tp->autoHide) {

			src.x = tp->x;
			src.y = tp->y;
			src.width = tp->width;
			src.height = tp->height;

			last = *box;
			SubtractBounds(&src, box);
			if(box->width * box->height <= 0) {
				*box = last;
				break;
			}

		}

	}

}

/****************************************************************************
 ****************************************************************************/
void UpdateStrutBounds(BoundingBox *box) {

	Strut *sp;
	BoundingBox last;

	for(sp = struts; sp; sp = sp->next) {
		if(sp->client->state.desktop == currentDesktop
			|| (sp->client->state.status & STAT_STICKY)) {
			continue;
		}
		last = *box;
		SubtractBounds(&sp->box, box);
		if(box->width * box->height <= 0) {
			*box = last;
			break;
		}
	}

}

/****************************************************************************
 ****************************************************************************/
void PlaceClient(ClientNode *np, int alreadyMapped) {

	static int prevx = -1;
	static int prevy = -1;
	static TimeType last = ZERO_TIME;

	BoundingBox box;
	const ScreenType *sp;
	int height, offset, overflow, width, winx, winy, x, y;
	int north, south, east, west;
	TimeType now;
        unsigned int mask;
        Window rootReturn, childReturn;

	Assert(np);

	GetBorderSize(np, &north, &south, &east, &west);

	if(np->x + np->width > rootWidth || np->y + np->height > rootWidth) {
		overflow = 1;
	} else {
		overflow = 0;
	}

	sp = GetMouseScreen();
	GetScreenBounds(sp, &box);

	if(!overflow && (alreadyMapped
		|| (!(np->state.status & STAT_PIGNORE)
		&& (np->sizeFlags & (PPosition | USPosition))))) {

		GravitateClient(np, 0);

	} else {

		UpdateTrayBounds(&box, np->state.layer);
		UpdateStrutBounds(&box);

		/* Check cursor location. */
		JXQueryPointer(display, rootWindow, &rootReturn, &childReturn,
			&x, &y, &winx, &winy, &mask);

		/* Set offset if needed. */
		if(prevx > -1 && prevy > -1
		&& (abs(x - prevx) <= borderWidth
		 || abs(y - prevy) <= borderWidth))
			offset = borderWidth + titleHeight;
		else
			offset = 0;

		/* Unset offset if too late. */
		GetCurrentTime(&now);
		if (GetTimeDifference(&now, &last) > 500)
			offset = 0;
		last = now;

		/* Show window at cursor. */
		width = np->width;
		height = np->height;
		if(np->state.border & BORDER_OUTLINE) {
			x += borderWidth;
			y += borderWidth;
			width += borderWidth * 2;
			height += borderWidth * 2;
		}
		if(np->state.border & BORDER_TITLE) {
			y += titleHeight;
			height += titleHeight;
		}
		x -= width / 2;
		y -= height / 2;
		np->x = x;
		np->y = y;

		/* Correct for overflow. */
		ReturnToBorder(np, north, west);

		np->x += offset;
		np->y += offset;
		MoveMouseToClient(np);

		/* Save cursor location. */
		JXQueryPointer(display, rootWindow, &rootReturn, &childReturn,
			&x, &y, &winx, &winy, &mask);
		prevx = x;
		prevy = y;
	}


	if(np->state.status & STAT_FULLSCREEN) {
		JXMoveWindow(display, np->parent, sp->x, sp->y);
	} else {
		JXMoveWindow(display, np->parent, np->x - west, np->y - north);
	}

}

/****************************************************************************
 ****************************************************************************/
void ConstrainSize(ClientNode *np) {

	BoundingBox box;
	const ScreenType *sp;
	int north, south, east, west;
	float ratio, minr, maxr;

	Assert(np);

	/* Determine if the size needs to be constrained. */
	sp = GetCurrentScreen(np->x, np->y);
	if(np->width < sp->width && np->height < sp->height) {
		return;
	}

	/* Constrain the size. */
	GetBorderSize(np, &north, &south, &east, &west);

	GetScreenBounds(sp, &box);
	UpdateTrayBounds(&box, np->state.layer);
	UpdateStrutBounds(&box);

	box.x += west;
	box.y += north;
	box.width -= east + west;
	box.height -= north + south;

	if(box.width > np->maxWidth) {
		box.width = np->maxWidth;
	}
	if(box.height > np->maxHeight) {
		box.height = np->maxHeight;
	}

	if(np->sizeFlags & PAspect) {

		ratio = (float)box.width / box.height;

		minr = (float)np->aspect.minx / np->aspect.miny;
		if(ratio < minr) {
			box.height = (int)((float)box.width / minr);
		}

		maxr = (float)np->aspect.maxx / np->aspect.maxy;
		if(ratio > maxr) {
			box.width = (int)((float)box.height * maxr);
		}

	}

	np->x = box.x;
	np->y = box.y;
	np->width = box.width - (box.width % np->xinc);
	np->height = box.height - (box.height % np->yinc);

}

/****************************************************************************
 ****************************************************************************/
void PlaceMaximizedClient(ClientNode *np) {

	BoundingBox box;
	const ScreenType *sp;
	int north, south, east, west;
	float ratio, minr, maxr;

	np->oldx = np->x;
	np->oldy = np->y;
	np->oldWidth = np->width;
	np->oldHeight = np->height;

	GetBorderSize(np, &north, &south, &east, &west);

	sp = GetCurrentScreen(
		np->x + (east + west + np->width) / 2,
		np->y + (north + south + np->height) / 2);
	GetScreenBounds(sp, &box);
	UpdateTrayBounds(&box, np->state.layer);
	UpdateStrutBounds(&box);

	box.x += west;
	box.y += north;
	box.width -= east + west;
	box.height -= north + south;

	if(box.width > np->maxWidth) {
		box.width = np->maxWidth;
	}
	if(box.height > np->maxHeight) {
		box.height = np->maxHeight;
	}

	if(np->sizeFlags & PAspect) {

		ratio = (float)box.width / box.height;

		minr = (float)np->aspect.minx / np->aspect.miny;
		if(ratio < minr) {
			box.height = (int)((float)box.width / minr);
		}

		maxr = (float)np->aspect.maxx / np->aspect.maxy;
		if(ratio > maxr) {
			box.width = (int)((float)box.height * maxr);
		}

	}

	np->x = box.x;
	np->y = box.y;
	np->width = box.width - (box.width % np->xinc);
	np->height = box.height - (box.height % np->yinc);

	np->state.status |= STAT_MAXIMIZED;

}

/****************************************************************************
 ****************************************************************************/
void GetGravityDelta(const ClientNode *np, int *x, int  *y) {

	int north, south, east, west;

	Assert(np);
	Assert(x);
	Assert(y);

	GetBorderSize(np, &north, &south, &east, &west);

	switch(np->gravity) {
	case NorthWestGravity:
		*y = -north;
		*x = -west;
		break;
	case NorthGravity:
		*y = -north;
		break;
	case NorthEastGravity:
		*y = -north;
		*x = west;
		break;
	case WestGravity:
		*x = -west;
		break;
	case CenterGravity:
		*y = (north + south) / 2;
		*x = (east + west) / 2;
		break;
	case EastGravity:
		*x = west;
		break;
	case SouthWestGravity:
		*y = south;
		*x = -west;
		break;
	case SouthGravity:
		*y = south;
		break;
	case SouthEastGravity:
		*y = south;
		*x = west;
		break;
	default: /* Static */
		*x = 0;
		*y = 0;
		break;
	}

}

/****************************************************************************
 * Move the window in the specified direction for reparenting.
 ****************************************************************************/
void GravitateClient(ClientNode *np, int negate) {

	int deltax, deltay;

	Assert(np);

	GetGravityDelta(np, &deltax, &deltay);

	if(negate) {
		np->x += deltax;
		np->y += deltay;
	} else {
		np->x -= deltax;
		np->y -= deltay;
	}

}