#include <u.h>
#include <libc.h>
#include <draw.h>
#include <event.h>
#include <panel.h>
#include "pldefs.h"
int pl_max(int a, int b){
	return a>b?a:b;
}
Point pl_sizesibs(Panel *p){
	Point s;
	if(p==0) return Pt(0,0);
	s=pl_sizesibs(p->next);
	switch(p->flags&PACK){
	case PACKN:
	case PACKS:
		s.x=pl_max(s.x, p->sizereq.x);
		s.y+=p->sizereq.y;
		break;
	case PACKE:
	case PACKW:
		s.x+=p->sizereq.x;
		s.y=pl_max(s.y, p->sizereq.y);
		break;
	}
	return s;
}
/*
 * Compute the requested size of p and its descendants.
 */
void pl_sizereq(Panel *p){
	Panel *cp;
	Point maxsize;
	maxsize=Pt(0,0);
	for(cp=p->child;cp;cp=cp->next){
		pl_sizereq(cp);
		if(cp->sizereq.x>maxsize.x) maxsize.x=cp->sizereq.x;
		if(cp->sizereq.y>maxsize.y) maxsize.y=cp->sizereq.y;
	}
	for(cp=p->child;cp;cp=cp->next){
		if(cp->flags&MAXX) cp->sizereq.x=maxsize.x;
		if(cp->flags&MAXY) cp->sizereq.y=maxsize.y;
	}
	p->childreq=pl_sizesibs(p->child);
	p->sizereq=addpt(addpt(p->getsize(p, p->childreq), p->ipad), p->pad);
	if(p->flags&FIXEDX) p->sizereq.x=p->fixedsize.x;
	if(p->flags&FIXEDY) p->sizereq.y=p->fixedsize.y;
}
Point pl_getshare(Panel *p){
	Point share;
	if(p==0) return Pt(0,0);
	share=pl_getshare(p->next);
	if(p->flags&EXPAND) switch(p->flags&PACK){
	case PACKN:
	case PACKS:
		if(share.x==0) share.x=1;
		share.y++;
		break;
	case PACKE:
	case PACKW:
		share.x++;
		if(share.y==0) share.y=1;
		break;
	}
	return share;
}
/*
 * Set the sizes and rectangles of p and its descendants, given their requested sizes.
 * Returns 1 if everything fit, 0 otherwise.
 * For now we punt in the case that the children don't all fit.
 * Possibly we should shrink all the children's sizereqs to fit,
 * by the same means used to do EXPAND, except clamping at some minimum size,
 * but that smacks of AI.
 */
Panel *pl_toosmall;
int pl_setrect(Panel *p, Point ul, Point avail){
	Point space, newul, newspace, slack, share;
	int l;
	Panel *c;
	p->size=subpt(p->sizereq, p->pad);
	ul=addpt(ul, divpt(p->pad, 2));
	avail=subpt(avail, p->pad);
	if(p->size.x>avail.x || p->size.y>avail.y){
		pl_toosmall=p;
		return 0;	/* not enough space! */
	}
	if(p->flags&(FILLX|EXPAND)) p->size.x=avail.x;
	if(p->flags&(FILLY|EXPAND)) p->size.y=avail.y;
	switch(p->flags&PLACE){
	case PLACECEN:	ul.x+=(avail.x-p->size.x)/2; ul.y+=(avail.y-p->size.y)/2; break;
	case PLACES:	ul.x+=(avail.x-p->size.x)/2; ul.y+= avail.y-p->size.y   ; break;
	case PLACEE:	ul.x+= avail.x-p->size.x   ; ul.y+=(avail.y-p->size.y)/2; break;
	case PLACEW:	                             ul.y+=(avail.y-p->size.y)/2; break;
	case PLACEN:	ul.x+=(avail.x-p->size.x)/2;                              break;
	case PLACENE:	ul.x+= avail.x-p->size.x   ;                              break;
	case PLACENW:                                                             break;
	case PLACESE:	ul.x+= avail.x-p->size.x   ; ul.y+= avail.y-p->size.y   ; break;
	case PLACESW:                                ul.y+= avail.y-p->size.y   ; break;
	}
	p->r=Rpt(ul, addpt(ul, p->size));
	space=p->size;
	p->childspace(p, &ul, &space);
	slack=subpt(space, p->childreq);
	share=pl_getshare(p->child);
	for(c=p->child;c;c=c->next){
		if(c->flags&EXPAND){
			switch(c->flags&PACK){
			case PACKN:
			case PACKS:
				c->sizereq.x+=slack.x;
				l=slack.y/share.y;
				c->sizereq.y+=l;
				slack.y-=l;
				--share.y;
				break;
			case PACKE:
			case PACKW:
				l=slack.x/share.x;
				c->sizereq.x+=l;
				slack.x-=l;
				--share.x;
				c->sizereq.y+=slack.y;
				break;
			}
		}
		switch(c->flags&PACK){
		case PACKN:
			newul=Pt(ul.x, ul.y+c->sizereq.y);
			newspace=Pt(space.x, space.y-c->sizereq.y);
			if(!pl_setrect(c, ul, Pt(space.x, c->sizereq.y))) return 0;
			break;
		case PACKW:
			newul=Pt(ul.x+c->sizereq.x, ul.y);
			newspace=Pt(space.x-c->sizereq.x, space.y);
			if(!pl_setrect(c, ul, Pt(c->sizereq.x, space.y))) return 0;
			break;
		case PACKS:
			newul=ul;
			newspace=Pt(space.x, space.y-c->sizereq.y);
			if(!pl_setrect(c, Pt(ul.x, ul.y+space.y-c->sizereq.y),
				Pt(space.x, c->sizereq.y))) return 0;
			break;
		case PACKE:
			newul=ul;
			newspace=Pt(space.x-c->sizereq.x, space.y);
			if(!pl_setrect(c, Pt(ul.x+space.x-c->sizereq.x, ul.y),
				Pt(c->sizereq.x, space.y))) return 0;
			break;
		}
		ul=newul;
		space=newspace;
	}
	return 1;
}
int plpack(Panel *p, Rectangle where){
	pl_sizereq(p);
	return pl_setrect(p, where.min, subpt(where.max, where.min));
}
/*
 * move an already-packed panel so that p->r=raddp(p->r, d)
 */
void plmove(Panel *p, Point d){
	if(strcmp(p->kind, "edit") == 0)	/* sorry */
		plemove(p, d);
	p->r=rectaddpt(p->r, d);
	for(p=p->child;p;p=p->next) plmove(p, d);
}