#include <thread.h>

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>
#include <cursor.h>
#include <mouse.h>
#include <keyboard.h>
#include <frame.h>
#include <fcall.h>
#include "dat.h"
#include "fns.h"

static Image *scrtmp;

static
Image*
scrtemps(void)
{
int h;

if(scrtmp == nil){
h = BIG*Dy(screen->r);
scrtmp = allocimage(display, Rect(0, 0, 32, h), screen->chan, 0, DNofill);
}
return scrtmp;
}

void
freescrtemps(void)
{
if(scrtmp){
freeimage(scrtmp);
scrtmp = nil;
}
}

static
Rectangle
scrpos(Rectangle r, uint p0, uint p1, uint tot)
{
Rectangle q;
int h;

q = r;
h = q.max.y-q.min.y;
if(tot == 0)
return q;
if(tot > 1024*1024){
tot>>=10;
p0>>=10;
p1>>=10;
}
if(p0 > 0)
q.min.y += h*p0/tot;
if(p1 < tot)
q.max.y -= h*(tot-p1)/tot;
if(q.max.y < q.min.y+2){
if(q.min.y+2 <= r.max.y)
q.max.y = q.min.y+2;
else
q.min.y = q.max.y-2;
}
return q;
}

void
wscrdraw(Window *w)
{
Rectangle r, r1, r2;
Image *b;

b = scrtemps();
if(b == nil || w->i == nil)
return;
r = w->scrollr;
r1 = r;
r1.min.x = 0;
r1.max.x = Dx(r);
r2 = scrpos(r1, w->org, w->org+w->nchars, w->nr);
if(!eqrect(r2, w->lastsr)){
w->lastsr = r2;
/* move r1, r2 to (0,0) to avoid clipping */
r2 = rectsubpt(r2, r1.min);
r1 = rectsubpt(r1, r1.min);
draw(b, r1, w->cols[BORD], nil, ZP);
draw(b, r2, w->cols[BACK], nil, ZP);
r2.min.x = r2.max.x-1;
draw(b, r2, w->cols[BORD], nil, ZP);
draw(w->i, r, b, nil, Pt(0, r1.min.y));
}
}

void
wscrsleep(Window *w, uint dt)
{
Timer *timer;
int y, b;
static Alt alts[3];

if(display->bufp > display->buf)
flushimage(display, 1);
timer = timerstart(dt);
y = w->mc.xy.y;
b = w->mc.buttons;
alts[0].c = timer->c;
alts[0].v = nil;
alts[0].op = CHANRCV;
alts[1].c = w->mc.c;
alts[1].v = &w->mc.Mouse;
alts[1].op = CHANRCV;
alts[2].op = CHANEND;
for(;;)
switch(alt(alts)){
case 0:
timerstop(timer);
return;
case 1:
if(abs(w->mc.xy.y-y)>2 || w->mc.buttons!=b){
timercancel(timer);
return;
}
break;
}
}

void
wscroll(Window *w, int but)
{
uint p0, oldp0;
Rectangle s;
int y, my, h, first;

s = insetrect(w->scrollr, 1);
h = s.max.y-s.min.y;
oldp0 = ~0;
first = TRUE;
do{
my = w->mc.xy.y;
if(my < s.min.y)
my = s.min.y;
if(my >= s.max.y)
my = s.max.y;
if(but == 2){
y = my;
if(y > s.max.y-2)
y = s.max.y-2;
if(w->nr > 1024*1024)
p0 = ((w->nr>>10)*(y-s.min.y)/h)<<10;
else
p0 = w->nr*(y-s.min.y)/h;
if(oldp0 != p0)
wsetorigin(w, p0, FALSE);
oldp0 = p0;
readmouse(&w->mc);
continue;
}
if(but == 1 || but == 4){
y = max(1, (my-s.min.y)/w->font->height);
p0 = wbacknl(w, w->org, y);
}else{
y = max(my, s.min.y+w->font->height);
p0 = w->org+frcharofpt(w, Pt(s.max.x, y));
}
if(oldp0 != p0)
wsetorigin(w, p0, TRUE);
oldp0 = p0;
/* debounce */
if(first){
if(display->bufp > display->buf)
flushimage(display, 1);
if(but > 3)
return;
sleep(200);
nbrecv(w->mc.c, &w->mc.Mouse);
first = FALSE;
}
wscrsleep(w, 100);
}while(w->mc.buttons & (1<<(but-1)));
while(w->mc.buttons)
readmouse(&w->mc);
}