#include <stdlib.h>

#include "lx.h"

#include "proto.h"
#include "internal.h"

typedef struct priv_GetMotionEvents PRIV_GetMotionEvents;

struct priv_GetMotionEvents {
  int *nevp;
  LX_TIMECOORD **evp;
  } ;

static void done_GetMotionEvents(LX_OP *op, const unsigned char *rep)
{
 PRIV_GetMotionEvents *p;
 unsigned int n;
 unsigned int i;
 size_t sz;
 LX_TIMECOORD *v;
 int o;

 p = op->reqpriv;
 do <"ret">
  { // We have to be careful of overflow....
    n = r_card32(rep+8);
    if (r_card32(rep+4) != n*2ULL)
     { lx__protoerr(op->conn,"GetMotionEvents response length wrong (%u, expecting %llu)",r_card32(rep+4),n*2ULL);
       break <"ret">;
     }
    sz = n * (size_t)8;
    if (sz>>3 != n)
     { lx__protoerr(op->conn,"GetMotionEvents response requires too much data (%llu, max size_t is %llu)",
		(unsigned long long int)(n*8ULL),(unsigned long long int)~(size_t)0);
       break <"ret">;
     }
    if (p->evp)
     { v = malloc(sz);
       if (! v)
	{ lx__nomem_fail(op->conn);
	  break <"ret">;
	}
       o = 32;
       for (i=0;i<n;i++)
	{ /*
	   * The R4 protocol document says x and y are CARD16s in the
	   *  encoding section, but it says INT16 in the request
	   *  description section.  I believe INT16 makes more sense, and
	   *  more recent protocol documents give INT16 for both.
	   */
	  v[i] = (LX_TIMECOORD){ .time = r_card32(rep+o), .x = r_int16(rep+o+4), .y = r_int16(rep+o+6) };
	  o += 8;
	}
       *p->evp = v;
     }
    if (p->nevp) *p->nevp = n;
  } while (0);
 op->reqpriv = 0;
 free(p);
}

LX_OP *lx_GetMotionEvents(LX_CONN *xc, LX_XID window, LX_TIME start, LX_TIME stop, int *nevp, LX_TIMECOORD **evp)
{
 unsigned char req[16];
 PRIV_GetMotionEvents *p;

 if (xc->flags & XCF_FAIL)
  { lx__bad_call(xc,"lx_GetMotionEvents");
    return(0);
  }
 lx__nochain(xc);
 p = malloc(sizeof(PRIV_GetMotionEvents));
 if (! p)
  { lx__nomem_fail(xc);
    return(0);
  }
 p->nevp = nevp;
 p->evp = evp;
 req[0] = XP_REQ_GetMotionEvents;
 req[1] = 0;
 w_card16(&req[2],4);
 w_card32(&req[4],window);
 w_card32(&req[8],start);
 w_card32(&req[12],stop);
 return(lx__expect_reply(xc,&req[0],-1,&done_GetMotionEvents,p));
}