#include "cyclone.h"

/**
 * Take list of args and call a function with them as params.
 *
 * Note memory scheme below is not compatible with GC, 
 * so macro calls funcs directly.
 */

// TODO: the following slows down compilation significantly.
// it's not just the hack, but rather the size of the expanded code.
// suggest creating a runtime library that will be linked to
// the compiled executable. maybe just a small static lib for now

/**
 * Receive a list of arguments and apply them to the given function
 */
void dispatch(int argc, function_type func, object clo, object cont, object args) {
 // TODO: is this portable? may be better to have a dedicated memory area and
//        just copy to it as needed
 object b[argc]; // OK to do this?
 int i; 
 for (i = 0; i < argc; i++){ 
   b[i] = car(args); 
   args = cdr(args); 
 } 

/* The following is based on the macro expansion code from CHICKEN's do_apply */

/* PTR_O_p<P>_<B>(o): list of COUNT = ((2 ** P) * B) '*(b+I)' arguments,
 * with offset I in range [o, o+COUNT-1].
 */
#define PTR_O_p0_0(o)
#define PTR_O_p1_0(o)
#define PTR_O_p2_0(o)
#define PTR_O_p3_0(o)
#define PTR_O_p4_0(o)
#define PTR_O_p5_0(o)
#define PTR_O_p6_0(o)
#define PTR_O_p7_0(o)
#define PTR_O_p0_1(o)   , *(b+(o))
#define PTR_O_p1_1(o)   , *(b+(o)), *(b+(o+1))
#define PTR_O_p2_1(o)   PTR_O_p1_1(o) PTR_O_p1_1(o+2)
#define PTR_O_p3_1(o)   PTR_O_p2_1(o) PTR_O_p2_1(o+4)
#define PTR_O_p4_1(o)   PTR_O_p3_1(o) PTR_O_p3_1(o+8)
#define PTR_O_p5_1(o)   PTR_O_p4_1(o) PTR_O_p4_1(o+16)
#define PTR_O_p6_1(o)   PTR_O_p5_1(o) PTR_O_p5_1(o+32)
#define PTR_O_p7_1(o)   PTR_O_p6_1(o) PTR_O_p6_1(o+64)

/* CASE_C_PROC_p0 (n0,  p6,p5,p4,p3,p2,p1,p0):
 *  let's note <N> = <n0> - 2; the macro inserts:
 *      case <N>: ((C_cproc<n0>)pr) (<n0>, fn, k, <rest>);
 *  where <rest> is:    *(b+1), ..., *(b+<N>)
 *  (<rest> is empty for <n0> == 2).
 *  We must have:   n0 = SUM (i = 7 to 0, p<i> * (1 << i)).
 * CASE_C_PROC_p<N+1> (...):
 *  like CASE_C_PROC_p<N>, but with doubled output...
 */
#define CASE_C_PROC_p0(n0,  p6,p5,p4,p3,p2,p1,p0) \
    case (n0-2): func(n0-1, clo, cont \
PTR_O_p6_##p6(((n0-2)&0x80)+0)\
PTR_O_p5_##p5(((n0-2)&0xC0)+0)\
PTR_O_p4_##p4(((n0-2)&0xE0)+0)\
PTR_O_p3_##p3(((n0-2)&0xF0)+0)\
PTR_O_p2_##p2(((n0-2)&0xF8)+0)\
PTR_O_p1_##p1(((n0-2)&0xFC)+0)\
PTR_O_p0_##p0(((n0-2)&0xFE)+0));
#define CASE_C_PROC_p1( n0,n1,  p6,p5,p4,p3,p2,p1) \
        CASE_C_PROC_p0 (n0,  p6,p5,p4,p3,p2,p1,0) \
        CASE_C_PROC_p0 (n1,  p6,p5,p4,p3,p2,p1,1)
#define CASE_C_PROC_p2( n0,n1,n2,n3,  p6,p5,p4,p3,p2) \
        CASE_C_PROC_p1 (n0,n1,  p6,p5,p4,p3,p2,0) \
        CASE_C_PROC_p1 (n2,n3,  p6,p5,p4,p3,p2,1)
#define CASE_C_PROC_p3( n0,n1,n2,n3,n4,n5,n6,n7,  p6,p5,p4,p3) \
        CASE_C_PROC_p2 (n0,n1,n2,n3,  p6,p5,p4,p3,0) \
        CASE_C_PROC_p2 (n4,n5,n6,n7,  p6,p5,p4,p3,1)
  switch(argc) {
    CASE_C_PROC_p3 (2,3,4,5,6,7,8,9,  0,0,0,0)
    CASE_C_PROC_p3 (10,11,12,13,14,15,16,17,  0,0,0,1)
    CASE_C_PROC_p3 (18,19,20,21,22,23,24,25,  0,0,1,0)
    CASE_C_PROC_p3 (26,27,28,29,30,31,32,33,  0,0,1,1)
    CASE_C_PROC_p3 (34,35,36,37,38,39,40,41,  0,1,0,0)
    CASE_C_PROC_p3 (42,43,44,45,46,47,48,49,  0,1,0,1)
    CASE_C_PROC_p3 (50,51,52,53,54,55,56,57,  0,1,1,0)
    CASE_C_PROC_p3 (58,59,60,61,62,63,64,65,  0,1,1,1)
    CASE_C_PROC_p0 (66,  1,0,0,0,0,0,0)
    CASE_C_PROC_p0 (67,  1,0,0,0,0,0,1)
    CASE_C_PROC_p1 (68,69,  1,0,0,0,0,1)
    CASE_C_PROC_p2 (70,71,72,73,  1,0,0,0,1)
    CASE_C_PROC_p3 (74,75,76,77,78,79,80,81,  1,0,0,1)
    CASE_C_PROC_p3 (82,83,84,85,86,87,88,89,  1,0,1,0)
    CASE_C_PROC_p3 (90,91,92,93,94,95,96,97,  1,0,1,1)
    CASE_C_PROC_p3 (98,99,100,101,102,103,104,105,  1,1,0,0)
    CASE_C_PROC_p3 (106,107,108,109,110,111,112,113,  1,1,0,1)
    CASE_C_PROC_p3 (114,115,116,117,118,119,120,121,  1,1,1,0)
    CASE_C_PROC_p2 (122,123,124,125,  1,1,1,1,0)
    CASE_C_PROC_p1 (126,127,  1,1,1,1,1,0)
    CASE_C_PROC_p0 (128,  1,1,1,1,1,1,0)
  default: //barf(C_TOO_MANY_PARAMETERS_ERROR, "apply");
   // TODO: not good enough, throw an exception instead, using (error)
   printf("Unhandled number of function arguments: %d\n", argc); 
   exit(1);
  }
}

/**
 * Same as above but for a varargs C function
 */
void dispatch_va(int argc, function_type_va func, object clo, object cont, object args) {
// TODO:    DISPATCH_RETURN_CALL_FUNC
  printf("TODO: implement\n");
  exit(1);
}