#include "fh_error.h"
#include "fh_runtime.h"
#include "fh_mem.h"
#include "fh_stack.h"
#include "fh_print.h"
#include "fh_builtins.h"

static enum fh_error wp_setbase(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  fh_setbase(fh, w->param);
  return FH_OK;
}

enum fh_error wp_const(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  enum fh_error rv;
  TRY(ds_push(fh, w->param));
  return FH_OK;
}

static enum fh_error w_plus(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_pop(fh, &b));
  TRY(ds_push(fh, a + b));
  return FH_OK;
}

static enum fh_error w_minus(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &b));
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, a - b));
  return FH_OK;
}

static enum fh_error w_star(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_pop(fh, &b));
  TRY(ds_push(fh, a * b));
  return FH_OK;
}

static enum fh_error w_and(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_pop(fh, &b));
  TRY(ds_push(fh, a & b));
  return FH_OK;
}

static enum fh_error w_or(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_pop(fh, &b));
  TRY(ds_push(fh, a | b));
  return FH_OK;
}

static enum fh_error w_xor(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_pop(fh, &b));
  TRY(ds_push(fh, a ^ b));
  return FH_OK;
}

static enum fh_error w_zero_less(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, TOBOOL(a < 0)));
  return FH_OK;
}

static enum fh_error w_zero_greater(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, TOBOOL((int32_t) a > 0)));
  return FH_OK;
}

static enum fh_error w_zero_equals(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, TOBOOL(a == 0)));
  return FH_OK;
}

static enum fh_error w_zero_not_equals(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, TOBOOL(a != 0)));
  return FH_OK;
}


static enum fh_error w_less(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &b));
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, TOBOOL((int32_t) a < (int32_t) b)));
  return FH_OK;
}

static enum fh_error w_greater(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &b));
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, TOBOOL((int32_t) a > (int32_t) b)));
  return FH_OK;
}


static enum fh_error w_u_less(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &b));
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, TOBOOL(a < b)));
  return FH_OK;
}

static enum fh_error w_u_greater(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &b));
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, TOBOOL(a > b)));
  return FH_OK;
}

static enum fh_error w_equals(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &b));
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, TOBOOL(a == b)));
  return FH_OK;
}

static enum fh_error w_not_equals(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &b));
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, TOBOOL(a != b)));
  return FH_OK;
}

enum fh_error wp_add(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  enum fh_error rv;
  uint32_t a = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, a + w->param));
  return FH_OK;
}

enum fh_error wp_mul(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  enum fh_error rv;
  uint32_t a = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, a * w->param));
  return FH_OK;
}

static enum fh_error wp_div(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  enum fh_error rv;
  uint32_t a = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, a * w->param));
  return FH_OK;
}

static enum fh_error w_star_slash(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0, c = 0;
  TRY(ds_pop(fh, &c));
  TRY(ds_pop(fh, &b));
  TRY(ds_pop(fh, &a));

  if (c == 0) {
    return FH_ERR_DIV_BY_ZERO;
  }

  uint64_t v = ((uint64_t) a * (uint64_t) b) / (uint64_t) c;

  TRY(ds_push(fh, (uint32_t) v));
  return FH_OK;
}

static enum fh_error w_star_slash_mod(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0, c = 0;
  TRY(ds_pop(fh, &c));
  TRY(ds_pop(fh, &b));
  TRY(ds_pop(fh, &a));

  if (c == 0) {
    return FH_ERR_DIV_BY_ZERO;
  }

  uint64_t product = ((uint64_t) a * (uint64_t) b);
  uint64_t v = product / (uint64_t) c;
  uint64_t m = product % (uint64_t) c;

  TRY(ds_push(fh, (uint32_t) m));
  TRY(ds_push(fh, (uint32_t) v));
  return FH_OK;
}

static enum fh_error w_slash(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &b));
  TRY(ds_pop(fh, &a));

  if (b == 0) {
    return FH_ERR_DIV_BY_ZERO;
  }

  TRY(ds_push(fh, a / b));
  return FH_OK;
}

static enum fh_error w_abs(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0;
  TRY(ds_pop(fh, &a));

  int32_t sa = (int32_t) a; // TODO is this right?

  if (sa < 0) { sa = -sa; }

  TRY(ds_push(fh, sa));
  return FH_OK;
}

static enum fh_error w_invert(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, ~a));
  return FH_OK;
}

static enum fh_error w_negate(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0;
  TRY(ds_pop(fh, &a));
  TRY(ds_push(fh, (uint32_t) (-(uint32_t) a)));
  return FH_OK;
}

static enum fh_error w_slash_mod(struct fh_thread_s *fh, const struct fh_word_s *w)
{
  (void) w;
  enum fh_error rv;
  uint32_t a = 0, b = 0;
  TRY(ds_pop(fh, &b));
  TRY(ds_pop(fh, &a));

  if (b == 0) {
    return FH_ERR_DIV_BY_ZERO;
  }

  uint32_t rem = a % b;
  uint32_t div = a / b;

  TRY(ds_push(fh, rem));
  TRY(ds_push(fh, div));
  return FH_OK;
}

const struct name_and_handler fh_builtins_arith[] = {
    /* Arithmetics */
    {"base",    wp_const,          0, MAGICADDR_BASE},
    {"decimal", wp_setbase,        0, 10},
    {"hex",     wp_setbase,        0, 16},
    {"false",   wp_const,          0, 0},
    {"true",    wp_const,          0, 0xFFFFFFFF},
    {"+",       w_plus,            0, 0},
    {"-",       w_minus,           0, 0},
    {"*",       w_star,            0, 0},
    {"*/",      w_star_slash,      0, 0},
    {"*/mod",   w_star_slash_mod,  0, 0},
    {"or",      w_or,              0, 0},
    {"and",     w_and,             0, 0},
    {"xor",     w_xor,             0, 0},
    {"/",       w_slash,           0, 0},
    {"abs",     w_abs,             0, 0},
    {"/mod",    w_slash_mod,       0, 0},
    {"invert",  w_invert,          0, 0},
    {"negate",  w_negate,          0, 0},
    {"0<",      w_zero_less,       0, 0},
    {"0=",      w_zero_equals,     0, 0},
    {"0<>",     w_zero_not_equals, 0, 0},
    {"0>",      w_zero_greater,    0, 0},
    {"<",       w_less,            0, 0},
    {"u<",      w_u_less,          0, 0},
    {"=",       w_equals,          0, 0},
    {"<>",      w_not_equals,      0, 0},
    {">",       w_greater,         0, 0},
    {"u>",      w_u_greater,       0, 0},
    {"1+",      wp_add,            0, 1},
    {"1-",      wp_add,            0, -1},
    {"2+",      wp_add,            0, 2},
    {"2-",      wp_add,            0, -2},
    {"2*",      wp_mul,            0, 2},
    {"2/",      wp_div,            0, 2},
    { /* end marker */ }
};