/* Copyright (c) 2007-2008 Massachusetts Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 
 */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include "redblack.h"

static int comp(rb_key k1, rb_key k2)
{
     if (*k1 < *k2) return -1;
     if (*k1 > *k2) return +1;
     return 0;
}

int main(int argc, char **argv)
{
     int N, M;
     int *k;
     double kd;
     rb_tree t;
     rb_node *n;
     int i, j;

     if (argc < 2) {
	  fprintf(stderr, "Usage: redblack_test Ntest [rand seed]\n");
	  return 1;
     }

     N = atoi(argv[1]);
     k = (int *) malloc(N * sizeof(int));
     rb_tree_init(&t, comp);

     srand((unsigned) (argc > 2 ? atoi(argv[2]) : time(NULL)));
     for (i = 0; i < N; ++i) {
	  double *newk = (double *) malloc(sizeof(double));
	  *newk = (k[i] = rand() % N);
	  if (!rb_tree_insert(&t, newk)) {
	       fprintf(stderr, "error in rb_tree_insert\n");
	       return 1;
	  }
	  if (!rb_tree_check(&t)) {
	       fprintf(stderr, "rb_tree_check_failed after insert!\n");
	       return 1;
	  }
     }
     
     if (t.N != N) {
	  fprintf(stderr, "incorrect N (%d) in tree (vs. %d)\n", t.N, N);
	  return 1;
     }

     for (i = 0; i < N; ++i) {
	  kd = k[i];
	  if (!rb_tree_find(&t, &kd)) {
	       fprintf(stderr, "rb_tree_find lost %d!\n", k[i]);
	       return 1;
	  }
     }
 
     n = rb_tree_min(&t);
     for (i = 0; i < N; ++i) {
	  if (!n) {
	       fprintf(stderr, "not enough successors %d\n!", i);
	       return 1;
	  }
	  printf("%d: %g\n", i, n->k[0]);
	  n = rb_tree_succ(n);
     }
     if (n) {
	  fprintf(stderr, "too many successors!\n");
	  return 1;
     }
     
     n = rb_tree_max(&t);
     for (i = 0; i < N; ++i) {
	  if (!n) {
	       fprintf(stderr, "not enough predecessors %d\n!", i);
	       return 1;
	  }
	  printf("%d: %g\n", i, n->k[0]);
	  n = rb_tree_pred(n);
     }
     if (n) {
	  fprintf(stderr, "too many predecessors!\n");
	  return 1;
     }
     
     for (M = N; M > 0; --M) {
	  int knew = rand() % N; /* random new key */
	  j = rand() % M; /* random original key to replace */
	  for (i = 0; i < N; ++i)
	       if (k[i] >= 0)
		    if (j-- == 0)
			 break;
	  if (i >= N) abort();
	  kd = k[i];
	  if (!(n = rb_tree_find(&t, &kd))) {
               fprintf(stderr, "rb_tree_find lost %d!\n", k[i]);
               return 1;
          }
	  n->k[0] = knew;
	  if (!rb_tree_resort(&t, n)) {
	       fprintf(stderr, "error in rb_tree_resort\n");
	       return 1;
	  }
	  if (!rb_tree_check(&t)) {
	       fprintf(stderr, "rb_tree_check_failed after change %d!\n",
		       N - M + 1);
	       return 1;
	  }
	  k[i] = -1 - knew;
     }

     if (t.N != N) {
	  fprintf(stderr, "incorrect N (%d) in tree (vs. %d)\n", t.N, N);
	  return 1;
     }

     for (i = 0; i < N; ++i)
	  k[i] = -1 - k[i]; /* undo negation above */
	  
     for (i = 0; i < N; ++i) {
	  rb_node *le, *gt;
	  kd = 0.01 * (rand() % (N * 150) - N*25);
	  le = rb_tree_find_le(&t, &kd);
	  gt = rb_tree_find_gt(&t, &kd);
	  n = rb_tree_min(&t);
	  double lek = le ? le->k[0] : -HUGE_VAL;
	  double gtk = gt ? gt->k[0] : +HUGE_VAL;
	  printf("%g <= %g < %g\n", lek, kd, gtk);
	  if (n->k[0] > kd) {
	       if (le) {
		    fprintf(stderr, "found invalid le %g for %g\n", lek, kd);
		    return 1;
	       }
	       if (gt != n) {
		    fprintf(stderr, "gt is not first node for k=%g\n", kd);
		    return 1;
	       }
	  }
	  else {
	       rb_node *succ = n;
	       do {
		    n = succ;
		    succ = rb_tree_succ(n);
	       } while (succ && succ->k[0] <= kd);
	       if (n != le) {
		    fprintf(stderr,
			    "rb_tree_find_le gave wrong result for k=%g\n",kd);
		    return 1;
	       }
	       if (succ != gt) {
		    fprintf(stderr,
			    "rb_tree_find_gt gave wrong result for k=%g\n",kd);
		    return 1;
	       }
	  }
     }
     
     for (M = N; M > 0; --M) {
	  j = rand() % M;
	  for (i = 0; i < N; ++i)
	       if (k[i] >= 0)
		    if (j-- == 0)
			 break;
	  if (i >= N) abort();
	  kd = k[i];
	  if (!(n = rb_tree_find(&t, &kd))) {
	       fprintf(stderr, "rb_tree_find lost %d!\n", k[i]);
	       return 1;
	  }
	  n = rb_tree_remove(&t, n);
	  free(n->k); 
	  free(n);
	  if (!rb_tree_check(&t)) {
	       fprintf(stderr, "rb_tree_check_failed after remove!\n");
	       return 1;
	  }
	  k[i] = -1 - k[i];
     }
     
     if (t.N != 0) {
	  fprintf(stderr, "nonzero N (%d) in tree at end\n", t.N);
	  return 1;
     }

     rb_tree_destroy(&t);
     free(k);

     printf("SUCCESS.\n");
     return 0;
}