#include <stdio.h>
#include "dlist.h"

bool is_positive(int data) {
  return data > 0;
}
bool is_even(int data) {
  return (data % 2) == 0;
}
bool is_odd(int data) {
  return !is_even(data);
}

int main(int argc, char** argv) {
  printf("Running tests...\n");
  
  int num_errors = 0;

  printf("creating empty list...\n");
  DList* dl1 = new_dlist();

  // test that the empty list is, in fact, empty
  if (first_dlink(dl1) == NULL) {
    printf("OK: first_dlink(new_dlist()) == NULL\n");
  } else {
    printf("ERROR: first_dlink(new_dlist()) != NULL\n"); 
    num_errors ++;
  }
  if (last_dlink(dl1) == NULL) {
    printf("OK: last_dlink(new_dlist()) == NULL\n");
  } else {
    printf("ERROR: last_dlink(new_dlist()) != NULL\n"); 
    num_errors ++;
  }

  // test additions at the first and back
  printf("adding before and after...\n");
  add_before_first(dl1, 3);
  add_before_first(dl1, 2);
  add_after_last(dl1, 4);
  add_after_last(dl1, 5);
  add_before_first(dl1, 1);
  add_after_last(dl1, 6);

  // test that forward iterations work (and that the additions did
  // what we expected)
  int i;
  DLink* n;
  printf("starting from first_dlink(...)...\n");
  for (n = first_dlink(dl1), i = 1; n != NULL; n = next_dlink(n), i++) {
    if (get_data(n) == i) {
      printf("OK: get_data(next_dlink(...)) == %d\n", i);
    } else {
      printf("ERROR: get_data(next_dlink(...)) != %d\n", i);
      num_errors ++;
    }
  }
  if (i == 7) {
    printf("OK: right number of links\n");
  } else {
    printf("ERROR: wrong number of links\n");
    num_errors ++;
  }

  // test that reverse iterations work (and that the additions did
  // what we expected)
  printf("starting from last_dlink(...)...\n");
  for (n = last_dlink(dl1), i = 6; n != NULL; n = prev_dlink(n), i--) {
    if (get_data(n) == i) {
      printf("OK: get_data(prev_dlink(...)) == %d\n", i);
    } else {
      printf("ERROR: get_data(prev_dlink(...)) != %d\n", i);
      num_errors ++;
    }
  }
  if (i == 0) {
    printf("OK: right number of links\n");
  } else {
    printf("ERROR: wrong number of links\n");
    num_errors ++;
  }

  // deleting this list
  printf("deleting...\n");
  delete_dlist(dl1);

  // restarting
  printf("creating empty list...\n");
  dl1 = new_dlist();

  // test additions at the back and front
  printf("adding after and before...\n");
  add_after_last(dl1, 4);
  add_after_last(dl1, 5);
  add_before_first(dl1, 3);
  add_before_first(dl1, 2);
  add_after_last(dl1, 6);
  add_before_first(dl1, 1);

  // test that forward iterations work (and that the additions did
  // what we expected)
  printf("starting from first_dlink(...)...\n");
  for (n = first_dlink(dl1), i = 1; n != NULL; n = next_dlink(n), i++) {
    if (get_data(n) == i) {
      printf("OK: get_data(next_dlink(...)) == %d\n", i);
    } else {
      printf("ERROR: get_data(next_dlink(...)) != %d\n", i);
      num_errors ++;
    }
  }
  if (i == 7) {
    printf("OK: right number of links\n");
  } else {
    printf("ERROR: wrong number of links\n");
    num_errors ++;
  }

  // test that reverse iterations work (and that the additions did
  // what we expected)
  printf("starting from last_dlink(...)...\n");
  for (n = last_dlink(dl1), i = 6; n != NULL; n = prev_dlink(n), i--) {
    if (get_data(n) == i) {
      printf("OK: get_data(prev_dlink(...)) == %d\n", i);
    } else {
      printf("ERROR: get_data(prev_dlink(...)) != %d\n", i);
      num_errors ++;
    }
  }
  if (i == 0) {
    printf("OK: right number of links\n");
  } else {
    printf("ERROR: wrong number of links\n");
    num_errors ++;
  }

  // insert before and after some links
  printf("inserting before and after...\n");
  DLink* n1 = insert_before(dl1, first_dlink(dl1), -3);
  DLink* n2 = insert_after(dl1, n1, -1);
  DLink* n3 = insert_before(dl1, n2, -2);
  DLink* n4 = insert_before(dl1, n1, -4);
  DLink* n5 = insert_after(dl1, n2, 0);

  n1 = insert_after(dl1, last_dlink(dl1), 10);
  n2 = insert_before(dl1, n1, 8);
  n3 = insert_after(dl1, n2, 9);
  n4 = insert_after(dl1, n1, 11);
  n5 = insert_before(dl1, n2, 7);

  // test that forward iterations work (and that the additions did
  // what we expected)
  printf("starting from first_dlink(...)...\n");
  for (n = first_dlink(dl1), i = -4; n != NULL; n = next_dlink(n), i++) {
    int d = get_data(n);
    if (d == i) {
      printf("OK: get_data(next_dlink(...)) == %d\n", i);
    } else {
      printf("ERROR: get_data(next_dlink(...)) == %d != %d\n", d, i);
      num_errors ++;
    }
  }
  if (i == 12) {
    printf("OK: right number of links\n");
  } else {
    printf("ERROR: wrong number of links\n");
    num_errors ++;
  }

  // test that reverse iterations work (and that the additions did
  // what we expected)
  printf("starting from last_dlink(...)...\n");
  for (n = last_dlink(dl1), i = 11; n != NULL; n = prev_dlink(n), i--) {
    int d = get_data(n);
    if (d == i) {
      printf("OK: get_data(prev_dlink(...)) == %d\n", i);
    } else {
      printf("ERROR: get_data(prev_dlink(...)) == %d != %d\n", d, i);
      num_errors ++;
    }
  }
  if (i == -5) {
    printf("OK: right number of links\n");
  } else {
    printf("ERROR: wrong number of links\n");
    num_errors ++;
  }

  // test deleting links
  printf("removing links...\n");
  delete_dlink(dl1, first_dlink(dl1));
  delete_dlink(dl1, first_dlink(dl1));
  delete_dlink(dl1, last_dlink(dl1));
  delete_dlink(dl1, last_dlink(dl1));
  delete_dlink(dl1, next_dlink(next_dlink(next_dlink(first_dlink(dl1)))));

  // test that forward iterations work (and that the additions did
  // what we expected)
  printf("starting from first_dlink(...)...\n");
  for (n = first_dlink(dl1), i = -2; n != NULL; n = next_dlink(n), i++) {
    int d = get_data(n);
    if (d == i) {
      printf("OK: get_data(next_dlink(...)) == %d\n", i);
    } else {
      printf("ERROR: get_data(next_dlink(...)) == %d != %d\n", d, i);
      num_errors ++;
    }
    if (i == 0) i++;
  }
  if (i == 10) {
    printf("OK: right number of links\n");
  } else {
    printf("ERROR: wrong number of links\n");
    num_errors ++;
  }

  // test that reverse iterations work (and that the additions did
  // what we expected)
  printf("starting from last_dlink(...)...\n");
  for (n = last_dlink(dl1), i = 9; n != NULL; n = prev_dlink(n), i--) {
    int d = get_data(n);
    if (d == i) {
      printf("OK: get_data(prev_dlink(...)) == %d\n", i);
    } else {
      printf("ERROR: get_data(prev_dlink(...)) == %d != %d\n", d, i);
      num_errors ++;
    }
    if (i == 2) i--;
  }
  if (i == -3) {
    printf("OK: right number of links\n");
  } else {
    printf("ERROR: wrong number of links\n");
    num_errors ++;
  }

  // find first positive elem [REMOVE THIS if extra credit not implemented]
  printf("finding first positive elem...\n");
  n = find(dl1, &is_positive);
  if (n == NULL) {
    printf("ERROR: didn't find a positive elem\n");
    num_errors ++;
  } else if (get_data(n) != 2) {
    printf("ERROR: found an unexpected elem (%d)\n", get_data(n));
    num_errors ++;
  } else {
    printf("OK: found it\n");
  }
  printf("finding first odd elem...\n");
  n = find(dl1, &is_odd);
  if (n == NULL) {
    printf("ERROR: didn't find an odd elem\n");
    num_errors ++;
  } else if (get_data(n) != -1) {
    printf("ERROR: found an unexpected elem (%d)\n", get_data(n));
    num_errors ++;
  } else {
    printf("OK: found it\n");
  }
  printf("finding first even elem...\n");
  n = find(dl1, &is_even);
  if (n == NULL) {
    printf("ERROR: didn't find an even elem\n");
    num_errors ++;
  } else if (get_data(n) != -2) {
    printf("ERROR: found an unexpected elem (%d)\n", get_data(n));
    num_errors ++;
  } else {
    printf("OK: found it\n");
  }

  // deleting this list
  printf("deleting...\n");
  delete_dlist(dl1);

  // restarting
  printf("creating empty list...\n");
  dl1 = new_dlist();

  // insert a single element
  printf("inserting link...\n");
  add_after_last(dl1, 4);

  // delete the last element
  printf("removing link...\n");
  delete_dlink(dl1, first_dlink(dl1));

  // test that the list is now empty
  if (first_dlink(dl1) == NULL) {
    printf("OK: first_dlink(...) == NULL\n");
  } else {
    printf("ERROR: first_dlink(...) != NULL\n"); 
    num_errors ++;
  }
  if (last_dlink(dl1) == NULL) {
    printf("OK: last_dlink(...) == NULL\n");
  } else {
    printf("ERROR: last_dlink(...) != NULL\n"); 
    num_errors ++;
  }

  // deleting this list
  printf("deleting...\n");
  delete_dlist(dl1);

  if (num_errors == 0) {
    printf("All tests passed!\n");
    return 0;
  } else {
    printf("There were %d errors\n", num_errors);
    return -1;
  }
}