#include "lichen.h"
#include <stdio.h>
#include <string.h>


void li_xorshift32_seed(struct li_xorshift32_t *xor, uint32_t seed) {
  xor->state = seed ? seed : 1;
  xor->generator.rand = li_xorshift32;
  xor->generator.state = &(xor->state);
}


uint32_t li_xorshift32(void *s) {
  uint64_t x = *((uint64_t*)s);
  x ^= x >> 12;
  x ^= x << 25;
  x ^= x >> 27;
  x *= 0x2545F4914F6CDD1DULL;
  *((uint64_t*)s) = x;
  // return just top 32 bits
  return x >> 32;
}



li_llnode_t * li_alloc_llnode() {
  li_llnode_t *n = malloc(sizeof(li_llnode_t));
  if (n == NULL) {
    fprintf(stderr, "failed to allocate linked-list node\n");
    return NULL;
  } else {
    n->tag = 0;
    n->data = 0;
    n->next = NULL;
    return n;
  }
}


li_llnode_t * li_copy_llnode(li_llnode_t *n) {
  li_llnode_t *m = li_alloc_llnode();
  if (m == NULL) {
    return NULL;
  }
  memcpy(m, n, sizeof(li_llnode_t));
  return m;
}

void li_free_llnode(li_llnode_t *n, void (*free_data)(void*)) {
  if (n != NULL) {
    free_data(n->data);
    li_free_llnode(n->next, free_data);
  }
  free(n);
}


struct li_ll_t * li_alloc_ll() {
  struct li_ll_t *list = malloc(sizeof(struct li_ll_t));
  if (list == NULL) {
    fprintf(stderr, "failed to allocate linked list\n");
    return NULL;
  }

  list->tag = 0;
  list->count = 0;
  list->head = NULL;
  list->end = NULL;
  return list;
}

void li_free_ll(struct li_ll_t *list, void (*free_data)(void*)) {
  if (list != NULL) {
    li_free_llnode(list->head, free_data);
  }
  free(list);
}


int li_ll_append(struct li_ll_t *list, void *data) {
  li_llnode_t *n = li_alloc_llnode();
  if (n == NULL) {
    return 1;
  }
  n->data = data;
  if (list->end != NULL) {
    list->end->next = n;
    list->end = n;
  } else {
    list->head = n;
    list->end = n;
  }
  list->count += 1;
  return 0;
}


int li_ll_prepend(struct li_ll_t *list, void *data) {
  li_llnode_t *n = li_alloc_llnode();
  if (n == NULL) {
    return 1;
  }
  n->data = data;
  if (list->head != NULL) {
    n->next = list->head;
    list->head = n;
  } else {
    list->head = n;
    list->end = n;
  }
  list->count += 1;
  return 0;
}


int li_copy_list(struct li_ll_t **dst, struct li_ll_t *src, void *(*copy_data)(void*)) {
  *dst = li_alloc_ll();
  if (*dst == NULL) {
    return 1;
  }

  (*dst)->tag = src->tag;

  for (li_llnode_t *n = src->head; n != NULL; n = n->next) {
    void *dup = copy_data(n->data);
    if (dup == NULL) {
      return 1;
    }
    if (li_ll_append(*dst, dup) != 0) {
      return 1;
    }
  }

  return 0;
}