#include <akstdlib.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <stdarg.h>

akerr_ErrorContext AKERR_NOIGNORE *aksl_malloc(size_t size, void **dst)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, dst, AKERR_NULLPOINTER, "NULL");
    *dst = malloc(size);
    FAIL_ZERO_RETURN(e, *dst, errno, "%ld bytes", size);
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_free(void *ptr)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, ptr, AKERR_NULLPOINTER, "NULL");
    free(ptr);
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_memset(void *s, int c, size_t n)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, s, AKERR_NULLPOINTER, "s=%p", s);
    FAIL_ZERO_RETURN(e, memset(s, c, n), errno, "Failed to memset");
    SUCCEED_RETURN(e);
}


akerr_ErrorContext AKERR_NOIGNORE *aksl_memcpy(void *d, void *s, size_t n)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, d, AKERR_NULLPOINTER, "d=%p, s=%p", d, s);
    FAIL_ZERO_RETURN(e, s, AKERR_NULLPOINTER, "d=%p, s=%p", d, s);
    FAIL_ZERO_RETURN(e, (memcpy(d, s, n) == d), errno, "Failed to memcpy");
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_fopen(
    char *pathname,
    char *mode,
    FILE **fp)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, fp, AKERR_NULLPOINTER, "NULL");
    *fp = fopen(pathname, mode);
    FAIL_ZERO_RETURN(e, *fp, errno, "%s", pathname);
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_fread(
    void *ptr,
    size_t size, size_t nmemb,
    FILE *fp)
{
    size_t nmemr;
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, fp, AKERR_NULLPOINTER, "NULL");
    nmemr = fread(ptr, size, nmemb, fp);
    if ( nmemr != nmemb ) {
	FAIL_NONZERO_RETURN(e, feof(fp), AKERR_EOF, "EOF reached");
	FAIL_NONZERO_RETURN(e, ferror(fp), AKERR_IO, "Error reading file");
    }
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_fwrite(
    void *ptr,
    size_t size, size_t nmemb,
    FILE *fp)
{
    size_t nmemw;
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, fp, AKERR_NULLPOINTER, "NULL argument");
    nmemw = fwrite(ptr, size, nmemb, fp);
    if ( nmemw != nmemb ) {
	FAIL_NONZERO_RETURN(e, feof(fp), AKERR_EOF, "EOF reached");
	FAIL_NONZERO_RETURN(e, ferror(fp), AKERR_IO, "Error reading file");
    }
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_fclose(FILE *stream)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, stream, AKERR_NULLPOINTER, "NULL");
    FAIL_NONZERO_RETURN(e, fclose(stream), errno, "Failed to fclose");
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_printf(int *count, const char *restrict format, ...)
{
    va_list args;
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, count, AKERR_NULLPOINTER, "count=%p, format=%p", (void *)count, (void *)format);
    FAIL_ZERO_RETURN(e, format, AKERR_NULLPOINTER, "count=%p, format=%p", (void *)count, (void *)format);
    va_start(args, format);    
    *count = vprintf(format, args);
    FAIL_NONZERO_RETURN(e, (*count == -1), errno, "Short write");
    SUCCEED_RETURN(e);
}


akerr_ErrorContext AKERR_NOIGNORE *aksl_fprintf(int *count, FILE *restrict stream, const char *restrict format, ...)
{
    va_list args;
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, count, AKERR_NULLPOINTER, "count=%p, stream=%p, format=%p", (void *)count, (void *)stream, (void *)format);
    FAIL_ZERO_RETURN(e, stream, AKERR_NULLPOINTER, "count=%p, stream=%p, format=%p", (void *)count, (void *)stream, (void *)format);
    FAIL_ZERO_RETURN(e, format, AKERR_NULLPOINTER, "count=%p, stream=%p, format=%p", (void *)count, (void *)stream, (void *)format);
    va_start(args, format);
    *count = vfprintf(stream, format, args);
    FAIL_NONZERO_RETURN(e, (*count == -1), errno, "Short write");
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_sprintf(int *count, char *restrict str, const char *restrict format, ...)
{
    va_list args;
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, count, AKERR_NULLPOINTER, "count=%p, str=%p, format=%p", (void *)count, (void *)str, (void *)format);
    FAIL_ZERO_RETURN(e, str, AKERR_NULLPOINTER, "count=%p, str=%p, format=%p", (void *)count, (void *)str, (void *)format);
    FAIL_ZERO_RETURN(e, format, AKERR_NULLPOINTER, "count=%p, str=%p, format=%p", (void *)count, (void *)str, (void *)format);
    va_start(args, format);
    *count = vsprintf(str, format, args);
    FAIL_NONZERO_RETURN(e, (*count == -1), errno, "Short write");
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_atoi(const char *nptr, int *dest)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, nptr, AKERR_NULLPOINTER, "nptr=%p, dest=%p", (void *)nptr, (void *)dest);
    FAIL_ZERO_RETURN(e, dest, AKERR_NULLPOINTER, "nptr=%p, dest=%p", (void *)nptr, (void *)dest);
    *dest = atoi(nptr);
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_atol(const char *nptr, long *dest)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, nptr, AKERR_NULLPOINTER, "nptr=%p, dest=%p", (void *)nptr, (void *)dest);
    FAIL_ZERO_RETURN(e, dest, AKERR_NULLPOINTER, "nptr=%p, dest=%p", (void *)nptr, (void *)dest);
    *dest = atol(nptr);
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_atoll(const char *nptr, long long *dest)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, nptr, AKERR_NULLPOINTER, "nptr=%p, dest=%p", (void *)nptr, (void *)dest);
    FAIL_ZERO_RETURN(e, dest, AKERR_NULLPOINTER, "nptr=%p, dest=%p", (void *)nptr, (void *)dest);
    *dest = atoll(nptr);
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_atof(const char *nptr, double *dest)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, nptr, AKERR_NULLPOINTER, "nptr=%p, dest=%p", (void *)nptr, (void *)dest);
    FAIL_ZERO_RETURN(e, dest, AKERR_NULLPOINTER, "nptr=%p, dest=%p", (void *)nptr, (void *)dest);
    *dest = atof(nptr);
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_realpath(const char *restrict path, char *restrict resolved_path)
{
    char *result = NULL;
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, path, AKERR_NULLPOINTER, "path=%p, dest=%p", (void *)path, (void *)resolved_path);
    result = realpath(path, resolved_path);
    FAIL_ZERO_RETURN(e, result, errno, "path=%s, dest=%s", path, resolved_path);
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_list_push(aksl_ListNode *list, aksl_ListNode *obj)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, list, AKERR_NULLPOINTER, "list");
    FAIL_ZERO_RETURN(e, obj, AKERR_NULLPOINTER, "obj");
    aksl_ListNode *slow = list;
    aksl_ListNode *fast = list;
    aksl_ListNode *tail = list;
    do { 
	if ( fast != NULL && fast->next != NULL ) {
	    fast = fast->next->next;
	}
	tail = slow;
	slow = slow->next;
	if ( fast != NULL && fast == slow) {
	    FAIL(e, AKERR_CIRCULAR_REFERENCE, "%p", list);
	}
    } while ( slow != NULL || (fast != NULL && fast->next != NULL) );
    tail->next = obj;
    obj->next = NULL;
    obj->prev = slow;
    SUCCEED_RETURN(e);
}

akerr_ErrorContext AKERR_NOIGNORE *aksl_list_pop(aksl_ListNode *node)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, node, AKERR_NULLPOINTER, "node");
    if ( node->prev != NULL ) {
	node->prev->next = node->next;
    }
    if ( node->next != NULL ) {	
	node->next->prev = node->prev;
    }
    node->next = NULL;
    node->prev = NULL;
    SUCCEED_RETURN(e);
}

/**
 * @brief Iterates over a tree structure in breadth or depth first order, executing a callback function on each node.
 *
 * This function recursively calls itself to traverse a binary tree datastructure. 
 *
 * @param[in] root The tree structure to search
 * @param[in] iter An aksl_TreeNodeIterator function which will be called for each node found
 * @param[in] lalloc An aksl_AllocFunc function which will be used to allocate aksl_ListNode elements for the search, or NULL to use the default allocator (aksl_malloc)
 * @param[in] lfree An aksl_FreeFunc function which will be used to free the elements procured with lalloc, or NULL to use the default free function (aksl_free)
 * @param[in] searchmode One of the AKSL_TREE_SEARCH_BFS* defines
 * @param[in] data Any user data that should be provided when the iterator is called
 * @param[in] queue The linked list node to use as the head of the queue. The caller should pass NULL here.
 *
 * @throws AKERR_NULLPOINTER On null pointer inputs
 * @return akerr_ErrorContext
 */

akerr_ErrorContext AKERR_NOIGNORE *aksl_tree_iterate(
    aksl_TreeNode *root,
    aksl_TreeNodeIterator iter,
    aksl_AllocFunc lalloc,
    aksl_FreeFunc lfree,
    uint8_t searchmode,
    void *data,
    aksl_ListNode *queue)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, root, AKERR_NULLPOINTER, "root");
    FAIL_ZERO_RETURN(e, iter, AKERR_NULLPOINTER, "iter");
    if ( lalloc == NULL ) {
	lalloc = &aksl_malloc;
    }
    if ( lfree == NULL ) {
	lfree = &aksl_free;
    }
    switch ( searchmode ) {
    case AKSL_TREE_SEARCH_DFS_PREORDER:
	PASS(e, iter(root, data));
	if ( root->left != NULL ) {
	    PASS(e, aksl_tree_iterate(root->left, iter, lalloc, lfree, searchmode, data, NULL));
	}
	if ( root-> right != NULL ) {
	    PASS(e, aksl_tree_iterate(root->right, iter, lalloc, lfree, searchmode, data, NULL));
	}
	break;
    case AKSL_TREE_SEARCH_DFS_POSTORDER:
	if ( root->left != NULL ) {
	    PASS(e, aksl_tree_iterate(root->left, iter, lalloc, lfree, searchmode, data, NULL));
	}
	if ( root-> right != NULL ) {
	    PASS(e, aksl_tree_iterate(root->right, iter, lalloc, lfree, searchmode, data, NULL));
	}
	PASS(e, iter(root, data));
	break;
    case AKSL_TREE_SEARCH_DFS_INORDER:
	if ( root->left != NULL ) {
	    PASS(e, aksl_tree_iterate(root->left, iter, lalloc, lfree, searchmode, data, NULL));
	}
	PASS(e, iter(root, data));
	if ( root-> right != NULL ) {
	    PASS(e, aksl_tree_iterate(root->right, iter, lalloc, lfree, searchmode, data, NULL));
	}
	break;
    case AKSL_TREE_SEARCH_BFS:
    case AKSL_TREE_SEARCH_BFS_RIGHT:
	FAIL_RETURN(e, AKERR_NOT_IMPLEMENTED, "Searchmode %d", searchmode);
	break;
    }
    SUCCEED_RETURN(e);
}

/**
 * @brief Iterates over a linked list and execute a callback function on each node
 *
 * @param[in] list The linked list to iterate
 * @param[in] iter An aksl_ListNodeIterator function which will be called for each node found
 * @param[in] data Any user data that should be provided when the iterator is called
 *
 * @throws AKERR_NULLPOINTER on null pointer inputs
 * @throws AKERR_CIRCULAR_REFERENCE when the linked list contains a circular reference
 * 
 * @return akerr_ErrorContext
 */
akerr_ErrorContext AKERR_NOIGNORE *aksl_list_iterate(aksl_ListNode *list, aksl_ListNodeIterator iter, void *data)
{
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, list, AKERR_NULLPOINTER, "list");
    FAIL_ZERO_RETURN(e, iter, AKERR_NULLPOINTER, "iter");
    aksl_ListNode *slow = list;
    aksl_ListNode *fast = list;
    aksl_ListNode *tail = list;
    do {
	if ( fast != NULL && fast->next != NULL ) {
	    fast = fast->next->next;
	}
	PASS(e, iter(slow, data));
	slow = slow->next;
	if ( fast != NULL && fast == slow) {
	    FAIL(e, AKERR_CIRCULAR_REFERENCE, "%p", list);
	}
    } while ( slow != NULL || (fast != NULL && fast->next != NULL) );
    SUCCEED_RETURN(e);
}