/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2019 Mike Becker, Olaf Wintermann All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
/**
 * Dynamically allocated array implementation.
 * 
 * @file   array.h
 * @author Mike Becker
 * @author Olaf Wintermann
 */

#ifndef UCX_ARRAY_H
#define	UCX_ARRAY_H

#include "ucx.h"
#include "allocator.h"

#ifdef	__cplusplus
extern "C" {
#endif

/**
 * UCX array type.
 */
typedef struct {
    /**
     * The current capacity of the array.
     */
    size_t capacity;
    /**
     * The actual number of elements in the array.
     */
    size_t size;
    /**
     * The size of an individual element in bytes.
     */
    size_t elemsize;
    /**
     * A pointer to the data.
     */
    void* data;
    /**
     * The allocator used for the data.
     */
    UcxAllocator* allocator;
} UcxArray;

/**
 * Sets an element in an arbitrary user defined array.
 * The data is copied from the specified data location.
 * 
 * If the capacity is insufficient, the array is automatically reallocated and
 * the possibly new pointer is stored in the <code>array</code> argument.
 * 
 * On reallocation the capacity of the array is doubled until it is sufficient.
 * The new capacity is stored back to <code>capacity</code>.
 *  
 * @param array a pointer to location of the array pointer
 * @param capacity a pointer to the capacity
 * @param elmsize the size of each element
 * @param idx the index of the element to set
 * @param data a pointer to the element data
 * @return zero on success or non-zero on error (errno will be set)
 */
#define ucx_array_util_set(array, capacity, elmsize, idx, data) \
    ucx_array_util_set_a(ucx_default_allocator(), (void**)(array), capacity, \
                         elmsize, idx, data)

/**
 * Sets an element in an arbitrary user defined array.
 * The data is copied from the specified data location.
 * 
 * If the capacity is insufficient, the array is automatically reallocated
 * using the specified allocator and the possibly new pointer is stored in
 * the <code>array</code> argument.
 * 
 * On reallocation the capacity of the array is doubled until it is sufficient.
 * The new capacity is stored back to <code>capacity</code>. 
 * 
 * @param alloc the allocator that shall be used to reallocate the array
 * @param array a pointer to location of the array pointer
 * @param capacity a pointer to the capacity
 * @param elmsize the size of each element
 * @param idx the index of the element to set
 * @param data a pointer to the element data
 * @return zero on success or non-zero on error (errno will be set)
 */
int ucx_array_util_set_a(UcxAllocator* alloc, void** array, size_t* capacity,
    size_t elmsize, size_t idx, void* data);

/**
 * Stores a pointer in an arbitrary user defined array.
 * The element size of the array must be sizeof(void*).
 * 
 * If the capacity is insufficient, the array is automatically reallocated and
 * the possibly new pointer is stored in the <code>array</code> argument.
 * 
 * On reallocation the capacity of the array is doubled until it is sufficient.
 * The new capacity is stored back to <code>capacity</code>.
 *  
 * @param array a pointer to location of the array pointer
 * @param capacity a pointer to the capacity
 * @param idx the index of the element to set
 * @param ptr the pointer to store
 * @return zero on success or non-zero on error (errno will be set)
 */
#define ucx_array_util_setptr(array, capacity, idx, ptr) \
    ucx_array_util_setptr_a(ucx_default_allocator(), (void**)(array), \
                            capacity, idx, ptr)

/**
 * Stores a pointer in an arbitrary user defined array.
 * The element size of the array must be sizeof(void*).
 * 
 * If the capacity is insufficient, the array is automatically reallocated
 * using the specified allocator and the possibly new pointer is stored in
 * the <code>array</code> argument.
 * 
 * On reallocation the capacity of the array is doubled until it is sufficient.
 * The new capacity is stored back to <code>capacity</code>. 
 * 
 * @param alloc the allocator that shall be used to reallocate the array
 * @param array a pointer to location of the array pointer
 * @param capacity a pointer to the capacity
 * @param idx the index of the element to set
 * @param ptr the pointer to store
 * @return zero on success or non-zero on error (errno will be set)
 */
int ucx_array_util_setptr_a(UcxAllocator* alloc, void** array, size_t* capacity,
    size_t idx, void* ptr);


/**
 * Creates a new UCX array with the given capacity and element size.
 * @param capacity the initial capacity
 * @param elemsize the element size
 * @return a pointer to a new UCX array structure
 */
UcxArray* ucx_array_new(size_t capacity, size_t elemsize);

/**
 * Creates a new UCX array using the specified allocator.
 * 
 * @param capacity the initial capacity
 * @param elemsize the element size
 * @param allocator the allocator to use
 * @return a pointer to new UCX array structure
 */
UcxArray* ucx_array_new_a(size_t capacity, size_t elemsize,
        UcxAllocator* allocator);

/**
 * Initializes a UCX array structure with the given capacity and element size.
 * The structure must be uninitialized as the data pointer will be overwritten.
 * 
 * @param array the structure to initialize
 * @param capacity the initial capacity
 * @param elemsize the element size
 */
void ucx_array_init(UcxArray* array, size_t capacity, size_t elemsize);

/**
 * Initializes a UCX array structure using the specified allocator.
 * The structure must be uninitialized as the data pointer will be overwritten.
 * 
 * @param array the structure to initialize
 * @param capacity the initial capacity
 * @param elemsize the element size
 * @param allocator the allocator to use
 */
void ucx_array_init_a(UcxArray* array, size_t capacity, size_t elemsize,
        UcxAllocator* allocator);

/**
 * Creates an shallow copy of an array.
 * 
 * This function clones the specified array by using memcpy().
 * If the destination capacity is insufficient, an automatic reallocation is
 * attempted.
 * 
 * Note: if the destination array is uninitialized, the behavior is undefined.
 * 
 * @param dest the array to copy to
 * @param src the array to copy from
 * @return zero on success, non-zero on reallocation failure.
 */
int ucx_array_clone(UcxArray* dest, UcxArray const* src);


/**
 * Compares two UCX arrays element-wise by using a compare function.
 *
 * Elements of the two specified arrays are compared by using the specified
 * compare function and the additional data. The type and content of this
 * additional data depends on the cmp_func() used.
 * 
 * This function always returns zero, if the element sizes of the arrays do
 * not match and performs no comparisons in this case.
 * 
 * @param array1 the first array
 * @param array2 the second array
 * @param cmpfnc the compare function
 * @param data additional data for the compare function
 * @return 1, if and only if the two arrays equal element-wise, 0 otherwise
 */
int ucx_array_equals(UcxArray const *array1, UcxArray const *array2,
        cmp_func cmpfnc, void* data);

/**
 * Destroys the array.
 * 
 * The data is freed and both capacity and count are reset to zero.
 * If the array structure itself has been dynamically allocated, it has to be
 * freed separately.
 * 
 * @param array the array to destroy
 */
void ucx_array_destroy(UcxArray *array);

/**
 * Destroys and frees the array.
 * 
 * @param array the array to free
 */
void ucx_array_free(UcxArray *array);

/**
 * Inserts elements at the end of the array.
 * 
 * This is an O(1) operation.
 * The array will automatically grow, if the capacity is exceeded.
 * If a pointer to data is provided, the data is copied into the array with
 * memcpy(). Otherwise the new elements are completely zeroed.
 * 
 * @param array a pointer the array where to append the data
 * @param data a pointer to the data to insert (may be <code>NULL</code>)
 * @param count number of elements to copy from data (if data is
 * <code>NULL</code>, zeroed elements are appended)
 * @return zero on success, non-zero if a reallocation was necessary but failed
 * @see ucx_array_set_from()
 * @see ucx_array_append()
 */
int ucx_array_append_from(UcxArray *array, void *data, size_t count);


/**
 * Inserts elements at the beginning of the array.
 * 
 * This is an expensive operation, because the contents must be moved.
 * If there is no particular reason to prepend data, you should use
 * ucx_array_append_from() instead.
 * 
 * @param array a pointer the array where to prepend the data
 * @param data a pointer to the data to insert (may be <code>NULL</code>)
 * @param count number of elements to copy from data (if data is
 * <code>NULL</code>, zeroed elements are inserted)
 * @return zero on success, non-zero if a reallocation was necessary but failed
 * @see ucx_array_append_from()
 * @see ucx_array_set_from()
 * @see ucx_array_prepend()
 */
int ucx_array_prepend_from(UcxArray *array, void *data, size_t count);


/**
 * Sets elements starting at the specified index.
 * 
 * If the any index is out of bounds, the array automatically grows.
 * The pointer to the data may be NULL, in which case the elements are zeroed. 
 * 
 * @param array a pointer the array where to set the data
 * @param index the index of the element to set
 * @param data a pointer to the data to insert (may be <code>NULL</code>)
 * @param count number of elements to copy from data (if data is
 * <code>NULL</code>, the memory in the array is zeroed)
 * @return zero on success, non-zero if a reallocation was necessary but failed
 * @see ucx_array_append_from()
 * @see ucx_array_set()
 */
int ucx_array_set_from(UcxArray *array, size_t index, void *data, size_t count);

/**
 * Concatenates two arrays.
 * 
 * The contents of the second array are appended to the first array in one
 * single operation. The second array is otherwise left untouched.
 * 
 * The first array may grow automatically. If this fails, both arrays remain
 * unmodified.
 * 
 * @param array1 first array
 * @param array2 second array
 * @return zero on success, non-zero if reallocation was necessary but failed 
 * or the element size does not match
 */
int ucx_array_concat(UcxArray *array1, const UcxArray *array2);

/**
 * Returns a pointer to the array element at the specified index.
 * 
 * @param array the array to retrieve the element from
 * @param index index of the element to return
 * @return a pointer to the element at the specified index or <code>NULL</code>,
 * if the index is greater than the array size
 */
void *ucx_array_at(UcxArray const* array, size_t index);

/**
 * Returns the index of an element containing the specified data.
 *
 * This function uses a cmp_func() to compare the data of each list element
 * with the specified data. If no cmp_func is provided, memcmp() is used.
 * 
 * If the array contains the data more than once, the index of the first
 * occurrence is returned.
 * If the array does not contain the data, the size of array is returned.
 *  
 * @param array the array where to search for the data
 * @param elem the element data
 * @param cmpfnc the compare function
 * @param data additional data for the compare function
 * @return the index of the element containing the specified data or the size of
 * the array, if the data is not found in this array
 */
size_t ucx_array_find(UcxArray const *array, void *elem,
    cmp_func cmpfnc, void *data);

/**
 * Checks, if an array contains a specific element.
 * 
 * An element is found, if ucx_array_find() returns a value less than the size.
 * 
 * @param array the array where to search for the data
 * @param elem the element data
 * @param cmpfnc the compare function
 * @param data additional data for the compare function
 * @return 1, if and only if the array contains the specified element data
 * @see ucx_array_find()
 */
int ucx_array_contains(UcxArray const *array, void *elem,
    cmp_func cmpfnc, void *data);

/**
 * Sorts a UcxArray with the best available sort algorithm.
 * 
 * The qsort_r() function is used, if available (glibc, FreeBSD or MacOS).
 * The order of arguments is automatically adjusted for the FreeBSD and MacOS
 * version of qsort_r().
 * 
 * If qsort_r() is not available, a merge sort algorithm is used, which is
 * guaranteed to use no more additional memory than for exactly one element.
 * 
 * @param array the array to sort
 * @param cmpfnc the function that shall be used to compare the element data
 * @param data additional data for the cmp_func() or <code>NULL</code>
 */
void ucx_array_sort(UcxArray* array, cmp_func cmpfnc, void *data);

/**
 * Removes an element from the array.
 * 
 * This is in general an expensive operation, because several elements may
 * be moved. If the order of the elements is not relevant, use
 * ucx_array_remove_fast() instead.
 * 
 * @param array pointer to the array from which the element shall be removed
 * @param index the index of the element to remove
 */
void ucx_array_remove(UcxArray *array, size_t index);

/**
 * Removes an element from the array.
 * 
 * This is an O(1) operation, but does not maintain the order of the elements.
 * The last element in the array is moved to the location of the removed
 * element.
 * 
 * @param array pointer to the array from which the element shall be removed
 * @param index the index of the element to remove
 */
void ucx_array_remove_fast(UcxArray *array, size_t index);

/**
 * Shrinks the memory to exactly fit the contents.
 * 
 * After this operation, the capacity equals the size.
 * 
 * @param array a pointer to the array
 * @return zero on success, non-zero if reallocation failed
 */
int ucx_array_shrink(UcxArray* array);

/**
 * Sets the capacity of the array.
 * 
 * If the new capacity is smaller than the size of the array, the elements
 * are removed and the size is adjusted accordingly.
 * 
 * @param array a pointer to the array
 * @param capacity the new capacity
 * @return zero on success, non-zero if reallocation failed
 */
int ucx_array_resize(UcxArray* array, size_t capacity);

/**
 * Resizes the array only, if the capacity is insufficient.
 * 
 * If the requested capacity is smaller than the current capacity, this
 * function does nothing.
 * 
 * @param array a pointer to the array
 * @param capacity the guaranteed capacity
 * @return zero on success, non-zero if reallocation failed
 */
int ucx_array_reserve(UcxArray* array, size_t capacity);

/**
 * Resizes the capacity, if the specified number of elements would not fit.
 * 
 * A call to ucx_array_grow(array, count) is effectively the same as
 * ucx_array_reserve(array, array->size+count).
 * 
 * @param array a pointer to the array
 * @param count the number of elements that should additionally fit
 * into the array
 * @return zero on success, non-zero if reallocation failed
 */
int ucx_array_grow(UcxArray* array, size_t count);


#ifdef	__cplusplus
}
#endif

#endif	/* UCX_ARRAY_H */