/*
 * 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.
 */

#define _GNU_SOURCE /* we want to use qsort_r(), if available */
#define __STDC_WANT_LIB_EXT1__ 1 /* use qsort_s, if available */


#include "ucx/array.h"
#include "ucx/utils.h"

#include <string.h>
#include <stdlib.h>
#include <errno.h>

#ifndef UCX_ARRAY_DISABLE_QSORT
#ifdef __GLIBC__
#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 8)
#define ucx_array_sort_impl qsort_r
#endif /* glibc version >= 2.8 */
#elif /* not  __GLIBC__ */ defined(__APPLE__) || defined(__FreeBSD__)
#define ucx_array_sort_impl ucx_qsort_r
#define USE_UCX_QSORT_R
#elif /* not (__APPLE || __FreeBSD__) */ defined(__sun)
#if __STDC_VERSION__ >= 201112L
#define ucx_array_sort_impl qsort_s
#endif
#endif /* __GLIBC__, __APLE__, __FreeBSD__, __sun */
#endif /* UCX_ARRAY_DISABLE_QSORT */

#ifndef ucx_array_sort_impl
#define ucx_array_sort_impl ucx_mergesort
#endif

static int ucx_array_ensurecap(UcxArray *array, size_t reqcap) {
    size_t required_capacity = array->capacity;
    while (reqcap > required_capacity) {
        if (required_capacity * 2 < required_capacity)
            return 1;
        required_capacity <<= 1;
    }
    if (ucx_array_reserve(array, required_capacity)) {
        return 1;
    }
    return 0;
}

int ucx_array_util_set_a(UcxAllocator* alloc, void** array, size_t* capacity,
    size_t elmsize, size_t index, void* data) {
    
    if(!alloc || !capacity || !array) {
        errno = EINVAL;
        return 1;
    }
    
    size_t newcapacity = *capacity;
    while(index >= newcapacity) {
        if(ucx_szmul(newcapacity, 2, &newcapacity)) {
            errno = EOVERFLOW;
            return 1;
        }        
    }

    size_t memlen, offset;
    if(ucx_szmul(newcapacity, elmsize, &memlen)) {
        errno = EOVERFLOW;
        return 1;
    }
    /* we don't need to check index*elmsize - it is smaller than memlen */
    
    
    void* newptr = alrealloc(alloc, *array, memlen);
    if(newptr == NULL) {
        errno = ENOMEM; /* we cannot assume that every allocator sets this */
        return 1;
    }
    *array = newptr;
    *capacity = newcapacity;
    
    
    char* dest = *array;
    dest += elmsize*index;
    memcpy(dest, data, elmsize);
    
    return 0;
}

int ucx_array_util_setptr_a(UcxAllocator* alloc, void** array, size_t* capacity,
    size_t index, void* data) {
    
    return ucx_array_util_set_a(alloc, array, capacity, sizeof(void*),
            index, &data);
}

UcxArray* ucx_array_new(size_t capacity, size_t elemsize) {
    return ucx_array_new_a(capacity, elemsize, ucx_default_allocator());
}

UcxArray* ucx_array_new_a(size_t capacity, size_t elemsize,
        UcxAllocator* allocator) {
    UcxArray* array = almalloc(allocator, sizeof(UcxArray));
    if(array) {
        ucx_array_init_a(array, capacity, elemsize, allocator);
    }
    return array;
}

void ucx_array_init(UcxArray* array, size_t capacity, size_t elemsize) {
    ucx_array_init_a(array, capacity, elemsize, ucx_default_allocator());
}

void ucx_array_init_a(UcxArray* array, size_t capacity, size_t elemsize,
        UcxAllocator* allocator) {
    
    array->allocator = allocator;
    array->elemsize = elemsize;
    array->size = 0;
    array->data = alcalloc(allocator, capacity, elemsize);
    
    if (array->data) {
        array->capacity = capacity;
    } else {
        array->capacity = 0;
    }
}

int ucx_array_clone(UcxArray* dest, UcxArray const* src) {
    if (ucx_array_ensurecap(dest, src->capacity)) {
        return 1;
    }
    
    dest->elemsize = src->elemsize;
    dest->size = src->size;
    
    if (dest->data) {
        memcpy(dest->data, src->data, src->size*src->elemsize);
    }
    
    return 0;
}

int ucx_array_equals(UcxArray const *array1, UcxArray const *array2,
        cmp_func cmpfnc, void* data) {
    
    if (array1->size != array2->size || array1->elemsize != array2->elemsize) {
        return 0;
    } else {
        if (array1->size == 0)
            return 1;
        
        size_t elemsize;
        if (cmpfnc == NULL) {
            cmpfnc = ucx_cmp_mem;
            elemsize = array1->elemsize;
            data = &elemsize;
        }
        
        for (size_t i = 0 ; i < array1->size ; i++) {
            int r = cmpfnc(
                    ucx_array_at(array1, i),
                    ucx_array_at(array2, i),
                    data);
            if (r != 0)
                return 0;
        }
        return 1;
    }
}

void ucx_array_destroy(UcxArray *array) {
    if(array->data)
        alfree(array->allocator, array->data);
    array->data = NULL;
    array->capacity = array->size = 0;
}

void ucx_array_free(UcxArray *array) {
    ucx_array_destroy(array);
    alfree(array->allocator, array);
}

int ucx_array_append_from(UcxArray *array, void *data, size_t count) {
    if (ucx_array_ensurecap(array, array->size + count))
        return 1;
    
    void* dest = ucx_array_at(array, array->size);
    if (data) {
        memcpy(dest, data, array->elemsize*count);
    } else {
        memset(dest, 0, array->elemsize*count);
    }
    array->size += count;
    
    return 0;
}

int ucx_array_prepend_from(UcxArray *array, void *data, size_t count) {
    if (ucx_array_ensurecap(array, array->size + count))
        return 1;
    
    if (array->size > 0) {
        void *dest = ucx_array_at(array, count);
        memmove(dest, array->data, array->elemsize*array->size);
    }
    
    if (data) {
        memcpy(array->data, data, array->elemsize*count);
    } else {
        memset(array->data, 0, array->elemsize*count);
    }
    array->size += count;
        
    return 0;
}

int ucx_array_set_from(UcxArray *array, size_t index,
        void *data, size_t count) {
    if (ucx_array_ensurecap(array, index + count))
        return 1;
    
    if (index+count > array->size) {
        array->size = index+count;
    }
    
    void *dest = ucx_array_at(array, index);
    if (data) {
        memcpy(dest, data, array->elemsize*count);
    } else {
        memset(dest, 0, array->elemsize*count);
    }
    
    return 0;
}

int ucx_array_concat(UcxArray *array1, const UcxArray *array2) {
    
    if (array1->elemsize != array2->elemsize)
        return 1;
    
    size_t capacity = array1->capacity+array2->capacity;
        
    if (array1->capacity < capacity) {
        if (ucx_array_reserve(array1, capacity)) {
            return 1;
        }
    }
    
    void* dest = ucx_array_at(array1, array1->size);
    memcpy(dest, array2->data, array2->size*array2->elemsize);
    
    array1->size += array2->size;
    
    return 0;
}

void *ucx_array_at(UcxArray const *array, size_t index) {
    char* memory = array->data;
    char* loc = memory + index*array->elemsize;
    return loc;
}

size_t ucx_array_find(UcxArray const *array, void *elem,
        cmp_func cmpfnc, void *data) {
    
    size_t elemsize;
    if (cmpfnc == NULL) {
        cmpfnc = ucx_cmp_mem;
        elemsize = array->elemsize;
        data = &elemsize;
    }

    if (array->size > 0) {
        for (size_t i = 0 ; i < array->size ; i++) {
            void* ptr = ucx_array_at(array, i);
            if (cmpfnc(ptr, elem, data) == 0) {
                return i;
            }
        }
        return array->size;
    } else {
        return 0;
    }
}

int ucx_array_contains(UcxArray const *array, void *elem,
        cmp_func cmpfnc, void *data) {
    return ucx_array_find(array, elem, cmpfnc, data) != array->size;
}

static void ucx_mergesort_merge(void *arrdata,size_t elemsize,
        cmp_func cmpfnc, void *data,
        size_t start, size_t mid, size_t end) { 
    
    char* array = arrdata;
    
    size_t rightstart = mid + 1; 
  
    if (cmpfnc(array + mid*elemsize,
            array + rightstart*elemsize, data) <= 0) {
        /* already sorted */
        return;
    }
  
    /* we need memory for one element */
    void *value = malloc(elemsize);
    
    while (start <= mid && rightstart <= end) { 
        if (cmpfnc(array + start*elemsize,
                array + rightstart*elemsize, data) <= 0) { 
            start++; 
        } else {
            /* save the value from the right */
            memcpy(value, array + rightstart*elemsize, elemsize);
                        
            /* shift all left elements one element to the right */
            size_t shiftcount = rightstart-start;
            void *startptr = array + start*elemsize;
            void *dest = array + (start+1)*elemsize;
            memmove(dest, startptr, shiftcount*elemsize);
            
            /* bring the first value from the right to the left */
            memcpy(startptr, value, elemsize);
  
            start++; 
            mid++; 
            rightstart++; 
        }
    }
    
    /* free the temporary memory */
    free(value);
} 
  
static void ucx_mergesort_impl(void *arrdata, size_t elemsize,
        cmp_func cmpfnc, void *data, size_t l, size_t r) { 
    if (l < r) {
        size_t m = l + (r - l) / 2; 
  
        ucx_mergesort_impl(arrdata, elemsize, cmpfnc, data, l, m); 
        ucx_mergesort_impl(arrdata, elemsize, cmpfnc, data, m + 1, r); 
        ucx_mergesort_merge(arrdata, elemsize, cmpfnc, data, l, m, r);
    } 
}

static void ucx_mergesort(void *arrdata, size_t count, size_t elemsize,
        cmp_func cmpfnc, void *data) {
    
    ucx_mergesort_impl(arrdata, elemsize, cmpfnc, data, 0, count-1);
}

#ifdef USE_UCX_QSORT_R
struct cmpfnc_swapargs_info {
    cmp_func func;
    void *data;
};

static int cmp_func_swap_args(void *data, const void *x, const void *y) {
    struct cmpfnc_swapargs_info* info = data;
    return info->func(x, y, info->data);
}

static void ucx_qsort_r(void *array, size_t count, size_t elemsize,
		     cmp_func cmpfnc, void *data) {
    struct cmpfnc_swapargs_info info;
    info.func = cmpfnc;
    info.data = data;
    qsort_r(array, count, elemsize, &info, cmp_func_swap_args);
}
#endif /* USE_UCX_QSORT_R */

void ucx_array_sort(UcxArray* array, cmp_func cmpfnc, void *data) {
    ucx_array_sort_impl(array->data, array->size, array->elemsize,
            cmpfnc, data);
}

void ucx_array_remove(UcxArray *array, size_t index) {
    array->size--;
    if (index < array->size) {
        void* dest = ucx_array_at(array, index);
        void* src = ucx_array_at(array, index+1);
        memmove(dest, src, (array->size - index)*array->elemsize);
    }
}

void ucx_array_remove_fast(UcxArray *array, size_t index) {
    array->size--;
    if (index < array->size) {       
        void* dest = ucx_array_at(array, index);
        void* src = ucx_array_at(array, array->size);
        memcpy(dest, src, array->elemsize);
    }
}

int ucx_array_shrink(UcxArray* array) {
    void* newptr = alrealloc(array->allocator, array->data,
                array->size*array->elemsize);
    if (newptr) {
        array->data = newptr;
        array->capacity = array->size;
        return 0;
    } else {
        return 1;
    }
}

int ucx_array_resize(UcxArray* array, size_t capacity) {
    if (array->capacity >= capacity) {
        void* newptr = alrealloc(array->allocator, array->data,
                capacity*array->elemsize);
        if (newptr) {
            array->data = newptr;
            array->capacity = capacity;
            if (array->size > array->capacity) {
                array->size = array->capacity;
            }
            return 0;
        } else {
            return 1;
        }
    } else {
        return ucx_array_reserve(array, capacity);
    }
}

int ucx_array_reserve(UcxArray* array, size_t capacity) {
    if (array->capacity > capacity) {
        return 0;
    } else {
        void* newptr = alrealloc(array->allocator, array->data,
                capacity*array->elemsize);
        if (newptr) {
            array->data = newptr;
            array->capacity = capacity;
            return 0;
        } else {
            return 1;
        }
    }
}

int ucx_array_grow(UcxArray* array, size_t count) {
    return ucx_array_reserve(array, array->size+count);
}