/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2017 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.
 */

#include "ucx/list.h"

UcxList *ucx_list_clone(const UcxList *l, copy_func fnc, void *data) {
    return ucx_list_clone_a(ucx_default_allocator(), l, fnc, data);
}

UcxList *ucx_list_clone_a(UcxAllocator *alloc, const UcxList *l,
        copy_func fnc, void *data) {
    UcxList *ret = NULL;
    while (l) {
        if (fnc) {
            ret = ucx_list_append_a(alloc, ret, fnc(l->data, data));
        } else {
            ret = ucx_list_append_a(alloc, ret, l->data);
        }
        l = l->next;
    }
    return ret;
}

int ucx_list_equals(const UcxList *l1, const UcxList *l2,
        cmp_func fnc, void* data) {
    if (l1 == l2) return 1;
    
    while (l1 != NULL && l2 != NULL) {
        if (fnc == NULL) {
            if (l1->data != l2->data) return 0;
        } else {
            if (fnc(l1->data, l2->data, data) != 0) return 0;
        }
        l1 = l1->next;
        l2 = l2->next;
    }
    
    return (l1 == NULL && l2 == NULL);
}

void ucx_list_free(UcxList *l) {
    ucx_list_free_a(ucx_default_allocator(), l);
}

void ucx_list_free_a(UcxAllocator *alloc, UcxList *l) {
    UcxList *e = l, *f;
    while (e != NULL) {
        f = e;
        e = e->next;
        alfree(alloc, f);
    }
}

void ucx_list_free_content(UcxList* list, ucx_destructor destr) {
    if (!destr) destr = free;
    while (list != NULL) {
        destr(list->data);
        list = list->next;
    }
}

UcxList *ucx_list_append(UcxList *l, void *data)  {
    return ucx_list_append_a(ucx_default_allocator(), l, data);
}

UcxList *ucx_list_append_a(UcxAllocator *alloc, UcxList *l, void *data)  {
    UcxList *nl = (UcxList*) almalloc(alloc, sizeof(UcxList));
    if (!nl) {
        return NULL;
    }
    
    nl->data = data;
    nl->next = NULL;
    if (l) {
        UcxList *t = ucx_list_last(l);
        t->next = nl;
        nl->prev = t;
        return l;
    } else {
        nl->prev = NULL;
        return nl;
    }
}

UcxList *ucx_list_prepend(UcxList *l, void *data) {
    return ucx_list_prepend_a(ucx_default_allocator(), l, data);
}

UcxList *ucx_list_prepend_a(UcxAllocator *alloc, UcxList *l, void *data) {
    UcxList *nl = ucx_list_append_a(alloc, NULL, data);
    if (!nl) {
        return NULL;
    }
    l = ucx_list_first(l);
    
    if (l) {
        nl->next = l;
        l->prev = nl;
    }
    return nl;
}

UcxList *ucx_list_concat(UcxList *l1, UcxList *l2) {
    if (l1) {
        UcxList *last = ucx_list_last(l1);
        last->next = l2;
        if (l2) {
            l2->prev = last;
        }
        return l1;
    } else {
        return l2;
    }
}

UcxList *ucx_list_last(const UcxList *l) {
    if (l == NULL) return NULL;
    
    const UcxList *e = l;
    while (e->next != NULL) {
        e = e->next;
    }
    return (UcxList*)e;
}

ssize_t ucx_list_indexof(const UcxList *list, const UcxList *elem) {
    ssize_t index = 0;
    while (list) {
        if (list == elem) {
            return index;
        }
        list = list->next;
        index++;
    }
    return -1;
}

UcxList *ucx_list_get(const UcxList *l, size_t index) {
    if (l == NULL) return NULL;

    const UcxList *e = l;
    while (e->next && index > 0) {
        e = e->next;
        index--;
    }
    
    return (UcxList*)(index == 0 ? e : NULL);
}

ssize_t ucx_list_find(const UcxList *l, void *elem,
        cmp_func fnc, void *cmpdata) {
    ssize_t index = 0;
    UCX_FOREACH(e, l) {
        if (fnc) {
            if (fnc(elem, e->data, cmpdata) == 0) {
                return index;
            }
        } else {
            if (elem == e->data) {
                return index;
            }
        }
        index++;
    }
    return -1;
}

int ucx_list_contains(const UcxList *l, void *elem,
        cmp_func fnc, void *cmpdata) {
    return ucx_list_find(l, elem, fnc, cmpdata) > -1;
}

size_t ucx_list_size(const UcxList *l) {
    if (l == NULL) return 0;
    
    const UcxList *e = l;
    size_t s = 1;
    while (e->next != NULL) {
        e = e->next;
        s++;
    }

    return s;
}

static UcxList *ucx_list_sort_merge(size_t length,
        UcxList* ls, UcxList* le, UcxList* re,
        cmp_func fnc, void* data) {

    UcxList** sorted = (UcxList**) malloc(sizeof(UcxList*)*length);
    UcxList *rc, *lc;

    lc = ls; rc = le;
    size_t n = 0;
    while (lc && lc != le && rc != re) {
        if (fnc(lc->data, rc->data, data) <= 0) {
            sorted[n] = lc;
            lc = lc->next;
        } else {
            sorted[n] = rc;
            rc = rc->next;
        }
        n++;
    }
    while (lc && lc != le) {
        sorted[n] = lc;
        lc = lc->next;
        n++;
    }
    while (rc && rc != re) {
        sorted[n] = rc;
        rc = rc->next;
        n++;
    }

    // Update pointer
    sorted[0]->prev = NULL;
    for (int i = 0 ; i < length-1 ; i++) {
        sorted[i]->next = sorted[i+1];
        sorted[i+1]->prev = sorted[i];
    }
    sorted[length-1]->next = NULL;

    UcxList *ret = sorted[0];
    free(sorted);
    return ret;
}

UcxList *ucx_list_sort(UcxList *l, cmp_func fnc, void *data) {
    if (l == NULL) {
        return NULL;
    }

    UcxList *lc;
    size_t ln = 1;

    UcxList *ls = l, *le, *re;
    
    // check how many elements are already sorted
    lc = ls;
    while (lc->next != NULL && fnc(lc->next->data, lc->data, data) > 0) {
        lc = lc->next;
        ln++;
    }
    le = lc->next;

    if (le == NULL) {
        return l; // this list is already sorted :)
    } else {
        UcxList *rc;
        size_t rn = 1;
        rc = le;
        // skip already sorted elements
        while (rc->next != NULL && fnc(rc->next->data, rc->data, data) > 0) {
            rc = rc->next;
            rn++;
        }
        re = rc->next;

        // {ls,...,le->prev} and {rs,...,re->prev} are sorted - merge them
        UcxList *sorted = ucx_list_sort_merge(ln+rn,
                ls, le, re,
                fnc, data);
        
        // Something left? Sort it!
        size_t remainder_length = ucx_list_size(re);
        if (remainder_length > 0) {
            UcxList *remainder = ucx_list_sort(re, fnc, data);

            // merge sorted list with (also sorted) remainder
            l = ucx_list_sort_merge(ln+rn+remainder_length,
                    sorted, remainder, NULL, fnc, data);
        } else {
            // no remainder - we've got our sorted list
            l = sorted;
        }

        return l;
    }
}

UcxList *ucx_list_first(const UcxList *l) {
    if (!l) {
        return NULL;
    }
    
    const UcxList *e = l;
    while (e->prev) {
        e = e->prev;
    }
    return (UcxList *)e;
}

UcxList *ucx_list_remove(UcxList *l, UcxList *e) {
    return ucx_list_remove_a(ucx_default_allocator(), l, e);
}
    
UcxList *ucx_list_remove_a(UcxAllocator *alloc, UcxList *l, UcxList *e) {
    if (l == e) {
        l = e->next;
    }
    
    if (e->next) {
        e->next->prev = e->prev;
    }
    
    if (e->prev) {
        e->prev->next = e->next;
    }
    
    alfree(alloc, e);
    return l;
}


static UcxList* ucx_list_setoperation_a(UcxAllocator *allocator,
        UcxList const *left, UcxList const *right,
        cmp_func cmpfnc, void* cmpdata,
        copy_func cpfnc, void* cpdata,
        int op) {
    
    UcxList *res = NULL;
    UcxList *cur = NULL;
    const UcxList *src = left;
    
    do {
        UCX_FOREACH(node, src) {
            void* elem = node->data;
            if (
                (op == 0 && !ucx_list_contains(res, elem, cmpfnc, cmpdata)) ||
                (op == 1 && ucx_list_contains(right, elem, cmpfnc, cmpdata)) ||
                (op == 2 && !ucx_list_contains(right, elem, cmpfnc, cmpdata))) {
                UcxList *nl = almalloc(allocator, sizeof(UcxList));
                nl->prev = cur;
                nl->next = NULL;
                if (cpfnc) {
                    nl->data = cpfnc(elem, cpdata);
                } else {
                    nl->data = elem;
                }
                if (cur != NULL)
                    cur->next = nl;
                cur = nl;
                if (res == NULL)
                    res = cur;
            }
        }
        if (op == 0 && src == left)
            src = right;
        else
            src = NULL;
    } while (src != NULL);
    
    return res;
}

UcxList* ucx_list_union(UcxList const *left, UcxList const *right,
        cmp_func cmpfnc, void* cmpdata,
        copy_func cpfnc, void* cpdata) {
    return ucx_list_union_a(ucx_default_allocator(),
            left, right, cmpfnc, cmpdata, cpfnc, cpdata);
}

UcxList* ucx_list_union_a(UcxAllocator *allocator,
        UcxList const *left, UcxList const *right,
        cmp_func cmpfnc, void* cmpdata,
        copy_func cpfnc, void* cpdata) {
    
    return ucx_list_setoperation_a(allocator, left, right,
            cmpfnc, cmpdata, cpfnc, cpdata, 0);
}

UcxList* ucx_list_intersection(UcxList const *left, UcxList const *right,
        cmp_func cmpfnc, void* cmpdata,
        copy_func cpfnc, void* cpdata) {
    return ucx_list_intersection_a(ucx_default_allocator(), left, right,
            cmpfnc, cmpdata, cpfnc, cpdata);
}

UcxList* ucx_list_intersection_a(UcxAllocator *allocator,
        UcxList const *left, UcxList const *right,
        cmp_func cmpfnc, void* cmpdata,
        copy_func cpfnc, void* cpdata) {
    
    return ucx_list_setoperation_a(allocator, left, right,
            cmpfnc, cmpdata, cpfnc, cpdata, 1);
}

UcxList* ucx_list_difference(UcxList const *left, UcxList const *right,
        cmp_func cmpfnc, void* cmpdata,
        copy_func cpfnc, void* cpdata) {
    return ucx_list_difference_a(ucx_default_allocator(), left, right,
            cmpfnc, cmpdata, cpfnc, cpdata);
}

UcxList* ucx_list_difference_a(UcxAllocator *allocator,
        UcxList const *left, UcxList const *right,
        cmp_func cmpfnc, void* cmpdata,
        copy_func cpfnc, void* cpdata) {
    
    return ucx_list_setoperation_a(allocator, left, right,
            cmpfnc, cmpdata, cpfnc, cpdata, 2);
}