/* This software is licensed by the MIT License, see LICENSE file */
/*                                Copyright © 2022 Gregory Lirent */

#include "include.h"

/*#####################################################################################################################*/

static void dict_rehash(dict_t* s, size_t capacity) {
    stack_t z;
    int cmp;
    dnode_t *c, *p, *n, **r;

    dnode_t **nodes = malloc(capacity * sizeof(*nodes));

    while (s->capacity--) {
        if (!dnode_is_empty(s->nodes[s->capacity]))
            stack_push(&z, s->nodes[s->capacity]);
    }

    while ((c = stack_pop(&z))) {

        if (!dnode_is_empty(c->right)) {
            stack_push(&z, c->right);
            c->right = dnode_empty;
        }

        if (!dnode_is_empty(c->left)) {
            stack_push(&z, c->left);
            c->left = dnode_empty;
        }

        n = *(r = &nodes[vnode_hash(c->key, c->key_type) / capacity]);

        if (!dnode_is_empty(*r)) {
            do {
                p   = n;
                cmp = vnode_compare(&c->key, c->key_type, &n->key, n->key_type);
                n   = (cmp <= 0) ? n->left : n->right;
            } while (!dnode_is_empty(n));

            if (cmp < 0) p->left  = c;
            else         p->right = c;

            c->parent  = p;
            c->colored = 1;

            if (!dnode_is_root(p))
                dnode_fixup(r, n);

        } else {
            *r         = c;
            c->colored = 0;
            c->parent  = dnode_empty;
        }
    }

    free(s->nodes);

    s->capacity = capacity;
    s->nodes    = nodes;
}

/*#####################################################################################################################*/

bool libcdsb_dict_shrink_to_fit(dict_t* s) {

    size_t capacity;

    capacity  = (s->size / CAPACITY_BLOCK) + 1;
    capacity *= CAPACITY_BLOCK;

    while (((double)s->size / capacity) > 0.65)
        capacity += CAPACITY_BLOCK;

    if (capacity >= s->capacity)
        return false;

    dict_rehash(s, capacity);

    return true;
}


bool libcdsb_dict_update(dict_t* x, const void* k, vtype kt, const void* v, vtype vt) {

    dnode_t **r, *n, *p;
    vnode_t kn, vn;
    int cmp;

    if (!x->capacity || (double)x->size / x->capacity > REBUILD_POINT_MAX) {
        dict_rehash(x, x->capacity + CAPACITY_BLOCK);
    }

    n  = *(r = &x->nodes[vnode_hash(k, kt) / x->capacity]);
    kn = vnode_create(k, kt);
    vn = vnode_create(v, vt);

    if (!dnode_is_empty(n)) {
        do {
            p   = n;
            cmp = vtype_compare(k, kt, vnode_peek(&n->key, n->key_type), n->key_type);

            if (cmp == 0) {
                dnode_free(n, nullptr);

                n->key      = kn;
                n->value    = vn;
                n->key_type = kt;
                n->val_type = vt;

                return true;
            }

            n = (cmp < 0) ? n->left : n->right;
        } while (!dnode_is_empty(n));

        n = dnode_create(kn, p, 1);

        if (cmp < 0) p->left  = n;
        else         p->right = n;

        if (!dnode_is_root(p))
            dnode_fixup(r, n);

    } else n = *r = dnode_create(kn, dnode_empty, 0);

    n->value    = vn;
    n->key_type = kt;
    n->val_type = vt;

    return false;
}


int libcdsb_dict_get(dict_t* x, const void* k, vtype t, void* _, dict_access_callback callback, bool cut) {

    dnode_t *c, **r;
    void* key;
    int cmp;

    if (x->capacity) {
        c = *(r = &x->nodes[vnode_hash(k, t) / x->capacity]);

        while (!dnode_is_empty(c)) {
            key = vnode_peek(&c->key, c->key_type);
            cmp = vtype_compare(k, t, key, c->key_type);

            if (cmp == 0) {
                cmp = (callback) ? callback(key, t, vnode_peek(&c->value, c->val_type), c->val_type, _) : 0;

                if (cut) {
                    c = dnode_delete(r, c);
                    dnode_free(c, nullptr);
                    free(c);
                }

                return cmp;
            } else c = (cmp < 0) ? c->left : c->right;
        }
    }

    return -1;
}


int libcdsb_dict_foreach(dict_t* x, void* dt, dict_access_callback callback, bool flush) {
    stack_t z;
    int r;
    dnode_t* c;

    r       = 0;
    z.prev  = 0;
    z.value = 0;

    for (size_t i = 0; i < x->capacity; ++i) {
        if (!dnode_is_empty(x->nodes[i]))
            stack_push(&z, x->nodes[i]);
    }

    while ((c = stack_pop(&z))) {
        if ((r = callback(vnode_peek(&c->key, c->key_type), c->key_type, vnode_peek(&c->value, c->val_type), c->val_type, dt)))
            break;

        if (!dnode_is_empty(c->right)) stack_push(&z, c->right);
        if (!dnode_is_empty(c->left))  stack_push(&z, c->left);

        if (flush) {
            dnode_free(c, nullptr);
            free(c);
        }
    }

    if (flush) {
        while (c) {
            if (!dnode_is_empty(c->right)) stack_push(&z, c->right);
            if (!dnode_is_empty(c->left))  stack_push(&z, c->left);

            dnode_free(c, nullptr);
            free(c);

            c = stack_pop(&z);
        }

        free(x->nodes);
        memset(x, 0, sizeof(*x));
    } else stack_flush(&z);

    return r;
}