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

#include "include.h"

bool libcdsb_list_insert(list_t* x, ssize_t i, var_t value, int ins, void* dt, list_access_callback callback) {
    ldir_t dir;
    lnode_t* c;

    if (i < 0) {
        i   = ~i;
        dir = LD_PREV;
    } else dir = LD_NEXT;

    c = ldir_dir((lnode_t*)x, dir);

    while (i && !is_null(c)) {
        c = ldir_dir(c, dir);
        --i;
    }

    if (i && dir == LD_PREV) {
        c = x->first;
    } else if (i) return false;

    if (is_null(c)) {
        x->first = x->last = c = calloc(sizeof(*c), 1);
    } else if (ins) {
        lnode_t *v = malloc(sizeof(*v));

        dir = (ins < 0) ? LD_PREV : LD_NEXT;

        ldir_dir(v, dir) = ldir_dir(c, dir);
        ldir_inv(v, dir) = c;

        c = v;

        if (!is_null(ldir_dir(c, dir))) {
            ldir_inv(ldir_dir(c, dir), dir) = c;
        } else ldir_inv((lnode_t*)x, dir) = c;

        ldir_dir(ldir_inv(c, dir), dir) = c;
    } else {
        if (callback) callback(vnode_peek(&c->node, c->type), -1, dt);
        vnode_free(&c->node, c->type);
    }

    c->node = vnode_create(value);
    c->type = value.type;

    return true;
}


bool libcdsb_list_attach(list_t* x, ssize_t i, var_t value, int ins, void* dt, list_access_callback callback) {
    ldir_t dir;
    lnode_t* c;

    if (i < 0) {
        i   = ~i;
        dir = LD_PREV;
    } else dir = LD_NEXT;

    c = ldir_dir((lnode_t*)x, dir);

    while (i && !is_null(c)) {
        c = ldir_dir(c, dir);
        --i;
    }

    if (i && dir == LD_PREV) {
        c = x->first;
    } else if (i) return false;

    if (is_null(c)) {
        x->first = x->last = c = calloc(sizeof(*c), 1);
    } else if (ins) {
        lnode_t *v = malloc(sizeof(*v));

        dir = (ins < 0) ? LD_PREV : LD_NEXT;

        ldir_dir(v, dir) = ldir_dir(c, dir);
        ldir_inv(v, dir) = c;

        c = v;

        if (!is_null(ldir_dir(c, dir))) {
            ldir_inv(ldir_dir(c, dir), dir) = c;
        } else ldir_inv((lnode_t*)x, dir) = c;

        ldir_dir(ldir_inv(c, dir), dir) = c;
    } else {
        if (callback) callback(vnode_peek(&c->node, c->type), -1, dt);
        vnode_free(&c->node, c->type);
    }

    vnode_attach(&c->node, value);
    c->type = value.type;

    return true;
}