/*
 * Copyright (c) 2026 Mirocom Laboratories and MSP engineers.
 * All Rights Reserved.
 */

#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <errno.h>
#include "mvm/bus.h"

int
bus_ctl_init(struct mvm_bus_ctl *busctl)
{
    if (busctl == NULL) {
        errno = EINVAL;
        return -1;
    }

    busctl->head = NULL;
    busctl->tail = NULL;
    busctl->dev_count = 0;
    return 0;
}

int
bus_dev_alloc(mvm_devtype_t type, void *data, struct mvm_bus_dev **res)
{
    struct mvm_bus_dev *dev;

    if (type == BUS_DEV_NONE || data == NULL) {
        errno = EINVAL;
        return -1;
    }

    if (res == NULL) {
        errno = EINVAL;
        return -1;
    }

    if ((dev = malloc(sizeof(*dev))) == NULL) {
        errno = ENOMEM;
        return -1;
    }

    dev->type = type;
    dev->data = data;
    dev->next = NULL;
    *res = dev;
    return 0;
}

void
bus_dev_free(struct mvm_bus_dev *dev)
{
    if (dev == NULL) {
        return;
    }

    free(dev);
}

int
bus_ctl_append(struct mvm_bus_ctl *busctl, struct mvm_bus_dev *dev)
{
    if (busctl == NULL || dev == NULL) {
        errno = EINVAL;
        return -1;
    }

    if (busctl->head == NULL || busctl->tail == NULL) {
        busctl->head = dev;
        busctl->tail = dev;
    } else {
        busctl->tail->next = dev;
        busctl->tail = dev;
    }

    ++busctl->dev_count;
    return 0;
}

void
bus_ctl_free(struct mvm_bus_ctl *busctl)
{
    struct mvm_bus_dev *dev, *tmp;

    if (busctl == NULL) {
        return;
    }

    if ((dev = busctl->head) == NULL) {
        return;
    }

    while (dev != NULL) {
        tmp = dev;
        bus_dev_free(tmp);
        dev = dev->next;
    }

    busctl->head = NULL;
    busctl->tail = NULL;
}