/*
 * domain_event.c: domain event queue processing helpers
 *
 * Copyright (C) 2008 VirtualIron
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
 *
 * Author: Ben Guthro
 */

#include <config.h>

#include "domain_event.h"
#include "logging.h"
#include "datatypes.h"
#include "memory.h"


/**
 * virDomainEventCallbackListFree:
 * @list: event callback list head
 *
 * Free the memory in the domain event callback list
 */
void
virDomainEventCallbackListFree(virDomainEventCallbackListPtr list)
{
    int i;
    for (i=0; i<list->count; i++) {
        virFreeCallback freecb = list->callbacks[i]->freecb;
        if (freecb)
            (*freecb)(list->callbacks[i]->opaque);
        VIR_FREE(list->callbacks[i]);
    }
    VIR_FREE(list);
}
/**
 * virDomainEventCallbackListRemove:
 * @conn: pointer to the connection
 * @cbList: the list
 * @callback: the callback to remove
 *
 * Internal function to remove a callback from a virDomainEventCallbackListPtr
 */
int
virDomainEventCallbackListRemove(virConnectPtr conn,
                                 virDomainEventCallbackListPtr cbList,
                                 virConnectDomainEventCallback callback)
{
    int i;
    for (i = 0 ; i < cbList->count ; i++) {
        if(cbList->callbacks[i]->cb == callback &&
           cbList->callbacks[i]->conn == conn) {
            virFreeCallback freecb = cbList->callbacks[i]->freecb;
            if (freecb)
                (*freecb)(cbList->callbacks[i]->opaque);
            virUnrefConnect(cbList->callbacks[i]->conn);
            VIR_FREE(cbList->callbacks[i]);

            if (i < (cbList->count - 1))
                memmove(cbList->callbacks + i,
                        cbList->callbacks + i + 1,
                        sizeof(*(cbList->callbacks)) *
                                (cbList->count - (i + 1)));

            if (VIR_REALLOC_N(cbList->callbacks,
                              cbList->count - 1) < 0) {
                ; /* Failure to reduce memory allocation isn't fatal */
            }
            cbList->count--;

            return 0;
        }
    }
    return -1;
}

/**
 * virDomainEventCallbackListRemoveConn:
 * @conn: pointer to the connection
 * @cbList: the list
 *
 * Internal function to remove all of a given connection's callback
 * from a virDomainEventCallbackListPtr
 */
int
virDomainEventCallbackListRemoveConn(virConnectPtr conn,
                                     virDomainEventCallbackListPtr cbList)
{
    int old_count = cbList->count;
    int i;
    for (i = 0 ; i < cbList->count ; i++) {
        if(cbList->callbacks[i]->conn == conn) {
            virFreeCallback freecb = cbList->callbacks[i]->freecb;
            if (freecb)
                (*freecb)(cbList->callbacks[i]->opaque);
            virUnrefConnect(cbList->callbacks[i]->conn);
            VIR_FREE(cbList->callbacks[i]);

            if (i < (cbList->count - 1))
                memmove(cbList->callbacks + i,
                        cbList->callbacks + i + 1,
                        sizeof(*(cbList->callbacks)) *
                                (cbList->count - (i + 1)));
            cbList->count--;
            i--;
        }
    }
    if (cbList->count < old_count &&
        VIR_REALLOC_N(cbList->callbacks, cbList->count) < 0) {
        ; /* Failure to reduce memory allocation isn't fatal */
    }
    return 0;
}

int virDomainEventCallbackListMarkDelete(virConnectPtr conn,
                                         virDomainEventCallbackListPtr cbList,
                                         virConnectDomainEventCallback callback)
{
    int i;
    for (i = 0 ; i < cbList->count ; i++) {
        if (cbList->callbacks[i]->conn == conn &&
            cbList->callbacks[i]->cb == callback) {
            cbList->callbacks[i]->deleted = 1;
            return 0;
        }
    }
    return -1;
}

int virDomainEventCallbackListPurgeMarked(virDomainEventCallbackListPtr cbList)
{
    int old_count = cbList->count;
    int i;
    for (i = 0 ; i < cbList->count ; i++) {
        if (cbList->callbacks[i]->deleted) {
            virFreeCallback freecb = cbList->callbacks[i]->freecb;
            if (freecb)
                (*freecb)(cbList->callbacks[i]->opaque);
            virUnrefConnect(cbList->callbacks[i]->conn);
            VIR_FREE(cbList->callbacks[i]);

            if (i < (cbList->count - 1))
                memmove(cbList->callbacks + i,
                        cbList->callbacks + i + 1,
                        sizeof(*(cbList->callbacks)) *
                                (cbList->count - (i + 1)));
            cbList->count--;
            i--;
        }
    }
    if (cbList->count < old_count &&
        VIR_REALLOC_N(cbList->callbacks, cbList->count) < 0) {
        ; /* Failure to reduce memory allocation isn't fatal */
    }
    return 0;
}

/**
 * virDomainEventCallbackListAdd:
 * @conn: pointer to the connection
 * @cbList: the list
 * @callback: the callback to add
 * @opaque: opaque data tio pass to callback
 *
 * Internal function to add a callback from a virDomainEventCallbackListPtr
 */
int
virDomainEventCallbackListAdd(virConnectPtr conn,
                              virDomainEventCallbackListPtr cbList,
                              virConnectDomainEventCallback callback,
                              void *opaque,
                              virFreeCallback freecb)
{
    virDomainEventCallbackPtr event;
    int n;

    /* Check incoming */
    if ( !cbList ) {
        return -1;
    }

    /* check if we already have this callback on our list */
    for (n=0; n < cbList->count; n++) {
        if(cbList->callbacks[n]->cb == callback &&
           conn == cbList->callbacks[n]->conn) {
            DEBUG0("WARNING: Callback already tracked");
            return -1;
        }
    }
    /* Allocate new event */
    if (VIR_ALLOC(event) < 0) {
        DEBUG0("Error allocating event");
        return -1;
    }
    event->conn = conn;
    event->cb = callback;
    event->opaque = opaque;
    event->freecb = freecb;

    /* Make space on list */
    n = cbList->count;
    if (VIR_REALLOC_N(cbList->callbacks, n + 1) < 0) {
        DEBUG0("Error reallocating list");
        VIR_FREE(event);
        return -1;
    }

    event->conn->refs++;

    cbList->callbacks[n] = event;
    cbList->count++;
    return 0;
}

void virDomainEventFree(virDomainEventPtr event)
{
    if (!event)
        return;

    VIR_FREE(event->name);
    VIR_FREE(event);
}


virDomainEventQueuePtr virDomainEventQueueNew(void)
{
    virDomainEventQueuePtr ret;

    if (VIR_ALLOC(ret) < 0)
        return NULL;

    return ret;
}

virDomainEventPtr virDomainEventNew(int id, const char *name,
                                    const unsigned char *uuid,
                                    int type, int detail)
{
    virDomainEventPtr event;

    if (VIR_ALLOC(event) < 0)
        return NULL;

    event->type = type;
    event->detail = detail;
    if (!(event->name = strdup(name))) {
        VIR_FREE(event);
        return NULL;
    }
    event->id = id;
    memcpy(event->uuid, uuid, VIR_UUID_BUFLEN);

    return event;
}

virDomainEventPtr virDomainEventNewFromDom(virDomainPtr dom, int type, int detail)
{
    return virDomainEventNew(dom->id, dom->name, dom->uuid, type, detail);
}

virDomainEventPtr virDomainEventNewFromObj(virDomainObjPtr obj, int type, int detail)
{
    return virDomainEventNewFromDef(obj->def, type, detail);
}

virDomainEventPtr virDomainEventNewFromDef(virDomainDefPtr def, int type, int detail)
{
    return virDomainEventNew(def->id, def->name, def->uuid, type, detail);
}

/**
 * virDomainEventQueueFree:
 * @queue: pointer to the queue
 *
 * Free the memory in the queue. We process this like a list here
 */
void
virDomainEventQueueFree(virDomainEventQueuePtr queue)
{
    int i;
    if (!queue)
        return;

    for (i = 0; i < queue->count ; i++) {
        virDomainEventFree(queue->events[i]);
    }
    VIR_FREE(queue->events);
    VIR_FREE(queue);
}

/**
 * virDomainEventQueuePop:
 * @evtQueue: the queue of events
 *
 * Internal function to pop off, and return the front of the queue
 * NOTE: The caller is responsible for freeing the returned object
 *
 * Returns: virDomainEventPtr on success NULL on failure.
 */
virDomainEventPtr
virDomainEventQueuePop(virDomainEventQueuePtr evtQueue)
{
    virDomainEventPtr ret;

    if(!evtQueue || evtQueue->count == 0 )
        return NULL;

    ret = evtQueue->events[0];

    memmove(evtQueue->events,
            evtQueue->events + 1,
            sizeof(*(evtQueue->events)) *
                    (evtQueue->count - 1));

    if (VIR_REALLOC_N(evtQueue->events,
                        evtQueue->count - 1) < 0) {
        ; /* Failure to reduce memory allocation isn't fatal */
    }
    evtQueue->count--;

    return ret;
}

/**
 * virDomainEventQueuePush:
 * @evtQueue: the dom event queue
 * @event: the event to add
 *
 * Internal function to push onto the back of an virDomainEventQueue
 *
 * Returns: 0 on success, -1 on failure
 */
int
virDomainEventQueuePush(virDomainEventQueuePtr evtQueue,
                        virDomainEventPtr event)
{
    if (!evtQueue) {
        return -1;
    }

    /* Make space on queue */
    if (VIR_REALLOC_N(evtQueue->events,
                      evtQueue->count + 1) < 0) {
        DEBUG0("Error reallocating queue");
        return -1;
    }

    evtQueue->events[evtQueue->count] = event;
    evtQueue->count++;
    return 0;
}


void virDomainEventDispatchDefaultFunc(virConnectPtr conn,
                                       virDomainEventPtr event,
                                       virConnectDomainEventCallback cb,
                                       void *cbopaque,
                                       void *opaque ATTRIBUTE_UNUSED)
{
    virDomainPtr dom = virGetDomain(conn, event->name, event->uuid);
    if (dom) {
        dom->id = event->id;
        (*cb)(conn, dom, event->type, event->detail, cbopaque);
        virDomainFree(dom);
    }
}


void virDomainEventDispatch(virDomainEventPtr event,
                            virDomainEventCallbackListPtr callbacks,
                            virDomainEventDispatchFunc dispatch,
                            void *opaque)
{
    int i;
    /* Cache this now, since we may be dropping the lock,
       and have more callbacks added. We're guarenteed not
       to have any removed */
    int cbCount = callbacks->count;

    for (i = 0 ; i < cbCount ; i++) {
        if (callbacks->callbacks[i] &&
            !callbacks->callbacks[i]->deleted) {
            (*dispatch)(callbacks->callbacks[i]->conn,
                        event,
                        callbacks->callbacks[i]->cb,
                        callbacks->callbacks[i]->opaque,
                        opaque);
        }
    }
}


void virDomainEventQueueDispatch(virDomainEventQueuePtr queue,
                                 virDomainEventCallbackListPtr callbacks,
                                 virDomainEventDispatchFunc dispatch,
                                 void *opaque)
{
    int i;

    for (i = 0 ; i < queue->count ; i++) {
        virDomainEventDispatch(queue->events[i], callbacks, dispatch, opaque);
        virDomainEventFree(queue->events[i]);
    }
    VIR_FREE(queue->events);
    queue->count = 0;
}