/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/kdev_t.h>

#define LOG_TAG "Vold"

#include <cutils/log.h>

#include <sysutils/NetlinkEvent.h>

#include "VolumeManager.h"
#include "DirectVolume.h"
#include "ResponseCode.h"

VolumeManager *VolumeManager::sInstance = NULL;

VolumeManager *VolumeManager::Instance() {
    if (!sInstance)
        sInstance = new VolumeManager();
    return sInstance;
}

VolumeManager::VolumeManager() {
    mBlockDevices = new BlockDeviceCollection();
    mVolumes = new VolumeCollection();
    mBroadcaster = NULL;
    mUsbMassStorageConnected = false;
}

VolumeManager::~VolumeManager() {
    delete mBlockDevices;
}

int VolumeManager::start() {
    return 0;
}

int VolumeManager::stop() {
    return 0;
}

int VolumeManager::addVolume(Volume *v) {
    mVolumes->push_back(v);
    return 0;
}

void VolumeManager::notifyUmsConnected(bool connected) {
    char msg[255];

    if (connected) {
        mUsbMassStorageConnected = true;
    } else {
        mUsbMassStorageConnected = false;
    }
    snprintf(msg, sizeof(msg), "Share method ums now %s",
             (connected ? "available" : "unavailable"));

    getBroadcaster()->sendBroadcast(ResponseCode::ShareAvailabilityChange,
                                    msg, false);
}

void VolumeManager::handleSwitchEvent(NetlinkEvent *evt) {
    const char *name = evt->findParam("SWITCH_NAME");
    const char *state = evt->findParam("SWITCH_STATE");

    if (!strcmp(name, "usb_mass_storage")) {

        if (!strcmp(state, "online"))  {
            notifyUmsConnected(true);
        } else {
            notifyUmsConnected(false);
        }
    } else {
        LOGW("Ignoring unknown switch '%s'", name);
    }
}

void VolumeManager::handleBlockEvent(NetlinkEvent *evt) {
    const char *devpath = evt->findParam("DEVPATH");

    /* Lookup a volume to handle this device */
    VolumeCollection::iterator it;
    bool hit = false;
    for (it = mVolumes->begin(); it != mVolumes->end(); ++it) {
        if (!(*it)->handleBlockEvent(evt)) {
#ifdef NETLINK_DEBUG
            LOGD("Device '%s' event handled by volume %s\n", devpath, (*it)->getLabel());
#endif
            hit = true;
            break;
        }
    }

    if (!hit) {
#ifdef NETLINK_DEBUG
        LOGW("No volumes handled block event for '%s'", devpath);
#endif
    }
}

int VolumeManager::listVolumes(SocketClient *cli) {
    VolumeCollection::iterator i;

    for (i = mVolumes->begin(); i != mVolumes->end(); ++i) {
        char *buffer;
        asprintf(&buffer, "%s %s %d",
                 (*i)->getLabel(), (*i)->getMountpoint(),
                 (*i)->getState());
        cli->sendMsg(ResponseCode::VolumeListResult, buffer, false);
        free(buffer);
    }
    cli->sendMsg(ResponseCode::CommandOkay, "Volumes listed.", false);
    return 0;
}

int VolumeManager::formatVolume(const char *label) {
    Volume *v = lookupVolume(label);

    if (!v) {
        errno = ENOENT;
        return -1;
    }

    return v->formatVol();
}

int VolumeManager::mountVolume(const char *label) {
    Volume *v = lookupVolume(label);

    if (!v) {
        errno = ENOENT;
        return -1;
    }

    return v->mountVol();
}

int VolumeManager::shareAvailable(const char *method, bool *avail) {

    if (strcmp(method, "ums")) {
        errno = ENOSYS;
        return -1;
    }

    if (mUsbMassStorageConnected)
        *avail = true;
    else
        *avail = false;
    return 0;
}

int VolumeManager::simulate(const char *cmd, const char *arg) {

    if (!strcmp(cmd, "ums")) {
        if (!strcmp(arg, "connect")) {
            notifyUmsConnected(true);
        } else if (!strcmp(arg, "disconnect")) {
            notifyUmsConnected(false);
        } else {
            errno = EINVAL;
            return -1;
        }
    } else {
        errno = EINVAL;
        return -1;
    }
    return 0;
}

int VolumeManager::shareVolume(const char *label, const char *method) {
    Volume *v = lookupVolume(label);

    if (!v) {
        errno = ENOENT;
        return -1;
    }

    /*
     * Eventually, we'll want to support additional share back-ends,
     * some of which may work while the media is mounted. For now,
     * we just support UMS
     */
    if (strcmp(method, "ums")) {
        errno = ENOSYS;
        return -1;
    }

    if (v->getState() == Volume::State_NoMedia) {
        errno = ENODEV;
        return -1;
    }

    if (v->getState() != Volume::State_Idle) {
        // You need to unmount manually befoe sharing
        errno = EBUSY;
        return -1;
    }

    dev_t d = v->getDiskDevice();
    if ((MAJOR(d) == 0) && (MINOR(d) == 0)) {
        // This volume does not support raw disk access
        errno = EINVAL;
        return -1;
    }

    int fd;
    char nodepath[255];
    snprintf(nodepath,
             sizeof(nodepath), "/dev/block/vold/%d:%d",
             MAJOR(d), MINOR(d));

    if ((fd = open("/sys/devices/platform/usb_mass_storage/lun0", O_WRONLY)) < 0) {
        LOGE("Unable to open ums lunfile (%s)", strerror(errno));
        return -1;
    }

    if (write(fd, nodepath, strlen(nodepath)) < 0) {
        LOGE("Unable to write to ums lunfile (%s)", strerror(errno));
        close(fd);
        return -1;
    }

    close(fd);
    v->handleVolumeShared();
    return 0;
}

int VolumeManager::unshareVolume(const char *label, const char *method) {
    Volume *v = lookupVolume(label);

    if (!v) {
        errno = ENOENT;
        return -1;
    }

    if (strcmp(method, "ums")) {
        errno = ENOSYS;
        return -1;
    }

    if (v->getState() != Volume::State_Shared) {
        errno = EINVAL;
        return -1;
    }

    dev_t d = v->getDiskDevice();

    int fd;
    char nodepath[255];
    snprintf(nodepath,
             sizeof(nodepath), "/dev/block/vold/%d:%d",
             MAJOR(d), MINOR(d));

    if ((fd = open("/sys/devices/platform/usb_mass_storage/lun0", O_WRONLY)) < 0) {
        LOGE("Unable to open ums lunfile (%s)", strerror(errno));
        return -1;
    }

    char ch = 0;
    if (write(fd, &ch, 1) < 0) {
        LOGE("Unable to write to ums lunfile (%s)", strerror(errno));
        close(fd);
        return -1;
    }

    close(fd);
    v->handleVolumeUnshared();
    return 0;
}

int VolumeManager::unmountVolume(const char *label) {
    Volume *v = lookupVolume(label);

    if (!v) {
        errno = ENOENT;
        return -1;
    }

    if (v->getState() == Volume::State_NoMedia) {
        errno = ENODEV;
        return -1;
    }

    if (v->getState() != Volume::State_Mounted) {
        LOGW("Attempt to unmount volume which isn't mounted (%d)\n",
             v->getState());
        errno = EBUSY;
        return -1;
    }

    return v->unmountVol();
}

/*
 * Looks up a volume by it's label or mount-point
 */
Volume *VolumeManager::lookupVolume(const char *label) {
    VolumeCollection::iterator i;

    for (i = mVolumes->begin(); i != mVolumes->end(); ++i) {
        if (label[0] == '/') {
            if (!strcmp(label, (*i)->getMountpoint()))
                return (*i);
        } else {
            if (!strcmp(label, (*i)->getLabel()))
                return (*i);
        }
    }
    return NULL;
}