// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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.
package org.apache.cloudstack.metrics;

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import javax.inject.Inject;

import org.apache.cloudstack.engine.subsystem.api.storage.ZoneScope;
import org.apache.cloudstack.storage.datastore.db.ImageStoreDao;
import org.apache.commons.lang3.StringUtils;

import com.cloud.alert.AlertManager;
import com.cloud.api.ApiDBUtils;
import com.cloud.api.query.dao.DomainJoinDao;
import com.cloud.api.query.dao.StoragePoolJoinDao;
import com.cloud.api.query.vo.DomainJoinVO;
import com.cloud.api.query.vo.StoragePoolJoinVO;
import com.cloud.capacity.Capacity;
import com.cloud.capacity.CapacityManager;
import com.cloud.capacity.CapacityState;
import com.cloud.capacity.CapacityVO;
import com.cloud.capacity.dao.CapacityDao;
import com.cloud.capacity.dao.CapacityDaoImpl;
import com.cloud.configuration.Resource;
import com.cloud.configuration.dao.ResourceCountDao;
import com.cloud.dc.DataCenterVO;
import com.cloud.dc.DedicatedResourceVO;
import com.cloud.dc.Vlan;
import com.cloud.dc.dao.DataCenterDao;
import com.cloud.dc.dao.DataCenterIpAddressDao;
import com.cloud.dc.dao.DedicatedResourceDao;
import com.cloud.host.Host;
import com.cloud.host.HostStats;
import com.cloud.host.HostTagVO;
import com.cloud.host.HostVO;
import com.cloud.host.Status;
import com.cloud.host.dao.HostDao;
import com.cloud.host.dao.HostTagsDao;
import com.cloud.network.dao.IPAddressDao;
import com.cloud.storage.ImageStore;
import com.cloud.storage.StorageStats;
import com.cloud.storage.Volume;
import com.cloud.storage.VolumeVO;
import com.cloud.storage.dao.VolumeDao;
import com.cloud.user.Account;
import com.cloud.user.dao.AccountDao;
import com.cloud.utils.Ternary;
import com.cloud.utils.component.Manager;
import com.cloud.utils.component.ManagerBase;
import com.cloud.vm.VirtualMachine.State;
import com.cloud.vm.dao.UserVmDao;
import com.cloud.vm.dao.VMInstanceDao;

public class PrometheusExporterImpl extends ManagerBase implements PrometheusExporter, Manager {

    private static final String USED = "used";
    private static final String ALLOCATED = "allocated";
    private static final String UNALLOCATED = "unallocated";
    private static final String TOTAL = "total";
    private static final String ONLINE = "online";
    private static final String OFFLINE = "offline";

    enum MissingInfoFilter {
        Host_Stats("hostStats"),
        CPU_CAPACITY("cpuCapacity"),
        MEM_CAPACITY("memCapacity"),
        CORE_CAPACITY("coreCapacity");

        private final String name;

        MissingInfoFilter(String name){
            this.name = name;
        }

        @Override
        public String toString() {
            return name;
        }
    }

    private static List<Item> metricsItems = new ArrayList<>();

    @Inject
    private DataCenterDao dcDao;
    @Inject
    private HostDao hostDao;
    @Inject
    private VMInstanceDao vmDao;
    @Inject
    private UserVmDao uservmDao;
    @Inject
    private VolumeDao volumeDao;
    @Inject
    private IPAddressDao publicIpAddressDao;
    @Inject
    private DataCenterIpAddressDao privateIpAddressDao;
    @Inject
    private CapacityDao capacityDao;
    @Inject
    private StoragePoolJoinDao storagePoolJoinDao;
    @Inject
    private ImageStoreDao imageStoreDao;
    @Inject
    private DomainJoinDao domainDao;
    @Inject
    private AlertManager alertManager;
    @Inject
    DedicatedResourceDao _dedicatedDao;
    @Inject
    private AccountDao _accountDao;
    @Inject
    private ResourceCountDao _resourceCountDao;
    @Inject
    private HostTagsDao _hostTagsDao;

    public PrometheusExporterImpl() {
        super();
    }

    private void addHostMetrics(final List<Item> metricsList, final long dcId, final String zoneName, final String zoneUuid) {
        int total = 0;
        int up = 0;
        int down = 0;
        Map<String, Integer> totalHosts = new HashMap<>();
        Map<String, Integer> upHosts = new HashMap<>();
        Map<String, Integer> downHosts = new HashMap<>();

        for (final HostVO host : hostDao.listAll()) {
            if (host == null || host.getType() != Host.Type.Routing || host.getDataCenterId() != dcId) {
                continue;
            }
            total++;
            if (host.getStatus() == Status.Up && !host.isInMaintenanceStates()) {
                up++;
            } else if (host.getStatus() == Status.Disconnected || host.getStatus() == Status.Down ||
                        host.isInMaintenanceStates()) {
                down++;
            }

            final DedicatedResourceVO dr = _dedicatedDao.findByHostId(host.getId());
            int isDedicated = (dr != null) ? 1 : 0;
            metricsList.add(new ItemHostIsDedicated(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), isDedicated));


            // Get account, domain details for dedicated hosts
            if (isDedicated == 1) {
                String accountName;
                Account account = (dr.getAccountId() != null) ? _accountDao.findById(dr.getAccountId()) : null;
                accountName = (account != null) ? account.getAccountName() : "";

                DomainJoinVO domain = domainDao.findById(dr.getDomainId());
                metricsList.add(new ItemHostDedicatedToAccount(zoneName, host.getName(), accountName, domain.getPath(), isDedicated));
            }

            String hostTags = markTagMaps(host, totalHosts, upHosts,  downHosts);
            HostStats hostStats = ApiDBUtils.getHostStatistics(host.getId());

            if (hostStats == null){
                metricsList.add(new MissingHostInfo(zoneName, host.getName(), MissingInfoFilter.Host_Stats));
            }

            final String cpuFactor = String.valueOf(CapacityManager.CpuOverprovisioningFactor.valueIn(host.getClusterId()));
            final CapacityVO cpuCapacity = capacityDao.findByHostIdType(host.getId(), Capacity.CAPACITY_TYPE_CPU);

            if (cpuCapacity == null && !host.isInMaintenanceStates()){
                metricsList.add(new MissingHostInfo(zoneName, host.getName(), MissingInfoFilter.CPU_CAPACITY));
            }

            if (hostStats != null && cpuCapacity != null && cpuCapacity.getCapacityState() == CapacityState.Enabled) {
                final double cpuUsedMhz = hostStats.getCpuUtilization() * host.getCpus() * host.getSpeed() / 100.0 ;
                metricsList.add(new ItemHostCpu(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), cpuFactor, ALLOCATED, cpuCapacity.getUsedCapacity(), isDedicated, hostTags));
                metricsList.add(new ItemHostCpu(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), cpuFactor, USED, cpuUsedMhz, isDedicated, hostTags));
                metricsList.add(new ItemHostCpu(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), cpuFactor, TOTAL, cpuCapacity.getTotalCapacity(), isDedicated, hostTags));
            } else {
                metricsList.add(new ItemHostCpu(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), cpuFactor, ALLOCATED, 0L, isDedicated, hostTags));
                metricsList.add(new ItemHostCpu(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), cpuFactor, USED, 0L, isDedicated, hostTags));
                metricsList.add(new ItemHostCpu(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), cpuFactor, TOTAL, 0L, isDedicated, hostTags));
            }

            final String memoryFactor = String.valueOf(CapacityManager.MemOverprovisioningFactor.valueIn(host.getClusterId()));
            final CapacityVO memCapacity = capacityDao.findByHostIdType(host.getId(), Capacity.CAPACITY_TYPE_MEMORY);

            if (memCapacity == null && !host.isInMaintenanceStates()){
                metricsList.add(new MissingHostInfo(zoneName, host.getName(), MissingInfoFilter.MEM_CAPACITY));
            }

            if (hostStats != null && memCapacity != null && memCapacity.getCapacityState() == CapacityState.Enabled) {
                metricsList.add(new ItemHostMemory(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), memoryFactor, ALLOCATED, memCapacity.getUsedCapacity(), isDedicated, hostTags));
                metricsList.add(new ItemHostMemory(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), memoryFactor, USED, hostStats.getUsedMemory(), isDedicated, hostTags));
                metricsList.add(new ItemHostMemory(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), memoryFactor, TOTAL, memCapacity.getTotalCapacity(), isDedicated, hostTags));
            } else {
                metricsList.add(new ItemHostMemory(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), memoryFactor, ALLOCATED, 0L, isDedicated, hostTags));
                metricsList.add(new ItemHostMemory(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), memoryFactor, USED, 0, isDedicated, hostTags));
                metricsList.add(new ItemHostMemory(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), memoryFactor, TOTAL, 0L, isDedicated, hostTags));
            }

            metricsList.add(new ItemHostVM(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), vmDao.listByHostId(host.getId()).size()));
            final CapacityVO coreCapacity = capacityDao.findByHostIdType(host.getId(), Capacity.CAPACITY_TYPE_CPU_CORE);

            if (coreCapacity == null && !host.isInMaintenanceStates()){
                metricsList.add(new MissingHostInfo(zoneName, host.getName(), MissingInfoFilter.CORE_CAPACITY));
            }

            if (hostStats != null && coreCapacity != null && coreCapacity.getCapacityState() == CapacityState.Enabled) {
                metricsList.add(new ItemVMCore(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), USED, coreCapacity.getUsedCapacity(), isDedicated, hostTags));
                metricsList.add(new ItemVMCore(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), TOTAL, coreCapacity.getTotalCapacity(), isDedicated, hostTags));
            } else {
                metricsList.add(new ItemVMCore(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), USED, 0L, isDedicated, hostTags));
                metricsList.add(new ItemVMCore(zoneName, zoneUuid, host.getName(), host.getUuid(), host.getPrivateIpAddress(), TOTAL, 0L, isDedicated, hostTags));
            }
        }

        final List<CapacityDaoImpl.SummedCapacity> cpuCapacity = capacityDao.findCapacityBy((int) Capacity.CAPACITY_TYPE_CPU, dcId, null, null);
        if (cpuCapacity != null && !cpuCapacity.isEmpty()) {
            metricsList.add(new ItemHostCpu(zoneName, zoneUuid, null, null, null, null, ALLOCATED, cpuCapacity.get(0).getAllocatedCapacity() != null ? cpuCapacity.get(0).getAllocatedCapacity() : 0, 0, ""));
        }

        final List<CapacityDaoImpl.SummedCapacity> memCapacity = capacityDao.findCapacityBy((int) Capacity.CAPACITY_TYPE_MEMORY, dcId, null, null);
        if (memCapacity != null && !memCapacity.isEmpty()) {
            metricsList.add(new ItemHostMemory(zoneName, zoneUuid, null, null, null, null, ALLOCATED, memCapacity.get(0).getAllocatedCapacity() != null ? memCapacity.get(0).getAllocatedCapacity() : 0, 0, ""));
        }

        final List<CapacityDaoImpl.SummedCapacity> coreCapacity = capacityDao.findCapacityBy((int) Capacity.CAPACITY_TYPE_CPU_CORE, dcId, null, null);
        if (coreCapacity != null && !coreCapacity.isEmpty()) {
            metricsList.add(new ItemVMCore(zoneName, zoneUuid, null, null, null, ALLOCATED, coreCapacity.get(0).getAllocatedCapacity() != null ? coreCapacity.get(0).getAllocatedCapacity() : 0, 0, ""));
        }

        metricsList.add(new ItemHost(zoneName, zoneUuid, ONLINE, up, null));
        metricsList.add(new ItemHost(zoneName, zoneUuid, OFFLINE, down, null));
        metricsList.add(new ItemHost(zoneName, zoneUuid, TOTAL, total, null));

        addHostTagsMetrics(metricsList, dcId, zoneName, zoneUuid, totalHosts, upHosts, downHosts, total, up, down);
    }

    private String markTagMaps(HostVO host, Map<String, Integer> totalHosts, Map<String, Integer> upHosts, Map<String, Integer> downHosts) {
        List<HostTagVO> hostTagVOS = _hostTagsDao.getHostTags(host.getId());
        List<String> hostTags = new ArrayList<>();
        hostTagVOS.forEach(hostTagVO -> hostTags.add(hostTagVO.getTag()));
        markTags(hostTags,totalHosts);
        if (host.getStatus() == Status.Up && !host.isInMaintenanceStates()) {
            markTags(hostTags, upHosts);
        } else if (host.getStatus() == Status.Disconnected || host.getStatus() == Status.Down || host.isInMaintenanceStates()) {
            markTags(hostTags, downHosts);
        }
        return StringUtils.join(hostTags, ",");
    }

    private void markTags(List<String> tags, Map<String, Integer> tagMap) {
        tags.forEach(tag -> {
            int current = tagMap.get(tag) != null ? tagMap.get(tag) : 0;
            tagMap.put(tag, current + 1);
        });
    }

    private void addHostTagsMetrics(final List<Item> metricsList, final long dcId, final String zoneName, final String zoneUuid, Map<String, Integer> totalHosts, Map<String, Integer> upHosts, Map<String, Integer> downHosts, int total, int up, int down) {

        for (Map.Entry<String, Integer> entry : totalHosts.entrySet()) {
            String tag = entry.getKey();
            Integer count = entry.getValue();
            metricsList.add(new ItemHost(zoneName, zoneUuid, TOTAL, count, tag));
            if (upHosts.get(tag) != null) {
                metricsList.add(new ItemHost(zoneName, zoneUuid, ONLINE, upHosts.get(tag), tag));
            } else {
                metricsList.add(new ItemHost(zoneName, zoneUuid, ONLINE, 0, tag));
            }
            if (downHosts.get(tag) != null) {
                metricsList.add(new ItemHost(zoneName, zoneUuid, OFFLINE, downHosts.get(tag), tag));
            } else {
                metricsList.add(new ItemHost(zoneName, zoneUuid, OFFLINE, 0, tag));
            }
        }

        totalHosts.keySet()
                .forEach( tag -> {
                    Ternary<Long, Long, Long> allocatedCapacityByTag = capacityDao.findCapacityByZoneAndHostTag(dcId, tag);
                    metricsList.add(new ItemVMCore(zoneName, zoneUuid, null, null, null, ALLOCATED, allocatedCapacityByTag.first(), 0, tag));
                    metricsList.add(new ItemHostCpu(zoneName, zoneUuid, null, null, null, null, ALLOCATED, allocatedCapacityByTag.second(), 0, tag));
                    metricsList.add(new ItemHostMemory(zoneName, zoneUuid, null, null, null, null, ALLOCATED, allocatedCapacityByTag.third(), 0, tag));
                });

        List<HostTagVO> allHostTagVOS = hostDao.listAllIds().stream()
                .flatMap( h -> _hostTagsDao.getHostTags(h).stream())
                .distinct()
                .collect(Collectors.toList());
        HashSet<String> allHostTags = new HashSet<>();
        allHostTagVOS.forEach(hostTagVO -> allHostTags.add(hostTagVO.getTag()));

        for (final State state : State.values()) {
            for (final String hostTag : allHostTags) {
                final Long count = vmDao.countByZoneAndStateAndHostTag(dcId, state, hostTag);
                metricsList.add(new ItemVMByTag(zoneName, zoneUuid, state.name().toLowerCase(), count, hostTag));
            }
        }
    }

    private void addVMMetrics(final List<Item> metricsList, final long dcId, final String zoneName, final String zoneUuid) {
        for (final State state : State.values()) {
            final Long count = vmDao.countByZoneAndState(dcId, state);
            if (count == null) {
                continue;
            }
            metricsList.add(new ItemVM(zoneName, zoneUuid, state.name().toLowerCase(), count));
        }
    }

    private void addVolumeMetrics(final List<Item> metricsList, final long dcId, final String zoneName, final String zoneUuid) {
        int total = 0;
        int ready = 0;
        int destroyed = 0;
        for (final VolumeVO volume : volumeDao.findByDc(dcId)) {
            if (volume == null) {
                continue;
            }
            total++;
            if (volume.getState() == Volume.State.Ready) {
                ready++;
            } else if (volume.getState() == Volume.State.Destroy) {
                destroyed++;
            }
        }
        metricsList.add(new ItemVolume(zoneName, zoneUuid, Volume.State.Ready.name().toLowerCase(), ready));
        metricsList.add(new ItemVolume(zoneName, zoneUuid, Volume.State.Destroy.name().toLowerCase(), destroyed));
        metricsList.add(new ItemVolume(zoneName, zoneUuid, TOTAL, total));
    }

    private void addStorageMetrics(final List<Item> metricsList, final long dcId, final String zoneName, final String zoneUuid) {
        for (final StoragePoolJoinVO pool: storagePoolJoinDao.listAll()) {
            if (pool == null || pool.getZoneId() != dcId) {
                continue;
            }
            final String poolName = pool.getName();
            final String poolPath = pool.getHostAddress() + ":" + pool.getPath();

            long usedCapacity = 0L;
            long allocatedCapacity = pool.getUsedCapacity() + pool.getReservedCapacity();
            final long totalCapacity = pool.getCapacityBytes();

            final StorageStats stats = ApiDBUtils.getStoragePoolStatistics(pool.getId());
            if (stats != null) {
                usedCapacity = stats.getByteUsed();
            }

            final BigDecimal poolOverProvisioningFactor = BigDecimal.valueOf(CapacityManager.StorageOverprovisioningFactor.valueIn(pool.getId()));
            final String poolFactor = poolOverProvisioningFactor.toString();

            metricsList.add(new ItemPool(zoneName, zoneUuid, poolName, poolPath, "primary", poolFactor, USED, usedCapacity));
            metricsList.add(new ItemPool(zoneName, zoneUuid, poolName, poolPath, "primary", poolFactor, ALLOCATED, allocatedCapacity));
            metricsList.add(new ItemPool(zoneName, zoneUuid, poolName, poolPath, "primary", poolFactor, UNALLOCATED, poolOverProvisioningFactor.multiply(BigDecimal.valueOf(totalCapacity)).longValue() - allocatedCapacity));
            metricsList.add(new ItemPool(zoneName, zoneUuid, poolName, poolPath, "primary", poolFactor, TOTAL, totalCapacity));
        }

        for (final ImageStore imageStore : imageStoreDao.findByZone(new ZoneScope(dcId), null)) {
            final StorageStats stats = ApiDBUtils.getSecondaryStorageStatistics(imageStore.getId());
            metricsList.add(new ItemPool(zoneName, zoneUuid, imageStore.getName(), imageStore.getUrl(), "secondary", null, USED, stats != null ? stats.getByteUsed() : 0));
            metricsList.add(new ItemPool(zoneName, zoneUuid, imageStore.getName(), imageStore.getUrl(), "secondary", null, TOTAL, stats != null ? stats.getCapacityBytes() : 0));
        }
    }

    private void addIpAddressMetrics(final List<Item> metricsList, final long dcId, final String zoneName, final String zoneUuid) {
        metricsList.add(new ItemPrivateIp(zoneName, zoneUuid, ALLOCATED, privateIpAddressDao.countIPs(dcId, true)));
        metricsList.add(new ItemPrivateIp(zoneName, zoneUuid, TOTAL, privateIpAddressDao.countIPs(dcId, false)));
        metricsList.add(new ItemPublicIp(zoneName, zoneUuid, ALLOCATED, publicIpAddressDao.countIPsForNetwork(dcId, true, Vlan.VlanType.VirtualNetwork)));
        metricsList.add(new ItemPublicIp(zoneName, zoneUuid, TOTAL, publicIpAddressDao.countIPsForNetwork(dcId, false, Vlan.VlanType.VirtualNetwork)));
        metricsList.add(new ItemSharedNetworkIp(zoneName, zoneUuid, ALLOCATED, publicIpAddressDao.countIPsForNetwork(dcId, true, Vlan.VlanType.DirectAttached)));
        metricsList.add(new ItemSharedNetworkIp(zoneName, zoneUuid, TOTAL, publicIpAddressDao.countIPsForNetwork(dcId, false, Vlan.VlanType.DirectAttached)));
    }

    private void addVlanMetrics(final List<Item> metricsList, final long dcId, final String zoneName, final String zoneUuid) {
        metricsList.add(new ItemVlan(zoneName, zoneUuid, ALLOCATED, dcDao.countZoneVlans(dcId, true)));
        metricsList.add(new ItemVlan(zoneName, zoneUuid, TOTAL, dcDao.countZoneVlans(dcId, false)));
    }

    private void addDomainLimits(final List<Item> metricsList) {
        Long totalCpuLimit = 0L;
        Long totalMemoryLimit = 0L;

        for (final DomainJoinVO domain: domainDao.listAll()) {
            if (domain == null || domain.getLevel() != 1) {
                continue;
            }
            long cpuLimit = ApiDBUtils.findCorrectResourceLimitForDomain(domain.getCpuLimit(), false,
                    Resource.ResourceType.cpu, domain.getId());
            if (cpuLimit > 0) {
                totalCpuLimit += cpuLimit;
            }

            long memoryLimit = ApiDBUtils.findCorrectResourceLimitForDomain(domain.getMemoryLimit(), false,
                    Resource.ResourceType.memory, domain.getId());
            if (memoryLimit > 0) {
                totalMemoryLimit += memoryLimit;
            }

            long primaryStorageLimit = ApiDBUtils.findCorrectResourceLimitForDomain(domain.getPrimaryStorageLimit(), false,
                    Resource.ResourceType.primary_storage, domain.getId());
            long secondaryStorageLimit = ApiDBUtils.findCorrectResourceLimitForDomain(domain.getSecondaryStorageLimit(), false,
                    Resource.ResourceType.secondary_storage, domain.getId());

            // Add per domain cpu, memory and storage count
            metricsList.add(new ItemPerDomainResourceLimit(cpuLimit, domain.getPath(), Resource.ResourceType.cpu.getName()));
            metricsList.add(new ItemPerDomainResourceLimit(memoryLimit, domain.getPath(), Resource.ResourceType.memory.getName()));
            metricsList.add(new ItemPerDomainResourceLimit(primaryStorageLimit, domain.getPath(), Resource.ResourceType.primary_storage.getName()));
            metricsList.add(new ItemPerDomainResourceLimit(secondaryStorageLimit, domain.getPath(), Resource.ResourceType.secondary_storage.getName()));
        }
        metricsList.add(new ItemDomainLimitCpu(totalCpuLimit));
        metricsList.add(new ItemDomainLimitMemory(totalMemoryLimit));
    }

    /**
     * Function to export the domain level resource count for specified resource type
     *
     * @param metricsList
     */
    private void addDomainResourceCount(final List<Item> metricsList) {
        for (final DomainJoinVO domain: domainDao.listAll()) {
            // Display stats for ROOT domain also
            if (domain == null) {
                continue;
            }

            long memoryUsed = _resourceCountDao.getResourceCount(domain.getId(), Resource.ResourceOwnerType.Domain,
                    Resource.ResourceType.memory, null);
            long cpuUsed = _resourceCountDao.getResourceCount(domain.getId(), Resource.ResourceOwnerType.Domain,
                    Resource.ResourceType.cpu, null);
            long primaryStorageUsed = _resourceCountDao.getResourceCount(domain.getId(), Resource.ResourceOwnerType.Domain,
                    Resource.ResourceType.primary_storage, null);
            long secondaryStorageUsed = _resourceCountDao.getResourceCount(domain.getId(), Resource.ResourceOwnerType.Domain,
                    Resource.ResourceType.secondary_storage, null);

            metricsList.add(new ItemPerDomainResourceCount(memoryUsed, domain.getPath(), Resource.ResourceType.memory.getName()));
            metricsList.add(new ItemPerDomainResourceCount(cpuUsed, domain.getPath(), Resource.ResourceType.cpu.getName()));
            metricsList.add(new ItemPerDomainResourceCount(primaryStorageUsed, domain.getPath(),
                    Resource.ResourceType.primary_storage.getName()));
            metricsList.add(new ItemPerDomainResourceCount(secondaryStorageUsed, domain.getPath(),
                    Resource.ResourceType.secondary_storage.getName()));
        }
    }

    private void addDomainMetrics(final List<Item> metricsList, final String zoneName, final String zoneUuid) {
        metricsList.add(new ItemActiveDomains(zoneName, zoneUuid, _accountDao.getActiveDomains()));
    }

    private void addAccountMetrics(final List<Item> metricsList, final long dcId, final String zoneName, final String zoneUuid) {
        metricsList.add(new ItemActiveAccounts(zoneName, zoneUuid, uservmDao.getActiveAccounts(dcId)));
    }

    private void addVMsBySizeMetrics(final List<Item> metricsList, final long dcId, final String zoneName, final String zoneUuid) {
        List<Ternary<Integer, Integer, Integer>> vms = uservmDao.countVmsBySize(dcId, PrometheusExporterServer.PrometheusExporterOfferingCountLimit.value());
        for (Ternary<Integer, Integer, Integer> vm : vms) {
            metricsList.add(new ItemVMsBySize(zoneName, zoneUuid, vm.first(), vm.second(), vm.third()));
        }
    }

    @Override
    public void updateMetrics() {
        final List<Item> latestMetricsItems = new ArrayList<Item>();
        try {
            for (final DataCenterVO dc : dcDao.listAll()) {
                final String zoneName = dc.getName();
                final String zoneUuid = dc.getUuid();
                alertManager.recalculateCapacity();
                addHostMetrics(latestMetricsItems, dc.getId(), zoneName, zoneUuid);
                addVMMetrics(latestMetricsItems, dc.getId(), zoneName, zoneUuid);
                addVolumeMetrics(latestMetricsItems, dc.getId(), zoneName, zoneUuid);
                addStorageMetrics(latestMetricsItems, dc.getId(), zoneName, zoneUuid);
                addIpAddressMetrics(latestMetricsItems, dc.getId(), zoneName, zoneUuid);
                addVlanMetrics(latestMetricsItems, dc.getId(), zoneName, zoneUuid);
                addDomainMetrics(latestMetricsItems, zoneName, zoneUuid);
                addAccountMetrics(latestMetricsItems, dc.getId(), zoneName, zoneUuid);
                addVMsBySizeMetrics(latestMetricsItems, dc.getId(), zoneName, zoneUuid);
            }
            addDomainLimits(latestMetricsItems);
            addDomainResourceCount(latestMetricsItems);
        } catch (Exception e) {
            logger.warn("Getting metrics failed ", e);
        }
        metricsItems = latestMetricsItems;
    }

    @Override
    public String getMetrics() {
        final StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append("# Cloudstack Prometheus Metrics\n");
        for (final Item item : metricsItems) {
            stringBuilder.append(item.toMetricsString()).append("\n");
        }
        return stringBuilder.toString();
    }

    private abstract class Item {
        String name;

        public Item(final String nm) {
            name = nm;
        }

        public abstract String toMetricsString();
    }

    class ItemVM extends Item {
        String zoneName;
        String zoneUuid;
        String filter;
        long total;

        public ItemVM(final String zn, final String zu, final String st, long cnt) {
            super("cloudstack_vms_total");
            zoneName = zn;
            zoneUuid = zu;
            filter = st;
            total = cnt;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",filter=\"%s\"} %d", name, zoneName, filter, total);
        }
    }

    class ItemVMByTag extends Item {
        String zoneName;
        String zoneUuid;
        String filter;
        long total;
        String hosttags;

        public ItemVMByTag(final String zn, final String zu, final String st, long cnt, final String tags) {
            super("cloudstack_vms_total_by_tag");
            zoneName = zn;
            zoneUuid = zu;
            filter = st;
            total = cnt;
            hosttags = tags;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",filter=\"%s\",tags=\"%s\"} %d", name, zoneName, filter, hosttags, total);
        }
    }

    class ItemVolume extends Item {
        String zoneName;
        String zoneUuid;
        String filter;
        int total;

        public ItemVolume(final String zn, final String zu, final String st, int cnt) {
            super("cloudstack_volumes_total");
            zoneName = zn;
            zoneUuid = zu;
            filter = st;
            total = cnt;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",filter=\"%s\"} %d", name, zoneName, filter, total);
        }
    }

    class ItemHost extends Item {
        String zoneName;
        String zoneUuid;
        String state;
        int total;
        String hosttags;

        public ItemHost(final String zn, final String zu, final String st, int cnt, final String tags) {
            super("cloudstack_hosts_total");
            zoneName = zn;
            zoneUuid = zu;
            state = st;
            total = cnt;
            hosttags = tags;
        }

        @Override
        public String toMetricsString() {
            if (StringUtils.isNotEmpty(hosttags)) {
                name = "cloudstack_hosts_total_by_tag";
                return String.format("%s{zone=\"%s\",filter=\"%s\",tags=\"%s\"} %d", name, zoneName, state, hosttags, total);
            }
            return String.format("%s{zone=\"%s\",filter=\"%s\"} %d", name, zoneName, state, total);
        }
    }

    class ItemVMCore extends Item {
        String zoneName;
        String zoneUuid;
        String hostName;
        String uuid;
        String ip;
        String filter;
        long core = 0;
        int isDedicated;
        String hosttags;

        public ItemVMCore(final String zn, final String zu, final String hn, final String hu, final String hip, final String fl, final Long cr, final int dedicated, final String tags) {
            super("cloudstack_host_vms_cores_total");
            zoneName = zn;
            zoneUuid = zu;
            hostName = hn;
            uuid = hu;
            ip = hip;
            filter = fl;
            if (cr != null) {
                core = cr;
            }
            isDedicated = dedicated;
            hosttags = tags;
        }

        @Override
        public String toMetricsString() {
            if (StringUtils.isAllEmpty(hostName, ip)) {
                if (StringUtils.isEmpty(hosttags)) {
                    return String.format("%s{zone=\"%s\",filter=\"%s\"} %d", name, zoneName, filter, core);
                } else {
                    name = "cloudstack_host_vms_cores_total_by_tag";
                    return String.format("%s{zone=\"%s\",filter=\"%s\",tags=\"%s\"} %d", name, zoneName, filter, hosttags, core);
                }
            }
            return String.format("%s{zone=\"%s\",hostname=\"%s\",ip=\"%s\",filter=\"%s\",dedicated=\"%d\",tags=\"%s\"} %d", name, zoneName, hostName, ip, filter, isDedicated, hosttags, core);
        }
    }

    class MissingHostInfo extends Item {

        String zoneName;
        String hostName;
        MissingInfoFilter filter;

        public MissingHostInfo(String zoneName, String hostname, MissingInfoFilter filter) {
            super("cloudstack_host_missing_info");
            this.zoneName = zoneName;
            this.hostName = hostname;
            this.filter = filter;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",hostname=\"%s\",filter=\"%s\"} -1", name, zoneName, hostName, filter);
        }
    }

    class ItemHostCpu extends Item {
        String zoneName;
        String zoneUuid;
        String hostName;
        String uuid;
        String ip;
        String overProvisioningFactor;
        String filter;
        double mhertz;
        int isDedicated;
        String hosttags;

        public ItemHostCpu(final String zn, final String zu, final String hn, final String hu, final String hip, final String of, final String fl, final double mh, final int dedicated, final String tags) {
            super("cloudstack_host_cpu_usage_mhz_total");
            zoneName = zn;
            zoneUuid = zu;
            hostName = hn;
            uuid = hu;
            ip = hip;
            overProvisioningFactor = of;
            filter = fl;
            mhertz = mh;
            isDedicated = dedicated;
            hosttags = tags;
        }

        @Override
        public String toMetricsString() {
            if (StringUtils.isAllEmpty(hostName, ip)) {
                if (StringUtils.isEmpty(hosttags)) {
                    return String.format("%s{zone=\"%s\",filter=\"%s\"} %.2f", name, zoneName, filter, mhertz);
                } else {
                    name = "cloudstack_host_cpu_usage_mhz_total_by_tag";
                    return String.format("%s{zone=\"%s\",filter=\"%s\",tags=\"%s\"} %.2f", name, zoneName, filter, hosttags, mhertz);
                }
            }
            return String.format("%s{zone=\"%s\",hostname=\"%s\",ip=\"%s\",overprovisioningfactor=\"%s\",filter=\"%s\",tags=\"%s\"} %.2f", name, zoneName, hostName, ip, overProvisioningFactor, filter, hosttags, mhertz);
        }
    }

    class ItemHostMemory extends Item {
        String zoneName;
        String zoneUuid;
        String hostName;
        String uuid;
        String ip;
        String overProvisioningFactor;
        String filter;
        double miBytes;
        int isDedicated;
        String hosttags;

        public ItemHostMemory(final String zn, final String zu, final String hn, final String hu, final String hip, final String of, final String fl, final double membytes, final int dedicated, final String tags) {
            super("cloudstack_host_memory_usage_mibs_total");
            zoneName = zn;
            zoneUuid = zu;
            hostName = hn;
            uuid = hu;
            ip = hip;
            overProvisioningFactor = of;
            filter = fl;
            miBytes = membytes / (1024.0 * 1024.0);
            isDedicated = dedicated;
            hosttags = tags;
        }

        @Override
        public String toMetricsString() {
            if (StringUtils.isAllEmpty(hostName, ip)) {
                if (StringUtils.isEmpty(hosttags)) {
                    return String.format("%s{zone=\"%s\",filter=\"%s\"} %.2f", name, zoneName, filter, miBytes);
                } else {
                    name = "cloudstack_host_memory_usage_mibs_total_by_tag";
                    return String.format("%s{zone=\"%s\",filter=\"%s\",tags=\"%s\"} %.2f", name, zoneName, filter, hosttags, miBytes);
                }
            }
            return String.format("%s{zone=\"%s\",hostname=\"%s\",ip=\"%s\",overprovisioningfactor=\"%s\",filter=\"%s\",dedicated=\"%d\",tags=\"%s\"} %.2f", name, zoneName, hostName, ip, overProvisioningFactor, filter, isDedicated, hosttags, miBytes);
        }
    }

    class ItemHostVM extends Item {
        String zoneName;
        String zoneUuid;
        String hostName;
        String hostUuid;
        String hostIp;
        int total;

        public ItemHostVM(final String zoneName, final String zoneUuid, final String hostName, final String hostUuid, final String hostIp, final int total) {
            super("cloudstack_host_vms_total");
            this.zoneName = zoneName;
            this.zoneUuid = zoneUuid;
            this.hostName = hostName;
            this.hostUuid = hostUuid;
            this.hostIp = hostIp;
            this.total = total;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",hostname=\"%s\",address=\"%s\"} %d", name, zoneName, hostName, hostIp, total);
        }
    }

    class ItemPool extends Item {
        String zoneName;
        String zoneUuid;
        String type;
        String overProvisioningFactor;
        String filter;
        String pname;
        String address;
        double total;

        public ItemPool(final String zn, final String zu, final String pn, final String pa, final String typ, final String of, final String fl, double cnt) {
            super("cloudstack_storage_pool_gibs_total");
            zoneName = zn;
            zoneUuid = zu;
            pname = pn;
            address = pa;
            type = typ;
            overProvisioningFactor = of;
            filter = fl;
            total = cnt / (1024.0 * 1024.0 * 1024.0);
        }

        @Override
        public String toMetricsString() {
            if (StringUtils.isEmpty(overProvisioningFactor)) {
                return String.format("%s{zone=\"%s\",name=\"%s\",address=\"%s\",type=\"%s\",filter=\"%s\"} %.2f", name, zoneName, pname, address, type, filter, total);
            }
            return String.format("%s{zone=\"%s\",name=\"%s\",address=\"%s\",type=\"%s\",overprovisioningfactor=\"%s\",filter=\"%s\"} %.2f", name, zoneName, pname, address, type, overProvisioningFactor, filter, total);
        }
    }

    class ItemPrivateIp extends Item {
        String zoneName;
        String zoneUuid;
        String filter;
        int total;

        public ItemPrivateIp(final String zn, final String zu, final String fl, int cnt) {
            super("cloudstack_private_ips_total");
            zoneName = zn;
            zoneUuid = zu;
            filter = fl;
            total = cnt;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",filter=\"%s\"} %d", name, zoneName, filter, total);
        }
    }

    class ItemPublicIp extends Item {
        String zoneName;
        String zoneUuid;
        String filter;
        int total;

        public ItemPublicIp(final String zn, final String zu, final String fl, int cnt) {
            super("cloudstack_public_ips_total");
            zoneName = zn;
            zoneUuid = zu;
            filter = fl;
            total = cnt;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",filter=\"%s\"} %d", name, zoneName, filter, total);
        }
    }

    class ItemSharedNetworkIp extends Item {
        String zoneName;
        String zoneUuid;
        String filter;
        int total;

        public ItemSharedNetworkIp(final String zn, final String zu, final String fl, int cnt) {
            super("cloudstack_shared_network_ips_total");
            zoneName = zn;
            zoneUuid = zu;
            filter = fl;
            total = cnt;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",filter=\"%s\"} %d", name, zoneName, filter, total);
        }
    }

    class ItemVlan extends Item {
        String zoneName;
        String zoneUuid;
        String filter;
        int total;

        public ItemVlan(final String zn, final String zu, final String fl, int cnt) {
            super("cloudstack_vlans_total");
            zoneName = zn;
            zoneUuid = zu;
            filter = fl;
            total = cnt;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",filter=\"%s\"} %d", name, zoneName, filter, total);
        }
    }

    class ItemDomainLimitCpu extends Item {
        long cores;

        public ItemDomainLimitCpu(final long c) {
            super("cloudstack_domain_limit_cpu_cores_total");
            cores = c;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s %d", name, cores);
        }
    }

    class ItemDomainLimitMemory extends Item {
        long miBytes;

        public ItemDomainLimitMemory(final long mb) {
            super("cloudstack_domain_limit_memory_mibs_total");
            miBytes = mb;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s %d", name, miBytes);
        }
    }

    class ItemHostIsDedicated extends Item {
        String zoneName;
        String zoneUuid;
        String hostName;
        String hostUuid;
        String hostIp;
        int isDedicated;

        public ItemHostIsDedicated(final String zoneName, final String zoneUuid, final String hostName, final String hostUuid, final String hostIp, final int isDedicated) {
            super("cloudstack_host_is_dedicated");
            this.zoneName = zoneName;
            this.zoneUuid = zoneUuid;
            this.hostName = hostName;
            this.hostUuid = hostUuid;
            this.hostIp = hostIp;
            this.isDedicated = isDedicated;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",hostname=\"%s\",ip=\"%s\"} %d", name, zoneName, hostName, hostIp, isDedicated);
        }

    }

    class ItemActiveDomains extends Item {
        String zoneName;
        String zoneUuid;
        int total;

        public ItemActiveDomains(final String zn, final String zu, final int cnt) {
            super("cloudstack_active_domains_total");
            zoneName = zn;
            zoneUuid = zu;
            total = cnt;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\"} %d", name, zoneName, total);
        }
    }

    class ItemHostDedicatedToAccount extends Item {
        String zoneName;
        String hostName;
        String accountName;
        String domainName;
        int isDedicated;

        public ItemHostDedicatedToAccount(final String zoneName, final String hostName,
                                          final String accountName, final String domainName, int isDedicated) {
            super("cloudstack_host_dedicated_to_account");
            this.zoneName = zoneName;
            this.hostName = hostName;
            this.accountName = accountName;
            this.domainName = domainName;
            this.isDedicated = isDedicated;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",hostname=\"%s\",account=\"%s\",domain=\"%s\"} %d",
                    name, zoneName, hostName, accountName, domainName, isDedicated);
        }
    }

    class ItemPerDomainResourceLimit extends Item {
        long cores;
        String domainName;
        String resourceType;

        public ItemPerDomainResourceLimit(final long c, final String domainName, final String resourceType) {
            super("cloudstack_domain_resource_limit");
            this.cores = c;
            this.domainName = domainName;
            this.resourceType = resourceType;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{domain=\"%s\", type=\"%s\"} %d", name, domainName, resourceType, cores);
        }
    }

    class ItemPerDomainResourceCount extends Item {
        long miBytes;
        String domainName;
        String resourceType;

        public ItemPerDomainResourceCount(final long mb, final String domainName, final String resourceType) {
            super("cloudstack_domain_resource_count");
            this.miBytes = mb;
            this.domainName = domainName;
            this.resourceType = resourceType;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{domain=\"%s\", type=\"%s\"} %d", name, domainName, resourceType, miBytes);
        }
    }

    class ItemActiveAccounts extends Item {
        String zoneName;
        String zoneUuid;
        int total;

        public ItemActiveAccounts(final String zn, final String zu, final int cnt) {
            super("cloudstack_active_accounts_total");
            zoneName = zn;
            zoneUuid = zu;
            total = cnt;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\"} %d", name, zoneName, total);
        }
    }

    class ItemVMsBySize extends Item {
        String zoneName;
        String zoneUuid;
        int cpu;
        int memory;
        int total;

        public ItemVMsBySize(final String zn, final String zu, final int c, final int m, int cnt) {
            super("cloudstack_vms_total_by_size");
            zoneName = zn;
            zoneUuid = zu;
            cpu = c;
            memory = m;
            total = cnt;
        }

        @Override
        public String toMetricsString() {
            return String.format("%s{zone=\"%s\",cpu=\"%d\",memory=\"%d\"} %d", name, zoneName, cpu, memory, total);
        }
    }
}
