/**
 * 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.curator.x.discovery;

import com.google.common.base.Preconditions;
import com.google.common.collect.Maps;
import java.net.InetAddress;
import java.util.Collection;
import java.util.Map;
import java.util.UUID;

import org.codehaus.jackson.annotate.JsonTypeInfo;
import org.codehaus.jackson.annotate.JsonTypeInfo.Id;

/**
 * POJO that represents a service instance
 */
public class ServiceInstance<T>
{
    private final String        name;
    private final String        id;
    private final String        address;
    private final Integer       port;
    private final Integer       sslPort;
    private final T             payload;
    private final long          registrationTimeUTC;
    private final ServiceType   serviceType;
    private final UriSpec       uriSpec;
    private final boolean       enabled;

    /**
     * Return a new builder. The {@link #address} is set to the ip of the first
     * NIC in the system. The {@link #id} is set to a random UUID.
     *
     * @return builder
     * @throws Exception errors getting the local IP
     */
    public static<T> ServiceInstanceBuilder<T>builder() throws Exception
    {
        String                  address = null;
        Collection<InetAddress> ips = ServiceInstanceBuilder.getAllLocalIPs();
        if ( ips.size() > 0 )
        {
            address = ips.iterator().next().getHostAddress();   // default to the first address
        }

        String                  id = UUID.randomUUID().toString();

        return new ServiceInstanceBuilder<T>().address(address).id(id).registrationTimeUTC(System.currentTimeMillis());
    }

    /**
     * @param name name of the service
     * @param id id of this instance (must be unique)
     * @param address address of this instance
     * @param port the port for this instance or null
     * @param sslPort the SSL port for this instance or null
     * @param payload the payload for this instance or null
     * @param registrationTimeUTC the time (in UTC) of the registration
     * @param serviceType type of the service
     * @param uriSpec the uri spec or null
     */
    public ServiceInstance(String name, String id, String address, Integer port, Integer sslPort, T payload, long registrationTimeUTC, ServiceType serviceType, UriSpec uriSpec)
    {
        this(name, id, address, port, sslPort, payload, registrationTimeUTC, serviceType, uriSpec, true);
    }

    /**
     * IMPORTANT: Due to CURATOR-275 the <code>enabled</code> field is <strong>NOT</strong> supported
     * by default. If you wish to use the enabled field, you must set a {@link org.apache.curator.x.discovery.details.InstanceSerializer}
     * that serializes this field. The default serializer, {@link org.apache.curator.x.discovery.details.JsonInstanceSerializer} does not
     * serialize the field by default. You must use the alternate constructor {@link org.apache.curator.x.discovery.details.JsonInstanceSerializer#JsonInstanceSerializer(Class, boolean)}
     * passing false for <code>compatibleSerializationMode</code>.
     *
     * @param name name of the service
     * @param id id of this instance (must be unique)
     * @param address address of this instance
     * @param port the port for this instance or null
     * @param sslPort the SSL port for this instance or null
     * @param payload the payload for this instance or null
     * @param registrationTimeUTC the time (in UTC) of the registration
     * @param serviceType type of the service
     * @param uriSpec the uri spec or null
     * @param enabled true if the instance should be considered enabled
     */
    public ServiceInstance(String name, String id, String address, Integer port, Integer sslPort, T payload, long registrationTimeUTC, ServiceType serviceType, UriSpec uriSpec, boolean enabled)
    {
        name = Preconditions.checkNotNull(name, "name cannot be null");
        id = Preconditions.checkNotNull(id, "id cannot be null");

        this.serviceType = serviceType;
        this.uriSpec = uriSpec;
        this.name = name;
        this.id = id;
        this.address = address;
        this.port = port;
        this.sslPort = sslPort;
        this.payload = payload;
        this.registrationTimeUTC = registrationTimeUTC;
        this.enabled = enabled;
    }

    /**
     * Inits to default values. Only exists for deserialization
     */
    ServiceInstance()
    {
        this("", "", null, null, null, null, 0, ServiceType.DYNAMIC, null, true);
    }

    public String getName()
    {
        return name;
    }

    public String getId()
    {
        return id;
    }

    public String getAddress()
    {
        return address;
    }

    public Integer getPort()
    {
        return port;
    }

    public Integer getSslPort()
    {
        return sslPort;
    }

    @JsonTypeInfo(use=Id.CLASS, defaultImpl=Object.class)
    public T getPayload()
    {
        return payload;
    }

    public long getRegistrationTimeUTC()
    {
        return registrationTimeUTC;
    }

    public ServiceType getServiceType()
    {
        return serviceType;
    }

    public UriSpec getUriSpec()
    {
        return uriSpec;
    }

    /**
     * IMPORTANT: Due to CURATOR-275 the <code>enabled</code> field is <strong>NOT</strong> supported
     * by default. If you wish to use the enabled field, you must set a {@link org.apache.curator.x.discovery.details.InstanceSerializer}
     * that serializes this field. The default serializer, {@link org.apache.curator.x.discovery.details.JsonInstanceSerializer} does not
     * serialize the field by default. You must use the alternate constructor {@link org.apache.curator.x.discovery.details.JsonInstanceSerializer#JsonInstanceSerializer(Class, boolean)}
     * passing false for <code>compatibleSerializationMode</code>.
     *
     * @return true/false
     */
    public boolean isEnabled()
    {
        return enabled;
    }

    public String buildUriSpec()
    {
        return buildUriSpec(Maps.<String, Object>newHashMap());
    }

    public String buildUriSpec(Map<String, Object> variables)
    {
        return (uriSpec != null) ? uriSpec.build(this, variables) : "";
    }

    @SuppressWarnings("RedundantIfStatement")
    @Override
    public boolean equals(Object o)
    {
        if ( this == o )
        {
            return true;
        }
        if ( o == null || getClass() != o.getClass() )
        {
            return false;
        }

        ServiceInstance that = (ServiceInstance)o;

        if ( registrationTimeUTC != that.registrationTimeUTC )
        {
            return false;
        }
        if ( address != null ? !address.equals(that.address) : that.address != null )
        {
            return false;
        }
        if ( id != null ? !id.equals(that.id) : that.id != null )
        {
            return false;
        }
        if ( name != null ? !name.equals(that.name) : that.name != null )
        {
            return false;
        }
        if ( payload != null ? !payload.equals(that.payload) : that.payload != null )
        {
            return false;
        }
        if ( port != null ? !port.equals(that.port) : that.port != null )
        {
            return false;
        }
        if ( serviceType != that.serviceType )
        {
            return false;
        }
        if ( sslPort != null ? !sslPort.equals(that.sslPort) : that.sslPort != null )
        {
            return false;
        }
        if ( uriSpec != null ? !uriSpec.equals(that.uriSpec) : that.uriSpec != null )
        {
            return false;
        }
        if ( enabled != that.enabled )
        {
            return false;
        }

        return true;
    }

    @Override
    public int hashCode()
    {
        int result = name != null ? name.hashCode() : 0;
        result = 31 * result + (id != null ? id.hashCode() : 0);
        result = 31 * result + (address != null ? address.hashCode() : 0);
        result = 31 * result + (port != null ? port.hashCode() : 0);
        result = 31 * result + (sslPort != null ? sslPort.hashCode() : 0);
        result = 31 * result + (payload != null ? payload.hashCode() : 0);
        result = 31 * result + (int)(registrationTimeUTC ^ (registrationTimeUTC >>> 32));
        result = 31 * result + (serviceType != null ? serviceType.hashCode() : 0);
        result = 31 * result + (uriSpec != null ? uriSpec.hashCode() : 0);
        result = 31 * result + (enabled ? 1 : 0);
        return result;
    }

    @Override
    public String toString()
    {
        return "ServiceInstance{" +
            "name='" + name + '\'' +
            ", id='" + id + '\'' +
            ", address='" + address + '\'' +
            ", port=" + port +
            ", sslPort=" + sslPort +
            ", payload=" + payload +
            ", registrationTimeUTC=" + registrationTimeUTC +
            ", serviceType=" + serviceType +
            ", uriSpec=" + uriSpec +
            ", enabled=" + enabled +
            '}';
    }
}
