/*
 * Copyright 2015-present Open Networking Laboratory
 *
 * 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.
 */
package org.onosproject.net.flowobjective;

import com.google.common.annotations.Beta;

import org.onosproject.core.ApplicationId;
import org.onosproject.net.flow.TrafficSelector;
import org.onosproject.net.flow.TrafficTreatment;

import java.util.Objects;
import java.util.Optional;

import static com.google.common.base.MoreObjects.toStringHelper;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;

/**
 * Default implementation of a forwarding objective.
 */
@Beta
public final class DefaultForwardingObjective implements ForwardingObjective {

    private final TrafficSelector selector;
    private final Flag flag;
    private final boolean permanent;
    private final int timeout;
    private final ApplicationId appId;
    private final int priority;
    private final Integer nextId;
    private final TrafficTreatment treatment;
    private final Operation op;
    private final Optional<ObjectiveContext> context;
    private final TrafficSelector meta;

    private final int id;

    private DefaultForwardingObjective(Builder builder) {
        this.selector = builder.selector;
        this.flag = builder.flag;
        this.permanent = builder.permanent;
        this.timeout = builder.timeout;
        this.appId = builder.appId;
        this.priority = builder.priority;
        this.nextId = builder.nextId;
        this.treatment = builder.treatment;
        this.op = builder.op;
        this.context = Optional.ofNullable(builder.context);
        this.meta = builder.meta;

        this.id = Objects.hash(selector, flag, permanent,
                timeout, appId, priority, nextId,
                treatment, op);
    }


    @Override
    public TrafficSelector selector() {
        return selector;
    }

    @Override
    public Integer nextId() {
        return nextId;
    }

    @Override
    public TrafficTreatment treatment() {
        return treatment;
    }


    @Override
    public Flag flag() {
        return flag;
    }

    @Override
    public int id() {
        return id;
    }

    @Override
    public int priority() {
        return priority;
    }

    @Override
    public ApplicationId appId() {
        return appId;
    }

    @Override
    public int timeout() {
        return timeout;
    }

    @Override
    public boolean permanent() {
        return permanent;
    }

    @Override
    public Operation op() {
        return op;
    }

    @Override
    public Optional<ObjectiveContext> context() {
        return context;
    }

    @Override
    public TrafficSelector meta() {
        return meta;
    }

    @Override
    public int hashCode() {
        return Objects.hash(selector, flag, permanent, timeout, appId,
                            priority, nextId, treatment, op, meta);
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof DefaultForwardingObjective) {
            final DefaultForwardingObjective other = (DefaultForwardingObjective) obj;
            return Objects.equals(this.selector, other.selector)
                    && Objects.equals(this.flag, other.flag)
                    && Objects.equals(this.permanent, other.permanent)
                    && Objects.equals(this.timeout, other.timeout)
                    && Objects.equals(this.appId, other.appId)
                    && Objects.equals(this.priority, other.priority)
                    && Objects.equals(this.nextId, other.nextId)
                    && Objects.equals(this.treatment, other.treatment)
                    && Objects.equals(this.op, other.op)
                    && Objects.equals(this.meta, other.meta);
        }
        return false;
    }

    @Override
    public String toString() {
        return toStringHelper(this)
                .add("id", id())
                .add("op", op())
                .add("priority", priority())
                .add("selector", selector())
                .add("treatment", treatment())
                .add("nextId", nextId())
                .add("meta", meta())
                .add("flag", flag())
                .add("appId", appId())
                .add("permanent", permanent())
                .add("timeout", timeout())
                .toString();
    }

    /**
     * Returns a new builder.
     *
     * @return new builder
     */
    public static Builder builder() {
        return new Builder();
    }


    @Override
    public Builder copy() {
        return new Builder(this);
    }


    public static final class Builder implements ForwardingObjective.Builder {

        private TrafficSelector selector;
        private Flag flag;
        private boolean permanent = DEFAULT_PERMANENT;
        private int timeout = DEFAULT_TIMEOUT;
        private int priority = DEFAULT_PRIORITY;
        private ApplicationId appId;
        private Integer nextId;
        private TrafficTreatment treatment;
        private Operation op;
        private ObjectiveContext context;
        private TrafficSelector meta;

        // Creates an empty builder
        private Builder() {
        }

        // Creates a builder set to create a copy of the specified objective.
        private Builder(ForwardingObjective objective) {
            this.selector = objective.selector();
            this.flag = objective.flag();
            this.permanent = objective.permanent();
            this.timeout = objective.timeout();
            this.priority = objective.priority();
            this.appId = objective.appId();
            this.nextId = objective.nextId();
            this.treatment = objective.treatment();
            this.op = objective.op();
            this.meta = objective.meta();
        }

        @Override
        public Builder withSelector(TrafficSelector selector) {
            this.selector = selector;
            return this;
        }

        @Override
        public Builder nextStep(int nextId) {
            this.nextId = nextId;
            return this;
        }

        @Override
        public Builder withTreatment(TrafficTreatment treatment) {
            this.treatment = treatment;
            return this;
        }

        @Override
        public Builder withFlag(Flag flag) {
            this.flag = flag;
            return this;
        }

        @Override
        public Builder makeTemporary(int timeout) {
            this.timeout = timeout;
            this.permanent = false;
            return this;
        }

        @Override
        public Builder makePermanent() {
            this.permanent = true;
            return this;
        }

        @Override
        public Builder fromApp(ApplicationId appId) {
            this.appId = appId;
            return this;
        }

        @Override
        public Builder withPriority(int priority) {
            this.priority = priority;
            return this;
        }

        @Override
        public Builder withMeta(TrafficSelector meta) {
            this.meta = meta;
            return this;
        }

        @Override
        public ForwardingObjective add() {
            checkNotNull(selector, "Must have a selector");
            checkNotNull(flag, "A flag must be set");
            checkArgument(nextId != null || treatment != null, "Must supply at " +
                    "least a treatment and/or a nextId");
            checkNotNull(appId, "Must supply an application id");
            checkArgument(priority <= MAX_PRIORITY && priority >= MIN_PRIORITY, "Priority " +
                    "out of range");
            op = Operation.ADD;
            return new DefaultForwardingObjective(this);
        }

        @Override
        public ForwardingObjective remove() {
            checkNotNull(selector, "Must have a selector");
            checkNotNull(flag, "A flag must be set");
            checkArgument(nextId != null || treatment != null, "Must supply at " +
                    "least a treatment and/or a nextId");
            checkNotNull(appId, "Must supply an application id");
            op = Operation.REMOVE;
            return new DefaultForwardingObjective(this);
        }

        @Override
        public ForwardingObjective add(ObjectiveContext context) {
            checkNotNull(selector, "Must have a selector");
            checkNotNull(flag, "A flag must be set");
            checkArgument(nextId != null || treatment != null, "Must supply at " +
                    "least a treatment and/or a nextId");
            checkNotNull(appId, "Must supply an application id");
            op = Operation.ADD;
            this.context = context;

            return new DefaultForwardingObjective(this);
        }

        @Override
        public ForwardingObjective remove(ObjectiveContext context) {
            checkNotNull(selector, "Must have a selector");
            checkNotNull(flag, "A flag must be set");
            checkArgument(nextId != null || treatment != null, "Must supply at " +
                    "least a treatment and/or a nextId");
            checkNotNull(appId, "Must supply an application id");
            op = Operation.REMOVE;
            this.context = context;

            return new DefaultForwardingObjective(this);
        }
    }

}