/*
 * 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 com.google.common.collect.ImmutableList;
import org.onosproject.core.ApplicationId;
import org.onosproject.net.flow.TrafficTreatment;
import org.onosproject.net.flow.criteria.Criteria;
import org.onosproject.net.flow.criteria.Criterion;

import java.util.Collection;
import java.util.List;
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 filtering objective.
 */
@Beta
public final class DefaultFilteringObjective implements FilteringObjective {

    private final Type type;
    private final boolean permanent;
    private final int timeout;
    private final ApplicationId appId;
    private final int priority;
    private final Criterion key;
    private final List<Criterion> conditions;
    private final int id;
    private final Operation op;
    private final Optional<ObjectiveContext> context;
    private final TrafficTreatment meta;

    private DefaultFilteringObjective(Builder builder) {
        this.key = builder.key;
        this.type = builder.type;
        this.permanent = builder.permanent;
        this.timeout = builder.timeout;
        this.appId = builder.appId;
        this.priority = builder.priority;
        this.conditions = builder.conditions;
        this.op = builder.op;
        this.context = Optional.ofNullable(builder.context);
        this.meta = builder.meta;

        this.id = Objects.hash(type, key, conditions, permanent,
                               timeout, appId, priority);
    }

    @Override
    public Criterion key() {
        return key;
    }

    @Override
    public Type type() {
        return this.type;
    }

    @Override
    public Collection<Criterion> conditions() {
        return conditions;
    }

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

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


    @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 int hashCode() {
        return Objects.hash(type, permanent, timeout, appId, priority, key,
                            conditions, op, meta);
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof DefaultFilteringObjective) {
            final DefaultFilteringObjective other = (DefaultFilteringObjective) obj;
            return Objects.equals(this.type, other.type)
                    && 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.key, other.key)
                    && Objects.equals(this.conditions, other.conditions)
                    && 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("type", type())
                .add("op", op())
                .add("priority", priority())
                .add("key", key())
                .add("conditions", conditions())
                .add("meta", meta())
                .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 FilteringObjective.Builder {
        private final ImmutableList.Builder<Criterion> listBuilder
                = ImmutableList.builder();

        private Type type;
        private boolean permanent = DEFAULT_PERMANENT;
        private int timeout = DEFAULT_TIMEOUT;
        private ApplicationId appId;
        private int priority = DEFAULT_PRIORITY;
        private Criterion key = Criteria.dummy();
        private List<Criterion> conditions;
        private Operation op;
        private ObjectiveContext context;
        private TrafficTreatment meta;

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

        // Creates a builder set to create a copy of the specified objective.
        private Builder(FilteringObjective objective) {
            this.type = objective.type();
            this.key = objective.key();
            objective.conditions().forEach(this::addCondition);
            this.permanent = objective.permanent();
            this.timeout = objective.timeout();
            this.priority = objective.priority();
            this.appId = objective.appId();
            this.meta = objective.meta();
            this.op = objective.op();
        }

        @Override
        public Builder withKey(Criterion key) {
            this.key = key;
            return this;
        }

        @Override
        public Builder addCondition(Criterion criterion) {
            listBuilder.add(criterion);
            return this;
        }

        @Override
        public Builder permit() {
            this.type = Type.PERMIT;
            return this;
        }

        @Override
        public Builder deny() {
            this.type = Type.DENY;
            return this;
        }

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

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

        @Override
        public FilteringObjective add() {
            conditions = listBuilder.build();
            op = Operation.ADD;
            checkNotNull(type, "Must have a type.");
            checkArgument(!conditions.isEmpty(), "Must have at least one condition.");
            checkNotNull(appId, "Must supply an application id");
            checkArgument(priority <= MAX_PRIORITY && priority >= MIN_PRIORITY, "Priority " +
                    "out of range");

            return new DefaultFilteringObjective(this);
        }

        @Override
        public FilteringObjective remove() {
            conditions = listBuilder.build();
            checkNotNull(type, "Must have a type.");
            checkArgument(!conditions.isEmpty(), "Must have at least one condition.");
            checkNotNull(appId, "Must supply an application id");
            op = Operation.REMOVE;

            return new DefaultFilteringObjective(this);
        }

        @Override
        public FilteringObjective add(ObjectiveContext context) {
            conditions = listBuilder.build();
            checkNotNull(type, "Must have a type.");
            checkArgument(!conditions.isEmpty(), "Must have at least one condition.");
            checkNotNull(appId, "Must supply an application id");
            op = Operation.ADD;
            this.context = context;

            return new DefaultFilteringObjective(this);
        }

        @Override
        public FilteringObjective remove(ObjectiveContext context) {
            conditions = listBuilder.build();
            checkNotNull(type, "Must have a type.");
            checkArgument(!conditions.isEmpty(), "Must have at least one condition.");
            checkNotNull(appId, "Must supply an application id");
            op = Operation.REMOVE;
            this.context = context;

            return new DefaultFilteringObjective(this);
        }

    }

}