/*
 * 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.ignite.spi.tracing;

import org.apache.ignite.internal.util.typedef.internal.S;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

/**
 * Specifies to which traces, specific configuration will be applied. In other words it's a sort of tracing
 * configuration locator.
 */
public class TracingConfigurationCoordinates {
    /**
     * Specifies the {@link Scope} of a trace's root span to which some specific tracing configuration will be applied.
     * It's a mandatory attribute.
     */
    private final Scope scope;

    /**
     * Specifies the label of a traced operation. It's an optional attribute.
     */
    private final String lb;

    /**
     * Private constructor to be used with builder.
     *
     * @param scope scope Specifies the {@link Scope} of a trace's root span to which some specific
     *  tracing configuration will be applied.
     * @param lb Specifies the label of a traced operation.
     */
    private TracingConfigurationCoordinates(@NotNull Scope scope, @Nullable String lb) {
        this.scope = scope;
        this.lb = lb;
    }

    /**
     * @return {@link Scope} of a trace's root span to which some specific tracing configuration will be applied.
     */
    @NotNull public Scope scope() {
        return scope;
    }

    /**
     * @return Label of a traced operation, to which some specific tracing configuration will be applied.
     */
    @Nullable public String label() {
        return lb;
    }

    /** {@inheritDoc} */
    @Override public boolean equals(Object o) {
        if (this == o)
            return true;

        if (o == null || getClass() != o.getClass())
            return false;

        TracingConfigurationCoordinates that = (TracingConfigurationCoordinates)o;

        if (scope != that.scope)
            return false;

        return lb != null ? lb.equals(that.lb) : that.lb == null;
    }

    /** {@inheritDoc} */
    @Override public int hashCode() {
        int res = scope != null ? scope.hashCode() : 0;

        res = 31 * res + (lb != null ? lb.hashCode() : 0);

        return res;
    }

    /** {@inheritDoc} */
    @Override public String toString() {
        return S.toString(TracingConfigurationCoordinates.class, this);
    }

    /**
     * {@code TracingConfigurationCoordinates} builder.
     */
    @SuppressWarnings("PublicInnerClass") public static class Builder {
        /** Counterpart of {@code TracingConfigurationCoordinator}'s scope. */
        private final Scope scope;

        /** Counterpart of {@code TracingConfigurationCoordinator}'s lb. */
        private String lb;

        /**
         * Constructor.
         *
         * @param scope Mandatory scope attribute.
         * @throws IllegalArgumentException if null scope is specified.
         */
        public Builder(Scope scope) {
            if (scope == null)
                throw new IllegalArgumentException("Null scope is not valid for tracing coordinates.");

            this.scope = scope;
        }

        /**
         * Builder method that allows to set optional label attribute.
         *
         * @param lb Label of traced operation. It's an optional attribute.
         * @return Current {@code TracingConfigurationCoordinates} instance.
         */
        public @NotNull Builder withLabel(@Nullable String lb) {
            this.lb = lb;

            return this;
        }

        /**
         * Builder's build() method.
         *
         * @return {@code TracingConfigurationCoordinates} instance.
         */
        public TracingConfigurationCoordinates build() {
            return new TracingConfigurationCoordinates(scope, lb);
        }
    }
}