/*
 * Copyright 2002-2018 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.cache.interceptor;

import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Set;

import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * Base class for cache operations.
 *
 * @author Costin Leau
 * @author Stephane Nicoll
 * @author Marcin Kamionowski
 * @since 3.1
 */
public abstract class CacheOperation implements BasicOperation {

        private final String name;

        private final Set<String> cacheNames;

        private final String key;

        private final String keyGenerator;

        private final String cacheManager;

        private final String cacheResolver;

        private final String condition;

        private final String toString;


        /**
         * Create a new {@link CacheOperation} instance from the given builder.
         * @since 4.3
         */
        protected CacheOperation(Builder b) {
                this.name = b.name;
                this.cacheNames = b.cacheNames;
                this.key = b.key;
                this.keyGenerator = b.keyGenerator;
                this.cacheManager = b.cacheManager;
                this.cacheResolver = b.cacheResolver;
                this.condition = b.condition;
                this.toString = b.getOperationDescription().toString();
        }


        public String getName() {
                return this.name;
        }

        @Override
        public Set<String> getCacheNames() {
                return this.cacheNames;
        }

        public String getKey() {
                return this.key;
        }

        public String getKeyGenerator() {
                return this.keyGenerator;
        }

        public String getCacheManager() {
                return this.cacheManager;
        }

        public String getCacheResolver() {
                return this.cacheResolver;
        }

        public String getCondition() {
                return this.condition;
        }


        /**
         * This implementation compares the {@code toString()} results.
         * @see #toString()
         */
        @Override
        public boolean equals(@Nullable Object other) {
                return (other instanceof CacheOperation && toString().equals(other.toString()));
        }

        /**
         * This implementation returns {@code toString()}'s hash code.
         * @see #toString()
         */
        @Override
        public int hashCode() {
                return toString().hashCode();
        }

        /**
         * Return an identifying description for this cache operation.
         * <p>Returned value is produced by calling {@link Builder#getOperationDescription()}
         * during object construction. This method is used in {@link #hashCode} and
         * {@link #equals}.
         * @see Builder#getOperationDescription()
         */
        @Override
        public final String toString() {
                return this.toString;
        }


        /**
         * Base class for builders that can be used to create a {@link CacheOperation}.
         * @since 4.3
         */
        public abstract static class Builder {

                private String name = "";

                private Set<String> cacheNames = Collections.emptySet();

                private String key = "";

                private String keyGenerator = "";

                private String cacheManager = "";

                private String cacheResolver = "";

                private String condition = "";

                public void setName(String name) {
                        Assert.hasText(name, "Name must not be empty");
                        this.name = name;
                }

                public void setCacheName(String cacheName) {
                        Assert.hasText(cacheName, "Cache name must not be empty");
                        this.cacheNames = Collections.singleton(cacheName);
                }

                public void setCacheNames(String... cacheNames) {
                        this.cacheNames = new LinkedHashSet<>(cacheNames.length);
                        for (String cacheName : cacheNames) {
                                Assert.hasText(cacheName, "Cache name must be non-empty if specified");
                                this.cacheNames.add(cacheName);
                        }
                }

                public Set<String> getCacheNames() {
                        return this.cacheNames;
                }

                public void setKey(String key) {
                        Assert.notNull(key, "Key must not be null");
                        this.key = key;
                }

                public String getKey() {
                        return this.key;
                }

                public String getKeyGenerator() {
                        return this.keyGenerator;
                }

                public String getCacheManager() {
                        return this.cacheManager;
                }

                public String getCacheResolver() {
                        return this.cacheResolver;
                }

                public void setKeyGenerator(String keyGenerator) {
                        Assert.notNull(keyGenerator, "KeyGenerator name must not be null");
                        this.keyGenerator = keyGenerator;
                }

                public void setCacheManager(String cacheManager) {
                        Assert.notNull(cacheManager, "CacheManager name must not be null");
                        this.cacheManager = cacheManager;
                }

                public void setCacheResolver(String cacheResolver) {
                        Assert.notNull(cacheResolver, "CacheResolver name must not be null");
                        this.cacheResolver = cacheResolver;
                }

                public void setCondition(String condition) {
                        Assert.notNull(condition, "Condition must not be null");
                        this.condition = condition;
                }

                /**
                 * Return an identifying description for this caching operation.
                 * <p>Available to subclasses, for inclusion in their {@code toString()} result.
                 */
                protected StringBuilder getOperationDescription() {
                        StringBuilder result = new StringBuilder(getClass().getSimpleName());
                        result.append("[").append(this.name);
                        result.append("] caches=").append(this.cacheNames);
                        result.append(" | key='").append(this.key);
                        result.append("' | keyGenerator='").append(this.keyGenerator);
                        result.append("' | cacheManager='").append(this.cacheManager);
                        result.append("' | cacheResolver='").append(this.cacheResolver);
                        result.append("' | condition='").append(this.condition).append("'");
                        return result;
                }

                public abstract CacheOperation build();
        }

}