001/*
002 * Copyright 2015 SirWellington Tech.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANYTIME KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package tech.sirwellington.alchemy.test.junit.runners;
018
019import java.lang.annotation.Retention;
020import java.lang.annotation.Target;
021import java.time.Instant;
022import tech.sirwellington.alchemy.annotations.access.Internal;
023import tech.sirwellington.alchemy.annotations.access.NonInstantiable;
024import tech.sirwellington.alchemy.generator.AlchemyGenerator;
025import tech.sirwellington.alchemy.generator.TimeGenerators;
026
027import static java.lang.annotation.ElementType.FIELD;
028import static java.lang.annotation.RetentionPolicy.RUNTIME;
029import static tech.sirwellington.alchemy.test.Checks.Internal.checkNotNull;
030import static tech.sirwellington.alchemy.test.Checks.Internal.checkThat;
031
032/**
033 * Used in with the {@link AlchemyTestRunner}, this Annotations allows the Runtime Injection of 
034 * Generated {@linkplain Instant Instants}  using {@link TimeGenerators} from the {@link AlchemyGenerator} library.
035 *
036 * Example:
037 * <pre>
038 * {@code
039 * `@RunWith(AlchemyTestRunner.class)
040 * public class ExampleTest
041 * {
042 *   `@GenerateInstant(ANYTIME)
043 *    private Instant timeOfOrder;
044 *
045 *    ...
046 * }
047 * }
048 * </pre> 
049 * Note, ticks (`) used to escape Javadocs. 
050 * 
051 * @see GenerateString
052 * @see GenerateDate
053 * 
054 * @author SirWellington
055 */
056@Target(FIELD)
057@Retention(RUNTIME)
058public @interface GenerateInstant
059{
060
061    Type value() default Type.ANYTIME;
062
063    /**
064     * If using the {@link Type#RANGE} type, specify a beginning time, in Epoch Millis.
065     *
066     * @return
067     */
068    long startTime() default 0;
069
070    /**
071     * If using the {@link Type#RANGE} type, specify an end time, in Epoch Millis.
072     *
073     * @return
074     */
075    long endTime() default 0;
076
077    public enum Type
078    {
079        PAST,
080        PRESENT,
081        FUTURE,
082        ANYTIME,
083        RANGE
084    }
085
086    @Internal
087    @NonInstantiable
088    static class Values
089    {
090
091        private Values() throws IllegalAccessException
092        {
093            throw new IllegalAccessException("cannot instantiate");
094        }
095
096        static AlchemyGenerator<Instant> createGeneratorFor(GenerateInstant annotation) throws IllegalArgumentException
097        {
098            checkNotNull(annotation, "missing annotation");
099
100            switch (annotation.value())
101            {
102                case PAST:
103                    return TimeGenerators.pastInstants();
104                case PRESENT:
105                    return TimeGenerators.presentInstants();
106                case FUTURE:
107                    return TimeGenerators.futureInstants();
108                case ANYTIME:
109                    return TimeGenerators.anytime();
110                case RANGE:
111                    return timesInRange(annotation.startTime(), annotation.endTime());
112                default:
113                    return TimeGenerators.anytime();
114            }
115        }
116
117        private static AlchemyGenerator<Instant> timesInRange(long startTime, long endDate)
118        {
119            checkThat(startTime < endDate, "startDate must come before endDate");
120            
121            Instant start = Instant.ofEpochMilli(startTime);
122            Instant end = Instant.ofEpochMilli(endDate);
123            
124            return TimeGenerators.timesBetween(start, end);
125        }
126    }
127
128}