de.rwth.swc.coffee4j.model.Combination Maven / Gradle / Ivy

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package de.rwth.swc.coffee4j.model;

import de.rwth.swc.coffee4j.engine.util.Preconditions;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.stream.Collectors;

/**
 * A encapsulation of a mapping from {@link Parameter} to {@link Value}. Can be used to represent an arbitrary
 * combination or a test input.
 */
public final class Combination {
    
    private final Map parameterValueMap;
    
    /**
     * Creates a new combination with the mappings.
     *
     * @param parameterValueMap the mapping. Must not be, nor contain as key or value {@code null}. All values
     *                          to which parameters are mapped must come out of the respective parameters
     */
    public Combination(Map parameterValueMap) {
        Preconditions.notNull(parameterValueMap);
        Preconditions.check(!parameterValueMap.containsKey(null));
        Preconditions.check(!parameterValueMap.containsValue(null));
        assertValidValues(parameterValueMap);
        
        this.parameterValueMap = new HashMap<>(parameterValueMap);
    }
    
    private static void assertValidValues(Map parameterValueMap) {
        for (Map.Entry mapping : parameterValueMap.entrySet()) {
            Preconditions.check(mapping.getKey().getValues().contains(mapping.getValue()));
        }
    }
    
    /**
     * Retrieves the value of the specific parameter.
     *
     * @param parameter a parameter
     * @return the value to which this parameter is mapped or {@code null} if it is not mapped
     */
    public Value getValue(Parameter parameter) {
        return parameterValueMap.get(parameter);
    }
    
    /**
     * Retrives the value of the parameter corresponding to the name.
     *
     * @param parameterName the name of a parameter. Should be unique in the combination
     * @return the value to which the parameter with this name i mapped or {@code null} if there is not parameter
     * with this name
     */
    public Value getValue(String parameterName) {
        for (Map.Entry mapping : parameterValueMap.entrySet()) {
            if (mapping.getKey().getName().equals(parameterName)) {
                return mapping.getValue();
            }
        }
        
        return null;
    }
    
    /**
     * The same as {@link #getValue(Parameter)} only with {@link Value#get()} begin called afterwards.
     *
     * @param parameter a parameter
     * @return the raw object value to which this parameter is mapped or {@code null} if it is not mapped. This may be
     * ambiguous as {@code null} can also be a valid value object
     */
    public Object getRawValue(Parameter parameter) {
        Preconditions.check(parameterValueMap.containsKey(parameter));
        
        return parameterValueMap.get(parameter).get();
    }
    
    /**
     * The same as {@link #getValue(Parameter)} only with {@link Value#get()} begin called afterwards.
     *
     * @param parameterName the name of a parameter. Should be unique in the combination
     * @return the raw object value to which this parameter is mapped or {@code null} if it is not mapped. This may be
     * ambiguous as {@code null} can also be a valid value object
     */
    public Object getRawValue(String parameterName) {
        for (Map.Entry mapping : parameterValueMap.entrySet()) {
            if (mapping.getKey().getName().equals(parameterName)) {
                return mapping.getValue().get();
            }
        }
        
        throw new IllegalArgumentException("There is no parameter with the name " + parameterName);
    }
    
    /**
     * @return a copy of the complete map of all parameter value mappings
     */
    public Map getParameterValueMap() {
        return Collections.unmodifiableMap(parameterValueMap);
    }
    
    /**
     * @return the number of parameters which are mapped to a value
     */
    public int size() {
        return parameterValueMap.size();
    }
    
    @Override
    public boolean equals(Object object) {
        if (this == object) {
            return true;
        }
        if (object == null || getClass() != object.getClass()) {
            return false;
        }
        
        final Combination other = (Combination) object;
        return Objects.equals(parameterValueMap, other.parameterValueMap);
    }
    
    @Override
    public int hashCode() {
        return Objects.hash(parameterValueMap);
    }
    
    @Override
    public String toString() {
        return "Combination{" + parameterValueMap.entrySet().stream().map(entry -> entry.getKey().getName() + "=" + entry.getValue().toString()).collect(Collectors.joining(", ")) + '}';
    }
    
    public static Builder combination() {
        return new Builder();
    }
    
    /**
     * Realization of the builder pattern for the {@link Combination} class. Entry point is {@link #combination()}.
     */
    public static final class Builder {
        
        private final Map parameterValueMap = new HashMap<>();
        
        /**
         * Adds a mapping from a parameter to a value to this combination.
         *
         * @param parameter the parameter. Must not be {@code null}
         * @param value     the value to which the parameter is mapped. Must not ben {@code null}
         * @return this
         */
        public Builder value(Parameter parameter, Value value) {
            Preconditions.notNull(parameter);
            Preconditions.notNull(value);
            
            parameterValueMap.put(parameter, value);
            
            return this;
        }
        
        /**
         * Builds the complete combination out of the parameter mappings.
         *
         * @return the constructed combination
         */
        public Combination build() {
            return new Combination(parameterValueMap);
        }
        
    }
    
}