Dimension.java

package de.zalando.toga.generator.dimensions;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.TextNode;

import java.util.ArrayList;
import java.util.List;

import static java.util.stream.Collectors.toList;

public abstract class Dimension {

    private enum Type {
        OBJECT,
        STRING,
        ENUM
    }

    protected final String name;
    protected final List<String> values = new ArrayList<>();


    public Dimension(String name) {
        this.name = name;
    }

    public static Dimension from(String name, JsonNode node) {

        Type type = deriveType(node);

        switch (type) {
            case OBJECT:
                return new ObjectDimension(name, node);
            case STRING:
                return new StringDimension(name, node);
            case ENUM:
                return new EnumDimension(name, node);
            default:
                throw new IllegalArgumentException("JSON attribute with type [" + type + "] is not supported.");
        }
    }

    private static Type deriveType(JsonNode node) {
        JsonNode typeNode = node.path("type");
        if (typeNode.isMissingNode() || !typeNode.isValueNode()) {
            JsonNode enumNode = node.path("enum");

            if (!enumNode.isMissingNode() && enumNode.isArray()) {
                return Type.ENUM;
            }

            throw new IllegalArgumentException("Could not derive type from node [" + node.toString() + "].");
        }

        return Type.valueOf(typeNode.asText().toUpperCase());
    }

    public String getFieldName() {
        return name;
    }

    /**
     * Generate a list of JSON representations of the dimension.
     * This generated JSON is intended to be combined into JSON objects right away without further modification.
     * 
     * @return a list of json representations with all the different options the dimension contains.
     */
    public List<JsonNode> getValueDimensions() {
        return values.stream().map(TextNode::valueOf).collect(toList());
    };
}