package org.cyclopsgroup.jmxterm.io;
   
   import org.apache.commons.lang3.StringUtils;
   import org.apache.commons.lang3.Validate;
   
   import javax.management.openmbean.CompositeData;
   import java.lang.reflect.Array;
   import java.util.Collection;
   import java.util.Map;
  
  /**
   * A utility to print out object values in particular format.
   * 
   * @author <a href="mailto:jiaqi.guo@gmail.com">Jiaqi Guo</a>
   */
  public class ValueOutputFormat {
    private final int indentSize;
  
    private final boolean showDescription;
  
    private final boolean showQuotationMarks;
  
    /**
     * Default constructor with indentiation = 2, showDescription and showQuotationMarks are both true
     */
    public ValueOutputFormat() {
      this(2, true, true);
    }
  
    /**
     * @param indentSize Size of indentation
     * @param showDescription True if value description is printed
     * @param showQuotationMarks True if quotation mark is printed
     */
    public ValueOutputFormat(int indentSize, boolean showDescription, boolean showQuotationMarks) {
      Validate.isTrue(indentSize >= 0, "Invalid indent size value " + indentSize);
      this.indentSize = indentSize;
      this.showDescription = showDescription;
      this.showQuotationMarks = showQuotationMarks;
    }
  
    /**
     * Print out equal expression of an variable with description
     * 
     * @param output Output to print to
     * @param name Name of variable
     * @param value Value of variable
     * @param description Description of variable
     */
    public void printExpression(CommandOutput output, Object name, Object value, String description) {
      printExpression(output, name, value, description, 0);
    }
  
    /**
     * Print out equal expression of an variable with description
     * 
     * @param output Output to print to
     * @param name Name of variable
     * @param value Value of variable
     * @param description Description of variable
     * @param indent Starting indent position
     */
    private void printExpression(CommandOutput output, Object name, Object value, String description,
        int indent) {
      output.print(StringUtils.repeat(" ", indent));
      printValue(output, name, indent);
      output.print(" = ");
      printValue(output, value, indent);
      output.print(";");
      if (showDescription && description != null) {
        output.print(" (" + description + ")");
      }
      output.println("");
    }
  
    /**
     * @param output Output writer where value is printed to
     * @param value Value to print
     */
    public void printValue(CommandOutput output, Object value) {
      printValue(output, value, 0);
    }
  
    /**
     * Print out expression of given value considering various possible types of value
     * 
     * @param output Output writer where value is printed
     * @param value Object value which can be anything
     * @param indent Starting indentation length
     */
    private void printValue(CommandOutput output, Object value, int indent) {
      if (value == null) {
        output.print("null");
      } else if (value.getClass().isArray()) {
        int length = Array.getLength(value);
        output.print("[ ");
        for (int i = 0; i < length; i++) {
          if (i != 0) {
            output.print(", ");
         }
         printValue(output, Array.get(value, i), indent);
       }
       output.print(" ]");
     } else if (Collection.class.isAssignableFrom(value.getClass())) {
       boolean start = true;
       output.print("( ");
       for (Object obj : ((Collection<?>) value)) {
         if (!start) {
           output.print(", ");
         }
         start = false;
         printValue(output, obj, indent);
       }
       output.print(" )");
     } else if (Map.class.isAssignableFrom(value.getClass())) {
       output.println("{ ");
       for (Map.Entry<?, ?> entry : ((Map<?, ?>) value).entrySet()) {
         printExpression(output, entry.getKey(), entry.getValue(), null, indent + indentSize);
       }
       output.print(StringUtils.repeat(" ", indent) + " }");
     } else if (CompositeData.class.isAssignableFrom(value.getClass())) {
       output.println("{ ");
       CompositeData data = (CompositeData) value;
       for (Object key : data.getCompositeType().keySet()) {
         Object v = data.get((String) key);
         printExpression(output, key, v, data.getCompositeType().getDescription((String) key),
             indent + indentSize);
       }
       output.print(StringUtils.repeat(" ", indent) + " }");
     } else if (value instanceof String && showQuotationMarks) {
       output.print("\"" + value + "\"");
     } else {
       output.print(value.toString());
     }
   }
 }