import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

/**
 * Annotation to simplify output hints and errors for scripts. Hints and errors
 * are directly set in code.
 * 
 * @author Dr. Matthias Wegner
 * @since 2014-11-01
 * 
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface ScriptDocumentation {

	/**
	 * Description of annotation
	 * 
	 * @return text of description
	 */
	public String desc() default "";

	/**
	 * Parameters of parameters
	 * 
	 * @return Array of parameters. Used Syntax should be: parameter - Some text
	 */
	public String[] params();

	/**
	 * Static Helper class to create a String representation of the annotation
	 * 
	 * @author Dr. Matthias Wegner
	 * 
	 */
	public class ServiceDisplay {
		/**
		 * Returns a string of the annotation of given class and method
		 * 
		 * @param clazz
		 *            Class which holds the annotation
		 * @param methodName
		 *            method which should be used
		 * @return String of Service annotation
		 */
		public static String show(Class clazz, String methodName) {
			for (Method method : clazz.getMethods()) {
				if (Modifier.isPublic(method.getModifiers()) && method.getName().equals(methodName)) {
					ScriptDocumentation serviceDescription = method.getAnnotation(ScriptDocumentation.class);
					if (serviceDescription != null) {
						StringBuilder sb = new StringBuilder();
						sb.append(serviceDescription.desc() + ": ");
						String[] params = serviceDescription.params();
						for (int i = 0; i < params.length; i++) {
							sb.append(params[i]);
							if ((i + 1) != params.length) {
								sb.append(", ");
							}
						}

						return sb.toString();
					}
				}
			}
			return "";
		}

		/**
		 * String of all annotations in one class
		 * 
		 * @param clazz
		 *            Class to show annotations
		 * @return String of all annotations
		 */
		public static String createString(Class<?> clazz) {
			StringBuilder sb = new StringBuilder();
			sb.append("<h2> Methods of " + clazz.getName() + "</h2>");
			for (Method method : clazz.getMethods()) {
				if (Modifier.isPublic(method.getModifiers())) {
					ScriptDocumentation serviceDescription = method.getAnnotation(ScriptDocumentation.class);
					if (serviceDescription != null) {
						sb.append("*" + method.getName() + " (");
						Class<?>[] parameters = method.getParameterTypes();
						for (int i = 0; i < parameters.length; i++) {
							sb.append(parameters[i].getName());
							if ((i + 1) != parameters.length) {
								sb.append(", ");
							}
						}
						sb.append(")* <BR/>");
						sb.append("~~" + serviceDescription.desc() + "~~ <BR/>");
						sb.append("<ul>");
						String[] params = serviceDescription.params();
						for (int i = 0; i < params.length; i++) {
							sb.append("<li> " + params[i] + "</li>");
						}
						sb.append("</ul>");
						sb.append("~~returns~~ " + method.getGenericReturnType() + " <BR/>");
						sb.append("----");
						sb.append("<br/>");
					}
				}
			}
			return sb.toString();
		}
	}

}