package pt.linkare.ant.propreaders;

import java.io.UnsupportedEncodingException;
import java.util.Collection;
import java.util.HashMap;

import pt.linkare.ant.InputProperty;
import pt.linkare.ant.InvalidPropertySpecException;
import pt.linkare.ant.NoPropertyReaderException;

public class PropertyReaderManager {

	private boolean debug=false;
	
	private String propertyCryptPassword=null;
	
	private String encoding="iso-8859-1";
	
	public String getEncoding() {
		return encoding;
	}
	public void setEncoding(String encoding) {
		this.encoding = encoding;
	}
	private PropertyReaderManager(String encoding) {
		super();
		setEncoding(encoding);
	}
	
	private static PropertyReaderManager instance=null;
	private String additionalPackageForPropertyReaders=null;
	
	public static PropertyReaderManager getInstance(boolean debug,String encoding)
	{
		if(instance==null)
			instance=new PropertyReaderManager(encoding);
		instance.setDebug(debug);
		return instance;
	}
	public static PropertyReaderManager getInstance(String encoding)
	{
		if(instance==null)
			instance=new PropertyReaderManager(encoding);
		return instance;
	}
	
	private HashMap<String, PropertyReader> registeredPropertyReaders=new HashMap<String, PropertyReader>();
	
	
	private static Class getClassForPropertyTypeFromSystemProperty(String type)
	{
		String className=System.getProperty("property.reader."+type);
		if(className==null) return null;
		try
		{
			Class cPropReader=Class.forName(className);
			if(PropertyReader.class.isAssignableFrom(cPropReader))
				return cPropReader;
			else
				return null;
		}catch (Exception e) {
			return null;
		}
	}
	
	private static Class getClassForPropertyTypeFromClassPath(String type)
	{	
		String className=PropertyReader.class.getPackage().getName()+"."+capitalize(type)+"PropertyReader";
		try
		{
			Class cPropReader=Class.forName(className);
			if(PropertyReader.class.isAssignableFrom(cPropReader))
				return cPropReader;
			else
				return null;
		}catch (Exception e) {
			return null;
		}
		
	}
	
	private static Class getClassForPropertyTypeFromAdditionalPackage(String type,String encoding) {
		String packagePrefix=getInstance(encoding).getAdditionalPackageForPropertyReaders();
		if(packagePrefix==null)
			return null;
		String className=packagePrefix+"."+capitalize(type)+"PropertyReader";
		try
		{
			Class cPropReader=Class.forName(className);
			if(PropertyReader.class.isAssignableFrom(cPropReader))
				return cPropReader;
			else
				return null;
		}catch (Exception e) {
			return null;
		}
	}
	
	private static Class getClassForPropertyType(String type,String encoding)
	{
		Class c=getClassForPropertyTypeFromSystemProperty(type);
		if(c==null)
		{
			c=getClassForPropertyTypeFromClassPath(type);
		}
		if(c==null)
		{
			c=getClassForPropertyTypeFromAdditionalPackage(type,encoding);
		}
		return c;
	}
	
	

	private static PropertyReader getPropertyReaderForType(String type,String encoding)
	{
		if(getInstance(encoding).registeredPropertyReaders.containsKey(type))
			return getInstance(encoding).registeredPropertyReaders.get(type);
	
		Class cPropReader=getClassForPropertyType(type,encoding);
		if(cPropReader!=null)
		{
			PropertyReader reader;
			try {
				reader = (PropertyReader)cPropReader.newInstance();
				getInstance(encoding).registeredPropertyReaders.put(type, reader);
				reader.setDebug(getInstance(encoding).isDebug());
				return reader;
			}
			catch (InstantiationException e) {
				System.out.println("Unable to instantiate class "+cPropReader.getName());
			}
			catch (IllegalAccessException e) {
				System.out.println("Illegal access trying to instantiate class "+cPropReader.getName());
			}
			catch(ClassCastException e)
			{
				System.out.println("Class "+cPropReader.getName()+" is not of type PropertyReader");
			}
			
			return null;
		}
		else
			return null;
			
	}
	
	private static String capitalize(String name)
	{
		if(name==null || name.length()==0) return name;
		return name.substring(0,1).toUpperCase()+name.substring(1);
	}
	
	public Collection<InputProperty> readProperty(InputProperty prop,boolean fromDefault) throws InvalidPropertySpecException,NoPropertyReaderException, UnsupportedEncodingException
	{
		if(prop!=null)
		{
				PropertyReader propReader=getPropertyReaderForType(prop.getPropertyType(),encoding);
				if(propReader==null)
					throw new NoPropertyReaderException("No property reader available for property of type "+prop.getPropertyType());
				propReader.setProperty(prop);
				propReader.setEncoding(getEncoding());
				return propReader.readPropertyValue(fromDefault);
			
		}
		else
			throw new RuntimeException("Trying to read null property");
	}

	/**
	 * @return Returns the additionalPackageForPropertyReaders.
	 */
	public String getAdditionalPackageForPropertyReaders() {
		return additionalPackageForPropertyReaders;
	}

	/**
	 * @param additionalPackageForPropertyReaders The additionalPackageForPropertyReaders to set.
	 */
	public void setAdditionalPackageForPropertyReaders(String additionalPackageForPropertyReaders) {
		this.additionalPackageForPropertyReaders = additionalPackageForPropertyReaders;
	}

	/**
	 * @return Returns the debug.
	 */
	public boolean isDebug() {
		return debug;
	}

	/**
	 * @param debug The debug to set.
	 */
	public void setDebug(boolean debug) {
		this.debug = debug;
	}
	public String getPropertyCryptPassword() {
		return propertyCryptPassword;
	}
	public void setPropertyCryptPassword(String propertyCryptPassword) {
		this.propertyCryptPassword = propertyCryptPassword;
	}
	
	
}