package foundation.variant.provider;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;

import foundation.json.IJSONProvider;
import foundation.json.IJSONWriter;

public class VariantCenter implements IJSONProvider {

	private static Object lock = new Object();
	private static VariantCenter instance;
	private static Map<String, IVariantGuide> listenerMap;
	private static Set<String> QAlistenerSet;
	private static TreeSet<VariantProviderInfo> namedListenerInfoSet;
	private static TreeSet<VariantProviderInfo> QAListenerInfoSet;
	
	
	private VariantCenter() {
		listenerMap = new HashMap<String, IVariantGuide>();
		QAlistenerSet = new HashSet<String>();
		
		namedListenerInfoSet = new TreeSet<VariantProviderInfo>();
		QAListenerInfoSet = new TreeSet<VariantProviderInfo>();
	}
	
	public static VariantCenter getInstance() {
		if (instance == null) {
			synchronized(lock) {
				try {
					if (instance == null) {
						instance = new VariantCenter();
					}
				}
				catch(Exception e) {
					e.printStackTrace();
				}
			}
		}
		
		return instance;
	}
	
	public static Object getValue(DataEvent dataEvent, String variantName, IVariantsProvider... providers) {
		if (variantName == null) { 
			return null;
		}
		
		Object result = null;
		
		variantName = variantName.toLowerCase();
		IVariantGuide guide = listenerMap.get(variantName);
		
		//1. 
		if (guide != null) {
			result = guide.getValue(dataEvent, variantName, providers);
			return result;
		}
		
		//2. 
		if (providers == null || providers.length == 0) {
			return result;
		}
		
		for (IVariantsProvider provider: providers) {
			if (provider == null) {
				continue;
			}
			
			String providerName = provider.getProviderName();
			providerName = providerName.toLowerCase();
			
			if (QAlistenerSet.contains(providerName)) {
				if (provider.containsVariant(variantName)) {
					result = provider.getVariantValue(dataEvent, variantName);
					break;
				}
			}
		}
		
		return result;
	}
	
	public static String getStringValue(DataEvent dataEvent, String variantName, IVariantsProvider... providers) {
		Object value = getValue(dataEvent, variantName, providers);
		
		if (value == null) {
			return null;
		}
		
		if (value instanceof String) {
			return (String)value;
		}
		
		return String.valueOf(value);
	}

	public void registPersist(Set<String> variantNames, IVariantsProvider provider) {
		if (variantNames == null) {
			return;
		}
		
		for (String name: variantNames) {
			if (name == null) {
				continue;
			}
			
			String lower = name.toLowerCase();
			PersistGuide guide = new PersistGuide(provider);
			
			listenerMap.put(lower, guide);
			namedListenerInfoSet.add(new VariantProviderInfo("PersistProvider", name, guide.getVariantProvider().getClass()));
		}
	}
	
	public void registTransiant(Set<String> variantNames, String providerName, Class<?> clazz) {
		if (variantNames == null) {
			return;
		}
		
		for (String name: variantNames) {
			if (name == null) {
				continue;
			}
			
			String lower = name.toLowerCase();
			TransiantGuide guide = new TransiantGuide(providerName);
			
			listenerMap.put(lower, guide);
			namedListenerInfoSet.add(new VariantProviderInfo("TransiantProvider", name, clazz));
		}
	}

	public void registQAProvider(String providerName, Class<?> clazz) {
		if (providerName == null) {
			return;
		}
		
		String lower = providerName.toLowerCase();
		
		QAlistenerSet.add(lower);
		QAListenerInfoSet.add(new VariantProviderInfo("Q&A", "", clazz));
	}

	public static Map<String, IVariantGuide> getListenerMap() {
		return listenerMap;
	}

	public static Set<String> getQAlistenerSet() {
		return QAlistenerSet;
	}

	@Override
	public void writeJSON(IJSONWriter writer) {
		writer.beginObject();
		
		//1. named listener
		writer.beginArray("namedListeners");
		for (VariantProviderInfo providerInfo: namedListenerInfoSet) {
			writer.beginObject();
			writer.write("type", providerInfo.getTypeCode());
			writer.write("variant", providerInfo.getVariantName());
			writer.write("provider", providerInfo.getClassName());
			writer.endObject();
		}
		writer.endArray();
		
		//2. QA listener
		writer.beginArray("qaListeners");
		for (VariantProviderInfo providerInfo: QAListenerInfoSet) {
			writer.beginObject();
			writer.write("type", providerInfo.getTypeCode());
			writer.write("variant", providerInfo.getVariantName());
			writer.write("provider", providerInfo.getClassName());
			writer.endObject();
		}	
		writer.endArray();		
		
		writer.endObject();
	}
	
}