package org.gcube.data.access.storagehub.handlers.plugins;

import java.util.HashMap;
import java.util.Map;

import javax.annotation.PostConstruct;
import javax.enterprise.inject.Instance;
import javax.inject.Inject;
import javax.inject.Singleton;

import org.gcube.common.storagehub.model.exceptions.PluginNotFoundException;
import org.gcube.common.storagehub.model.items.nodes.PayloadBackend;
import org.gcube.common.storagehub.model.storages.StorageBackendFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Singleton
public class StorageBackendHandler {

	private static Logger log = LoggerFactory.getLogger(StorageBackendHandler.class);
	
	@Inject
	Instance<StorageBackendFactory> factories;
		
	Map<String, StorageBackendFactory> storagebackendMap= new HashMap<String, StorageBackendFactory>();
	
	@PostConstruct
	void init(){
		if (factories !=null) 
			for (StorageBackendFactory connector : factories) {
				if (storagebackendMap.containsKey(connector.getName())) {
					log.error("multiple storage backend with the same name");
					throw new RuntimeException("multiple storage backend with the same name");
				}
				storagebackendMap.put(connector.getName(), connector);
				
			}
		else 
			throw new RuntimeException("storage backend implementation not found");
	}

	public StorageBackendFactory get(PayloadBackend payload) throws PluginNotFoundException {
		if (payload == null ||  !storagebackendMap.containsKey(payload.getStorageName())) 
			throw new PluginNotFoundException(String.format("implementation for storage %s not found", payload.getStorageName()));
		return storagebackendMap.get(payload.getStorageName());
	}
	
}