package ejava.examples.ejbwar.customer.client;
   
   import java.net.URI;
   
   
   import javax.ws.rs.core.HttpHeaders;
   import javax.ws.rs.core.MediaType;
   import javax.ws.rs.core.Response;
   import javax.ws.rs.core.UriBuilder;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.http.HttpResponse;
  import org.apache.http.client.HttpClient;
  import org.apache.http.client.methods.HttpDelete;
  import org.apache.http.client.methods.HttpGet;
  import org.apache.http.client.methods.HttpPost;
  import org.apache.http.entity.StringEntity;
  import org.apache.http.util.EntityUtils;
  
  import ejava.examples.ejbwar.customer.bo.Customer;
  import ejava.examples.ejbwar.customer.bo.CustomerRepresentation;
  import ejava.examples.ejbwar.customer.bo.Customers;
  import ejava.examples.ejbwar.customer.rs.CustomersResource;
  
  /**
   * This class implements an HTTP Client interface to the customer 
   * web application. All commands are through HTTP POST, GET, PUT, and DELETE
   * methods to specific resource URIs for products and categories.
   */
  public class CustomerClientImpl implements CustomerClient {
  	private static final Log log = LogFactory.getLog(CustomerClientImpl.class);
  	private HttpClient client;
  	/**
  	 * Defines the HTTP URL for the WAR that hosts the JAX-RS resources.
  	 */
  	private URI appURI;
  
  	public void setHttpClient(HttpClient client) {
  		this.client = client;
  	}
  	public void setAppURI(URI appURI) {
  		this.appURI = appURI;
  	}	
  	
  	/**
  	 * Helper method that returns a URIBuilder fully initialized to point
  	 * to the URI that will reach the specified method within the inventory
  	 * resource classes.
  	 * @param resourceClass
  	 * @param method
  	 * @return
  	 */
  	protected <T> UriBuilder buildURI(Class<T> resourceClass, String method) {
  		//start with the URI for the WAR deployed to the server 
  		//that ends with the context-root
  		return UriBuilder.fromUri(appURI)
  				//add path info from the 
  				//javax.ws.rs.core.Application @ApplicationPath
  				.path("rest")
  				//add in @Path added by resource class
  				.path(resourceClass)
  				//add in @Path added by resource class' method
  				.path(resourceClass,method);
  				//the result will be a URI template that 
  				//must be passed arguments by the caller during build()
  	}
  
  	@Override
  	public Customer addCustomer(Customer customer) throws Exception {
  		URI uri = buildURI(CustomersResource.class,"addCustomer")
  				.build();
  			
  		//build overall request
  		HttpPost post = new HttpPost(uri);
  		post.addHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_XML);
  		post.setEntity(new StringEntity(customer.toString(), "UTF-8"));
  		
  		//issue request and look for OK with entity
  		HttpResponse response = client.execute(post);
  		log.info(String.format("%s %s", post.getURI(), response));
  		if (Response.Status.CREATED.getStatusCode() == response.getStatusLine().getStatusCode()) {
  			return CustomerRepresentation.unmarshall(Customer.class,
  					response.getEntity().getContent());
  		}
  		log.warn(EntityUtils.toString(response.getEntity()));
  		return null;
  	}
  
  	@Override
  	public Customers findCustomersByName(String firstName, String lastName, int offset, int limit) throws Exception {
  		//build a URI to the specific method that is hosted within the app
  		URI uri = buildURI(CustomersResource.class,"findCustomersByName")
  				//marshall @QueryParams into URI
  				.queryParam("firstName", firstName)
  				.queryParam("lastName", lastName)
  				.queryParam("offset", offset)
  				.queryParam("limit", limit)
  				.build();
 		
 		//build the overall request 
 		HttpGet get = new HttpGet(uri);
 		get.addHeader(HttpHeaders.ACCEPT, MediaType.APPLICATION_XML);
 		
 		//issue request and look for an OK response with entity
 		HttpResponse response = client.execute(get);
 		log.info(String.format("%s %s", get.getURI(), response));
 		if (Response.Status.OK.getStatusCode() == response.getStatusLine().getStatusCode()) {
 			return CustomerRepresentation.unmarshall(Customers.class,
 					response.getEntity().getContent());
 		}
 		log.warn(EntityUtils.toString(response.getEntity()));
 		return null;
 	}
 	
 	@Override
 	public Customer getCustomer(int id) throws Exception {
 		URI uri = buildURI(CustomersResource.class,"getCustomer")
 				//marshall @PathParm into the URI
 				.build(id);
 		
 		//build the overall request
 		HttpGet get = new HttpGet(uri);
 
 		//execute request and look for an OK response without an entity
 		HttpResponse response = client.execute(get);
 		log.info(String.format("%s %s", get.getURI(), response));
 		if (Response.Status.OK.getStatusCode() == response.getStatusLine().getStatusCode()) {
 			return CustomerRepresentation.unmarshall(Customer.class,
 					response.getEntity().getContent());
 		}
 		log.warn(EntityUtils.toString(response.getEntity()));
 		return null;
 	}
 
 	@Override
 	public boolean deleteCustomer(int id) throws Exception {
 		URI uri = buildURI(CustomersResource.class,"deleteCustomer")
 				//marshall @PathParm into the URI
 				.build(id);
 		
 		//build the overall request
 		HttpDelete delete = new HttpDelete(uri);
 
 		//execute request and look for an OK response without an entity
 		HttpResponse response = client.execute(delete);
 		log.info(String.format("%s %s", delete.getURI(), response));
 		if (Response.Status.OK.getStatusCode() == response.getStatusLine().getStatusCode()) {
 			EntityUtils.consume(response.getEntity());
 			return true;
 		}
 		log.warn(EntityUtils.toString(response.getEntity()));
 		return false;
 	}
 }