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// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
// *                                                                                                                         *
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package org.apache.juneau.rest.annotation;

import java.io.*;
import java.util.*;
import java.util.logging.*;

import javax.servlet.*;
import javax.servlet.http.*;

import org.apache.juneau.*;
import org.apache.juneau.dto.swagger.*;
import org.apache.juneau.http.*;
import org.apache.juneau.ini.*;
import org.apache.juneau.internal.*;
import org.apache.juneau.rest.*;
import org.apache.juneau.utils.*;

/**
 * Identifies servlet and REST call lifecycle events which cause {@link RestHook @RestHook}-annotated Java methods
 * to be called.
 */
public enum HookEvent {

	/**
	 * Identifies a method that should be called immediately after the HttpServlet.service(HttpServletRequest, HttpServletResponse)
	 * method is called.
	 *
	 * 
	 * Note that you only have access to the raw request and response objects at this point.
	 *
	 * 

	 * The list of valid parameter types are as follows:
	 * 

	 * 	Servlet request/response objects:
	 * 		
	 * 			{@link HttpServletRequest}
	 * 			
{@link HttpServletResponse}
	 * 		
	 * 
	 *
	 * Example:
	 * 
	 * 	@RestResource(...)
	 * 	public class MyResource extends RestServletDefault {
	 *
	 * 		// Add a request attribute to all incoming requests.
	 * 		@RestHook(START_CALL)
	 * 		public void onStartCall(HttpServletRequest req) {
	 * 			req.setAttribute("foobar", new FooBar());
	 * 		}
	 * 	}
	 * 
	 *
	 * Notes:
	 * 
	 * 	The method should return void although if it does return any value, the value will be ignored.
	 * 	
The method should be public although other visibilities are valid if the security manager allows it.
	 * 	
Static methods can be used.
	 * 	
Multiple START_CALL methods can be defined on a class.
	 * 		
START_CALL methods on parent classes are invoked before START_CALL methods on child classes.
	 * 		
The order of START_CALL method invocations within a class is alphabetical, then by parameter count, then by parameter types.
	 * 	
The method can throw any exception.
	 * 		
{@link RestException RestExceptions} can be thrown to cause a particular HTTP error status code.
	 * 		
All other exceptions cause an HTTP 500 error status code.
	 * 	
Note that if you override a parent method, you probably need to call super.parentMethod(...).
	 * 		
The method is still considered part of the parent class for ordering purposes even though it's
	 * 		overridden by the child class.
	 * 
	 */
	START_CALL,

	/**
	 * Identifies a method that gets called immediately before the @RestMethod annotated method gets called.
	 *
	 * 
	 * At this point, the {@link RestRequest} object has been fully initialized, and all {@link RestGuard} and
	 * {@link RestMatcher} objects have been called.
	 *
	 * 

	 * The list of valid parameter types are as follows:
	 * 

	 * 	Servlet request/response objects:
	 * 		
	 * 			{@link HttpServletRequest}
	 * 			
{@link HttpServletResponse}
	 * 		
	 * 	
Extended request/response objects:
	 * 		
	 * 			{@link RestRequest}
	 * 			
{@link RestResponse}
	 * 		
	 * 	
Header objects:
	 * 		
	 * 			{@link Accept}
	 * 			
{@link AcceptCharset}
	 * 			
{@link AcceptEncoding}
	 * 			
{@link AcceptLanguage}
	 * 			
{@link Authorization}
	 * 			
{@link CacheControl}
	 * 			
{@link Connection}
	 * 			
{@link ContentLength}
	 * 			
{@link ContentType}
	 * 			
{@link org.apache.juneau.http.Date}
	 * 			
{@link Expect}
	 * 			
{@link From}
	 * 			
{@link Host}
	 * 			
{@link IfMatch}
	 * 			
{@link IfModifiedSince}
	 * 			
{@link IfNoneMatch}
	 * 			
{@link IfRange}
	 * 			
{@link IfUnmodifiedSince}
	 * 			
{@link MaxForwards}
	 * 			
{@link Pragma}
	 * 			
{@link ProxyAuthorization}
	 * 			
{@link Range}
	 * 			
{@link Referer}
	 * 			
{@link TE}
	 * 			
{@link UserAgent}
	 * 			
{@link Upgrade}
	 * 			
{@link Via}
	 * 			
{@link Warning}
	 * 			
{@link TimeZone}
	 * 		
	 * 	
Other objects:
	 * 		
	 * 			{@link ResourceBundle}
	 * 			
{@link MessageBundle}
	 * 			
{@link InputStream}
	 * 			
{@link ServletInputStream}
	 * 			
{@link Reader}
	 * 			
{@link OutputStream}
	 * 			
{@link ServletOutputStream}
	 * 			
{@link Writer}
	 * 			
{@link RequestHeaders}
	 * 			
{@link RequestQuery}
	 * 			
{@link RequestFormData}
	 * 			
{@link HttpMethod}
	 * 			
{@link Logger}
	 * 			
{@link JuneauLogger}
	 * 			
{@link RestContext}
	 * 			
{@link org.apache.juneau.parser.Parser}
	 * 			
{@link Locale}
	 * 			
{@link Swagger}
	 * 			
{@link RequestPathMatch}
	 * 			
{@link RequestBody}
	 * 			
{@link ConfigFile}
	 * 			
{@link UriContext}
	 * 			
{@link UriResolver}
	 * 		
	 * 
	 *
	 * Example:
	 * 
	 * 	@RestResource(...)
	 * 	public class MyResource extends RestServletDefault {
	 *
	 * 		// Log the incoming request.
	 * 		@RestHook(PRE_CALL)
	 * 		public void onPreCall(Accept accept, Logger logger) {
	 * 			logger.fine("Accept {0} header found.", accept);
	 * 		}
	 * 	}
	 * 
	 *
	 * Notes:
	 * 
	 * 	The method should return void although if it does return any value, the value will be ignored.
	 * 	
The method should be public although other visibilities are valid if the security manager allows it.
	 * 	
Static methods can be used.
	 * 	
Multiple PRE_CALL methods can be defined on a class.
	 * 		
PRE_CALL methods on parent classes are invoked before PRE_CALL methods on child classes.
	 * 		
The order of PRE_CALL method invocations within a class is alphabetical, then by parameter count, then by parameter types.
	 * 	
The method can throw any exception.
	 * 		
{@link RestException RestExceptions} can be thrown to cause a particular HTTP error status code.
	 * 		
All other exceptions cause an HTTP 500 error status code.
	 * 	
Note that if you override a parent method, you probably need to call super.parentMethod(...).
	 * 		
The method is still considered part of the parent class for ordering purposes even though it's
	 * 		overridden by the child class.
	 * 	
It's advisable not to mess around with the HTTP body itself since you may end up consuming the body
	 * 		before the actual REST method has a chance to use it.
	 * 
	 */
	PRE_CALL,

	/**
	 * Identifies a method that gets called immediately after the @RestMethod annotated method gets called.
	 *
	 * 
	 * At this point, the output object returned by the method call has been set on the response, but
	 * {@link RestConverter RestConverters} have not yet been executed and the response has not yet been written.
	 *
	 * 

	 * The list of valid parameter types are the same as {@link #PRE_CALL}.
	 *
	 * 
Example:
	 * 
	 * 	@RestResource(...)
	 * 	public class MyResource extends RestServletDefault {
	 *
	 * 		// Log the result of the request.
	 * 		@RestHook(POST_CALL)
	 * 		public void onPostCall(RestResponse res, Logger logger) {
	 * 			logger.fine(Output {0} was set on the response.", res.getOutput());
	 * 		}
	 * 	}
	 * 
	 *
	 * Notes:
	 * 
	 * 	The method should return void although if it does return any value, the value will be ignored.
	 * 	
The method should be public although other visibilities are valid if the security manager allows it.
	 * 	
Static methods can be used.
	 * 	
Multiple POST_CALL methods can be defined on a class.
	 * 		
POST_CALL methods on parent classes are invoked before POST_CALL methods on child classes.
	 * 		
The order of POST_CALL method invocations within a class is alphabetical, then by parameter count, then by parameter types.
	 * 	
The method can throw any exception, although at this point it is too late to set an HTTP error status code.
	 * 	
Note that if you override a parent method, you probably need to call super.parentMethod(...).
	 * 		
The method is still considered part of the parent class for ordering purposes even though it's
	 * 		overridden by the child class.
	 * 
	 */
	POST_CALL,

	/**
	 * Identifies a method that gets called right before we exit the servlet service method.
	 *
	 * 
	 * At this point, the output has been written and flushed.
	 *
	 * 

	 * The list of valid parameter types are as follows:
	 * 

	 * 	Servlet request/response objects:
	 * 		
	 * 			{@link HttpServletRequest}
	 * 			
{@link HttpServletResponse}
	 * 		
	 * 
	 *
	 * 
	 * The following attributes are set on the {@link HttpServletRequest} object that can be useful for logging purposes:
	 * 

	 * 	"Exception" - Any exceptions thrown during the request.
	 * 	
"ExecTime" - Execution time of the request.
	 * 
	 *
	 * Example:
	 * 
	 * 	@RestResource(...)
	 * 	public class MyResource extends RestServletDefault {
	 *
	 * 		// Log the time it took to execute the request.
	 * 		@RestHook(END_CALL)
	 * 		public void onEndCall(HttpServletRequest req, Logger logger) {
	 * 			Exception e = (Exception)req.getAttribute("Exception");
	 * 			Long execTime = (Long)req.getAttribute("ExecTime");
	 * 			if (e != null)
	 * 				logger.warn(e, "Request failed in {0}ms.", execTime);
	 * 			else
	 * 				logger.fine("Request finished in {0}ms.", execTime);
	 * 		}
	 * 	}
	 * 
	 *
	 * Notes:
	 * 
	 * 	The method should return void although if it does return any value, the value will be ignored.
	 * 	
The method should be public although other visibilities are valid if the security manager allows it.
	 * 	
Static methods can be used.
	 * 	
Multiple END_CALL methods can be defined on a class.
	 * 		
END_CALL methods on parent classes are invoked before END_CALL methods on child classes.
	 * 		
The order of END_CALL method invocations within a class is alphabetical, then by parameter count, then by parameter types.
	 * 	
The method can throw any exception, although at this point it is too late to set an HTTP error status code.
	 * 	
Note that if you override a parent method, you probably need to call super.parentMethod(...).
	 * 		
The method is still considered part of the parent class for ordering purposes even though it's
	 * 		overridden by the child class.
	 * 
	 */
	END_CALL,

	/**
	 * Identifies a method that gets called during servlet initialization.
	 *
	 * 
	 * This method is called from within the {@link Servlet#init(ServletConfig)} method after the {@link RestConfig}
	 * object has been created and initialized with the annotations defined on the class, but before the
	 * {@link RestContext} object has been created.
	 *
	 * 

	 * The only valid parameter type for this method is {@link RestConfig} which can be used to configure the servlet.
	 *
	 * 

	 * An example of this is the PetStoreResource class that uses an init method to perform initialization
	 * of an internal data structure.
	 *
	 * 
Example:
	 * 
	 * 	@RestResource(...)
	 * 	public class PetStoreResource extends ResourceJena {
	 *
	 * 		// Our database.
	 * 		private Map petDB;
	 *
	 * 		@RestHook(INIT)
	 * 		public void onInit(RestConfig config) throws Exception {
	 * 			// Load our database from a local JSON file.
	 * 			petDB = JsonParser.DEFAULT.parse(getClass().getResourceAsStream("PetStore.json"), LinkedHashMap.class, Integer.class, Pet.class);
	 * 		}
	 * 	}
	 * 
	 *
	 * Notes:
	 * 
	 * 	The method should return void although if it does return any value, the value will be ignored.
	 * 	
The method should be public although other visibilities are valid if the security manager allows it.
	 * 	
Static methods can be used.
	 * 	
Multiple INIT methods can be defined on a class.
	 * 		
INIT methods on parent classes are invoked before INIT methods on child classes.
	 * 		
The order of INIT method invocations within a class is alphabetical, then by parameter count, then by parameter types.
	 * 	
The method can throw any exception causing initialization of the servlet to fail.
	 * 	
Note that if you override a parent method, you probably need to call super.parentMethod(...).
	 * 		
The method is still considered part of the parent class for ordering purposes even though it's
	 * 		overridden by the child class.
	 * 
	 */
	INIT,

	/**
	 * Identifies a method that gets called immediately after servlet initialization.
	 *
	 * 
	 * This method is called from within the {@link Servlet#init(ServletConfig)} method after the {@link RestContext}
	 * object has been created.
	 *
	 * 

	 * The only valid parameter type for this method is {@link RestContext} which can be used to retrieve information
	 * about the servlet.
	 *
	 * 
Notes:
	 * 
	 * 	The method should return void although if it does return any value, the value will be ignored.
	 * 	
The method should be public although other visibilities are valid if the security manager allows it.
	 * 	
Static methods can be used.
	 * 	
Multiple POST_INIT methods can be defined on a class.
	 * 		
POST_INIT methods on parent classes are invoked before POST_INIT methods on child classes.
	 * 		
The order of POST_INIT method invocations within a class is alphabetical, then by parameter count, then by parameter types.
	 * 	
The method can throw any exception causing initialization of the servlet to fail.
	 * 	
Note that if you override a parent method, you probably need to call super.parentMethod(...).
	 * 		
The method is still considered part of the parent class for ordering purposes even though it's
	 * 		overridden by the child class.
	 * 
	 */
	POST_INIT,

	/**
	 * Identical to {@link #POST_INIT} except the order of execution is child-resources first.
	 *
	 * 
	 * Use this annotation if you need to perform any kind of initialization on child resources before the parent resource.
	 *
	 * 

	 * This method is called from within the {@link Servlet#init(ServletConfig)} method after the {@link RestContext}
	 * object has been created and after the {@link #POST_INIT} methods have been called.
	 *
	 * 

	 * The only valid parameter type for this method is {@link RestContext} which can be used to retrieve information
	 * about the servlet.
	 *
	 * 
Notes:
	 * 
	 * 	The method should return void although if it does return any value, the value will be ignored.
	 * 	
The method should be public although other visibilities are valid if the security manager allows it.
	 * 	
Static methods can be used.
	 * 	
Multiple POST_INIT_CHILD_FIRST methods can be defined on a class.
	 * 		
POST_INIT_CHILD_FIRST methods on parent classes are invoked before POST_INIT_CHILD_FIRST methods on child classes.
	 * 		
The order of POST_INIT_CHILD_FIRST method invocations within a class is alphabetical, then by parameter count, then by parameter types.
	 * 	
The method can throw any exception causing initialization of the servlet to fail.
	 * 
	 */
	POST_INIT_CHILD_FIRST,

	/**
	 * Identifies a method that gets called during servlet destroy.
	 *
	 * 
	 * This method is called from within the {@link Servlet#destroy()}.
	 *
	 * 

	 * The only valid parameter type for this method is {@link RestContext}, although typically no arguments will
	 * be specified.
	 *
	 * 
Example:
	 * 
	 * 	@RestResource(...)
	 * 	public class PetStoreResource extends ResourceJena {
	 *
	 * 		// Our database.
	 * 		private Map petDB;
	 *
	 * 		@RestHook(DESTROY)
	 * 		public void onDestroy() {
	 * 			petDB = null;
	 * 		}
	 * 	}
	 * 
	 *
	 * Notes:
	 * 
	 * 	The method should return void although if it does return any value, the value will be ignored.
	 * 	
The method should be public although other visibilities are valid if the security manager allows it.
	 * 	
Static methods can be used.
	 * 	
Multiple DESTROY methods can be defined on a class.
	 * 		
DESTROY methods on child classes are invoked before DESTROY methods on parent classes.
	 * 		
The order of DESTROY method invocations within a class is alphabetical, then by parameter count, then by parameter types.
	 * 	
In general, destroy methods should not throw any exceptions, although if any are thrown, the stack trace will be
	 * 		printed to System.err.
	 * 	
Note that if you override a parent method, you probably need to call super.parentMethod(...).
	 * 		
The method is still considered part of the parent class for ordering purposes even though it's
	 * 		overridden by the child class.
	 * 
	 */
	DESTROY
}