/* *******************************************************************

 * Copyright (c) 2005 Contributors.

 * All rights reserved. 

 * This program and the accompanying materials are made available 

 * under the terms of the Eclipse Public License v1.0 

 * which accompanies this distribution and is available at 

 * http://eclipse.org/legal/epl-v10.html 

 *  

 * Contributors: 

 * Andy Clement          initial implementation

 * ******************************************************************/

package org.aspectj.ajdt.internal.core.builder;



import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.util.Collection;

import java.util.Hashtable;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Set;



import org.aspectj.ajdt.internal.compiler.CompilationResultDestinationManager;

import org.aspectj.weaver.CompressingDataOutputStream;



/**

 * Central point for all things incremental... - keeps track of the state recorded for each different config file - allows limited

 * interaction with these states

 * 

 * - records dependency/change info for particular classpaths > this will become what JDT keeps in its 'State' object when its

 * finished

 */

public class IncrementalStateManager {



	// FIXME asc needs an API through Ajde for trashing its contents

	// FIXME asc needs some memory mgmt (softrefs?) to recover memory

	// SECRETAPI will consume more memory, so turn on at your own risk ;) Set to 'true' when memory usage is understood

	public static boolean recordIncrementalStates = false;

	public static boolean debugIncrementalStates = false;

	private static Hashtable incrementalStates = new Hashtable();



	public static void recordSuccessfulBuild(String buildConfig, AjState state) {

		if (!recordIncrementalStates) {

			return;

		}

		incrementalStates.put(buildConfig, state);

		// persist();

	}



	/**

	 * Store states on disk

	 */

	public static void persist() {

		// check serialization works

		Set entries = incrementalStates.entrySet();

		for (Iterator iterator = entries.iterator(); iterator.hasNext();) {

			Map.Entry entry = (Map.Entry) iterator.next();

			System.out.println("Name " + entry.getKey());

			File f = new File("n:/temp/foo.ajstate");

			try {

				AjState state = (AjState) entry.getValue();

				CompressingDataOutputStream dos = new CompressingDataOutputStream(new FileOutputStream(f));

				state.write(dos);

				dos.close();

			} catch (FileNotFoundException e) {

				throw new RuntimeException(e);

			} catch (IOException e) {

				throw new RuntimeException(e);

			}

		}

	}



	public static boolean removeIncrementalStateInformationFor(String buildConfig) {

		return incrementalStates.remove(buildConfig) != null;

	}



	public static void clearIncrementalStates() {

		for (Iterator iter = incrementalStates.values().iterator(); iter.hasNext();) {

			AjState element = (AjState) iter.next();

			element.wipeAllKnowledge();

		}

		incrementalStates.clear();

		// AsmManager.getDefault().createNewStructureModel(); // forget what you know...

	}



	public static Set getConfigFilesKnown() {

		return incrementalStates.keySet();

	}



	public static AjState retrieveStateFor(String configFile) {

		return (AjState) incrementalStates.get(configFile);

	}



	// now, managing changes to entries on a classpath



	public static AjState findStateManagingOutputLocation(File location) {

		Collection allStates = incrementalStates.values();

		if (debugIncrementalStates) {

			System.err.println("> findStateManagingOutputLocation(" + location + ") has " + allStates.size()

					+ " states to look through");

		}

		for (Iterator iter = allStates.iterator(); iter.hasNext();) {

			AjState element = (AjState) iter.next();

			AjBuildConfig ajbc = element.getBuildConfig();

			if (ajbc == null) {

				// FIXME asc why can it ever be null?

				if (debugIncrementalStates) {

					System.err.println("  No build configuration for state " + element);

				}

				continue;

			}

			File outputDir = ajbc.getOutputDir();

			if (outputDir != null && outputDir.equals(location)) {

				if (debugIncrementalStates) {

					System.err.println("< findStateManagingOutputLocation(" + location + ") returning " + element);

				}

				return element;

			}

			CompilationResultDestinationManager outputManager = ajbc.getCompilationResultDestinationManager();

			if (outputManager != null) {

				List outputDirs = outputManager.getAllOutputLocations();

				for (Iterator iterator = outputDirs.iterator(); iterator.hasNext();) {

					File dir = (File) iterator.next();

					if (dir.equals(location)) {

						if (debugIncrementalStates) {

							System.err.println("< findStateManagingOutputLocation(" + location + ") returning " + element);

						}

						return element;

					}

				}

			}

			if (outputDir == null && outputManager == null) {

				// FIXME why can it ever be null? due to using outjar?

				if (debugIncrementalStates) {

					System.err.println("  output directory and output location manager for " + ajbc + " are null");

				}

				continue;

			}



		}

		if (debugIncrementalStates) {

			System.err.println("< findStateManagingOutputLocation(" + location + ") returning null");

		}

		return null;

	}



	// FIXME asc needs a persistence mechanism for storing/loading all state info

	// FIXME asc needs to understand two config files might point at the same output dir... what to do about this?

}