// Copyright (c) 2005 by Leif Frenzel. All rights reserved.
// See http://leiffrenzel.de
package net.sourceforge.phpdt.ltk.core;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import net.sourceforge.phpdt.internal.ui.util.PHPFileUtil;
import net.sourceforge.phpeclipse.PHPeclipsePlugin;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.ltk.core.refactoring.Change;
import org.eclipse.ltk.core.refactoring.CompositeChange;
import org.eclipse.ltk.core.refactoring.RefactoringStatus;
import org.eclipse.ltk.core.refactoring.TextFileChange;
import org.eclipse.ltk.core.refactoring.participants.CheckConditionsContext;
import org.eclipse.ltk.core.refactoring.participants.IConditionChecker;
import org.eclipse.ltk.core.refactoring.participants.ValidateEditChecker;
import org.eclipse.text.edits.MultiTextEdit;
import org.eclipse.text.edits.ReplaceEdit;

/**
 * <p>
 * delegate object that contains the logic used by the processor.
 * </p>
 *
 * @author Leif Frenzel
 */
class RenamePropertyDelegate {

	// private static final String EXT_PROPERTIES = "properties"; //$NON-NLS-1$

	private final RenamePropertyInfo info;

	// properties file with the key to rename -> offset of the key
	private final Map phpFiles;

	RenamePropertyDelegate(final RenamePropertyInfo info) {
		this.info = info;
		phpFiles = new HashMap();
	}

	RefactoringStatus checkInitialConditions() {
		RefactoringStatus result = new RefactoringStatus();
		IFile sourceFile = info.getSourceFile();
		if (sourceFile == null || !sourceFile.exists()) {
			result.addFatalError(CoreTexts.renamePropertyDelegate_noSourceFile);
		} else if (info.getSourceFile().isReadOnly()) {
			result.addFatalError(CoreTexts.renamePropertyDelegate_roFile);
		} else if (isEmpty(info.getOldName())) {
			// || !isPropertyKey( info.getSourceFile(), info.getOldName() ) ) {
			result.addFatalError(CoreTexts.renamePropertyDelegate_noPHPKey);
		}
		return result;
	}

	RefactoringStatus checkFinalConditions(final IProgressMonitor pm, final CheckConditionsContext ctxt) {
		RefactoringStatus result = new RefactoringStatus();
		pm.beginTask(CoreTexts.renamePropertyDelegate_checking, 100);
		// do something long-running here: traverse the entire project (or even
		// workspace) to look for all *.properties files with the same bundle
		// base name
		IContainer rootContainer;
		if (info.isAllProjects()) {
			rootContainer = ResourcesPlugin.getWorkspace().getRoot();
		} else {
			rootContainer = info.getSourceFile().getProject();
		}
		search(rootContainer, result);
		pm.worked(50);

		if (ctxt != null) {
			IFile[] files = new IFile[phpFiles.size()];
			phpFiles.keySet().toArray(files);
			IConditionChecker checker = ctxt.getChecker(ValidateEditChecker.class);
			ValidateEditChecker editChecker = (ValidateEditChecker) checker;
			editChecker.addFiles(files);
		}
		pm.done();
		return result;
	}

	void createChange(final IProgressMonitor pm, final CompositeChange rootChange) {
		try {
			pm.beginTask(CoreTexts.renamePropertyDelegate_collectingChanges, 100);
			// the property which was directly selected by the user
			rootChange.add(createRenameChange());
			pm.worked(10);
			// all files in the same bundle
			if (info.isUpdateBundle()) {
				rootChange.addAll(createChangesForBundle());
			}
			pm.worked(90);
		} finally {
			pm.done();
		}
	}

	// helping methods
	// ////////////////

	private Change createRenameChange() {
		// create a change object for the file that contains the property the
		// user has selected to rename
		IFile file = info.getSourceFile();
		TextFileChange result = new TextFileChange(file.getName(), file);
		// a file change contains a tree of edits, first add the root of them
		MultiTextEdit fileChangeRootEdit = new MultiTextEdit();
		result.setEdit(fileChangeRootEdit);

		// edit object for the text replacement in the file, this is the only child
		ReplaceEdit edit = new ReplaceEdit(info.getOffset(), info.getOldName().length(), info.getNewName());
		fileChangeRootEdit.addChild(edit);
		return result;
	}

	private Change[] createChangesForBundle() {
		List result = new ArrayList();
		Iterator it = phpFiles.keySet().iterator();
		while (it.hasNext()) {
			IFile file = (IFile) it.next();

			TextFileChange tfc = new TextFileChange(file.getName(), file);
			MultiTextEdit fileChangeRootEdit = new MultiTextEdit();
			tfc.setEdit(fileChangeRootEdit);

			// edit object for the text replacement in the file, this is the only
			// child
			ReplaceEdit edit = new ReplaceEdit(getKeyOffset(file), info.getOldName().length(), info.getNewName());
			fileChangeRootEdit.addChild(edit);

			result.add(tfc);
		}
		return (Change[]) result.toArray(new Change[result.size()]);
	}

	private boolean isEmpty(final String candidate) {
		return candidate == null || candidate.trim().length() == 0;
	}

	// private boolean isPropertyKey( final IFile file, final String candidate ) {
	// boolean result = false;
	// try {
	// Properties props = new Properties();
	// props.load( file.getContents() );
	// result = props.containsKey( candidate );
	// } catch( Exception ex ) {
	// // ignore this, we just assume this is not a favourable situation
	// ex.printStackTrace();
	// }
	// return result;
	// }

	// whether the file is a PHP file with the same base name as the
	// one we refactor and contains the key that interests us
	private boolean isToRefactor(final IFile file) {
		return PHPFileUtil.isPHPFile(file);
		// && !file.equals( info.getSourceFile() )
		// && isPropertyKey( file, info.getOldName() );
	}

	// private String getBundleBaseName() {
	// String result = info.getSourceFile().getName();
	// int underscoreIndex = result.indexOf( '_' );
	// if( underscoreIndex != -1 ) {
	// result = result.substring( 0, underscoreIndex );
	// } else {
	// int index = result.indexOf( EXT_PROPERTIES ) - 1;
	// result = result.substring( 0, index );
	// }
	// return result;
	// }

	private void search(final IContainer rootContainer, final RefactoringStatus status) {
		try {
			IResource[] members = rootContainer.members();
			for (int i = 0; i < members.length; i++) {
				if (members[i] instanceof IContainer) {
					search((IContainer) members[i], status);
				} else {
					IFile file = (IFile) members[i];
					handleFile(file, status);
				}
			}
		} catch (final CoreException cex) {
			status.addFatalError(cex.getMessage());
		}
	}

	private void handleFile(final IFile file, final RefactoringStatus status) {
		if (isToRefactor(file)) {
			determineKeyOffsets(file, status);
			// if (keyOffsets.size() > 0) {
			// Integer offset = new Integer(keyOffsets);
			// phpFiles.put(file, offset);
			// }
		}
	}

	private int getKeyOffset(final IFile file) {
		return ((Integer) phpFiles.get(file)).intValue();
	}

	// finds the offset of the property key to rename
	// usually, this would be the job of a proper parser;
	// using a primitive brute-force approach here
	private void determineKeyOffsets(final IFile file, final RefactoringStatus status) {
		String content = readFileContent(file, status);
		int indx = 0;
		while ((indx = content.indexOf(info.getOldName(), indx)) >= 0) {
			phpFiles.put(file, Integer.valueOf(indx++));
		}
		// int result = -1;
		// int candidateIndex = content.indexOf(info.getOldName());
		// result = candidateIndex;
		// while( result == -1 && candidateIndex != -1 ) {
		// if( isKeyOccurrence( content, candidateIndex ) ) {
		// result = candidateIndex;
		// }
		// }
		// if( result == -1 ) {
		// // still nothing found, we add a warning to the status
		// // (we have checked the file contains the property, so that we can't
		// // determine it's offset is probably because of the rough way employed
		// // here to find it)
		// String msg = CoreTexts.renamePropertyDelegate_propNotFound
		// + file.getLocation().toOSString();
		// status.addWarning( msg );
		// }
		// return result;
	}

	private String readFileContent(final IFile file, final RefactoringStatus refStatus) {
		String result = null;
		try {
			InputStream is = file.getContents();
			byte[] buf = new byte[1024];
			ByteArrayOutputStream bos = new ByteArrayOutputStream();
			int len = is.read(buf);
			while (len > 0) {
				bos.write(buf, 0, len);
				len = is.read(buf);
			}
			is.close();
			result = new String(bos.toByteArray());
		} catch (Exception ex) {
			String msg = ex.toString();
			refStatus.addFatalError(msg);
			String pluginId = PHPeclipsePlugin.getPluginId();
			IStatus status = new Status(IStatus.ERROR, pluginId, 0, msg, ex);
			PHPeclipsePlugin.getDefault().getLog().log(status);
		}
		return result;
	}

	// we check only that there is a separator before the next line break (this
	// is not sufficient, the whole thing may be in a comment etc. ...)
	// private boolean isKeyOccurrence( final String content,
	// final int candidateIndex ) {
	// int index = candidateIndex + info.getOldName().length();
	// // skip whitespace
	// while( content.charAt( index ) == ' ' || content.charAt( index ) == '\t' )
	// {
	// index++;
	// }
	// return content.charAt( index ) == '=' || content.charAt( index ) == ':';
	// }
}