/*
 * Copyright (c) 2011 TMate Software Ltd
 *  
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * For information on how to redistribute this software under
 * the terms of a license other than GNU General Public License
 * contact TMate Software at support@hg4j.com
 */
package org.tmatesoft.hg.internal;

import static org.tmatesoft.hg.internal.RequiresFile.*;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.tmatesoft.hg.repo.HgInternals;
import org.tmatesoft.hg.repo.HgRepoConfig.ExtensionsSection;
import org.tmatesoft.hg.repo.HgRepository;
import org.tmatesoft.hg.util.PathRewrite;

/**
 * Fields/members that shall not be visible  
 * 
 * @author Artem Tikhomirov
 * @author TMate Software Ltd.
 */
public class Internals {
	
	private int requiresFlags = 0;
	private List<Filter.Factory> filterFactories;
	

	public Internals() {
	}
	
	public void parseRequires(HgRepository hgRepo, File requiresFile) {
		try {
			new RequiresFile().parse(this, requiresFile);
		} catch (IOException ex) {
			// FIXME not quite sure error reading requires file shall be silently logged only.
			HgInternals.getContext(hgRepo).getLog().error(getClass(), ex, null);
		}
	}

	public/*for tests, otherwise pkg*/ void setStorageConfig(int version, int flags) {
		requiresFlags = flags;
	}

	// XXX perhaps, should keep both fields right here, not in the HgRepository
	public PathRewrite buildDataFilesHelper() {
		return new StoragePathHelper((requiresFlags & STORE) != 0, (requiresFlags & FNCACHE) != 0, (requiresFlags & DOTENCODE) != 0);
	}

	public PathRewrite buildRepositoryFilesHelper() {
		if ((requiresFlags & STORE) != 0) {
			return new PathRewrite() {
				public CharSequence rewrite(CharSequence path) {
					return "store/" + path;
				}
			};
		} else {
			return new PathRewrite.Empty();
		}
	}

	public List<Filter.Factory> getFilters(HgRepository hgRepo) {
		if (filterFactories == null) {
			filterFactories = new ArrayList<Filter.Factory>();
			ExtensionsSection cfg = hgRepo.getConfiguration().getExtensions();
			if (cfg.isEnabled("eol")) {
				NewlineFilter.Factory ff = new NewlineFilter.Factory();
				ff.initialize(hgRepo);
				filterFactories.add(ff);
			}
			if (cfg.isEnabled("keyword")) {
				KeywordFilter.Factory ff = new KeywordFilter.Factory();
				ff.initialize(hgRepo);
				filterFactories.add(ff);
			}
		}
		return filterFactories;
	}
	
	public void initEmptyRepository(File hgDir) throws IOException {
		hgDir.mkdir();
		FileOutputStream requiresFile = new FileOutputStream(new File(hgDir, "requires"));
		StringBuilder sb = new StringBuilder(40);
		sb.append("revlogv1\n");
		if ((requiresFlags & STORE) != 0) {
			sb.append("store\n");
		}
		if ((requiresFlags & FNCACHE) != 0) {
			sb.append("fncache\n");
		}
		if ((requiresFlags & DOTENCODE) != 0) {
			sb.append("dotencode\n");
		}
		requiresFile.write(sb.toString().getBytes());
		requiresFile.close();
		new File(hgDir, "store").mkdir(); // with that, hg verify says ok.
	}

	public static boolean runningOnWindows() {
		return System.getProperty("os.name").indexOf("Windows") != -1;
	}

	public ConfigFile readConfiguration(HgRepository hgRepo, File repoRoot) throws IOException {
		ConfigFile configFile = new ConfigFile();
		if (runningOnWindows()) {
			// FIXME read install-dir
			//
			// XXX perhaps, makes sense to compare getenv(USERPROFILE) and getenv(HOME) and use 
			// them if set (and use both if their values do not match). Only if both not set, rely to user.home?
			// Also respect #getUserConfigurationFileToWrite() below
			configFile.addLocation(new File(System.getProperty("user.home"), "Mercurial.ini"));
		} else {
			// FIXME read from install-root
			//
			File d = new File("/etc/mercurial/hgrc.d/");
			if (d.isDirectory()) {
				for (File f : d.listFiles()) {
					// XXX in fact, need to sort in alphabetical order 
					if (f.getName().endsWith(".rc")) {
						configFile.addLocation(f);
					}
				}
			}
			configFile.addLocation(new File("/etc/mercurial/hgrc"));
		}
		configFile.addLocation(new File(System.getProperty("user.home"), ".hgrc"));
		// last one, overrides anything else
		// <repo>/.hg/hgrc
		configFile.addLocation(new File(repoRoot, "hgrc"));
		return configFile;
	}

	/**
	 * @return
	 */
	public static File getInstallationConfigurationFileToWrite() {
		// TODO Auto-generated method stub
		// FIXME find out install-root 
		throw new UnsupportedOperationException();
	}

	/**
	 * @return
	 */
	public static File getUserConfigurationFileToWrite() {
		final File rv = new File(System.getProperty("user.home"), ".hgrc");
		if (rv.exists() && rv.canWrite()) {
			return rv;
		}
		if (runningOnWindows()) {
			// try another well-known location
			// TODO comment above regarding USERPROFILE and HOME variables applies here as well
			File f = new File(System.getProperty("user.home"), "Mercurial.ini");
			if (f.exists() && f.canWrite()) {
				return f;
			}
		}
		// fallback to default value
		return rv; 
	}
}