package com.sun.tools.javac.file;

import java.io.File;

import java.io.IOException;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import java.util.StringTokenizer;

import java.util.jar.Attributes;

import java.util.jar.JarFile;

import java.util.jar.Manifest;

import com.sun.tools.javac.util.Context;

/**

 * Get meta-info about files. Default direct (non-caching) implementation.

 * @see CacheFSInfo

 */

public class FSInfo {

    /** Get the FSInfo instance for this context.

     *  @param context the context

     *  @return the Paths instance for this context

     */

    public static FSInfo instance(Context context) {

        FSInfo instance = context.get(FSInfo.class);

        if (instance == null)

            instance = new FSInfo();

        return instance;

    }

    protected FSInfo() {

    }

    protected FSInfo(Context context) {

        context.put(FSInfo.class, this);

    }

    public File getCanonicalFile(File file) {

        try {

            return file.getCanonicalFile();

        } catch (IOException e) {

            return file.getAbsoluteFile();

        }

    }

    public boolean exists(File file) {

        return file.exists();

    }

    public boolean isDirectory(File file) {

        return file.isDirectory();

    }

    public boolean isFile(File file) {

        return file.isFile();

    }

    public List<File> getJarClassPath(File file) throws IOException {

        String parent = file.getParent();

        JarFile jarFile = new JarFile(file);

        try {

            Manifest man = jarFile.getManifest();

            if (man == null)

                return Collections.emptyList();

            Attributes attr = man.getMainAttributes();

            if (attr == null)

                return Collections.emptyList();

            String path = attr.getValue(Attributes.Name.CLASS_PATH);

            if (path == null)

                return Collections.emptyList();

            List<File> list = new ArrayList<File>();

            for (StringTokenizer st = new StringTokenizer(path); st.hasMoreTokens(); ) {

                String elt = st.nextToken();

                File f = (parent == null ? new File(elt) : new File(parent, elt));

                list.add(f);

            }

            return list;

        } finally {

            jarFile.close();

        }

    }

}