package org.trianacode.config;

import org.trianacode.taskgraph.tool.ClassLoaders;

import java.io.*;
import java.net.URL;

/**
 * Class that attempts to look in various places for a specified file and its type.  At the core of
 * this class is the loading mechnism which currently attempts to load in the file from either
 * the specified path or from the classpath (e.g. a jar).   It then performs a number of higher level
 * searches for the file based on the file type, which can be specified as an argument.   For example,
 * if a file type is a tool, then it will iterate through all of the toolbox paths and attempt to
 * load the resource from each location. It will then try the classpath to see if this resource can
 * be found there.
 * <p/>
 * Date: Sep 23, 2010
 * Time: 5:10:21 PM
 * To change this template use File | Settings | File Templates.
 */
public class ResourceManagement {
    public enum Type {
        TEMPLATE, PROPERTY, TOOL
    }


    /**
     * Gets an input stream for the given filename and searches in locations specified for that type of
     * file.
     *
     * @param filen the name of the file to be searched for
     * @param type  the type of file this is.
     * @return
     */
    public static InputStream getInputStreamFor(String filen, Type type) throws FileNotFoundException, IOException {
        String filelist;
        InputStream stream;

        switch (type) {
            case PROPERTY:
                filelist = System.getProperty(TrianaProperties.PROPERTY_SEARCH_PATH_PROPERTY);
                break;
            case TEMPLATE:
                filelist = System.getProperty(TrianaProperties.TEMPLATE_SEARCH_PATH_PROPERTY);
                break;
            case TOOL:
                filelist = System.getProperty(TrianaProperties.TOOLBOX_SEARCH_PATH_PROPERTY);
                break;
            default:
                throw new IOException("Type for file " + filen + " Not Found!");
        }

        if (filelist != null) {
            String dirlistarr[];

            dirlistarr = filelist.split(",");
            for (String dir : dirlistarr) {
                String file = dir.trim() + File.separator + filen;
                stream = getInputStreamFor(file);
                if (stream != null)
                    return stream; // if we find a valid stream then return
            }
        }
        return getInputStreamFor(filen); // lastly try the filename itself
    }


    /**
     * Attempts to load the provided file from the file system and then try the jar file. The method
     * simply uses the absolute path provided.
     *
     * @param file
     * @return
     * @throws FileNotFoundException
     * @throws IOException
     */
    public static InputStream getInputStreamFor(String file) throws FileNotFoundException, IOException {
        if (file == null) return null;

        InputStream stream = null;

        File filen = new File(file);
        // try load the file from the filesystem and if not, search for it in a jar.
        if (filen.exists()) {
            stream = new FileInputStream(filen);
        } else {
            // ANDREW: always use ClassLoaders
            URL fileURL = ClassLoaders.getResource(file);
            if (fileURL != null) {
                stream = fileURL.openStream();
            }
        }
        if (stream == null && file.startsWith("/")) {
            return getInputStreamFor(file.substring(1));
        }
        return stream;
    }

}