package com.intridea.io.vfs.provider.s3;

import org.apache.commons.vfs.FileName;
import org.apache.commons.vfs.FileSystemException;
import org.apache.commons.vfs.FileType;
import org.apache.commons.vfs.provider.AbstractFileNameParser;
import org.apache.commons.vfs.provider.UriParser;
import org.apache.commons.vfs.provider.VfsComponentContext;

/**
 * @author Matthias L. Jugel
 */
public class S3FileNameParser extends AbstractFileNameParser {
	/**
	 * S3 file name parser instance
	 */
	private static final S3FileNameParser instance = new S3FileNameParser();

	/**
	 * Gets singleton
	 * 
	 * @return
	 */
	public static S3FileNameParser getInstance() {
		return instance;
	}

	private S3FileNameParser() {
	}

	/**
	 * Parses URI and constructs S3 file name.
	 */
	public FileName parseUri(final VfsComponentContext context, final FileName base, final String filename) throws FileSystemException {
		StringBuffer name = new StringBuffer();

		String scheme = UriParser.extractScheme(filename, name);
		UriParser.canonicalizePath(name, 0, name.length(), this);

		// Normalize separators in the path
		UriParser.fixSeparators(name);

		// Normalise the path
		FileType fileType = UriParser.normalisePath(name);

		// Extract bucket name
		final String bucketName = UriParser.extractFirstElement(name);

		return new S3FileName(scheme, bucketName, name.toString(), fileType);
	}

}