package dslog;

import java.io.BufferedInputStream;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;

class PdplogReader implements Closeable {

	/*============================================================*\
	|| Primitive IO                                               ||
	\*============================================================*/

	private final InputStream reader;
	public PdplogReader(InputStream reader) throws IOException {
		if (!reader.markSupported()) {
			reader = new BufferedInputStream(reader);
		}
		this.reader = reader;
	}

	private boolean atEOF() throws IOException {
		reader.mark(2);
		boolean eof = (reader.read() < 0);
		reader.reset();
		return eof;
	}


	/*============================================================* \
	|| Parsing                                                    ||
	\*============================================================*/

	private int m_version;
	private boolean m_haveVersion = false;
	public int version() throws IOException {
		if (!m_haveVersion) {
			m_version = Read.i32(reader);
			m_haveVersion = true;
		}
		return m_version;
	}

	public void read() throws IOException {
		switch (version()) {
		case 0: // ????-????
			throw new UnsupportedVersionException("PDPLOG (TODO)", 0);
		case 1: // ????-2015
			throw new UnsupportedVersionException("PDPLOG (TODO)", 1);
		default:
			throw new UnsupportedVersionException("PDPLOG", version(), 1);
		}
	}

	public void close() throws IOException {
		reader.close();
	}
}