package fr.upem.net.tcp.http;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;


public class HTTPReader {

    private final Charset ASCII_CHARSET = Charset.forName("ASCII");
    private final SocketChannel sc;
    private final ByteBuffer buff;

    public HTTPReader(SocketChannel sc, ByteBuffer buff) {
        this.sc = sc;
        this.buff = buff;
    }

    /**
     * @return The ASCII string terminated by CRLF
     * <p>
     * The method assume that buff is in write mode and leave it in write-mode
     * The method never reads from the socket as long as the buffer is not empty
     * @throws IOException HTTPException if the connection is closed before a line could be read
     */
    public String readLineCRLF() throws IOException {
      // TODO
      return null;
    }

    /**
     * @return The HTTPHeader object corresponding to the header read
     * @throws IOException HTTPException if the connection is closed before a header could be read
     *                     if the header is ill-formed
     */
    public HTTPHeader readHeader() throws IOException {
        // TODO
        return null;
    }

    /**
     * @param size
     * @return a ByteBuffer in write-mode containing size bytes read on the socket
     * @throws IOException HTTPException is the connection is closed before all bytes could be read
     */
    public ByteBuffer readBytes(int size) throws IOException {
        // TODO
        return null;
    }

    /**
     * @return a ByteBuffer in write-mode containing a content read in chunks mode
     * @throws IOException HTTPException if the connection is closed before the end of the chunks
     *                     if chunks are ill-formed
     */

    public ByteBuffer readChunks() throws IOException {
        // TODO
        return null;
    }


    public static void main(String[] args) throws IOException {
        Charset charsetASCII = Charset.forName("ASCII");
        String request = "GET / HTTP/1.1\r\n"
                + "Host: www.w3.org\r\n"
                + "\r\n";
        SocketChannel sc = SocketChannel.open();
        sc.connect(new InetSocketAddress("www.w3.org", 80));
        sc.write(charsetASCII.encode(request));
        ByteBuffer bb = ByteBuffer.allocate(50);
        HTTPReader reader = new HTTPReader(sc, bb);
        System.out.println(reader.readLineCRLF());
        System.out.println(reader.readLineCRLF());
        System.out.println(reader.readLineCRLF());
        sc.close();

        bb = ByteBuffer.allocate(50);
        sc = SocketChannel.open();
        sc.connect(new InetSocketAddress("www.w3.org", 80));
        reader = new HTTPReader(sc, bb);
        sc.write(charsetASCII.encode(request));
        System.out.println(reader.readHeader());
        sc.close();

        bb = ByteBuffer.allocate(50);
        sc = SocketChannel.open();
        sc.connect(new InetSocketAddress("www.w3.org", 80));
        reader = new HTTPReader(sc, bb);
        sc.write(charsetASCII.encode(request));
        HTTPHeader header = reader.readHeader();
        System.out.println(header);
        ByteBuffer content = reader.readBytes(header.getContentLength());
        content.flip();
        System.out.println(header.getCharset().decode(content));
        sc.close();

        bb = ByteBuffer.allocate(50);
        request = "GET / HTTP/1.1\r\n"
                + "Host: www.u-pem.fr\r\n"
                + "\r\n";
        sc = SocketChannel.open();
        sc.connect(new InetSocketAddress("www.u-pem.fr", 80));
        reader = new HTTPReader(sc, bb);
        sc.write(charsetASCII.encode(request));
        header = reader.readHeader();
        System.out.println(header);
        content = reader.readChunks();
        content.flip();
        System.out.println(header.getCharset().decode(content));
        sc.close();
    }
}