package fr.uge.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 = StandardCharsets.US_ASCII;
    private final SocketChannel sc;
    private final ByteBuffer buffer;

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

    /**
     * @return The ASCII string terminated by CRLF without the CRLF
     *         <p>
     *         The method assume that buffer is in write mode and leaves it in
     *         write mode The method process the data from the buffer and if necessary
     *         will read more data from the socket.
     * @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 or 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
     *         <p>
     *         The method assume that buffer is in write mode and leaves it in
     *         write mode The method process the data from the buffer and if necessary
     *         will read more data from 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 {
        var charsetASCII = Charset.forName("ASCII");
        var request = "GET / HTTP/1.1\r\n" + "Host: www.w3.org\r\n" + "\r\n";
        var sc = SocketChannel.open();
        sc.connect(new InetSocketAddress("www.w3.org", 80));
        sc.write(charsetASCII.encode(request));
        var buffer = ByteBuffer.allocate(50);
        var reader = new HTTPReader(sc, buffer);
        System.out.println(reader.readLineCRLF());
        System.out.println(reader.readLineCRLF());
        System.out.println(reader.readLineCRLF());
        sc.close();

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

        buffer = ByteBuffer.allocate(50);
        sc = SocketChannel.open();
        sc.connect(new InetSocketAddress("igm.univ-mlv.fr", 80));
        request = "GET /coursprogreseau/ HTTP/1.1\r\n" + "Host: igm.univ-mlv.fr\r\n" + "\r\n";
        reader = new HTTPReader(sc, buffer);
        sc.write(charsetASCII.encode(request));
        var header = reader.readHeader();
        System.out.println(header);
        var content = reader.readBytes(header.getContentLength());
        content.flip();
        System.out.println(header.getCharset().orElse(Charset.forName("UTF8")).decode(content));
        sc.close();

        buffer = 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, buffer);
        sc.write(charsetASCII.encode(request));
        header = reader.readHeader();
        System.out.println(header);
        content = reader.readChunks();
        content.flip();
        System.out.println(header.getCharset().orElse(Charset.forName("UTF8")).decode(content));
        sc.close();
    }
}