import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Date;

public class Server {
    public final static char CR  = (char) 0x0D;
    public final static char LF  = (char) 0x0A;
    public static void main(String[] args) throws IOException {
        /**
         * Port de base: 8080
         */
        int port;
        if(args.length == 0) {
            port = 8080;
        } else {
            port = Integer.valueOf(args[0]);
        }

        /**
         * Définition du Document-Root
         */
        String docroot = "C:\\Users\\Jules\\IdeaProjects\\http\\data";

        /**
         * Ouvre la socket
         */
        ServerSocket serv = new ServerSocket(port);
        System.out.println("Le serveur est lancé et écoute sur le port " + port);

        /**
         * Boucle infinie d'écoute
         */
        while(true) {
            Socket socket = serv.accept();
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            OutputStream out = new BufferedOutputStream(socket.getOutputStream());
            String request = in.readLine();

            /**
             * Evite d'avoir des requetes null
             */
            if(request == null) {
                continue;
            }

            /**
             * Traite la requete
             */
            System.out.println("[" + socket.getInetAddress().getHostAddress() + ":" + socket.getPort() + "] " + request);
            if(request.startsWith("GET")) {
                String fichier = request.substring(4, request.length()-9).trim();
                String chemin = docroot + "/" + fichier;
                File f = new File(chemin);
                if(f.isDirectory()) {
                    chemin = chemin + "index.html";
                    f = new File(chemin);
                }

                /**
                 * Récupère le type
                 */
                String type;
                if(chemin.endsWith(".html")) {
                    type = "text/html";
                } else if(chemin.endsWith(".jpg") || chemin.endsWith(".jpeg")) {
                    type = "image/jpeg";
                } else if(chemin.endsWith(".gif")) {
                    type = "image/gif";
                } else {
                    type = "text/plain";
                }

                /**
                 * Va chercher le fichier et l'envoie, s'il existe pas 404
                 */
                String http, content;
                String today = "Date: " + new Date();
                String server = "Server: HttpServer 1.0";
                try {
                    InputStream is = new FileInputStream(f);
                    http = "HTTP/1.1 200 OK";
                    content = "Content-Type: " + type;
                    out.write(http.getBytes());
                    out.write(CR);
                    out.write(LF);
                    writeBasicThings(out, content, today, server);
                    while(is.available() > 0) {
                        out.write(is.read());
                    }
                    is.close();
                    System.out.println("[SERVER] Envoi d'un 200");
                } catch(FileNotFoundException e) {
                    http = "HTTP/1.1 404 Not Found";
                    writeBasicThings(out, http, today, server);
                    System.out.println("[SERVER] Envoi d'un 404");
                }
            }
            out.flush();
            socket.close();
        }
    }

    /**
     * Méthode permettant de write les choses basique
     * tel que le code de réponse HTTP, la date ou encore le serveur
     * @param out outputtream
     * @param http réponse
     * @param today date
     * @param server serveur
     * @throws IOException
     */
    private static void writeBasicThings(OutputStream out, String http, String today, String server) throws IOException {
        out.write(http.getBytes());
        out.write(CR);
        out.write(LF);
        out.write(today.getBytes());
        out.write(CR);
        out.write(LF);
        out.write(server.getBytes());
        out.write(CR);
        out.write(LF);
        out.write(CR);
        out.write(LF);
    }
}