package com.myjavatools.web;

import java.net.URLConnection;
import java.net.URL;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.io.File;
import java.io.InputStream;
import java.util.Random;
import java.io.OutputStream;
import java.io.FileInputStream;
import java.util.Iterator;

/**
 * <p>Title: Client HTTP Request class</p>
 * <p>Description: this class helps to send POST HTTP requests with various form data,
 * including files. Cookies can be added to be included in the request.</p>
 *
 * @author Vlad Patryshev
 * @version 1.0
 */
public class ClientHttpRequest {
  URLConnection connection;
  OutputStream os = null;
  Map cookies = new HashMap();

  protected void connect() throws IOException {
    if (os == null) os = connection.getOutputStream();
  }

  protected void write(char c) throws IOException {
    connect();
    os.write(c);
  }

  protected void write(String s) throws IOException {
    connect();
    os.write(s.getBytes());
  }

  protected void newline() throws IOException {
    connect();
    write("\r\n");
  }

  protected void writeln(String s) throws IOException {
    connect();
    write(s);
    newline();
  }

  private static Random random = new Random();

  protected static String randomString() {
    return Long.toString(random.nextLong(), 36);
  }

  String boundary = "---------------------------" + randomString() + randomString() + randomString();

  private void boundary() throws IOException {
    write("--");
    write(boundary);
  }

  /**
   * Creates a new multipart POST HTTP request on a freshly opened URLConnection
   *
   * @param connection an already open URL connection
   * @throws IOException
   */
  public ClientHttpRequest(URLConnection connection) throws IOException {
    this.connection = connection;
    connection.setDoOutput(true);
    connection.setRequestProperty("Content-Type",
                                  "multipart/form-data; boundary=" + boundary);
  }

  /**
   * Creates a new multipart POST HTTP request for a specified URL
   *
   * @param url the URL to send request to
   * @throws IOException
   */
  public ClientHttpRequest(URL url) throws IOException {
    this(url.openConnection());
  }

  /**
   * Creates a new multipart POST HTTP request for a specified URL string
   *
   * @param urlString the string representation of the URL to send request to
   * @throws IOException
   */
  public ClientHttpRequest(String urlString) throws IOException {
    this(new URL(urlString));
  }


  private void postCookies() {
    StringBuffer cookieList = new StringBuffer();

    for (Iterator i = cookies.entrySet().iterator(); i.hasNext();) {
      Map.Entry entry = (Map.Entry)(i.next());
      cookieList.append(entry.getKey().toString() + "=" + entry.getValue());

      if (i.hasNext()) {
        cookieList.append("; ");
      }
    }
    if (cookieList.length() > 0) {
      connection.setRequestProperty("Cookie", cookieList.toString());
    }
  }

  /**
   * adds a cookie to the requst
   * @param name cookie name
   * @param value cookie value
   * @throws IOException
   */
  public void setCookie(String name, String value) throws IOException {
    cookies.put(name, value);
  }

  /**
   * adds cookies to the request
   * @param cookies the cookie "name-to-value" map
   * @throws IOException
   */
  public void setCookies(Map cookies) throws IOException {
    if (cookies == null) return;
    this.cookies.putAll(cookies);
  }

  /**
   * adds cookies to the request
   * @param cookies array of cookie names and values (cookies[2*i] is a name, cookies[2*i + 1] is a value)
   * @throws IOException
   */
  public void setCookies(String[] cookies) throws IOException {
    if (cookies == null) return;
    for (int i = 0; i < cookies.length - 1; i+=2) {
      setCookie(cookies[i], cookies[i+1]);
    }
  }

  private void writeName(String name) throws IOException {
    newline();
    write("Content-Disposition: form-data; name=\"");
    write(name);
    write('"');
  }

  /**
   * adds a string parameter to the request
   * @param name parameter name
   * @param value parameter value
   * @throws IOException
   */
  public void setParameter(String name, String value) throws IOException {
    boundary();
    writeName(name);
    newline(); newline();
    writeln(value);
  }

  private static void pipe(InputStream in, OutputStream out) throws IOException {
    byte[] buf = new byte[500000];
    int nread;
    int navailable;
    int total = 0;
    synchronized (in) {
      while((nread = in.read(buf, 0, buf.length)) >= 0) {
        out.write(buf, 0, nread);
        total += nread;
      }
    }
    out.flush();
    in.close();
    buf = null;
  }

  /**
   * adds a file parameter to the request
   * @param name parameter name
   * @param filename the name of the file
   * @param is input stream to read the contents of the file from
   * @throws IOException
   */
  public void setParameter(String name, String filename, InputStream is) throws IOException {
    boundary();
    writeName(name);
    write("; filename=\"");
    write(filename);
    write('"');
    newline();
    write("Content-Type: ");
    String type = connection.guessContentTypeFromName(filename);
    if (type == null) type = "application/octet-stream";
    writeln(type);
    newline();
    pipe(is, os);
    newline();
  }

  /**
   * adds a file parameter to the request
   * @param name parameter name
   * @param file the file to upload
   * @throws IOException
   */
  public void setParameter(String name, File file) throws IOException {
    setParameter(name, file.getPath(), new FileInputStream(file));
  }

  /**
   * adds a parameter to the request; if the parameter is a File, the file is uploaded, otherwise the string value of the parameter is passed in the request
   * @param name parameter name
   * @param object parameter value, a File or anything else that can be stringified
   * @throws IOException
   */
  public void setParameter(String name, Object object) throws IOException {
    if (object instanceof File) {
      setParameter(name, (File) object);
    } else {
      setParameter(name, object.toString());
    }
  }

  /**
   * adds parameters to the request
   * @param parameters "name-to-value" map of parameters; if a value is a file, the file is uploaded, otherwise it is stringified and sent in the request
   * @throws IOException
   */
  public void setParameters(Map parameters) throws IOException {
    if (parameters == null) return;
    for (Iterator i = parameters.entrySet().iterator(); i.hasNext();) {
      Map.Entry entry = (Map.Entry)i.next();
      setParameter(entry.getKey().toString(), entry.getValue());
    }
  }

  /**
   * adds parameters to the request
   * @param parameters array of parameter names and values (parameters[2*i] is a name, parameters[2*i + 1] is a value); if a value is a file, the file is uploaded, otherwise it is stringified and sent in the request
   * @throws IOException
   */
  public void setParameters(Object[] parameters) throws IOException {
    if (parameters == null) return;
    for (int i = 0; i < parameters.length - 1; i+=2) {
      setParameter(parameters[i].toString(), parameters[i+1]);
    }
  }

  /**
   * posts the requests to the server, with all the cookies and parameters that were added
   * @return input stream with the server response
   * @throws IOException
   */
  public InputStream post() throws IOException {
    boundary();
    writeln("--");
    os.close();
    return connection.getInputStream();
  }

  /**
   * posts the requests to the server, with all the cookies and parameters that were added before (if any), and with parameters that are passed in the argument
   * @param parameters request parameters
   * @return input stream with the server response
   * @throws IOException
   * @see setParameters
   */
  public InputStream post(Map parameters) throws IOException {
    setParameters(parameters);
    return post();
  }

  /**
   * posts the requests to the server, with all the cookies and parameters that were added before (if any), and with parameters that are passed in the argument
   * @param parameters request parameters
   * @return input stream with the server response
   * @throws IOException
   * @see setParameters
   */
  public InputStream post(Object[] parameters) throws IOException {
    setParameters(parameters);
    return post();
  }

  /**
   * posts the requests to the server, with all the cookies and parameters that were added before (if any), and with cookies and parameters that are passed in the arguments
   * @param cookies request cookies
   * @param parameters request parameters
   * @return input stream with the server response
   * @throws IOException
   * @see setParameters
   * @see setCookies
   */
  public InputStream post(Map cookies, Map parameters) throws IOException {
    setCookies(cookies);
    setParameters(parameters);
    return post();
  }

  /**
   * posts the requests to the server, with all the cookies and parameters that were added before (if any), and with cookies and parameters that are passed in the arguments
   * @param cookies request cookies
   * @param parameters request parameters
   * @return input stream with the server response
   * @throws IOException
   * @see setParameters
   * @see setCookies
   */
  public InputStream post(String[] cookies, Object[] parameters) throws IOException {
    setCookies(cookies);
    setParameters(parameters);
    return post();
  }

  /**
   * post the POST request to the server, with the specified parameter
   * @param name parameter name
   * @param value parameter value
   * @return input stream with the server response
   * @throws IOException
   * @see setParameter
   */
  public InputStream post(String name, Object value) throws IOException {
    setParameter(name, value);
    return post();
  }

  /**
   * post the POST request to the server, with the specified parameters
   * @param name1 first parameter name
   * @param value1 first parameter value
   * @param name2 second parameter name
   * @param value2 second parameter value
   * @return input stream with the server response
   * @throws IOException
   * @see setParameter
   */
  public InputStream post(String name1, Object value1, String name2, Object value2) throws IOException {
    setParameter(name1, value1);
    return post(name2, value2);
  }

  /**
   * post the POST request to the server, with the specified parameters
   * @param name1 first parameter name
   * @param value1 first parameter value
   * @param name2 second parameter name
   * @param value2 second parameter value
   * @param name3 third parameter name
   * @param value3 third parameter value
   * @return input stream with the server response
   * @throws IOException
   * @see setParameter
   */
  public InputStream post(String name1, Object value1, String name2, Object value2, String name3, Object value3) throws IOException {
    setParameter(name1, value1);
    return post(name2, value2, name3, value3);
  }

  /**
   * post the POST request to the server, with the specified parameters
   * @param name1 first parameter name
   * @param value1 first parameter value
   * @param name2 second parameter name
   * @param value2 second parameter value
   * @param name3 third parameter name
   * @param value3 third parameter value
   * @param name4 fourth parameter name
   * @param value4 fourth parameter value
   * @return input stream with the server response
   * @throws IOException
   * @see setParameter
   */
  public InputStream post(String name1, Object value1, String name2, Object value2, String name3, Object value3, String name4, Object value4) throws IOException {
    setParameter(name1, value1);
    return post(name2, value2, name3, value3, name4, value4);
  }

  /**
   * posts a new request to specified URL, with parameters that are passed in the argument
   * @param parameters request parameters
   * @return input stream with the server response
   * @throws IOException
   * @see setParameters
   */
  public static InputStream post(URL url, Map parameters) throws IOException {
    return new ClientHttpRequest(url).post(parameters);
  }

  /**
   * posts a new request to specified URL, with parameters that are passed in the argument
   * @param parameters request parameters
   * @return input stream with the server response
   * @throws IOException
   * @see setParameters
   */
  public static InputStream post(URL url, Object[] parameters) throws IOException {
    return new ClientHttpRequest(url).post(parameters);
  }

  /**
   * posts a new request to specified URL, with cookies and parameters that are passed in the argument
   * @param cookies request cookies
   * @param parameters request parameters
   * @return input stream with the server response
   * @throws IOException
   * @see setCookies
   * @see setParameters
   */
  public static InputStream post(URL url, Map cookies, Map parameters) throws IOException {
    return new ClientHttpRequest(url).post(cookies, parameters);
  }

  /**
   * posts a new request to specified URL, with cookies and parameters that are passed in the argument
   * @param cookies request cookies
   * @param parameters request parameters
   * @return input stream with the server response
   * @throws IOException
   * @see setCookies
   * @see setParameters
   */
  public static InputStream post(URL url, String[] cookies, Object[] parameters) throws IOException {
    return new ClientHttpRequest(url).post(cookies, parameters);
  }

  /**
   * post the POST request specified URL, with the specified parameter
   * @param name parameter name
   * @param value parameter value
   * @return input stream with the server response
   * @throws IOException
   * @see setParameter
   */
  public static InputStream post(URL url, String name1, Object value1) throws IOException {
    return new ClientHttpRequest(url).post(name1, value1);
  }

  /**
   * post the POST request to specified URL, with the specified parameters
   * @param name1 first parameter name
   * @param value1 first parameter value
   * @param name2 second parameter name
   * @param value2 second parameter value
   * @return input stream with the server response
   * @throws IOException
   * @see setParameter
   */
  public static InputStream post(URL url, String name1, Object value1, String name2, Object value2) throws IOException {
    return new ClientHttpRequest(url).post(name1, value1, name2, value2);
  }

  /**
   * post the POST request to specified URL, with the specified parameters
   * @param name1 first parameter name
   * @param value1 first parameter value
   * @param name2 second parameter name
   * @param value2 second parameter value
   * @param name3 third parameter name
   * @param value3 third parameter value
   * @return input stream with the server response
   * @throws IOException
   * @see setParameter
   */
  public static InputStream post(URL url, String name1, Object value1, String name2, Object value2, String name3, Object value3) throws IOException {
    return new ClientHttpRequest(url).post(name1, value1, name2, value2, name3, value3);
  }

  /**
   * post the POST request to specified URL, with the specified parameters
   * @param name1 first parameter name
   * @param value1 first parameter value
   * @param name2 second parameter name
   * @param value2 second parameter value
   * @param name3 third parameter name
   * @param value3 third parameter value
   * @param name4 fourth parameter name
   * @param value4 fourth parameter value
   * @return input stream with the server response
   * @throws IOException
   * @see setParameter
   */
  public static InputStream post(URL url, String name1, Object value1, String name2, Object value2, String name3, Object value3, String name4, Object value4) throws IOException {
    return new ClientHttpRequest(url).post(name1, value1, name2, value2, name3, value3, name4, value4);
  }
}