package freech.core;

import java.io.*;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.StringTokenizer;

public class HttpDecoder {

	private Socket s = null;
    private String method =null;
	private String action = null;

	private Hashtable params = null;
    private Hashtable header = null;
	private String cookie = null;

	public HttpDecoder(Socket s) {
		this.s = s;
		this.params = new Hashtable();
		this.header = new Hashtable();
		try {
			parse();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	private void parse() throws IOException, InterruptedException {
		InputStream is = s.getInputStream();
		BufferedReader in = new BufferedReader(new InputStreamReader(is));

		if (in == null) {
			//
		}
		StringTokenizer st = new StringTokenizer(in.readLine() );
		if (!st.hasMoreTokens()) {
			System.out
					.println("bad request:Syntax error. Usage: GET /example/file.html");
		}

		method = st.nextToken();// get,post
		if (!st.hasMoreTokens()) {
			System.out
					.println("BAD REQUEST: Missing URI. Usage: GET /example/file.html");
		}
		//讀取uri
		String uri = decodePercent(st.nextToken());
		int pos = uri.indexOf("?");//參數(shù)可能接在?之后
		
		if (pos > -1) {
			action = decodePercent(uri.substring(0, pos));
            DecodeParams(uri.substring( pos+1));
		}else{
			action =decodePercent(uri);
		}
		//讀頭部
		String line = in.readLine() ;
		while(line.trim() .length() >0){
			int p=line.indexOf( ":");
			String key = line.substring( 0,p).trim().toLowerCase();
			String value = line.substring( p+1).trim();
			if(key.equals( "cookie")){
				String[] cookiepair = value.split( ";");
				for(int i = 0;i<cookiepair.length ;i++){
					String[] cp = cookiepair[i].trim() .split( "=");
					if(cp.length <2){
						continue;
					}
					if(!cookiepair[i].trim() .startsWith( "FreeChSession")){
						continue;
					}
					value = cp[1].trim() ;//cookie的值
				}
			}
			header.put( key  ,value );
			line = in.readLine() ;
		}
		//到這里,是一個(gè)空行
	    
        //如果方法是POST, 可能參數(shù)在數(shù)據(jù)段中,讀取它:
		if(method.equalsIgnoreCase( "POST")){
			int size = Integer.MAX_VALUE ;
			String contentlength = (String)header.get( "content-length");
			if(contentlength!=null){
				size = Integer.parseInt( contentlength);
			}
			String postline="";//所有參數(shù)
			char[] buf = new char[512];
			int readlen=in.read(buf)  ;
			
			while(readlen >=0&&size>0&&!postline.endsWith( "\r\n")){
	
				size-=readlen;
				postline += String.valueOf(buf,0,readlen);
				if(size>0){
					readlen =in.read( buf);
				}
			}
			postline = postline.trim() ;
			DecodeParams(postline);
		}
		//in.close() ;
		
        printData();
	}
	
	private String decodePercent( String str ) throws InterruptedException
	{
		try
		{
			StringBuffer sb = new StringBuffer();
			for( int i=0; i<str.length(); i++ )
			{
			    char c = str.charAt( i );
			    switch ( c )
				{
			        case '+':
			            sb.append( ' ' );
			            break;
			        case '%':
		                sb.append((char)Integer.parseInt( str.substring(i+1,i+3), 16 ));
			            i += 2;
			            break;
			        default:
			            sb.append( c );
			            break;
			    }
			}
			return new String( sb.toString().getBytes());
		}
		catch( Exception e )
		{
			System.out.println("BAD REQUEST: Bad percent-encoding." );
			return null;
		}
	}

	
	private void DecodeParams(String param) throws InterruptedException, UnsupportedEncodingException{
		if (param == null){
			return;
		}
		StringTokenizer st = new StringTokenizer(param,"&");
		while(st.hasMoreTokens() ){
			String e = st.nextToken() ;
			//StringTokenizer st1 = new StringTokenizer(e,"=");
			//if(st1.hasMoreTokens() ){
			//String param_name =st1.nextToken().trim();
			//String param_value = st1.nextToken().trim();//此處出錯(cuò)
			
			int sep = e.indexOf( '=');
			if(sep>=0){
				String param_name=decodePercent(e.substring( 0,sep).trim());
				//param_name =new String(param_name.getBytes( "BIG5"),"gb2312");
				String param_value = decodePercent(e.substring( sep+1).trim());
				param_value =new String(param_value.getBytes( "UTF8"));
			    params.put( param_name,param_value);
		      }
		}
	}
	
	private void printData(){
		System.out.println( method + " '" + action + "' " );
		Enumeration e = header.keys() ;
		while(e.hasMoreElements() ){
			String name = (String)e.nextElement() ;
			String value = (String)header.get(name);
			System.out.println( "  HDR: '" + name + "' = '" + value + "'" );
		}
		e = params.keys() ;
		while(e.hasMoreElements() ){
			String name = (String)e.nextElement() ;
			String value = (String)params.get(name);
			System.out.println( "  PRM: '" + name + "' = '" + value + "'" );
		}
	}

	public String getAction() {
		if(action.length() !=1){
			int pos = action.indexOf('/');
			if(pos == 0){
				action = action.substring( 1);//去除"/"
			}
		}
		return action;
	}

	public Hashtable getParam() {
		return params;
	}

	public String getCookie() {
		return (String)header.get( "cookie");
	}

}