package luan.modules.http.jetty;

import java.io.InputStream;
import java.io.BufferedInputStream;
import java.io.PrintWriter;
import java.io.IOException;
import java.util.Map;
import java.util.Set;
import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.Enumeration;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import javax.servlet.ServletOutputStream;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.servlet.http.Part;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.eclipse.jetty.util.MultiPartInputStream;
import luan.Luan;
import luan.LuanState;
import luan.LuanFunction;
import luan.LuanException;
import luan.LuanTable;
import luan.LuanCloner;
import luan.modules.PackageLuan;
import luan.modules.IoLuan;
import luan.modules.TableLuan;
import luan.modules.Utils;
import luan.modules.url.LuanUrl;


public final class HttpServicer {
	private static final Logger logger = LoggerFactory.getLogger(HttpServicer.class);

	public static boolean service(LuanState luan,HttpServletRequest request,HttpServletResponse response,String modName)
		throws LuanException
	{
		LuanFunction fn;
		synchronized(luan) {
			PackageLuan.enableLoad(luan,"luan:http/Http.luan",modName);
			LuanTable module = (LuanTable)PackageLuan.require(luan,"luan:http/Http.luan");
			LuanTable per_session_pages = (LuanTable)module.rawGet("per_session_pages");
			Object mod = PackageLuan.load(luan,modName);
			if( mod.equals(Boolean.FALSE) )
				return false;
			if( !(mod instanceof LuanFunction) )
				throw new LuanException( "module '"+modName+"' must return a function" );
			if( Boolean.TRUE.equals(per_session_pages.rawGet(mod)) ) {
				HttpSession session = request.getSession();
				LuanState sessionLuan = (LuanState)session.getAttribute("luan");
				if( sessionLuan!=null ) {
					luan = sessionLuan;
				} else {
					LuanCloner cloner = new LuanCloner(LuanCloner.Type.COMPLETE);
					luan = (LuanState)cloner.clone(luan);
					session.setAttribute("luan",luan);
				}
				fn = (LuanFunction)PackageLuan.require(luan,modName);
			} else {
				LuanCloner cloner = new LuanCloner(LuanCloner.Type.INCREMENTAL);
				luan = (LuanState)cloner.clone(luan);
				fn = (LuanFunction)cloner.get(mod);
			}
		}

		LuanTable module = (LuanTable)PackageLuan.require(luan,"luan:http/Http.luan");

		// request
		LuanFunction newRequestFn = (LuanFunction)module.rawGet("new_request");
		LuanTable requestTbl = (LuanTable)newRequestFn.call(luan);
		module.rawPut("request",requestTbl);
		requestTbl.rawPut("java",request);
		requestTbl.rawPut("method",request.getMethod());
		requestTbl.rawPut("path",request.getRequestURI());
		requestTbl.rawPut("protocol",request.getProtocol());
		requestTbl.rawPut("scheme",request.getScheme());
		requestTbl.rawPut("port",request.getServerPort());

		LuanTable headersTbl = (LuanTable)requestTbl.rawGet("headers");
		for( Enumeration<String> enKeys = request.getHeaderNames(); enKeys.hasMoreElements(); ) {
			String key = enKeys.nextElement();
			List<String> values = new ArrayList<String>();
			for( Enumeration<String> en = request.getHeaders(key); en.hasMoreElements(); ) {
				values.add(en.nextElement());
			}
			int size = values.size();
			if(size==0) throw new RuntimeException();
			key = key.toLowerCase();
			Object value = size==1 ? values.get(0) : new LuanTable(values);
			headersTbl.rawPut(key,value);
		}

		LuanTable parametersTbl = (LuanTable)requestTbl.rawGet("parameters");
		String contentType = request.getContentType();
		if( contentType==null || !contentType.startsWith("multipart/form-data") ) {
			for( Map.Entry<String,String[]> entry : request.getParameterMap().entrySet() ) {
				String[] a = entry.getValue();
				Object value = a.length==1 ? a[0] : new LuanTable(Arrays.asList(a));
				parametersTbl.rawPut(entry.getKey(),value);
			}
		} else {  // multipart
			try {
				InputStream in = new BufferedInputStream(request.getInputStream());
				final MultiPartInputStream mpis = new MultiPartInputStream(in,contentType,null,null);
				mpis.setDeleteOnExit(true);
				for( Part p : mpis.getParts() ) {
					final MultiPartInputStream.MultiPart part = (MultiPartInputStream.MultiPart)p;
					String name = part.getName();
/*
System.out.println("name = "+name);
System.out.println("getContentType = "+part.getContentType());
System.out.println("getHeaderNames = "+part.getHeaderNames());
System.out.println("content-disposition = "+part.getHeader("content-disposition"));
System.out.println();
*/
					Object value;
					String filename = part.getContentDispositionFilename();
					if( filename == null ) {
						value = new String(part.getBytes());
					} else {
						LuanTable partTbl = new LuanTable();
						partTbl.rawPut("filename",filename);
						partTbl.rawPut("content_type",part.getContentType());
						{
							InputStream inPart = part.getInputStream();
							byte[] content = Utils.readAll(inPart);
							inPart.close();
							partTbl.rawPut("content",content);
						}
						value = partTbl;
					}
					Object obj = parametersTbl.rawGet(name);
					if( obj == null ) {
						parametersTbl.rawPut(name,value);
					} else if( obj instanceof LuanTable && ((LuanTable)obj).isList() ) {
						LuanTable list = (LuanTable)obj;
						list.rawPut(list.rawLength()+1,value);
					} else {
						LuanTable list = new LuanTable();
						list.rawPut(1,obj);
						list.rawPut(2,value);
						parametersTbl.rawPut(name,list);
					}
				}
			} catch(IOException e) {
				throw new RuntimeException(e);
			} catch(ServletException e) {
				throw new RuntimeException(e);
			}
		}

		LuanTable cookieTbl = (LuanTable)requestTbl.rawGet("cookies");
		for( Cookie cookie : request.getCookies() ) {
			cookieTbl.rawPut( cookie.getName(), unescape(cookie.getValue()) );
		}


		// response
		LuanTable responseTbl = new LuanTable();
		responseTbl.rawPut("java",response);
		LuanFunction newResponseFn = (LuanFunction)module.rawGet("new_response");
		newResponseFn.call( luan, new Object[]{responseTbl} );
		module.rawPut("response",responseTbl);

		fn.call(luan);
		handle_run_later(luan);
		return true;
	}

	public static void setResponse(LuanTable responseTbl,HttpServletResponse response) throws LuanException {
		int status = Luan.asInteger(responseTbl.rawGet("status"));
		response.setStatus(status);
		LuanTable responseHeaders = (LuanTable)responseTbl.rawGet("headers");
		for( Map.Entry<Object,Object> entry : responseHeaders.rawIterable() ) {
			String name = (String)entry.getKey();
			Object val = entry.getValue();
			if( val instanceof LuanTable ) {
				LuanTable values = (LuanTable)val;
				for( Object value : values.asList() ) {
					setResponse(response,name,value);
				}
			} else {
				setResponse(response,name,val);
			}
		}
	}

	private static void setResponse(HttpServletResponse response,String name,Object value) throws LuanException {
		if( value instanceof String ) {
			response.setHeader(name,(String)value);
			return;
		}
		Integer i = Luan.asInteger(value);
		if( i != null ) {
			response.setIntHeader(name,i);
			return;
		}
		throw new IllegalArgumentException("value must be string or integer for headers table");
	}



	// static utils

	private static String escape(String value) {
		return value.replaceAll(";", "%3B");
	}

	private static String unescape(String value) {
		return value.replaceAll("%3B", ";");
	}

	private static Cookie getCookie(HttpServletRequest request,String name) {
		Cookie[] cookies = request.getCookies();
		if( cookies == null )
			return null;
		for (Cookie cookie : cookies) {
			if (cookie.getName().equals(name))
				return cookie;
		}
		return null;
	}

	public static void setCookie(HttpServletRequest request,HttpServletResponse response,String name,String value,LuanTable attributes) {
		Cookie cookie = getCookie(request,name);
		if( cookie==null || !cookie.getValue().equals(value) ) {
			cookie = new Cookie(name, escape(value));
			if( attributes != null ) {
				String path = (String)attributes.rawGet("Path");
				if( path != null )
					cookie.setPath(path);
				String domain = (String)attributes.rawGet("Domain");
				if (domain != null && domain.length() > 0)
					cookie.setDomain(domain);
				String maxAge = (String)attributes.rawGet("Max-Age");
				if( maxAge != null )
					cookie.setMaxAge(Integer.parseInt(maxAge));
			}
			response.addCookie(cookie);
		}
	}



	private static String RUN_LATER_KEY = "Http.run_later";
	private static final Executor exec = Executors.newSingleThreadExecutor();

	public static void run_later(final LuanState luan,final LuanFunction fn,final Object... args) {
		List list = (List)luan.registry().get(RUN_LATER_KEY);
		if( list == null ) {
			list = new ArrayList();
			luan.registry().put(RUN_LATER_KEY,list);
		}
		list.add(
			new Runnable(){public void run() {
				try {
					fn.call(luan,args);
				} catch(LuanException e) {
					e.printStackTrace();
				}
			}}
		);
	}

	private static void handle_run_later(LuanState luan) {
		List list = (List)luan.registry().get(RUN_LATER_KEY);
		if( list==null )
			return;
		for( Object obj : list ) {
			exec.execute((Runnable)obj);
		}
	}
}