package luan.modules.http;

import java.io.Closeable;
import java.io.Writer;
import java.io.PrintWriter;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.BindException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import luan.webserver.Request;
import luan.webserver.Response;
import luan.webserver.Server;
import luan.webserver.Handler;
import luan.webserver.ResponseOutputStream;
import luan.Luan;
import luan.LuanState;
import luan.LuanTable;
import luan.LuanFunction;
import luan.LuanJavaFunction;
import luan.LuanCloner;
import luan.LuanException;
import luan.modules.PackageLuan;
import luan.modules.BasicLuan;


public final class LuanHandler implements Handler, Closeable {
	private final LuanState luanInit;
	private final Logger logger;
	private volatile LuanState luan;

	private static final Method resetLuanMethod;
	private static final Method evalInRootMethod;
	static {
		try {
			resetLuanMethod = LuanHandler.class.getMethod( "reset_luan" );
			evalInRootMethod = LuanHandler.class.getMethod( "eval_in_root", String.class );
		} catch(NoSuchMethodException e) {
			throw new RuntimeException(e);
		}
	}

	public LuanHandler(LuanState luanInit,String loggerRoot) {
		this.luanInit = luanInit;
		if( loggerRoot==null )
			loggerRoot = "";
		logger = LoggerFactory.getLogger(loggerRoot+LuanHandler.class.getName());
		try {
			LuanTable Http = (LuanTable)PackageLuan.require(luanInit,"luan:http/Http.luan");
			Http.rawPut( "reset_luan", new LuanJavaFunction(resetLuanMethod,this) );
			Http.rawPut( "eval_in_root", new LuanJavaFunction(evalInRootMethod,this) );
		} catch(LuanException e) {
			throw new RuntimeException(e);
		}
		setLuan();
		luanInit.onClose(this);
	}

	public LuanState getLuan() {
		return luan;
	}

	private void setLuan() {
		LuanCloner cloner = new LuanCloner(LuanCloner.Type.COMPLETE);
		luan = (LuanState)cloner.clone(luanInit);
		try {
			PackageLuan.load(luan,"site:/init.luan");
		} catch(LuanException e) {
			String err = e.getLuanStackTraceString();
			logger.error(err);
		}
	}

	@Override public Response handle(Request request) {
		if( request.path.endsWith("/") )
			return null;
		String modName = "site:" + request.path +".luan";
		return handle(request,modName);
	}

	Response handle(Request request,String modName) {
		Thread thread = Thread.currentThread();
		String oldName = thread.getName();
		thread.setName(request.headers.get("host")+request.path);
		try {
			return HttpServicer.service(luan,request,modName);
		} finally {
			thread.setName(oldName);
		}
	}

	public void close() {
		synchronized(luan) {
			luan.close();
		}
	}

	public Object call_rpc(String fnName,Object... args) throws LuanException {
		LuanFunction fn;
		LuanState luan = this.luan;
		synchronized(luan) {
			PackageLuan.enableLoad(luan,"luan:Rpc.luan");
			LuanTable rpc = (LuanTable)PackageLuan.require(luan,"luan:Rpc.luan");
			LuanTable fns = (LuanTable)rpc.get(luan,"functions");
			fn = (LuanFunction)fns.get(luan,fnName);
			if( fn == null )
				throw new LuanException( "function not found: " + fnName );
			LuanCloner cloner = new LuanCloner(LuanCloner.Type.INCREMENTAL);
			luan = (LuanState)cloner.clone(luan);
			fn = (LuanFunction)cloner.get(fn);
		}
		return fn.call(luan,args);
	}

	public void reset_luan() {
		setLuan();
	}

	public Object runLuan(String sourceText,String sourceName) throws LuanException {
		LuanFunction fn = Luan.load(sourceText,sourceName);
		synchronized(luan) {
			LuanCloner cloner = new LuanCloner(LuanCloner.Type.INCREMENTAL);
			LuanState luan = (LuanState)cloner.clone(this.luan);
			return fn.call(luan);
		}
	}

	public void eval_in_root(String text) throws LuanException {
		LuanState luan;
		synchronized(this.luan) {
			LuanCloner cloner = new LuanCloner(LuanCloner.Type.COMPLETE);
			luan = (LuanState)cloner.clone(this.luan);
		}
		BasicLuan.load(text,"<eval_in_root>",null).call(luan);
		this.luan = luan;
	}

	public static void start(Server server) throws Exception {
		try {
			server.start();
		} catch(BindException e) {
			throw new LuanException(e.toString());
		}
	}

}