package org.gcube.common.authorization.client.proxy;

import static org.gcube.common.authorization.client.Constants.CLIENT_ID_PARAM;
import static org.gcube.common.authorization.client.Constants.CONTEXT_PARAM;

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.net.ssl.HttpsURLConnection;

import org.gcube.common.authorization.client.Binder;
import org.gcube.common.authorization.client.exceptions.ObjectNotFound;
import org.gcube.common.authorization.library.AuthorizationEntry;
import org.gcube.common.authorization.library.endpoints.AuthorizationEndpoint;
import org.gcube.common.authorization.library.endpoints.AuthorizationEndpointScanner;
import org.gcube.common.authorization.library.endpoints.EndpointsContainer;
import org.gcube.common.authorization.library.provider.UserInfo;
import org.gcube.common.authorization.library.utils.AuthorizationEntryList;
import org.gcube.common.authorization.library.utils.ListMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DefaultAuthorizationProxy implements AuthorizationProxy {

	private static Logger log = LoggerFactory.getLogger(AuthorizationProxy.class);

	private static Map<String, AuthorizationEntryCache> cache = Collections.synchronizedMap(new HashMap<String, AuthorizationEntryCache>());

	private static EndpointsContainer endpoints;

	public DefaultAuthorizationProxy() {
		if (endpoints==null)
			endpoints = AuthorizationEndpointScanner.endpoints();
	}

	private String getInternalEnpoint(int infrastructureHash){
		AuthorizationEndpoint ae = getEndpoint(infrastructureHash);
		return getInternalEnpoint(ae);
	}
	
	private String getInternalEnpoint(AuthorizationEndpoint ae){
		StringBuilder endpoint = new StringBuilder(ae.isSecureConnection()?"https://":"http://").append(ae.getHost()).append(":")
				.append(ae.getPort()).append("/authorization-service/gcube/service");
		return endpoint.toString();
	}
	

	
	@Override
	public String resolveTokenByUserAndContext(String user, String context) throws ObjectNotFound, Exception {

		String methodPath = "/token/resolve/"; 

		int infrastructureHash = Utils.getInfrastructureHashfromContext(context);

		StringBuilder callUrl = new StringBuilder(getInternalEnpoint(infrastructureHash)).append(methodPath).append(user).append("?context=").append(context);

		URL url = new URL(callUrl.toString());
		HttpURLConnection connection = makeRequest(url, "GET");

		log.debug("response code for "+callUrl.toString()+" is "+connection.getResponseCode()+" "+connection.getResponseMessage());

		if (connection.getResponseCode()==404) throw new ObjectNotFound("token not found");
		if (connection.getResponseCode()!=200) throw new Exception("error contacting authorization service (error code is "+connection.getResponseCode()+")");
		if (connection.getContentLengthLong()==0) return null;
		String token= "";
		try(BufferedReader reader = new BufferedReader(new InputStreamReader((InputStream)connection.getContent()))){
			StringBuilder result = new StringBuilder();
			String line;
			while((line = reader.readLine()) != null) 
				result.append(line);
			token =  result.toString();
		}

		return Utils.addInfrastructureHashToToken(token, infrastructureHash);
	}

	@Override
	public String generateUserToken(UserInfo client, String context) throws Exception {

		String methodPath = "/token/user"; 

		int infrastructureHash = Utils.getInfrastructureHashfromContext(context);

		StringBuilder callUrl = new StringBuilder(getInternalEnpoint(infrastructureHash)).append(methodPath).append("?")
				.append(CONTEXT_PARAM).append("=").append(context);

		URL url = new URL(callUrl.toString());
		HttpURLConnection connection = makeRequest(url, "PUT");
		connection.setDoOutput(true);
		connection.setDoInput(true);
		connection.setRequestProperty("Content-type", "application/xml");

		try(OutputStream os = new BufferedOutputStream(connection.getOutputStream())){
			Binder.getContext().createMarshaller().marshal(client, os);
		}

		log.debug("response code for "+callUrl.toString()+" is "+connection.getResponseCode()+" "+connection.getResponseMessage());

		if (connection.getResponseCode()!=200) throw new Exception("error contacting authorization service");
		String token= "";
		try(BufferedReader reader = new BufferedReader(new InputStreamReader((InputStream)connection.getContent()))){
			StringBuilder result = new StringBuilder();
			String line;
			while((line = reader.readLine()) != null) 
				result.append(line);
			token =  result.toString();
		}

		return Utils.addInfrastructureHashToToken(token, infrastructureHash);
	}

	@Override
	public void setTokenRoles(String token, List<String> roles) throws Exception {

		String realToken = Utils.getRealToken(token);
		String methodPath = String.format("/token/user/%s/roles",realToken); 

		int infrastructureHash = Utils.getInfrastructureHashFromToken(token, endpoints.getDefaultInfrastructure());

		StringBuilder callUrl = new StringBuilder(getInternalEnpoint(infrastructureHash)).append(methodPath);

		URL url = new URL(callUrl.toString());
		HttpURLConnection connection = makeRequest(url, "PUT");
		connection.setDoOutput(true);
		connection.setDoInput(true);
		connection.setRequestProperty("Content-type", "application/xml");

		ListMapper listmapper = new ListMapper(roles);
		try(OutputStream os = new BufferedOutputStream(connection.getOutputStream())){
			Binder.getContext().createMarshaller().marshal(listmapper, os);
		}

		log.debug("response code for "+callUrl.toString()+" is "+connection.getResponseCode()+" "+connection.getResponseMessage());

		if (connection.getResponseCode()!=200) throw new Exception("error contacting authorization service");

	}


	@Override
	public void removeAllReleatedToken(String clientId, String context) throws Exception{
		String methodPath = "/token/user";
		int infrastructureHash = Utils.getInfrastructureHashfromContext(context);
						
		StringBuilder callUrl = new StringBuilder(getInternalEnpoint(infrastructureHash)).append(methodPath).append("?")
				.append(CONTEXT_PARAM).append("=").append(context).append("&").append(CLIENT_ID_PARAM).append("=").append(clientId);

		URL url = new URL(callUrl.toString());
		HttpURLConnection connection = makeRequest(url, "DELETE");
		//connection.setDoOutput(false);
		connection.setDoInput(true);

		log.debug("response code for "+callUrl.toString()+" is "+connection.getResponseCode()+" "+connection.getResponseMessage());

		if (connection.getResponseCode()!=200 && connection.getResponseCode()!=204) throw new Exception("error contacting authorization service");

	}


	@Override
	public AuthorizationEntry get(String token) throws ObjectNotFound, Exception{
		String realToken = Utils.getRealToken(token);
		String maskedToken= String.format("%s********",realToken.substring(0, realToken.length()-8));
		int infrastructureHashFromToken = Utils.getInfrastructureHashFromToken(token, endpoints.getDefaultInfrastructure());
		AuthorizationEndpoint endpoint = getEndpoint(infrastructureHashFromToken);

		if (cache.containsKey(realToken) && cache.get(realToken).isValid(endpoint.getClientCacheValidity())){
			log.trace("valid entry found in cache for token {}, returning it",maskedToken);
			return cache.get(realToken).getEntry();
		} else
			log.trace("invalid entry found in cache for token {}, contacting auth service",maskedToken);

		final String methodPath = "/token/"; 

		StringBuilder callUrl = new StringBuilder(getInternalEnpoint(infrastructureHashFromToken))
				.append(methodPath).append(realToken);

		URL url = new URL(callUrl.toString());
		HttpURLConnection connection = makeRequest(url, "GET");
		connection.setDoInput(true);

		if (connection.getResponseCode()==404) throw new ObjectNotFound("token "+maskedToken+" not found");
		if (connection.getResponseCode()!=200) throw new Exception("error contacting authorization service (error code is "+connection.getResponseCode()+")");
		if (connection.getContentLengthLong()==0) return null;

		try(InputStream stream = (InputStream)connection.getContent();){
			AuthorizationEntry entry = (AuthorizationEntry)Binder.getContext().createUnmarshaller().unmarshal(stream);
			if (entry!=null) cache.put(realToken, new AuthorizationEntryCache(entry));
			return entry;
		}
	}

	@Override
	public List<AuthorizationEntry> get(List<String> tokens) throws ObjectNotFound, Exception {
		
		List<String> realTokens = new ArrayList<String>(); 
		
		List<AuthorizationEntry> toReturn = new ArrayList<AuthorizationEntry>();
		
		AuthorizationEndpoint endpoint = null;
		
		for (String token : tokens) {
			String realToken = Utils.getRealToken(token);
			
			if (cache.containsKey(realToken) && cache.get(realToken).isValid(endpoint.getClientCacheValidity()))
				toReturn.add(cache.get(realToken).getEntry());
			else realTokens.add(realToken);
			
			if (endpoint==null) {
				int infrastructureHashFromToken = Utils.getInfrastructureHashFromToken(token, endpoints.getDefaultInfrastructure());
				endpoint = getEndpoint(infrastructureHashFromToken);
			}
		}
		
		final String methodPath = "/token/bunch/?"; 

		StringBuilder callUrl = new StringBuilder(getInternalEnpoint(endpoint))
				.append(methodPath);
		
		boolean first = true;
		for (String toAppend : realTokens) {
			if (first) {
				callUrl= callUrl.append("token=").append(toAppend);
				first = false;
			} else callUrl= callUrl.append("&token=").append(toAppend);
		
		}
		
		URL url = new URL(callUrl.toString());
		HttpURLConnection connection = makeRequest(url, "GET");
		connection.setDoInput(true);

		if (connection.getResponseCode()==404) throw new ObjectNotFound("token not found");
		if (connection.getResponseCode()!=200) throw new Exception("error contacting authorization service (error code is "+connection.getResponseCode()+")");
		if (connection.getContentLengthLong()==0) return null;

		try(InputStream stream = (InputStream)connection.getContent();){
			AuthorizationEntryList entries = (AuthorizationEntryList)Binder.getContext().createUnmarshaller().unmarshal(stream);
			return entries.getEntries();
		}
	}


	private HttpURLConnection makeRequest(URL url, String method) throws Exception{
		HttpURLConnection connection;
		if (url.toString().startsWith("https://"))
			connection = (HttpsURLConnection)url.openConnection();
		else connection = (HttpURLConnection)url.openConnection();
		
		connection.setRequestMethod(method);
		return connection;
	}

	@Override
	public AuthorizationEndpoint getEndpoint(int infrastructureHash) {
		for (String infra: endpoints.getEndpoints().keySet()) {
			if (Utils.getInfrastructureHashfromContext(infra)==infrastructureHash) 
				return endpoints.getEndpoints().get(infra);
		}
		throw new RuntimeException("Authorization Endpoint not found for the required infrastructure"); 
	}

	@Override
	public void setEndpoint(EndpointsContainer newEndpoints) {
		endpoints = newEndpoints;		
	}


}