package eu.eudat.security.validators.google;

import java.io.FileReader;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.security.Principal;
import java.util.*;
import java.util.stream.Collector;
import java.util.stream.Collectors;

import com.google.api.client.googleapis.auth.oauth2.*;
import eu.eudat.dao.entities.security.CredentialDao;
import eu.eudat.dao.entities.security.UserTokenDao;
import eu.eudat.entities.Credential;
import eu.eudat.entities.UserToken;
import eu.eudat.models.criteria.UserInfoCriteria;
import eu.eudat.models.login.LoginInfo;
import eu.eudat.models.loginprovider.LoginProviderUser;
import eu.eudat.security.validators.TokenValidator;
import eu.eudat.security.validators.TokenValidatorFactoryImpl;
import eu.eudat.services.ApiContext;
import eu.eudat.services.AuthenticationService;
import org.springframework.beans.factory.annotation.Autowired;

import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken.Payload;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.jackson2.JacksonFactory;

import eu.eudat.dao.entities.UserInfoDao;
import eu.eudat.entities.UserInfo;
import eu.eudat.exceptions.NonValidTokenException;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;

import static com.sun.org.apache.xalan.internal.xsltc.compiler.Constants.REDIRECT_URI;

@Component("googleTokenValidator")
public class GoogleTokenValidator implements TokenValidator {

	private static final HttpTransport transport = new NetHttpTransport();
	private ApiContext apiContext;
	private AuthenticationService authenticationService;
	private GoogleIdTokenVerifier verifier;
	private Environment environment;

	@Autowired
	public GoogleTokenValidator(ApiContext apiContext, Environment environment,AuthenticationService authenticationService){
		this.apiContext = apiContext;
		this.environment = environment;
		this.authenticationService = authenticationService;
		verifier = new GoogleIdTokenVerifier.Builder(transport, JacksonFactory.getDefaultInstance())
				.setAudience(Collections.singletonList(this.environment.getProperty("google.login.clientId")))
				.build();
	}

	private GoogleIdToken verifyUserAndGetUser(String idTokenString) throws IOException, GeneralSecurityException {
		GoogleIdToken idToken = verifier.verify(idTokenString);
		return idToken;
	}

	@Override
	public eu.eudat.models.security.Principal validateToken(LoginInfo credentials) throws NonValidTokenException, IOException, GeneralSecurityException {

		GoogleIdToken idToken = this.verifyUserAndGetUser(credentials.getTicket());
		Payload payload = idToken.getPayload();
		LoginProviderUser user = new LoginProviderUser();
		user.setSecret(credentials.getTicket());
		user.setProvider(TokenValidatorFactoryImpl.LoginProvider.GOOGLE);
		user.setName((String)payload.get("name"));
		user.setEmail(payload.getEmail());
		user.setIsVerified(payload.getEmailVerified());
		return this.authenticationService.Touch(user);
	}

}