package login;

import java.io.Serializable;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.concurrent.TimeUnit;

import javax.annotation.PostConstruct;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

import dao.entities.security.UserAuthDao;
import dao.entities.security.UserInfoDao;
import entities.security.UserAuth;
import entities.security.UserInfo;
import security.TokenSessionManager;


@RestController
@CrossOrigin
public class Login {

	
	@Autowired private UserInfoDao userInfoDao;
	@Autowired private UserAuthDao userAuthDao;
	
	@Autowired private TokenSessionManager tokenSessionManager; 
	
	
	
	@RequestMapping(method = RequestMethod.POST, value = { "/nativeLogin" }, consumes = "application/json", produces = "application/json")
	public @ResponseBody ResponseEntity<String> nativeLogin(@RequestBody Credentials credentials) {
		
		String token = null;
		
		if(credentials == null || credentials.getPassword() == null || credentials.getUsername() ==null || 
				credentials.getPassword().isEmpty() || credentials.getUsername().isEmpty()) {
			return ResponseEntity.status(HttpStatus.BAD_REQUEST).body("Username and/or password cannot be empty.");
		}

		UserAuth userAuth = userAuthDao.getUserAuthBy(credentials.getUsername());
		
		if(userAuth == null) userAuth = new UserAuth();
		
		String userHash = userAuth.getPassword();
		
		String providedHash = "";
		try {
			providedHash = tokenSessionManager.hashPassword(credentials.getPassword());
		}
		catch(NoSuchAlgorithmException ex) {
			return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("Internal error. Cannot authenticate.");
		}
		
		if(userHash == null || "".equals(userHash) || !userHash.equals(providedHash)) {
			return ResponseEntity.status(HttpStatus.NOT_ACCEPTABLE).body("Wrong username or password");
		}
		else if(userHash.equals(providedHash)) {
			// create a token
			token = tokenSessionManager.generateRandomAlphanumeric(512);
			// add it to the cache 
			tokenSessionManager.set(token, credentials.getUsername());
		}
		
		//get also the additional info of the user (if he has)
		UserInfo userInfo = userInfoDao.getByAuthenticationId((userAuth.getId() == null) ? "" : userAuth.getId().toString());
		if(userInfo == null) userInfo = new UserInfo();
		
		Response response = new Response();
		response.setToken(token);
		response.setEmail(userInfo.getEmail());
		response.setName(userInfo.getName());
		response.setUsername(credentials.getUsername());
		
		return new ResponseEntity<String>(response.toJson(), HttpStatus.OK);
		
	}
	
	
}

class Credentials implements Serializable{
	
	private static final long serialVersionUID = 3519634756673886633L;
	
	private String username;
	private String password;
	
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	
}

class Response implements Serializable {

	private static final long serialVersionUID = -3855159530298902864L;
	
	private String token;
	private String username;
	private String email;
	private String name;
	
	
	public String getToken() {
		return token;
	}

	public void setToken(String token) {
		this.token = token;
	}

	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	
	public String toJson() {
		ObjectMapper objMapper = new ObjectMapper();
		try {
			return objMapper.writeValueAsString(this);
		}
		catch(JsonProcessingException ex) {
			return "{}";
		}
	}
	
}