source: src/main/java/com/project/beautycenter/web/LoginController.java

package com.project.beautycenter.web;

import com.project.beautycenter.model.Users;
import com.project.beautycenter.model.exceptions.InvalidArgumentException;
import com.project.beautycenter.service.UsersService;
import com.project.beautycenter.service.VraboteniService;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;

import javax.servlet.http.HttpServletRequest;

@Controller
public class LoginController {
    private final UsersService usersService;
    private final PasswordEncoder passwordEncoder;
    private final VraboteniService vraboteniService;

    public LoginController(UsersService usersService, PasswordEncoder passwordEncoder, VraboteniService vraboteniService) {
        this.usersService = usersService;
        this.passwordEncoder = passwordEncoder;
        this.vraboteniService = vraboteniService;
    }

    @GetMapping("/login")
    public String showLoginForm(@RequestParam(required = false) String hasError,
                                @RequestParam(required = false) String error, Model model) {
        model.addAttribute("hasError", hasError);
        model.addAttribute("error", error);
        return "login_form.html";
    }

    @PostMapping("/login")
    public String login(HttpServletRequest request) {

        try {
            Users users = this.usersService.login(request.getParameter("username"),
                    request.getParameter("password"));
            request.getSession().setAttribute("user", users);
            if (users != null)
                return "redirect:/home";
            else return "redirect:/login?hasError=true&error=BadCredentials";
        } catch (InvalidArgumentException exception) {
            return "redirect:/login?hasError=true&error=" + exception.getMessage();

        }
    }


    @GetMapping("/logout")
    public String logout(HttpServletRequest request) {
        request.getSession().invalidate();
        return "redirect:/home";
    }

}