package company;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

import validation.ConsoleValidator;
import validation.Validator;

import java.util.Scanner;


public class Login {
    public static Map<String, String> users = new HashMap<>();
    public static ArrayList<Customer> customerList = new ArrayList<>();
    public static ArrayList<HashMap<String, String>> loginDetailsList = new ArrayList<>();
    Scanner sc = new Scanner(System.in);
    int numCustomers = 0;
    Validator v = new ConsoleValidator();

    /**
     * The function below asks for the username and password of the user it will
     * return the appropriate login menu depending on the login of the user
     * additionally if the "quit" command is inputed the while loop will exit
     * and the user will be returned to the main menu
     */
    public ArrayList<Customer> getCustomerList(){
        return customerList;
    }
    public String login() {
        while (true) {
            lineBreak();
            System.out.println("Type quit to return to main menu");
            System.out.println("Please enter your username: ");
            String username = sc.nextLine();

            if (username.equals("quit"))
                return "quit";
            lineBreak();
            System.out.println("Please enter your password: ");
            String password = sc.nextLine();

            if (password.equals("quit"))
                return "quit";
            if (isOwner(username, password))
                return "owner";
            if (isUser(username, password)) {
                return "customer";
            } else
                System.out.println("Invalid login details");
            lineBreak();
        }
    }

    /**
     * The register function is used when the user selects option 2 register it
     * analyzes the user name and password checking if the login details are
     * already registered as well as ensuring that the entered username or
     * password contain no spaces e.g they are only one word if the user
     * successfully registers then they are created using the HashMap as a
     * customer and their login details are stored
     */
    public void register() {

        String name = registerName();
        if(name == null)
            return;
        String username = registerUsername();
        if(username == null)
            return;
        String password = registerPassword();
        if(password == null)
            return;


        writeUsernameAndPasswordToFile(username, password, name);

        HashMap<String, String> hm = new HashMap<String, String>();
        hm.put(username, password);
        loginDetailsList.add(hm);
        customerList.add(new Customer(loginDetailsList.get(numCustomers), null, false));
        numCustomers++;
        return;

    }

    /**
     * As suggested by the name of this function it is used to write the
     * username and password to the customerinfo.txt file as a string,
     * additionally it is specified to write the username and password on one
     * line with a space in between and then move to the following line for the
     * next input
     */
    public void writeUsernameAndPasswordToFile(String username, String password, String name) {
        String fileName = "customerinfo.txt";
        try {
            FileWriter fw = new FileWriter(fileName, true);
            BufferedWriter bw = new BufferedWriter(fw);
            bw.write(username + " " + password + " " + name);
            bw.newLine();
            bw.close();
            lineBreak();
            System.out.println("Successfully registered!");
        } catch (IOException ex) {
            System.out.println("Error writing to file '" + fileName + "'");
        }
        createUsersFromFile();
    }

    /**
     * This function is used to authenticate the user input with the stored key
     * value if the user does not exist it will return false and an error
     * message will be printed in the function that userExists is called
     */
    public boolean userExists(String username) {
        for (Entry<String, String> entry : users.entrySet()) {
            String key = entry.getKey();
            if (key.equals(username)) {
                return true;
            }
        }
        return false;
    }

    // Store all details from file
    public void createUsersFromFile() {
        String fileName = "customerinfo.txt";
        String line = null;

        try {
            BufferedReader br = new BufferedReader(new FileReader(fileName));
            while ((line = br.readLine()) != null) {
                String delims[] = line.split(" ");
                users.put(delims[0], delims[1]);
            }
            br.close();
        } catch (FileNotFoundException ex) {
            System.out.println("Unable to open file '" + fileName + "'");
        } catch (IOException ex) {
            System.out.println("Error reading file '" + fileName + "'");
        }
        for (Entry<String, String> entry : users.entrySet()) {
            String username = entry.getKey();
            String password = entry.getValue();

            // create a customer and store their login details
            HashMap<String, String> hm = new HashMap<String, String>();
            hm.put(username, password);
            loginDetailsList.add(hm);
            customerList.add(new Customer(loginDetailsList.get(numCustomers), null, false));
            numCustomers++;
        }
    }

    /**
     * This function authenticates the login of the business owner by opening up
     * the business.txt where the details for the business owner are stored and
     * then comparing them to the login details the user has entered if the file
     * is not found or there is an issue reading the file an appropriate error
     * message is displayed.
     */
    public boolean isOwner(String username, String password) {
        String fileName = "business.txt";
        String line = null;
        try {
            BufferedReader br = new BufferedReader(new FileReader(fileName));
            while ((line = br.readLine()) != null) {
                String delims[] = line.split(" - ");
                for (int i = 0; i < delims.length; ++i) {
                    if (delims[i].equals("Username") && delims[i + 1].equals(username)) {
                    }
                }
                for (int i = 0; i < delims.length; ++i) {
                    if (delims[i].equals("Password") && delims[i + 1].equals(password)) {
                        return true;
                    }
                }
            }
            br.close();
        } catch (FileNotFoundException ex) {
            System.out.println("Unable to open file '" + fileName + "'");
        } catch (IOException ex) {
            System.out.println("Error reading file '" + fileName + "'");
        }
        return false;
    }

    /**
     * This function simply compares the username and the password that the
     * customer has entered with the stored key in the customer list, if they
     * match the user is greeted with a welcome message
     */
    public boolean isUser(String username, String password) {
        if (users.containsKey(username)) {
            if (users.get(username).equals(password)) {
                System.out.println("Welcome " + username);
                System.out.println(" ");
                for (int i = 0; i < customerList.size(); ++i) {
                    if (customerList.get(i).getLoginDetails().containsKey(username)) {
                        customerList.get(i).setLoggedOn(true);
                    }
                }
                return true;
            } else
                return false;
        } else
            return false;
    }


    public String registerName() {
        lineBreak();
        System.out.println("Type quit to return to main menu");
        System.out.println("Please enter your first name:");
        String firstName = sc.nextLine();
        if (!v.validInput(firstName, "letters"))
            return null;

        lineBreak();
        System.out.println("Please enter your last name:");
        String lastname = sc.nextLine();
        if (!v.validInput(lastname, "letters"))
            return null;

        String name = firstName + " " + lastname;
        return name;

    }

    public String registerUsername() {
        lineBreak();
        System.out.println("Please enter your new username: ");
        System.out.println("(Minimum of 4 Characters)");
        String username = sc.nextLine();

        if (!v.validInput(username, "letters and numbers"))
            return null;
        if (userExists(username)) {
            System.out.println("User already exists");
            return null;
        }
        return username;
    }

    public String registerPassword() {
        lineBreak();
        System.out.println("Please enter your password: ");
        System.out.println("Password must contain the following:");
        System.out.println("    Have a minumum of 8 characters");
        System.out.println("    Have a maximum of 20 characters");
        System.out.println("    At least one uppercase letter");
        System.out.println("    At least one lowercase letter");
        System.out.println("    At lease one special character");
        System.out.println("    At least one number");
        String password = sc.nextLine();
        lineBreak();
        if(!v.validInput(password, "password"))
            return null;
        System.out.println("Please re-enter your password: ");
        String password2 = sc.nextLine();
        if (!password.equals(password2)) {
            lineBreak();
            System.out.println("ERROR - password mismatch. Registration was not successful");
            lineBreak();
            return null;
        }
        return password;

    }

    public void lineBreak() {
        System.out.println();
    }
}