import java.util.ArrayList;
import java.util.Scanner;
import java.util.concurrent.TimeUnit;

import static java.lang.System.out;
import static java.lang.System.err;

public class Main {

    /**
    main() launches start()
    start() is the main method to allow other methods to return to the start method without having to pass String[] args
     */
    public static void main(String[] args) throws Exception {

        start();
    }

    /**
    start() controls the initial page of the program
    prompts users to either register a user or login using an existing account
    if there are no users registered it will not attempt to log in
    if the register returns a null value (registration failed) it will not add it to the list of known users
     */
    public static void start() throws Exception {

        ArrayList<User> users = new ArrayList<>();
        Scanner scanner = new Scanner(System.in);

        while(true) {


            // print formatted front page
            out.print("+----------------------------+\n" +
                    "| 1. Login                   |\n" +
                    "| 2. Register                |\n" +
                    "+----------------------------+\n" +
                    "\nPlease, select an option: ");

            // take in the option given and give it to the switch statement
            int option = 0;
            if (scanner.hasNextInt()) {
                option = scanner.nextInt();
            }

            switch (option) {
                // pass the users ArrayList to login() validation method
                // if no users exist abort the operation
                case 1:
                    System.out.println(users.size());
                    if(users.size() > 0) {
                        login(users);
                    } else {
                        err.println("\nNo users are registered\n");
                    }
                    TimeUnit.MILLISECONDS.sleep(5);
                    break;
                // initiate register() and create a user out of the parameters passed through the console
                // add the returned user to the users list, if the user returned is null remove the null value from the list
                case 2:
                    User user = register();
                    if(user != null) {
                        users.add(user);
                    }
                    System.out.println(users.size());
                    break;
                default:
                    err.println("\nError: invalid choice\nTry typing a number 1 or 2\n");
                    TimeUnit.MILLISECONDS.sleep(5);
                    break;
            }
        }
    }

    /**
    a simple validation method to verify that the user being created has proper credentials
    returns the user created if values passed through console are all valid
    returns null if user fails any validation check
     */
    public static User register() throws Exception {

        Scanner scanner = new Scanner(System.in);

        System.out.print("\nPlease enter a valid email: ");
        String email = scanner.nextLine();

        // If email is valid
        if (email.contains("@") && email.contains(".")) {
            out.print("Please enter your first and last name: ");
            String name = scanner.nextLine();

            // If name is valid
            if (name.contains(" ")) {
                out.print("Please enter a password at least 6 characters long: ");
                String pwd = scanner.nextLine();

                // If password is valid
                if (pwd.length() >= 6) {
                    User user = new User(email, name, pwd);
                    out.println(" ");
                    return user;

                // Error messages
                } else {
                    err.println("\nInvalid password,, must be at least 6 characters long\n");
                    TimeUnit.MILLISECONDS.sleep(5);
                }
            } else {
                err.println("\nInvalid name, needs to include a space\n");
                TimeUnit.MILLISECONDS.sleep(5);
            }
        } else {
            err.println("\nInvalid email, must contain a '@' and '.' character\n");
            TimeUnit.MILLISECONDS.sleep(5);
        }
        return null;
    }

    /**
    if the login method is invoked it will prompt the user for their login credentials
    it will then scan through the list of known users to validate that both the email exists and that the password give matches that email's stored password
     */
    public static void login(ArrayList<User> users) throws Exception {

        // cust ArrayList stores customers created
        // log ArrayList stores support tickets created
        ArrayList<Customer> cust = new ArrayList<>();
        ArrayList<Support> log = new ArrayList<>();

        Scanner scanner = new Scanner(System.in);

        // prompt the user for their email and password for their account
        out.println("\nEnter your email: ");
        String email = scanner.nextLine();
        out.print("Enter your password: ");
        String pwd = scanner.nextLine();

        /**
        for users in list
        validate that email exists in list
        validate that the password give matches the of the email given
         */
        for(int i = 0; i < users.size(); i++){
            if(users.get(i).email.equals(email)){
                email = users.get(i).email;
                for(User user : users){
                    if(user.getPwd().equals(pwd)){

                        while (true) {

                            // print the second screen
                            out.print("\n+----------------------------+\n" +
                                    "| 1. Add new customer        |\n" +
                                    "| 2. Remove customer         |\n" +
                                    "| 3. List all customers      |\n" +
                                    "| 4. Add support visit log   |\n" +
                                    "| 5. View stats              |\n" +
                                    "| 0. Logout                  |\n" +
                                    "+----------------------------+\n" +
                                    "\nPlease, select an option: ");

                            // take in the option given and give it to the switch statement
                            int option = 0;
                            if (scanner.hasNextInt()) {
                                option = scanner.nextInt();
                            }

                            switch (option) {
                                case 0: // return to login start() / login screen
                                    System.out.println("\n[Logging out]\n");
                                    start();
                                case 1: // branch to add() to take in customer credentials and store them in the cust ArrayList
                                    Customer customer = add();
                                    cust.add(customer);
                                    break;
                                case 2: // branch to remove() to remove a given customer from cust ArrayList
                                    remove(cust);
                                    break;
                                case 3: // branch to list() to list all users stored in the cust ArrayList and prints their information
                                    list(cust);
                                    break;
                                case 4: // branch to support() to add a new support ticket and stores the ticket in the log ArrayList
                                    Support support = support();
                                    log.add(support);
                                    break;
                                case 5: // branch to view() and prints stats about the total number of hours spent on support and the user that has spent the most (money)
                                    view(log, cust);
                                    break;
                                default:
                                    err.println("\nError: invalid choice\nTry typing a number 1 or 2\n");
                                    TimeUnit.MILLISECONDS.sleep(5);
                                    break;
                                }
                            }
                        } else {
                        // if password given is invalid
                        err.println("\nPassword is incorrect\n");
                        TimeUnit.MILLISECONDS.sleep(5);
                    }
                    }
                } else {
                // if email given is invalid
                System.out.println(users.get(i).email);
                err.println("\nEmail " + email + " does not exist\n");
                TimeUnit.MILLISECONDS.sleep(5);
            }
            }
        }

    /**
    collects information about a customer
    creates a customer object based on parameters passed through command line
    returns created customer to be added to cust ArrayList
     */
    private static Customer add() {

        // take input
        Scanner scanner = new Scanner(System.in);
        out.print("\n[Add a new customer]\n\nEnter the customer ID: ");
        String id = scanner.nextLine();
        out.print("Enter the customer name: ");
        String name = scanner.nextLine();
        out.print("Enter the customer email: ");
        String email = scanner.nextLine();
        out.print("Enter the customer phone: ");
        String phone = scanner.nextLine();
        out.print("Enter the address latitude: ");
        String latitude = scanner.nextLine();
        out.print("Enter the address longitude: ");
        String longitude = scanner.nextLine();
        out.println(" ");

        // create customer
        Customer customer = new Customer(id, name, email, phone, latitude, longitude);

        return customer;
    }

    /**
    prompts the user for an id of a customer to remove from the cust ArrayList
    if the id given exists in the cust ArrayList, remove it from the list
     */
    private static void remove(ArrayList<Customer> cust) {

        String id;

        // prompt user for the ID of the customer to remove
        Scanner scanner = new Scanner(System.in);
        out.print("\nEnter an ID to remove: ");
        id = scanner.nextLine();

        // for each customer in the cust ArrayList
        // if the id given equals the customer's id, remove that customer from the list
        for(int i = 0; i < cust.size(); i++){
            if(id == cust.get(i).id){
                cust.remove(i);
            }
        }
    }

    /**
    lists the information about every customer in the cust ArrayList
     */
    private static void list(ArrayList<Customer> cust) {

        System.out.println("\n[List all customers]");

        // for every customer in cust ArrayList, get that customer's credentials and print them
        for (int i = 0; i < cust.size(); i++) {
            out.println("\nCustomer ID: " + cust.get(i).id);
            out.println("Name: " + cust.get(i).name);
            out.println("Email: " + cust.get(i).email);
            out.println("Phone: " + cust.get(i).phone);

            // format latitude and longitude to be a google maps link
            out.println("Google maps link: https://www.google.com/maps/?q=" + cust.get(i).latitude + "," + cust.get(i).longitude + "\n");
        }
    }

    /**
    prompts user for input to create a new support ticket
     */
    private static Support support() {

        // collect informatino about the support ticket
        Scanner scanner = new Scanner(System.in);
        out.print("\n[Add a new support visit]\n" +
                "\nEnter the customer ID of the support: ");
        String id = scanner.nextLine();
        out.print("Enter the day: ");
        String day = scanner.nextLine();
        out.print("Enter the month: ");
        String month = scanner.nextLine();
        out.print("Enter the year: ");
        String year = scanner.nextLine();
        out.print("Enter the amount of support hours: ");
        int hours = scanner.nextInt();
        out.print("Enter the amount paid: ");


        /** For whatever reason the program will not run the scanner.nextLine() unless there are both of them
            So here's a piece of code that makes it work but I have no idea why this is happening */
        String weirdBud = scanner.nextLine();


        int paid = scanner.nextInt();
        out.println("\nNew support record added!");

        // create a new support ticket based on information given in command line
        Support support = new Support(id, day, month, year, hours, paid);

        // returns support ticket instantiated to be added to the log ArrayList
        return support;
    }

    /**
    prints the total number of hours in all support tickets
    prints the ID and name of the customer that has spent the most (money)
     */
    private static void view(ArrayList<Support> log, ArrayList<Customer> cust) {

        int time = 0;
        int count = 0;
        String id = "";
        String name = "";

        // for every support ticket create
        // add the sum of the time specified in each ticket
        // if support ticket being tested paid is larger than stored paid value (count) get the customer id on that ticket
        // for every customer in the cust ArrayList
        // check if the ID on the ticket is assigned to any customer in the cust ArrayList
        // if it is, set ID equal to the ID of that customer and name equal to the name of the customer associated with that ID
        for(int i = 0; i < log.size(); i++){
            time = time + log.get(i).hours;
            if(log.get(i).paid > count){
                count = log.get(i).paid;
                id = log.get(i).id;
                for(Customer customer : cust){
                    if(customer.getId().equals(id)){
                        name = cust.get(i).name;
                    }
                }
            }
        }

        // print stats determined about the support ticket
        out.println("\n[View stats of support logs]\n" +
                "Total number of hours spent on support: " + time +"\n\n" +
                "Customer that has spent the most (money) on support:\nID: " + id + "\n" +
                "Name: " + name);
    }
}

/**
support class stores information about support tickets created
 */
class Support {

    String id;
    String day;
    String month;
    String year;
    int hours;
    int paid;

    public Support(String id, String day, String month, String year, int hours, int paid){
        this.id = id;
        this.day = day;
        this.month = month;
        this.year = year;
        this.hours = hours;
        this.paid = paid;
    }
}

/**
user class stores information about users created for initial login screen
 */
class User {

    String email;
    String name;
    String pwd;

    public User(String email, String name, String pwd){
        this.email = email;
        this.name = name;
        this.pwd = pwd;
    }

    public String getPwd() {
        return pwd;
    }
}

/**
customer class stores information about customers to be stored in the cust ArrayList
 */
class Customer {

    String id;
    String name;
    String email;
    String phone;
    String latitude;
    String longitude;

    public Customer(String id, String name, String email, String phone, String latitude, String longitude){
        this.id = id;
        this.name = name;
        this.email = email;
        this.phone = phone;
        this.latitude = latitude;
        this.longitude = longitude;
    }

    public String getId() {
        return id;
    }
}