using Ophelias.Models;
using System.Data.SQLite;

namespace Ophelias.Managers
{
    internal static class Hotel
    {
        /*
         * This class is a large collection of SQL queries that did not belong
         * on a specific model. As a result they are viewed as functions of the "Hotel".
         * For details on what each does, see their docstrings. All queries here are
         * written using parameters to avoid SQL injection.
         */
        internal static (List<(DateTime, int, string, string)>, List<int>) GetDailyOccupancy()
        {
            /*
             * This function gets the daily occupancies by joining the reservation table
             * with the guests and rooms table. It looks for where the current date is between
             * any active/ changed reservation's, that has been checked in, start and end date.
             * The query is then put in ascending order, or, organized by room number.
             */
            List<int> previousOccupancies = new();
            List<(DateTime, int, string, string)> currentOccupancies = new();
            using (Database Manager = new()) // Open a new database connection
            {
                using SQLiteTransaction Transaction = Manager.con.BeginTransaction(); // Being a new SQL transaction
                using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Create a new command to execute
                {
                    cmd.CommandText = "SELECT RoomNum, Lname, Fname, EndDate FROM reservations " +
                      "INNER JOIN guests ON reservations.GuestID = guests.ID " +
                      "INNER JOIN rooms ON reservations.RoomNum = rooms.ID " +
                      "WHERE (DATE(@Date) BETWEEN StartDate AND EndDate) AND Status IN (@Status1,@Status2) AND CheckIn IS NOT NULL " +
                      "ORDER BY RoomNum ASC;";
                    cmd.Parameters.AddWithValue("@Date", DateTime.Now.Date.ToString("yyyy-MM-dd"));
                    cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                    cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);
                    using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new reader to read the SQL data
                    while (reader.Read())
                    {
                        currentOccupancies.Add((reader.GetDateTime(3), reader.GetInt32(0), reader.GetString(1), reader.GetString(2)));
                    }
                }
                using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Create a new command to execute
                {
                    cmd.CommandText = "SELECT RoomNum FROM reservations " +
                      "INNER JOIN guests ON reservations.GuestID = guests.ID " +
                      "INNER JOIN rooms ON reservations.RoomNum = rooms.ID " +
                      "WHERE DATE (DATE(@Date) BETWEEN StartDate AND EndDate) AND Status IN (@Status1);";
                    cmd.Parameters.AddWithValue("@Date", DateTime.Now.AddDays(-1).Date.ToString("yyyy-MM-dd"));
                    cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Ended);
                    using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new reader to read the SQL data
                    while (reader.Read())
                    {
                        foreach (int item in reader.GetValues())
                        {
                            previousOccupancies.Add(item);
                        }
                    }
                }
                Transaction.Commit(); // Commit the transaction changes if any made
            }
            return (currentOccupancies, previousOccupancies);
        }
        internal static List<Reservation> GetDailyArrivals()
        {
            /*
             * This function queries for daily arrivals. A daily arrival is considered to be someone
             * that arrives on the current date and has an active or changed reservation status.
             * Using these conditions, the transaction and guest table are joined and then the
             * data is ordered by the guests last name in ascending order.
             */
            List<Reservation> reservations = new();
            using (Database Manager = new()) // Open a new database connection
            {
                using SQLiteCommand cmd = Manager.con.CreateCommand(); // Create a new command to execute
                cmd.CommandText = "SELECT * FROM reservations " +
                      "INNER JOIN transactions ON reservations.TransactionID = transactions.ID " +
                      "INNER JOIN guests ON reservations.GuestID = guests.ID " +
                      "WHERE DATE (@Date) = StartDate AND Status IN (@Status1,@Status2)" +
                      "ORDER BY Lname ASC;";
                cmd.Parameters.AddWithValue("@Date", DateTime.Now.Date.ToString("yyyy-MM-dd"));
                cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);
                using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new reader to read the SQL data
                while (reader.Read())
                {
                    /*
                     * Since we cannot get by string keys, each column is represented by a numerical value
                     * like an array. The column is as follows:
                     * 
                     *      0. ID (reservations.ID)
                     *      1. RoomNum
                     *      2. GuestID
                     *      3. TransactionID
                     *      4. IsNoShow
                     *      5. Type
                     *      6. Status
                     *      7. CreationDate
                     *      8. StartDate
                     *      9. EndDate
                     *     10. CheckIn
                     *     11. CheckOut
                     *     12. DateChanged
                     *     13. ID (rooms.ID)
                     *     14. Rate
                     *     15. Owed
                     *     16. Penalty
                     *     17. Multiplier
                     *     18. RefundAmount
                     *     19. AmountPaid
                     *     20. PayBy
                     *     21. LastPaid
                     *     22. PaidOn
                     *     23. ID (guests.ID)
                     *     24. Fname
                     *     25. Lname
                     *     26. Email
                     *     27. CreditCard
                     *     28. Expiration
                     *     29. CCV
                     *     
                     */
                    Reservation? r;
                    Transaction? t;
                    Guest g;
                    int? RoomNumber = null;
                    DateTime? CheckIn = null, CheckOut = null, DateChanged = null, LastPaid = null, PaidOn = null;

                    if (reader.HasRows && !reader.IsDBNull(0))
                    {
                        if (reader[21].GetType() != typeof(DBNull))
                        {
                            LastPaid = reader.GetDateTime(21);
                        }

                        if (reader[22].GetType() != typeof(DBNull))
                        {
                            PaidOn = reader.GetDateTime(22);
                        }

                        t = new(reader.GetInt32(13), reader.GetDouble(14), reader.GetDouble(15), reader.GetDouble(17), reader.GetDateTime(20),  // Creates a new transaction implicitly
                            LastPaid: LastPaid, PaidOn: PaidOn, RefundAmount: reader.GetDouble(18), Penalty: reader.GetDouble(16), AmountPaid: reader.GetDouble(19));

                        g = new(reader.GetInt32(23), reader.GetString(24), reader.GetString(25), reader.GetString(26), reader.GetString(27), reader.GetString(28), reader.GetString(29));  // Creates a new guest implicitly

                        if (reader[1].GetType() != typeof(DBNull))
                        {
                            RoomNumber = reader.GetInt32(1);
                        }

                        if (reader[10].GetType() != typeof(DBNull))
                        {
                            CheckIn = reader.GetDateTime(10);
                        }

                        if (reader[11].GetType() != typeof(DBNull))
                        {
                            CheckOut = reader.GetDateTime(11);
                        }

                        if (reader[12].GetType() != typeof(DBNull))
                        {
                            DateChanged = reader.GetDateTime(12);
                        }

                        r = new(reader.GetInt32(0), g, t, (ReservationType)reader.GetInt32(5), (ReservationStatus)reader.GetInt32(6),  // Creates a new reservation implicitly
                            reader.GetDateTime(7), reader.GetDateTime(8), reader.GetDateTime(9), RoomNum: RoomNumber, IsNoShow: reader.GetBoolean(4),
                            CheckIn: CheckIn, CheckOut: CheckOut, DateChanged: DateChanged);
                        reservations.Add(r);
                    }
                }
            }
            return reservations;
        }
        internal static (double, double, List<(DateTime, double)>) GetIncentiveTransactions()
        {
            /*
             * Creates a list of incentive transactions based on a query that gets reservations, and their associated transactions,
             * if they match the Incentive type and are active and changed. The matching dates and rates and amount owed are caluclated
             * to produce a new column losses. The losses are then added to a list, averaged, and totalled. These are returned.
             */
            double losses;
            double totalLosses = 0;
            int days = 30;
            DateTime dt = DateTime.Now;
            List<(DateTime, double)> dailyLosses = new();
            using (Database Manager = new()) // Create a new database connection
            {
                for (int i = 0; i < days; i++)
                {
                    using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Create a new command to execute
                    {
                        cmd.CommandText = "SELECT sum(((julianday(EndDate) - julianday(StartDate)) * transactions.Rate) - transactions.Owed) AS Loss " +
                                          "FROM reservations " +
                                          "INNER JOIN transactions ON reservations.TransactionID = transactions.ID " +
                                          "WHERE (DATE(@Date) BETWEEN StartDate AND EndDate) AND STATUS IN (@Status1,@Status2) AND Type = @Type";
                        cmd.Parameters.AddWithValue("@Date", dt.AddDays(i).Date.ToString("yyyy-MM-dd"));
                        cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                        cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);
                        cmd.Parameters.AddWithValue("@Type", (int)ReservationType.Incentive);
                        using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new reader to read the SQL data
                        reader.Read();
                        if (reader.HasRows && !reader.IsDBNull(0))
                        {
                            totalLosses += reader.GetDouble(0);
                            losses = reader.GetDouble(0);
                        }
                        else // No losses found
                        {
                            losses = 0;
                        }
                    }
                    dailyLosses.Add((dt.AddDays(i), losses));
                }
            }
            return (totalLosses, totalLosses / 30, dailyLosses);
        }
        internal static (List<(DateTime, double)>, double, double) GetExpectedIncomeCount()
        {
            /*
             * This query gets the the expected income for the next thirty days. The query looks
             * for and sums transactions that cover the specified date range and are active or
             * changed in status. The expected income is averaged as well and returned as daily
             * values.
             */
            double totalIncome = 0;
            double income;
            int days = 30;
            DateTime dt = DateTime.Now;
            List<(DateTime, double)> dailyIncomes = new();
            using (Database Manager = new()) // Create a new database connection
            {
                for (int i = 0; i < days; i++)
                {
                    using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Create a new command to execute
                    {
                        cmd.CommandText = "SELECT sum(transactions.Owed) FROM reservations " +
                                           "INNER JOIN transactions ON reservations.TransactionID = transactions.ID " +
                                           "WHERE (DATE(@Date) BETWEEN StartDate AND EndDate) AND Status IN (@Status1,@Status2);";
                        cmd.Parameters.AddWithValue("@Date", dt.AddDays(i).Date.ToString("yyyy-MM-dd"));
                        cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                        cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);

                        using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new reader to read the SQL data
                        reader.Read();
                        if (reader.HasRows && !reader.IsDBNull(0))
                        {
                            totalIncome += reader.GetDouble(0);
                            income = reader.GetDouble(0);
                        }
                        else
                        {
                            income = 0;
                        }
                    }
                    dailyIncomes.Add((dt.AddDays(i), income));
                }
            }
            return (dailyIncomes, totalIncome, totalIncome / 30);
        }
        internal static (double, List<(DateTime, int, int, int, int, int)>) GetExpectedOccupancyCount()
        {
            /*
             * This function gets the expected occupancy for the next thirty days. The query looks for
             * active or changed reservations based on the current date between matching reservations
             * start and end dates. It also runs the query for all and each reservation respectively.
             */
            double thirtyDayOcc = 0;
            int days = 30;
            DateTime dt = DateTime.Now;
            List<(DateTime, int, int, int, int, int)> occData = new();
            using (Database Manager = new()) // Create a new database connection
            {
                for (int i = 0; i < days; i++)
                {
                    int rooms, conventional, prepaid, sixty, incentive;
                    using (SQLiteTransaction Transaction = Manager.con.BeginTransaction()) // Create a new transaction
                    {
                        using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Create a new command to execute
                        {
                            cmd.CommandText = "SELECT COUNT(*) " +
                                              "FROM reservations " +
                                              "WHERE (DATE(@Date) BETWEEN StartDate AND EndDate) AND Status in (@Status1,@Status2);";
                            cmd.Parameters.AddWithValue("@Date", dt.AddDays(i).Date.ToString("yyyy-MM-dd"));
                            cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                            cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);

                            using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new reader to read the SQL data
                            reader.Read();
                            if (reader.HasRows && !reader.IsDBNull(0))
                            {
                                thirtyDayOcc += reader.GetInt32(0);
                                rooms = reader.GetInt32(0);
                            }
                            else
                            {
                                rooms = 0;
                            }
                        }
                        using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Create a new command to execute
                        {
                            /*
                             * Get total conventional count
                             */
                            cmd.CommandText = "SELECT COUNT(*) " +
                                              "FROM reservations " +
                                              "WHERE (DATE(@Date) BETWEEN StartDate AND EndDate) AND Status in (@Status1,@Status2) AND Type = @Type;";
                            cmd.Parameters.AddWithValue("@Date", dt.AddDays(i).Date.ToString("yyyy-MM-dd"));
                            cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                            cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);
                            cmd.Parameters.AddWithValue("@Type", (int)ReservationType.Conventional);

                            using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new reader to read the SQL data
                            reader.Read();
                            if (reader.HasRows && !reader.IsDBNull(0))
                            {
                                conventional = reader.GetInt32(0);
                            }
                            else
                            {
                                conventional = 0;
                            }
                        }
                        using (SQLiteCommand cmd = Manager.con.CreateCommand())
                        {
                            /*
                             * Get total prepaid count
                             */
                            cmd.CommandText = "SELECT COUNT(*) " +
                                              "FROM reservations " +
                                              "WHERE (DATE(@Date) BETWEEN StartDate AND EndDate) AND Status in (@Status1,@Status2) AND Type = @Type;";
                            cmd.Parameters.AddWithValue("@Date", dt.AddDays(i).Date.ToString("yyyy-MM-dd"));
                            cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                            cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);
                            cmd.Parameters.AddWithValue("@Type", (int)ReservationType.Prepaid);

                            using SQLiteDataReader reader = cmd.ExecuteReader();
                            reader.Read();
                            if (reader.HasRows && !reader.IsDBNull(0))
                            {
                                prepaid = reader.GetInt32(0);
                            }
                            else
                            {
                                prepaid = 0;
                            }
                        }
                        using (SQLiteCommand cmd = Manager.con.CreateCommand())
                        {
                            /*
                             * Get total 60-day-in-advance count
                             */
                            cmd.CommandText = "SELECT COUNT(*) " +
                                              "FROM reservations " +
                                              "WHERE (DATE(@Date) BETWEEN StartDate AND EndDate) AND Status in (@Status1,@Status2) AND Type = @Type;";
                            cmd.Parameters.AddWithValue("@Date", dt.AddDays(i).Date.ToString("yyyy-MM-dd"));
                            cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                            cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);
                            cmd.Parameters.AddWithValue("@Type", (int)ReservationType.SixtyDayAdvance);

                            using SQLiteDataReader reader = cmd.ExecuteReader();
                            reader.Read();
                            if (reader.HasRows && !reader.IsDBNull(0))
                            {
                                sixty = reader.GetInt32(0);
                            }
                            else
                            {
                                sixty = 0;
                            }
                        }
                        using (SQLiteCommand cmd = Manager.con.CreateCommand())
                        {
                            /*
                             * Get total incentive count
                             */
                            cmd.CommandText = "SELECT COUNT(*) " +
                                              "FROM reservations " +
                                              "WHERE (DATE(@Date) BETWEEN StartDate AND EndDate) AND Status in (@Status1,@Status2) AND Type = @Type;";
                            cmd.Parameters.AddWithValue("@Date", dt.AddDays(i).Date.ToString("yyyy-MM-dd"));
                            cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                            cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);
                            cmd.Parameters.AddWithValue("@Type", (int)ReservationType.Incentive);

                            using SQLiteDataReader reader = cmd.ExecuteReader();
                            reader.Read();
                            if (reader.HasRows && !reader.IsDBNull(0))
                            {
                                incentive = reader.GetInt32(0);
                            }
                            else
                            {
                                incentive = 0;
                            }
                        }
                        Transaction.Commit(); // Commit transaction to database
                    }
                    occData.Add((dt.AddDays(i), rooms, conventional, prepaid, sixty, incentive));
                }
            }
            return (thirtyDayOcc / days, occData);
        }
        internal static (int, bool) AvgOccupancySpan(DateTime Start, DateTime End)
        {
            /*
             * This query gets the average occupancy and also reports if there was a
             * max capacity found within those 30 days. The count is averaged and returned
             * with the boolean value once all reservation queries are checked to match
             * the critiera. The search criteria is any active/ changed date where the
             * date specified is between the start and end date of any matching reservation.
             */
            int thirtyDayOcc = 0;
            bool maxCapacityInRange = false;
            int days = (int)(End.Date - Start.Date).TotalDays;
            using (Database Manager = new()) // Create a new database connection
            {
                for (int i = 0; i < days; i++)
                {
                    using SQLiteCommand cmd = Manager.con.CreateCommand(); // Create a new command
                    cmd.CommandText = $@"SELECT COUNT(*) 
                                    FROM reservations 
                                    WHERE (DATE(@Date) BETWEEN StartDate AND EndDate) AND Status in (@Status1,@Status2);";
                    cmd.Parameters.AddWithValue("@Date", Start.AddDays(i).Date.ToString("yyyy-MM-dd"));
                    cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                    cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);

                    using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new SQL data reader
                    reader.Read();
                    if (reader.HasRows && !reader.IsDBNull(0))
                    {
                        thirtyDayOcc += reader.GetInt32(0);
                        if (reader.GetInt32(0) == 45)
                        {
                            maxCapacityInRange = true;
                        }
                    }
                }
            }
            return (thirtyDayOcc / days, maxCapacityInRange);
        }
        internal static Guest? GetGuestByEmail(string Email)
        {
            /*
             * This function searches the database for a guest based off
             * the specified email. If a match is found the guest model is created and returned.
             * If no guest details are found, a null object is returned.
             */
            Guest? g = null;
            using (Database Manager = new()) // Creates a new database connection
            {
                using SQLiteCommand cmd = Manager.con.CreateCommand(); // Creates a new database command
                cmd.CommandText = $"SELECT * FROM guests WHERE Email = @Email";
                cmd.Parameters.AddWithValue("@Email", Email);
                using SQLiteDataReader reader = cmd.ExecuteReader(); // Creates a new SQL data reader
                reader.Read();
                if (reader.HasRows)
                {
                    string? CreditCard = null, Expiration = null, CCV = null;
                    if (reader[4].GetType() != typeof(DBNull))
                    {
                        CreditCard = reader[4].ToString();
                    }

                    if (reader[5].GetType() != typeof(DBNull))
                    {
                        Expiration = reader[5].ToString();
                    }

                    if (reader[6].GetType() != typeof(DBNull))
                    {
                        CCV = reader[6].ToString();
                    }

                    g = new(reader.GetInt32(0), reader.GetString(1), reader.GetString(2), reader.GetString(3), CreditCard, Expiration, CCV); // Create a guest model
                }
            }
            return g;
        }
        internal static Reservation? GetResByGuest(Guest g)
        {
            /*
             * This query gets a reservation by taking an existing guest as the "where" comparison.
             * Since the guest model is already passed into this query, there is no need to join the
             * guests table. Instead only the transaction and reservation details need to be populated
             * and then the guest object is passed into the creation of a reservation object.
             */
            Reservation? r = null;
            Transaction? t;
            using (Database Manager = new()) // Opens a database connection
            {
                using SQLiteCommand cmd = Manager.con.CreateCommand(); // Creates a new command
                int? RoomNumber = null;
                DateTime? CheckIn = null, CheckOut = null, DateChanged = null, LastPaid = null, PaidOn = null;

                cmd.CommandText = @"SELECT * FROM reservations 
                                         INNER JOIN transactions ON reservations.TransactionID = transactions.ID
                                         WHERE GuestID = @GuestID AND Status IN (@Status1,@Status2);";
                cmd.Parameters.AddWithValue("@GuestID", g.Id);
                cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);

                using SQLiteDataReader reader = cmd.ExecuteReader(); // Creates a new SQL data reader
                reader.Read();
                if (reader.HasRows)
                {
                    if (reader[21].GetType() != typeof(DBNull))
                    {
                        LastPaid = reader.GetDateTime(21);
                    }

                    if (reader[22].GetType() != typeof(DBNull))
                    {
                        PaidOn = reader.GetDateTime(22);
                    }

                    t = new(reader.GetInt32(13), reader.GetDouble(14), reader.GetDouble(15), reader.GetDouble(17), reader.GetDateTime(20), // Creates a new transaction model
                        LastPaid: LastPaid, PaidOn: PaidOn, RefundAmount: reader.GetDouble(18), Penalty: reader.GetDouble(16), AmountPaid: reader.GetDouble(19));

                    if (reader[1].GetType() != typeof(DBNull))
                    {
                        RoomNumber = reader.GetInt32(1);
                    }

                    if (reader[10].GetType() != typeof(DBNull))
                    {
                        CheckIn = reader.GetDateTime(10);
                    }

                    if (reader[11].GetType() != typeof(DBNull))
                    {
                        CheckOut = reader.GetDateTime(11);
                    }

                    if (reader[12].GetType() != typeof(DBNull))
                    {
                        DateChanged = reader.GetDateTime(12);
                    }

                    r = new(reader.GetInt32(0), g, t, (ReservationType)reader.GetInt32(5), (ReservationStatus)reader.GetInt32(6), // Creates a new reservation model
                        reader.GetDateTime(7), reader.GetDateTime(8), reader.GetDateTime(9), RoomNum: RoomNumber, IsNoShow: reader.GetBoolean(4),
                        CheckIn: CheckIn, CheckOut: CheckOut, DateChanged: DateChanged);
                }
            }
            return r;
        }
        internal static TimeRefs? CanBeCheckedIn(string Email)
        {
            /*
             * This query checks to see if a guest can be checked in. Guest are only
             * permitted to check in on the day that their reservation is due to start.
             * If they check in to early, the appropriate TimeRef enum is returned to.
             */
            TimeRefs? status = null;
            using (Database Manager = new()) // Opens a database connection
            {
                using SQLiteCommand cmd = Manager.con.CreateCommand(); // Creates a new command
                cmd.CommandText = $"SELECT * FROM reservation WHERE Email = @Email AND Status IN (@Status1,@Status2)";
                cmd.Parameters.AddWithValue("@Email", Email);
                using SQLiteDataReader reader = cmd.ExecuteReader(); // Creates a new SQL data reader
                reader.Read();
                if (reader.HasRows)
                {
                    DateTime dt = reader.GetDateTime(8);
                    if (dt.Date == DateTime.Now.Date)
                    {
                        status = TimeRefs.OnTime;
                    }
                    else if (dt.Date > DateTime.Now.Date)
                    {
                        status = TimeRefs.Late;
                    }
                    else if (dt.Date < DateTime.Now.Date)
                    {
                        status = TimeRefs.Early;
                    }
                }
                else
                {
                    status = null;
                }
            }
            return status;
        }
        internal static double? GetBaseRate()
        {
            /*
             * This function is used to get the current base rate that is configured
             * to be the default.
             */
            double? rate;
            using (Database Manager = new()) // Opens a database connection
            {
                using SQLiteCommand cmd = Manager.con.CreateCommand(); // Creates a new command
                string query = "SELECT Rate FROM rates WHERE DefaultRate = 1;";
                cmd.CommandText = query;
                using SQLiteDataReader reader = cmd.ExecuteReader(); // Creates a new SQL data reader
                reader.Read();
                if (reader.HasRows)
                {
                    rate = reader.GetDouble(0);
                }
                else
                {
                    rate = null;
                }
            }
            return rate;
        }
        internal static bool GetBaseRateByDate(DateTime dt)
        {
            /*
             * Gets the base rate by a specific date. This is typically used to check
             * if there is a conflicting rate for a given day and return if a rate has
             * been configured for that date.
             */
            bool configured;
            using (Database Manager = new()) // Opens a database connection
            {
                using SQLiteCommand cmd = Manager.con.CreateCommand(); // Creates a new command
                string query = "SELECT Rate FROM rates WHERE DateSet = @Date;";
                cmd.CommandText = query;
                cmd.Parameters.AddWithValue("@Date", dt.ToString("yyyy-MM-dd"));
                using SQLiteDataReader reader = cmd.ExecuteReader(); // Creates a new SQL data reader
                reader.Read();
                if (reader.HasRows)
                {
                    configured = true;
                }
                else
                {
                    configured = false;
                }
            }
            return configured;
        }
        internal static void SetBaseRate(double Rate, DateTime DateSet, bool? DefaultRate = null)
        {

            /*
             * This function is used to create a new base rate in the database and have the option to make it
             * the default base rate.
             */
            using Database Manager = new(); // Create a new database connection
            using SQLiteCommand cmd = Manager.con.CreateCommand(); // Create a new command
            string query = $"INSERT INTO rates (Rate, DateSet, DefaultRate) VALUES (@Rate, @DateSet, @DefaultRate);";
            cmd.CommandText = query;
            cmd.Parameters.AddWithValue("@Rate", Rate);
            cmd.Parameters.AddWithValue("@DateSet", DateSet.ToString("yyyy-MM-dd"));
            if (DefaultRate != null)
            {
                if (DefaultRate.Value == true)
                {
                    cmd.Parameters.AddWithValue("@DefaultRate", Convert.ToInt32(DefaultRate));
                }
                else
                {
                    cmd.Parameters.AddWithValue("@DefaultRate", null);
                }
            }
            else
            {
                cmd.Parameters.AddWithValue("@DefaultRate", null);
            }
            cmd.ExecuteNonQuery();
        }
        internal static void UpdateBaseRate(double Rate, DateTime DateSet, bool? DefaultRate = null)
        {
            /*
             * This command is used to update the base rate for an existing base rate.
             * It will replace the value of any rate, including the default rate if specified.
             */
            using Database Manager = new(); // Create a new database connection
            using SQLiteCommand cmd = Manager.con.CreateCommand(); // Create a new command
            if (DefaultRate != null)
            {
                if (DefaultRate.Value == true)
                {
                    cmd.CommandText = $"UPDATE rates SET rate = @Rate, defaultrate = @DefaultRate WHERE DateSet = @Date;";
                    cmd.Parameters.AddWithValue("@DefaultRate", Convert.ToInt32(DefaultRate)); // Replaces existing rate
                }
                else
                {
                    cmd.CommandText = $"UPDATE rates SET rate = @Rate WHERE DateSet = @Date;";
                }
            }
            else
            {
                cmd.CommandText = $"UPDATE rates SET rate = @Rate WHERE DateSet = @Date;";
            }
            cmd.Parameters.AddWithValue("@Rate", Rate);
            cmd.Parameters.AddWithValue("@Date", DateSet.ToString("yyyy-MM-dd"));
            cmd.ExecuteNonQuery();
        }
        internal static bool CheckBaseRate()
        {
            /*
             * This function is used to check and update if there is a new base rate.
             * It will check to see if there is a base rate set for the current day
             * and if that is the case it will set that as the new DefaultRate to use, 1,
             * while setting the other one to 0.
             */
            int? OldId = null;
            bool Success = true;
            using (Database Manager = new()) // Open a new database connection
            {
                using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Create a new command
                {
                    /*
                     * This query checks for the existing default base rate, if it does not find a rate
                     * and returns null, then the function will report a boolean value of false.
                     */
                    string query = "SELECT Id FROM rates WHERE DefaultRate = 1;";
                    cmd.CommandText = query;
                    using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new SQL data reader
                    reader.Read();
                    if (reader.HasRows)
                    {
                        OldId = reader.GetInt32(0);
                    }
                }
                int? Id;
                if (OldId != null)
                {
                    using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Create a new command
                    {
                        /*
                         * This query selects a base rate configured to the current date
                         * if it is set. If there is an Id, it will be used in the
                         * next query for swapping. No swap occurs if it does not exist.
                         */
                        string query = "SELECT Id FROM rates WHERE DateSet = @Date;";
                        cmd.CommandText = query;
                        cmd.Parameters.AddWithValue("@Date", DateTime.Now.Date.ToString("yyyy-MM-dd"));
                        using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new SQL data reader
                        reader.Read();
                        if (reader.HasRows)
                        {
                            Id = reader.GetInt32(0);
                        }
                        else
                        {
                            Id = null;
                        }
                    }
                    if (Id != null)
                    {
                        /*
                         * This query swaps the default indicator of the old base rate with the new base
                         * rate.
                         */
                        using SQLiteCommand cmd = Manager.con.CreateCommand(); // Create a new command
                        cmd.CommandText = @"UPDATE rates SET DefaultRate = NULL WHERE Id = @OldID;
                                            UPDATE rates SET DefaultRate = 1 WHERE Id = @ID;";
                        cmd.Parameters.AddWithValue("@OldID", OldId);
                        cmd.Parameters.AddWithValue("@ID", Id);
                        cmd.ExecuteNonQuery();
                    }
                }
                else
                {
                    Success = false;
                }
            }
            return Success;
        }
        internal static int? CheckInGuest(string Email, DateTime CheckIn)
        {
            /*
             * This query is used to check in a guest and is a multi-part query
             * with several updates to the database. Here the database tables
             * reservation and room will be updated based on whichever
             * room is available, not occupied, and then assigned to the reservation.
             * Once this is complete, the updated information is saved to the database
             * and the room number is returned.
             */
            int? RoomID = null;
            using (Database Manager = new()) // Opens a new database connection
            {
                using SQLiteTransaction Transaction = Manager.con.BeginTransaction(); // Begin a new SQL transaction
                using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Creates a new command
                {
                    /*
                     * This query looks at the rooms table for the first instance of an unoccupied
                     * room. This room is then set as the reservations associated room.
                     */
                    cmd.CommandText = "UPDATE reservations SET RoomNum = (SELECT ID FROM rooms WHERE Occupied = 0 LIMIT 1), CheckIn = @Date " +
                                      "WHERE GuestID = (SELECT ID FROM guests WHERE Email = @Email) AND RoomNum IS NULL AND Status in (@SActive,@SChanged);";
                    cmd.Parameters.AddWithValue("@Email", Email);
                    cmd.Parameters.AddWithValue("@SActive", (int)ReservationStatus.Active);
                    cmd.Parameters.AddWithValue("@SChanged", (int)ReservationStatus.Changed);
                    cmd.Parameters.AddWithValue("@Date", CheckIn.ToString("yyyy-MM-dd"));
                    cmd.ExecuteNonQuery();
                }
                using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Creates a new command
                {
                    /*
                     * This query sets the room that is assigned to the reservation as
                     * occupied as a guest has been assigned it.
                     */
                    cmd.CommandText = "UPDATE rooms SET Occupied = 1 " +
                                      "WHERE ID = (SELECT RoomNum FROM reservations WHERE GuestID = (SELECT ID FROM guests WHERE Email = @Email AND Status in (@SActive,@SChanged))));";
                    cmd.Parameters.AddWithValue("@Email", Email);
                    cmd.Parameters.AddWithValue("@SActive", (int)ReservationStatus.Active);
                    cmd.Parameters.AddWithValue("@SChanged", (int)ReservationStatus.Changed);
                    cmd.ExecuteNonQuery();
                }
                using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Creates a new command
                {
                    /*
                     * This query looks for the room number that was assigned as a result of the queries above.
                     * This room number is then stored so it can be returned.
                     */
                    cmd.CommandText = "SELECT RoomNum FROM reservations WHERE GuestID = (SELECT ID FROM guests WHERE Email = @Email AND Status in (@SActive,@SChanged))";
                    cmd.Parameters.AddWithValue("@Email", Email);
                    cmd.Parameters.AddWithValue("@SActive", (int)ReservationStatus.Active);
                    cmd.Parameters.AddWithValue("@SChanged", (int)ReservationStatus.Changed);
                    using SQLiteDataReader reader = cmd.ExecuteReader(); // Creates a new SQL reader
                    reader.Read();
                    if (reader.HasRows)
                    {
                        RoomID = (int)reader.GetValue(0);
                    }
                }
                Transaction.Commit(); // Commits the transaction
            }
            return RoomID;
        }
        internal static bool GuestCurrentlyCheckedIn(string Email)
        {
            /*
             * Checks if a guest is currently checked in. If there is a check-in date
             * on their reservation, that means thay have been checked in. A boolean
             * value is returned whether or not a matching reservation is found.
             */
            bool EntryFound;
            using (Database Manager = new()) // Creates a new database connection
            {
                using SQLiteCommand cmd = Manager.con.CreateCommand(); // Creates a new command
                cmd.CommandText = "SELECT * FROM reservations " +
                                  "WHERE GuestID = (SELECT ID FROM guests WHERE Email = @Email AND Status in (@SActive,@SChanged)) AND CheckIn IS NOT NULL";
                cmd.Parameters.AddWithValue("@Email", Email);
                cmd.Parameters.AddWithValue("@SActive", (int)ReservationStatus.Active);
                cmd.Parameters.AddWithValue("@SChanged", (int)ReservationStatus.Changed);
                using SQLiteDataReader reader = cmd.ExecuteReader(); // Creates a new SQL data reader
                reader.Read();
                if (reader.HasRows)
                {
                    EntryFound = true;
                }
                else
                {
                    EntryFound = false;
                }
            }
            return EntryFound;
        }
        internal static void CheckOutGuest(string Email, DateTime CheckOut)
        {
            /*
             * This function checks a guest out given that they have already checked in
             * and have an active reservation. If this criteria is not met, a reservation
             * will not be checked out. If a reservation does match this criteria, the reservation
             * check-out date is set and the status of the reservation is changed to Ended.
             */
            using Database Manager = new(); // Creates a new database connection
            using SQLiteTransaction Transaction = Manager.con.BeginTransaction(); // Creates a new SQL data reader
            using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Creates a new command
            {
                /*
                 * This query looks for the room that is checked in and marks them as unoccupied
                 * based on the corresponding room to reservation relation.
                 */
                cmd.CommandText = "UPDATE rooms SET Occupied = 0 " +
                                  "WHERE ID = (SELECT RoomNum FROM reservations WHERE GuestID = (SELECT ID FROM guests WHERE Email = @Email) AND Status in (@SActive,@SChanged) AND CheckIn IS NOT NULL);";
                cmd.Parameters.AddWithValue("@Email", Email);
                cmd.Parameters.AddWithValue("@SActive", (int)ReservationStatus.Active);
                cmd.Parameters.AddWithValue("@SChanged", (int)ReservationStatus.Changed);
                cmd.ExecuteNonQuery();
            }
            using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Creates a new command
            {
                /*
                 * This query updates the reservation status as Ended adn the checkout date.
                 */
                cmd.CommandText = "UPDATE reservations SET CheckOut = @Date, Status = @Status " +
                                  "WHERE GuestID = (SELECT ID FROM guests WHERE Email = @Email) AND RoomNum IS NOT NULL AND Status in (@SActive,@SChanged) AND CheckIn IS NOT NULL;";
                cmd.Parameters.AddWithValue("@Email", Email);
                cmd.Parameters.AddWithValue("@Status", (int)ReservationStatus.Ended);
                cmd.Parameters.AddWithValue("@SActive", (int)ReservationStatus.Active);
                cmd.Parameters.AddWithValue("@SChanged", (int)ReservationStatus.Changed);
                cmd.Parameters.AddWithValue("@Date", CheckOut.ToString("yyyy-MM-dd"));
                cmd.ExecuteNonQuery();
            }
            Transaction.Commit();
            return;
        }
        internal static List<Reservation> GetActiveSixtyDayRes()
        {
            /*
             * This query is used to build a list of active 60-day-in-advance reservations
             * and return them all as a list.
             */
            List<Reservation> list = new();
            using (Database Manager = new()) // Create a new database connection
            {
                using SQLiteCommand cmd = Manager.con.CreateCommand(); // Create a new command
                /*
                 * This query will find any reservation with the 60-day type that is Active or Changed
                 * and return them all in a table
                 */
                cmd.CommandText = "SELECT * FROM reservations " +
                                  "INNER JOIN transactions ON reservations.TransactionID = transactions.ID " +
                                  "INNER JOIN guests ON reservations.GuestID = guests.ID " +
                                  "WHERE Type = @Type AND Status IN (@Status1,@Status2);";
                cmd.Parameters.AddWithValue("@Type", (int)ReservationType.SixtyDayAdvance);
                cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);
                using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new SQL data reader
                while (reader.Read())
                {
                    Reservation? r;
                    Transaction? t;
                    Guest g;
                    int? RoomNumber = null;
                    DateTime? CheckIn = null, CheckOut = null, DateChanged = null, LastPaid = null, PaidOn = null;
                    if (reader.HasRows)
                    {
                        /*
                         * Since we cannot get by string keys, each column is represented by a numerical value
                         * like an array. The column is as follows:
                         * 
                         *      0. ID (reservations.ID)
                         *      1. RoomNum
                         *      2. GuestID
                         *      3. TransactionID
                         *      4. IsNoShow
                         *      5. Type
                         *      6. Status
                         *      7. CreationDate
                         *      8. StartDate
                         *      9. EndDate
                         *     10. CheckIn
                         *     11. CheckOut
                         *     12. DateChanged
                         *     13. ID (rooms.ID)
                         *     14. Rate
                         *     15. Owed
                         *     16. Penalty
                         *     17. Multiplier
                         *     18. RefundAmount
                         *     19. AmountPaid
                         *     20. PayBy
                         *     21. LastPaid
                         *     22. PaidOn
                         *     23. ID (guests.ID)
                         *     24. Fname
                         *     25. Lname
                         *     26. Email
                         *     27. CreditCard
                         *     28. Expiration
                         *     29. CCV
                         *     
                         */
                        if (reader[21].GetType() != typeof(DBNull))
                        {
                            LastPaid = reader.GetDateTime(21);
                        }

                        if (reader[22].GetType() != typeof(DBNull))
                        {
                            PaidOn = reader.GetDateTime(22);
                        }

                        t = new(reader.GetInt32(13), reader.GetDouble(14), reader.GetDouble(15), reader.GetDouble(17), reader.GetDateTime(20), // Creates a new transaction model
                            LastPaid: LastPaid, PaidOn: PaidOn, RefundAmount: reader.GetDouble(18), Penalty: reader.GetDouble(16), AmountPaid: reader.GetDouble(19));

                        g = new(reader.GetInt32(23), reader.GetString(24), reader.GetString(25), reader.GetString(26), reader.GetString(27), reader.GetString(28), reader.GetString(29)); // Creates a new guest model

                        if (reader[1].GetType() != typeof(DBNull))
                        {
                            RoomNumber = reader.GetInt32(1);
                        }

                        if (reader[10].GetType() != typeof(DBNull))
                        {
                            CheckIn = reader.GetDateTime(10);
                        }

                        if (reader[11].GetType() != typeof(DBNull))
                        {
                            CheckOut = reader.GetDateTime(11);
                        }

                        if (reader[12].GetType() != typeof(DBNull))
                        {
                            DateChanged = reader.GetDateTime(12);
                        }

                        r = new(reader.GetInt32(0), g, t, (ReservationType)reader.GetInt32(5), (ReservationStatus)reader.GetInt32(6),
                            reader.GetDateTime(7), reader.GetDateTime(8), reader.GetDateTime(9), RoomNum: RoomNumber, IsNoShow: reader.GetBoolean(4),
                            CheckIn: CheckIn, CheckOut: CheckOut, DateChanged: DateChanged);
                        list.Add(r);
                    }
                }
            }
            return list;
        }
        internal static List<Reservation> GetPastDueReservations()
        {
            /*
             * This function gets any reservation that is past due.
             * Past due is considered to be any reservation where the start date is
             * older than the current date, the reservation is active or changed, and
             * has not been checked in. This list is then returned.
             */
            List<Reservation> list = new();
            using (Database Manager = new()) // Create a new database connection
            {
                using SQLiteTransaction Transaction = Manager.con.BeginTransaction(); // Create a new SQL transaction
                using (SQLiteCommand cmd = Manager.con.CreateCommand()) // Create a new command
                {
                    /*
                     * This query selects non-checked in active and changed reeservations where
                     * the start date is older than the current day. These are considered no-shows.
                     */
                    cmd.CommandText = "SELECT * FROM reservations " +
                      "INNER JOIN transactions ON reservations.TransactionID = transactions.ID " +
                      "INNER JOIN guests ON reservations.GuestID = guests.ID " +
                      "WHERE DATE(@Date) > StartDate AND Status IN (@Status1,@Status2) AND CheckIn IS NULL;";
                    cmd.Parameters.AddWithValue("@Date", DateTime.Now.Date.ToString("yyyy-MM-dd"));
                    cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                    cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);
                    using SQLiteDataReader reader = cmd.ExecuteReader(); // Create a new SQL data reader
                    while (reader.Read())
                    {
                        Reservation? r;
                        Transaction? t;
                        Guest g;
                        int? RoomNumber = null;
                        DateTime? CheckIn = null, CheckOut = null, DateChanged = null, LastPaid = null, PaidOn = null;
                        if (reader.HasRows)
                        {
                            /*
                             * Since we cannot get by string keys, each column is represented by a numerical value
                             * like an array. The column is as follows:
                             * 
                             *      0. ID (reservations.ID)
                             *      1. RoomNum
                             *      2. GuestID
                             *      3. TransactionID
                             *      4. IsNoShow
                             *      5. Type
                             *      6. Status
                             *      7. CreationDate
                             *      8. StartDate
                             *      9. EndDate
                             *     10. CheckIn
                             *     11. CheckOut
                             *     12. DateChanged
                             *     13. ID (rooms.ID)
                             *     14. Rate
                             *     15. Owed
                             *     16. Penalty
                             *     17. Multiplier
                             *     18. RefundAmount
                             *     19. AmountPaid
                             *     20. PayBy
                             *     21. LastPaid
                             *     22. PaidOn
                             *     23. ID (guests.ID)
                             *     24. Fname
                             *     25. Lname
                             *     26. Email
                             *     27. CreditCard
                             *     28. Expiration
                             *     29. CCV
                             *     
                             */
                            if (reader[21].GetType() != typeof(DBNull))
                            {
                                LastPaid = reader.GetDateTime(21);
                            }

                            if (reader[22].GetType() != typeof(DBNull))
                            {
                                PaidOn = reader.GetDateTime(22);
                            }

                            t = new(reader.GetInt32(13), reader.GetDouble(14), reader.GetDouble(15), reader.GetDouble(17), reader.GetDateTime(20), // Create a new transaction model
                                LastPaid: LastPaid, PaidOn: PaidOn, RefundAmount: reader.GetDouble(18), Penalty: reader.GetDouble(16), AmountPaid: reader.GetDouble(19));

                            g = new(reader.GetInt32(23), reader.GetString(24), reader.GetString(25), reader.GetString(26), reader.GetString(27), reader.GetString(28), reader.GetString(29)); // Create a new guest model

                            if (reader[1].GetType() != typeof(DBNull))
                            {
                                RoomNumber = reader.GetInt32(1);
                            }

                            if (reader[10].GetType() != typeof(DBNull))
                            {
                                CheckIn = reader.GetDateTime(10);
                            }

                            if (reader[11].GetType() != typeof(DBNull))
                            {
                                CheckOut = reader.GetDateTime(11);
                            }

                            if (reader[12].GetType() != typeof(DBNull))
                            {
                                DateChanged = reader.GetDateTime(12);
                            }

                            r = new(reader.GetInt32(0), g, t, (ReservationType)reader.GetInt32(5), (ReservationStatus)reader.GetInt32(6), // Create a new reservation model
                                reader.GetDateTime(7), reader.GetDateTime(8), reader.GetDateTime(9), RoomNum: RoomNumber, IsNoShow: reader.GetBoolean(4),
                                CheckIn: CheckIn, CheckOut: CheckOut, DateChanged: DateChanged);
                            list.Add(r);
                        }
                    }
                }
                using (SQLiteCommand cmd = Manager.con.CreateCommand())
                {
                    /*
                     * This query updates reservations where the same criteria above is matched and then
                     * no-show is set. At some point the order of these queries should be swapped as the first
                     * can be simplified if we update the table first.
                     */
                    cmd.CommandText = "UPDATE reservations SET IsNoShow = 1, DateChanged = @DateChanged " +
                      "WHERE DATE (@Date) > StartDate AND Status IN (@Status1,@Status2) AND CheckIn IS NULL";
                    cmd.Parameters.AddWithValue("@Date", DateTime.Now.Date.ToString("yyyy-MM-dd"));
                    cmd.Parameters.AddWithValue("@DateChanged", DateTime.Now.Date.ToString("yyyy-MM-dd"));
                    cmd.Parameters.AddWithValue("@Status1", (int)ReservationStatus.Active);
                    cmd.Parameters.AddWithValue("@Status2", (int)ReservationStatus.Changed);
                    cmd.ExecuteNonQuery();
                }
                Transaction.Commit(); // Commits the transaction
            }
            return list;
        }
    }
    internal enum TimeRefs // Numerical values represented as words
    {
        OnTime,
        Early,
        Late
    }
}