using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        // InSevenDays

        // ThisMonth

        // NextMonth

        // InSixMonths

        // ThisYear

        // Custom | Custom is setup the same as for InSevenDays for ease

        var expirationFilter = QuoteExpirationDateFilter.InSevenDays;

        List<Quote> quotes = new() {

            new() { Id = 1, ExpirationDate = null },

            new() { Id = 2, ExpirationDate = new DateTimeOffset(2025, 2, 24, 0, 0, 0, TimeSpan.Zero) }, // Expires by end of 2025-02-23

            new() { Id = 3, ExpirationDate = new DateTimeOffset(2025, 2, 28, 0, 0, 0, TimeSpan.Zero) }, // Expires by end of 2025-02-27

            new() { Id = 4, ExpirationDate = new DateTimeOffset(2025, 3, 1, 0, 0, 0, TimeSpan.Zero) },  // Expires by end of 2025-02-28

            new() { Id = 5, ExpirationDate = new DateTimeOffset(2025, 3, 31, 0, 0, 0, TimeSpan.Zero) }, // Expires by end of 2025-03-30

            new() { Id = 6, ExpirationDate = new DateTimeOffset(2025, 4, 1, 0, 0, 0, TimeSpan.Zero) },  // Expires by end of 2025-03-31

            new() { Id = 7, ExpirationDate = new DateTimeOffset(2025, 2, 19, 0, 0, 0, TimeSpan.Zero) }, // Expires by end of 2025-02-18

            new() { Id = 8, ExpirationDate = new DateTimeOffset(2025, 9, 1, 0, 0, 0, TimeSpan.Zero) },  // Expires by end of 2025-08-31

            new() { Id = 9, ExpirationDate = new DateTimeOffset(2026, 1, 1, 0, 0, 0, TimeSpan.Zero) },  // Expires by end of 2025-12-31

            new() { Id = 10, ExpirationDate = new DateTimeOffset(2025, 3, 4, 0, 0, 0, TimeSpan.Zero) },  // Expires by end of 2025-03-03

        };

        DateTimeOffset? customStartDate = expirationFilter == QuoteExpirationDateFilter.Custom

            ? new DateTimeOffset(2025, 2, 24, 0, 0, 0, TimeSpan.Zero)

            : null;

        DateTimeOffset? customEndDate = expirationFilter == QuoteExpirationDateFilter.Custom

            ? new DateTimeOffset(2025, 3, 3, 23, 59, 59, TimeSpan.Zero)

            : null;

        var expirationStart = MapToExpirationStartDate(expirationFilter, customStartDate);

        var expirationStartOriginal = MapToExpirationStartDateOriginal(expirationFilter, customStartDate);

        var expirationEnd = MapToExpirationEndDate(expirationFilter, customEndDate);

        var expirationEndOriginal = MapToExpirationEndDateOriginal(expirationFilter, customEndDate);

        Console.WriteLine("Quotes");

        Console.WriteLine(new string('-', 131));

        foreach (var quote in quotes) {

            Console.WriteLine($"Id: {quote.Id,2:D} | Expiration date: {quote.ExpirationDate,19:yyyy-MM-dd HH:mm:ss} | Actual expiration date: {quote.ActualExpirationDate,19:yyyy-MM-dd HH:mm:ss} | Should be found: {(quote.ExpirationDate >= expirationStart && quote.ExpirationDate < expirationEnd ? "Yes" : "   ")} | Was found: {(quote.ExpirationDate >= expirationStartOriginal && quote.ExpirationDate < expirationEndOriginal ? "Yes" : "")}");

        }

        Console.WriteLine("");

        Console.WriteLine("Filter");

        Console.WriteLine(new string('-', 91));

        Console.WriteLine($"Type:  {expirationFilter}");

        Console.WriteLine($"Start: {expirationStart:yyyy-MM-dd HH:mm:ss.fff} | Original: {expirationStartOriginal:yyyy-MM-dd HH:mm:ss.fff}");

        Console.WriteLine($"End:   {expirationEnd:yyyy-MM-dd HH:mm:ss.fff} | Original: {expirationEndOriginal:yyyy-MM-dd HH:mm:ss.fff}");

        var query = quotes.AsQueryable();

        if (expirationStart.HasValue)

            query = query.Where(q => q.ExpirationDate >= expirationStart);

​

        if (expirationEnd.HasValue)

            query = query.Where(q => q.ExpirationDate < expirationEnd);

        var filteredQuotes = query.ToList();

        Console.WriteLine("");

        Console.WriteLine("Filtered quotes");

        Console.WriteLine(new string('-', 91));

        foreach (var quote in filteredQuotes)

            Console.WriteLine($"Id: {quote.Id,2:D} | Expiration date: {quote.ExpirationDate:yyyy-MM-dd HH:mm:ss} | Actual expiration date: {quote.ActualExpirationDate:yyyy-MM-dd HH:mm:ss}");

    }

    private static DateTimeOffset? MapToExpirationStartDate(QuoteExpirationDateFilter? quoteExpirationDateFilter, DateTimeOffset? startDate)

    {

        var nextMonth = DateTime.UtcNow.Date.AddMonths(1);

​

        return quoteExpirationDateFilter switch {

            QuoteExpirationDateFilter.InSevenDays or

            QuoteExpirationDateFilter.ThisMonth or

            QuoteExpirationDateFilter.InSixMonths => DateTime.UtcNow.Date.AddMilliseconds(1),

            QuoteExpirationDateFilter.NextMonth => new DateTime(nextMonth.Year, nextMonth.Month, 1).AddDays(1),

            QuoteExpirationDateFilter.ThisYear => new DateTime(DateTime.UtcNow.Year, 1, 1).AddMilliseconds(-1),

            // NOTE: The additions should be done in FE to be honest

            QuoteExpirationDateFilter.Custom => startDate?.Date.AddMilliseconds(1),

            _ => null

        };

    }

​

    private static DateTimeOffset? MapToExpirationEndDate(QuoteExpirationDateFilter? quoteExpirationDateFilter, DateTimeOffset? endDate)

    {

        var beginningOfThisMonth = new DateTime(DateTime.UtcNow.Year, DateTime.UtcNow.Month, 1);

​

        return quoteExpirationDateFilter switch {

            QuoteExpirationDateFilter.InSevenDays => DateTime.UtcNow.Date.AddDays(8).AddMilliseconds(1),

            QuoteExpirationDateFilter.ThisMonth => beginningOfThisMonth.AddMonths(1).AddMilliseconds(1),

            QuoteExpirationDateFilter.NextMonth => beginningOfThisMonth.AddMonths(2).AddMilliseconds(1),

            QuoteExpirationDateFilter.InSixMonths => beginningOfThisMonth.AddMonths(7).AddMilliseconds(1),

            QuoteExpirationDateFilter.ThisYear => new DateTime(DateTime.UtcNow.Year + 1, 1, 1).AddMilliseconds(1),

            // NOTE: The additions should be done in FE to be honest

            QuoteExpirationDateFilter.Custom => endDate?.Date.AddDays(1).AddMilliseconds(1),

            _ => null

        };

    }

​

    private static DateTimeOffset? MapToExpirationStartDateOriginal(QuoteExpirationDateFilter? quoteExpirationDateFilter, DateTimeOffset? startDate)

    {

        var nextMonth = DateTime.UtcNow.Date.AddMonths(1);

​

        return quoteExpirationDateFilter switch {

            QuoteExpirationDateFilter.InSevenDays or

            QuoteExpirationDateFilter.ThisMonth or

            QuoteExpirationDateFilter.InSixMonths => DateTime.UtcNow.Date,

            QuoteExpirationDateFilter.NextMonth => new DateTime(nextMonth.Year, nextMonth.Month, 1),

            QuoteExpirationDateFilter.ThisYear => new DateTime(DateTime.UtcNow.Year, 1, 1),

            QuoteExpirationDateFilter.Custom => startDate,

            _ => null

        };

    }

​

    private static DateTimeOffset? MapToExpirationEndDateOriginal(QuoteExpirationDateFilter? quoteExpirationDateFilter, DateTimeOffset? endDate)

    {

        var beginningOfThisMonth = new DateTime(DateTime.UtcNow.Year, DateTime.UtcNow.Month, 1);

​

        return quoteExpirationDateFilter switch {

            QuoteExpirationDateFilter.InSevenDays => DateTime.UtcNow.Date.AddDays(8).AddMilliseconds(-1),

            QuoteExpirationDateFilter.ThisMonth => beginningOfThisMonth.AddMonths(1).AddMilliseconds(-1),

            QuoteExpirationDateFilter.NextMonth => beginningOfThisMonth.AddMonths(2).AddMilliseconds(-1),

            QuoteExpirationDateFilter.InSixMonths => beginningOfThisMonth.AddMonths(7).AddMilliseconds(-1),

            QuoteExpirationDateFilter.ThisYear => new DateTime(DateTime.UtcNow.Year + 1, 1, 1).AddMilliseconds(-1),

            QuoteExpirationDateFilter.Custom => endDate,

            _ => null

        };

    }

}

​

public class Quote {

    public int Id { get; set; }

    public DateTimeOffset? ExpirationDate { get; set; }

    public DateTimeOffset? ActualExpirationDate => ExpirationDate?.AddSeconds(-1);

}

​

public enum QuoteExpirationDateFilter

{

    InSevenDays = 0,

    ThisMonth = 1,

    NextMonth = 2,

    InSixMonths = 3,

    ThisYear = 4,

    Custom = 5

}